Walking

Exercise and Hear Disease

Exercise reduces body weight, reduces the risk of getting diabetes, lowers blood pressure and keeps the arteries of the heart in tip-top condition.

There are three important parts to exercise. This is duration (how long), intensity (how fast), and frequency (how often). Although all parts are important, the good news is that low intensity workouts can be beneficial if done for enough time and on a regular basis.

The average 70 kg person burns about 110 calories whether he runs or walks a mile but it would take longer time to cover that distance by walking. The American College of Sport Medicine recommends burning a 1000 calories a week through exercise.

Exercise does not need to be done in one setting but can be done in intervals. Integrating exercise into a regular work routine can be helpful (eg. Taking the bus/MRT one stop prior to your destination. Parking your car further away from the exits. Taking the elevator to a level below your destination and walking up the stairs for the rest)

Numerous studies have shown exercise and its benefit on heart health. In the 1990s, the Honolulu Heart Study looked at older men aged above 70 with the oldest person aged 93. They found that men who walked more had a 50% less chance of developing heart disease than men who were sedentary. Another recent study done in the United Kingdom showed that people who cycled or walked to work also were less likely to suffer a heart attack or stroke then those who took public transport or drove.

Facts From The British Heart Foundation

  • Only 3 out of 10 people do enough exercise but 8 out of 10 think they do
  • 10,000 steps equals about 5 miles
  • Most of us only walk 4500 steps a day
  • In 1975, we walked 255 miles a year, in 2007, 192 miles
  • If present habits continue, by 2010, one in four people will not fit in a standard office chair
  • 37% of coronary heart disease deaths are related to inactivity, compared to 19% related to smoking

Pedometer

This is a small device that measures your steps. This can be useful in tracking your activity level and can act as a motivation to increase your physical exercise. A good goal to achieve would be to walk about 10,000 steps per day. This should be done by increasing the number of steps by 500 every week until this goal is reached.

Who is Exercise For?

The simple answer is that exercise is for everyone. In particular, people who have heart disease can reduce their risk of a recurrence by exercising. Persons who are overweight can also benefit. For patients with diabetes, exercise has been shown to reduce both risk of kidney and heart complications and result in an increased lifespan. Please check with your doctors first if exercise is safe for you.

High Blood Pressure

High blood pressure or hypertension is a common condition that increases the risk of various illnesses such as stroke, heart attacks and kidney damage. Blood pressure rises with age and even persons who have normal blood pressure at age 55 are estimated to have a 90% chance of developing hypertension in their lifetime.

A common misconception is that high blood pressure results in symptoms such as headaches and giddiness. The majority of people who have high blood pressure in fact have no symptoms and are only discovered incidentally when their doctor measures their blood pressure.

How High is High?

There are two components to a blood pressure reading. The higher reading taken when the heart is pumping at its maximum is called systolic and the lower reading taken when the heart is relaxing is called the diastolic. Both readings are important but with increasing age, the systolic number rises and the diastolic number fall.

A systolic level of below 140 and a diastolic level of 90 is considered the cut-off for hypertension and this applies to all age groups. For persons at high risk such as those who have diabetes, a lower cut-off of 130 systolic and 80 diastolic is recommended. This is due to the severe problems that a combination of both diabetes and high blood pressure has on various organs. Even lower blood pressure cut-offs are recommended in certain person groups.

Studies have also shown that risk of illnesses such as strokes, kidney disease and heart disease rises continuously with increasing blood pressure. In fact, a 20 point rise in the systolic blood pressure translates to a 2 times increase risk of these illnesses. Compared to a person with a systolic blood pressure of 115, a person with a level of 135 would be at 2 times, a person with 155 would be 4 times and a person with a level of 175 would be at 8 times higher risk.

Blood pressure is measured in units of mercury. The short form symbol is mmHg.

Life is Very Simple

There are numerous problems with these simple guides on blood pressure levels.

Different people may have different tolerance to blood pressure. Some individuals may be more susceptible to organ damage than others, translating to a need for lower blood pressure. It is therefore important in people with high blood pressure to assess certain organs for the bad effects of an elevated blood pressure. This includes evaluation of the kidneys, heart, blood vessels and eyes.

Blood pressure also varies with activity, stress and the time of day. Some people suffer from white-coat hypertension. These people have normal blood pressure at home but in a doctor’s office they have elevated blood pressure. Conversely, some people have elevated blood pressure at home but borderline or normal blood pressure when seeing their doctors.

Blood pressure should therefore be ideally measured at home as well as during doctor visits. The availability of home blood pressure monitoring sets has now made this possible. We encourage our patients with high blood pressure to purchase these sets and measure at home on a regular basis.

Home Blood Pressure Monitoring / 24 Hours Monitoring

It is important to ensure blood pressure is controlled round the clock.

Among persons with high blood pressure, there are variations in blood pressure during sleep and during the day. People whose blood pressure drop by more than 10% during sleep, often referred to as “dippers” are considered to have a normal response. “Non-dippers” whose blood pressure drops less than 10% during sleep are at higher risk of stroke and heart disease. Some individuals also exhibit a marked change from sleep to waking. Persons whose blood pressure rises more than 55 points on waking are in fact at the highest risk of stroke.

Ideally, 24 hour blood pressure should be considered in the majority of persons who have high blood pressure. Machines that can monitor 24 hour blood pressure are presently available.

Alternatively, home blood pressure sets could be used and blood pressure on waking, prior to the morning medication should be measured. This can be compared to blood pressure taken at other times of the day.

People at Risk of Developing High Blood Pressure

Persons, who have borderline blood pressure, defined as a level of 120 to 139 systolic or 80 to 89 diastolic have a higher risk of developing hypertension as they get older. These persons are often referred to as having “pre-hypertension”.

Women who develop high blood pressure during pregnancy also appear to have increased risk of hypertension later in life. Persons with a strong family history of hypertension are also more pre-disposed to high blood pressure.

We recommend that people who have a pre-disposition to developing hypertension embark on lifestyle changes to lower their blood pressure. This may prevent hypertension or at least delay the onset to hypertension.

Manament of High Blood Pressure

Modern medications are effective at controlling blood pressure. The majority of high blood pressure medicines today provide a good 24 hour control of pressure. However, the majority of individuals with hypertension require two or more pills to adequately control their blood pressure. The use of combination medications at lower doses results in good control without adverse side effects.

Lifestyle is also very important in controlling blood pressure. This includes regular exercise, a low salt diet and lots of fruits and fibres. People who are overweight should also aim to lose weight and smokers should stop smoking. Lifestyle alone can sometimes reduce blood pressure by 10 points or more.

Evaluate For Other Risk Factors

Persons with hypertension should be evaluated for the presence of other risk factors. This includes obesity, high cholesterol and diabetes. The combination of hypertension with other risk factors greatly elevates the potential for strokes and heart disease. All risk factors should also be well controlled in people with hypertension.

Sudden Cardiac Death (SCD)

The heart is a vital organ that pumps blood around the body and provides the oxygen that all living tissue in the body requires. Once the heart stops its pumping, there is a sudden loss of oxygen and death of vital organs occurs within minutes. Although there may be subtle warning signs and symptoms before sudden cardiac death occurs, in the majority of victims, the onset of collapse is unexpected.

It is estimated that in Singapore, about 4500 people a year may suffer from SCD. 90% of victims have underlying narrowing of the heart arteries. This occurs due to build up of cholesterol in the wall of arteries. This deposit and narrowing restricts blood supply to the muscle and electrical system of the heart. With reduced oxygen supply to the heart, the electrical activity of the heart becomes erratic and unstable. They may become too fast (medically the heart rhythm is termed ventricular tachycardia or ventricular fibrillation) or too slow (bradycardia). Eventually, after a period of abnormal electrical activity, the electrical activity stops and the heart stops pumping.

One area of common misconception is that SCD is due to a heart attack. Medically, heart attacks occur when the blood supply to the heart muscle becomes so compromised that there is damage to the heart muscle. While, a heart attack can cause SCD, not all SCD is due to heart attacks. Conversely, a person may suffer a heart attack without experiencing SCD.

In many instances, a reduction of blood and oxygen even without causing damage to the heart muscle can cause electrical instability of the heart. In younger people (usually less than 35 years of age), there can be other heart abnormalities that are unrelated to narrowing of the heart arteries. These can generally include electrical system faults, heart muscle abnormalities and other abnormalities relating to the structure of the heart. Some of these may be present since birth.

Exercise and SCD

Vigorous physical activity can precipitate electrical instability in certain individuals. The relative risk of suffering a heart attack can also be increased up to 5 times during physical exercise when compared to periods of more sedentary activity. However, the risk of death during exercise is probably less than 1 per 100000 in younger individuals and about 6 per 100000 in middle aged men.

Importantly, exercise has many favourable effects on reducing risk of a heart attack overall and in general; people who exercise regularly are at lower risk of death than people who are sedentary.

Healthe Screening and Exercise

Health screening is not needed for all individuals who exercise regularly. However, individual with risk factors that may predispose them to sudden collapse should consider screening. Individuals who should consider screening prior to undertaking regular exercise include those with any one of the conditions or symptoms below.

  1. Persons who experience chest discomfort or severe breathlessness during exercise
  2. Persons who have lost consciousness during or after exercise
  3. Persons who have experienced a dramatic deterioration in their exercise capacity
  4. Persons who have a strong family history of sudden death or heart disease in the family (defined as male relative <55 years of age or female relative <65 years of age) 5. Persons who have diabetes 6. Persons who have been previously diagnosed with heart abnormalities 7. Persons with two or more risk factors for heart artery narrowing. This includes: – High cholesterol. Total serum cholesterol > 200 mg / dl
    • Smoking
    • High blood pressure. Systolic blood pressure greater or equal to 140, or diastolic greater or equal to 90.
    • Obesity with BMI greater or equal to 30 or waist greater than 36 inches
    • Sedentary lifestyle

Persons who do not have the above risks are at low risk of developing heart complications during moderate exercise and generally do not benefit from further screening.

For persons involved in very vigorous exercise such as in marathon runners and other competitive sports, routine screening for all remains controversial but is conducted in certain countries. It would be best to speak to your individual doctor on the appropriateness of screening.

Screening Package Offered at The Novena Heart Center

At the Novena Heart Centre, we offer screening to detect possible abnormalities of the heart that may lead to problems during exercise. This includes

  1. An interview and physical examination by a Cardiologist
  2. Electrocardiogram
  3. Blood investigations including a fasting cholesterol, blood sugar and measurement of hs-CRP (an indicator of future risk of developing coronary artery disease).
  4. Exercise stress echocardiogram. This is a combination of an exercise stress test on a treadmill combined with ultrasound technology to evaluate heart function and structure.

Coronary calcium scoring using ultra-fast CT scanner. This allows us to pick up early cholesterol deposits in the heart arteries. Only severe narrowing of the heart arteries lead to restriction of oxygen to the heart and these are picked up by stress tests. Early narrowing that can still lead to heart problems is undetected by routine stress testing.

A review of all the results and its implications

For more information on the screening package, please click here.

Weight loss diets – Are they good for the heart?

Obesity is an increasing health problem in Singapore. According to the National Health Survey, obesity rates increased from 6.9% in 2004 to 10.8% in 2010. Correspondingly, the diabetes rate has gone up from 8.2% in 2004 to 11.3% in 2010. Obesity is a well-known risk factor for cardiovascular disease and for the development of type 2 diabetes mellitus and the metabolic syndrome.

Therefore, there is an increasing interest in weight loss diets to combat obesity.

Most of these weight reducing diets reduce the caloric intake of food and encourage people to consume more plant-based food instead of animal-based food.

Currently, there is a greater interest in low carbohydrate diets to aid in the weight loss. The more popular approach for weight loss in the past was to cut the fat in the diet which makes logical sense if you want to lose fat.

Low carbohydrate versus Low fat diet

With the interest in a low carbohydrate diet sparked off by the Atkin’s diet, in the early 2000s, a number of randomised controlled trials which are the gold standard of research studies were carried out to compare if a low carbohydrate diet with high intake of fat and protein is able to reduced weight and other cardiac risk factors.

Two studies were published in the prestigious New England Journal of Medicine in 2003 to test the low carbohydrate, high protein/fat diet versus the low fat diet in obese individuals. Both studies showed that at 6 months, the patients on a low carbohydrate diet lost more weight than patients on a low fat diet, about 5-6 kilograms versus 2-3 kilograms. The low carbohydrate diet lowered the blood triglyceride levels (28% versus 1.4%) and raised the good cholesterol levels (18% versus 3.1%) more than the low fat diet. Both diets also helped to lower the diastolic blood pressure by about 6 mmHg and reduce the tendency to be diabetic by increasing the insulin sensitivity.

The reinforcement of the superiority of a low carbohydrate diet in weight lost came in 2007 when a study comparing the Atkin’s diet, Zone diet, Ornish diet and LEARN diet was published in another prestigious journal the Journal of the American Medical Association. In that study, the amount of weight loss from the low carbohydrate diet (Atkin’s) was much greater at 4.7 kilogram versus the rest at 2 kilograms over a one year period. Again, it was shown that the low carbohydrate diet raised the good cholesterol and lowered the triglyceride levels more than the other diets. The systolic blood pressure was lowered more by the low carbohydrate diet.

Long term effects of a low carbohydrate diet

The main problem in all the above studies is that the drop out rate for these diets was very high, mostly in the region of 20% to 40%, so long term adherence is a problem. It was also expected that with the reduction in the risk factors for heart disease such as cholesterol levels and blood pressure, there would be a corresponding long term benefit of this diet on the reduction of heart disease and mortality. However, there is a concern about the increase in fat and protein intake which may be bad for the heart.

Looking at the evidence available, the studies were all done in cohorts of people in various countries and the diet assignment was not randomised but observed and based on food questionnaires. A Japanese researcher performed an analysis of all the studies of the low carbohydrate diets and other diets found that there was an increase in all-cause mortality with the low carbohydrate diet over a follow-up of 10 years or more. In 2012, Lagiou published a study of a 15.7 year follow-up of the diets of 43,396 Swedes and found that a decrease of 920 grams of carbohydrate and a 5 gram increase in protein caused a 5% increase in risk for coronary heart disease. These data are surprising as one would expect that a low carbohydrate diet would lead to less not more heart disease or deaths from heart disease.

The answer may lie in a study by Dr Fung published in 2010 in the Annals of Internal Medicine. Dr Fung looked at two cohorts, the Nurses Health Study and the Health professionals follow-up Study involving more than 120,000 individuals who were followed up for more than 20 years. Dr Fung found that low carbohydrate diets using animal protein had a 31% increase in death, a 14% increase in death from heart disease in men and 32% increase in cancer deaths. However, with low carbohydrate diet with vegetable proteins, this association was not found and a protective effect of a 20% reduction in all cause death and 23% reduction of death from heart disease.

Best food choices in a low carbohydrate diet

This revelation then puts the focus sharply on the individual components of the diet.  The low carbohydrate diet has less than 30% of the energy coming from carbohydrates, the rest of the calories must come from an increase in fat and protein. The type and quality of the protein source is important as shown above. Red meats have been shown to increase risk of heart disease. In contrast, eating fish and poultry may be more beneficial as a protein source. We can also use plant protein as a source as well especially soy and soy products. The best evidence comes from a Japanese study published in Circulation in 2007. It involved 40, 462 Japanese and found that in women who took soy products more or equal to 5 times a week versus none to 2 times a week had a 36% lower risk of stroke and 45% lower risk of heart attacks and 69% lower risk of death from heart disease. Cutting down red meat or fatty meat consumption, but including more leafy vegetables (or non-starchy vegetables) will be able to give us a heart-healthier and fuller meal.

We can also encourage the intake of complex carbohydrates which are usually in the form of dietary fiber in fruits, vegetables, whole grains and legumes. The high dietary fiber intake was found to reduce diabetes risk. Greater whole grain intake (2.5 servings per day versus almost none) has been found in an analysis of 7 large cohort studies to lead to a 21% lower risk of heart disease events and a 17% lower risk of stroke.

Healthful versus Unhealthful plant-based diet

Plant-based diet is a board term as it includes all kinds of vegetable, fruit, and non-animal products. Without any further thought, most people would regard plant-based vegetarian diet as healthy although it may not always be the case.

A recent study published in the Journal of the American College of Cardiology 2017 reported highest adherence to healthful plant-based diet (which includes whole grains, fruit, vegetables, nuts, oils and tea) being associated with  a reduced risk of heart disease by 25%. Healthful plant-based diet is high in dietary fiber, antioxidants, unsaturated fat and micronutrient content and low in saturated fat, which will benefit those who require weight loss, better glycaemic control and insulin regulation, improved blood pressure and lipids profile, as well as good vascular health.

Conversely, highest adherence to an unhealthful plant-based diet, which includes intake of fruit juices, refined grains, potatoes and its products, sugar sweetened beverages, sweets and desserts, increased risk of heart disease by 32%.  Unhealthful plant-based diet was also associated with higher glycaemic load and index, excessive sugar intake, lower levels of dietary fiber, unsaturated fat, micronutrients and antioxidants, all of which can lead to higher risk of heart disease.

Although this study may not be able to rule out all other lifestyle and environmental factors which may contribute to the risk of heart disease, it adds to the current evidence that a healthy balanced diet with emphasis on higher healthy plant food intake can help with cardiovascular health.

What should we do then?

A low carbohydrate diet may be a good short term solution for weight reduction in obese individuals but it may not be very safe to maintain this diet for the long term. For the maintenance phase, it may be recommended to be on a Mediterranean diet as this diet has been proven to be effective in preventing heart disease. In a study published in the New England Journal of Medicine in 2013 involving 7447 high risk individuals over 4.8 years, the Mediterranean diet was associated with a 30% reduction in the risk of stroke, heart attack and death from heart disease compared to a control diet. The drop-out rate for a Mediterranean diet was low, less than 5% and was highly sustainable for the long term. It is hoped that with a proper diet choice along with emphasis on higher intake of plant-based food, we can then stem the epidemic of obesity that is engulfing Singapore and the world.

Dr Kenneth Ng, Consultant Cardiologist

Ms Lee Yee Hong, Senior Dietitian, Mount Elizabeth Novena Hospital

Definitions

Low fat diet – A diet with reduced proportion of fat, which is usually less than 30% of total calories.

Low carbohydrate diet – The diet with lower carbohydrate, which is usually less than 30% of total calories or less than 130g carbohydrate/day.

Starchy vegetables – Vegetables with higher content of carbohydrate, it can be as high as 15g carbohydrate per serving. They are mostly the roots, bulbs or kernels of the plant, e.g.:  potatoes, sweet potatoes, corns, pumpkin, and so on.

Non-starchy vegetables – Vegetables with minimal starch content (lesser than 5g carbohydrate per 100g), usually comes with high fibre and low calorie. E.g.: cabbage, kale, lettuce, chye sim, broccoli, cauliflower and so on.

Wholegrains – Whole grains or wholegrain products must contain all the essential parts and naturally-occurring nutrients of the entire grain seed, which means that 100% of the original kernel, including all of the bran, germ, and endosperm must be present.

Mediterranean diet – Mediterranean diet encourages usage of olive oil as a healthier fat source to replace other saturated fat, high intake of fruit, vegetables including leafy green vegetables (or non-starchy vegetables), cereals, bread, nuts and pulses/legumes, low to moderate intakes of fish and other poultry, dairy products and red wine, and low intakes of red meat, eggs (0 to no more than 4 times/week) and sweets.

My Pounding Heart: Is it Anxiety or Atrial Fibrillation?

What are palpitations?

Palpitation is a general description of an increased awareness of our own heart beat. We may feel that the heart is beating faster, beating stronger, beating in a skipped way or beating irregularly. Some patients even describe their heart beats as fluttering or as popping out of the chest.

Are palpitations always abnormal?

Palpitations are not always abnormal. Some patients may feel their heart beating fast or differently but upon monitoring the heart rhythm, no abnormalities are found. So this palpitations can be psychological.

What are the causes of palpitations?

Palpitations can have triggers. They can be triggered by anxiety or emotional stress. Stimulants such as coffee or tea or exercise can also bring on palpitations. Traditional medicine products have stimulants which can also cause palpitations, for example ginseng or mah huang. Certain medical problems can also cause palpitations, the most famous of which are thyroid overactivity or thyrotoxicosis which is due to an excess of thyroid hormones.

Does atrial fibrillation cause palpitations?

Yes atrial fibrillation can cause palpitations as it can cause the heart to beat very fast and irregularly. The major clue is that the patient will complain of an irregular heart beat.

What is atrial fibrillation?

Atrial fibrillation is an irregular and often rapid heart beat. It is due to the chaotic and irregular beating of the two upper chambers of the heart. The irregular beating can come and go and the duration of the abnormal heart beat can be from seconds to hours to days. The heart rate can vary between 100 to 200 beats per minute.

What are the symptoms of atrial fibrillation?

The most common symptom of atrial fibrillation is that of a fast and irregular heart beat. It can also lead to giddiness, shortness of breathe, confusion, chest pain, and fatigue. However, in many cases, it does not cause any symptoms and is only picked up during a routine examination of the pulse or the electrocardiogram.

What are the causes of atrial fibrillation?

The most common cause is that of old age where there is degeneration of the body’s pacemaker and the heart beat goes wonky. Abnormalities and damage to the heart can also cause atrial fibrillation and these would include heart attacks, high blood pressure, congenital heart problems, abnormal heart valve, post-heart surgery, lung diseases, infections, sleep apnea, over active thyroid and exposure to stimulants such as alcohol.

What problems can atrial fibrillation cause?

Atrial fibrillation results from the chaotic electrical beating of the upper chambers of the heart. As such, the chambers are not really contracting but merely quivering. This cause the blood in the upper chamber of the heart to stagnate and form tiny clots. These clots can then migrate up to the brain and cause strokes.

Atrial fibrillation also causes the heart to beat very fast. If the heart continues to beat very fast for a long period of time, the heart function can weaken and it will then lead to the development of heart failure.

MANAGEMENT OF CHRONIC HEART FAILURE

A 60 year old man complains of progressive shortness of breath when he walks up the slope or when he walks to the nearby market. He also complains of breathlessness when he lies flat on the bed at night and has to sleep on two pillows to feel better. Occassionally, when he is sleeping, the breathlessness gets quite bad and he needs to sit up to catch his breath. He also complains that his feet are more swollen and his shoes do not fit very well anymore. On physical examination, there is a raised jugular venous pulse wave and pitting pedal edema up to the mid shin. On auscultation, there is a fourth heart sound and fine crepitations in the bases of both lung fields. The ECG shows Q waves in the anterior precordial leads and a QRS duration of 126ms. The transthoracic echocardiogram revealed an old left anterior descending artery territory scar, a moderately dilated left ventricle, moderately severe mitral regurgitation and an ejection fraction of 30%. The cardiac magnetic resonance imaging revealed an extensive scar over the anterior, apex and septal wall of the left ventricle with no viability. The coronary angiogram showed an occluded left anterior coronary artery and mild disease in the left circumflex and right coronary arteries.

Heart failure is one of the most common conditions for admissions to hospital. It is also a very common reason for admissions to hospital after an initial hospitalization episode. This is likely to be due to the aging population as well as better treatment for myocardial infarctions and coronary artery disease which allows the patient to live longer. The man above is suffering from decompensated heart failure and is in New York Heart Association functional class 3. The initial strategy would be to improve symptoms by decongesting him with diuretics and vasodilators. Diuretic therapy has been around since the 1940s but the evidenced based trial was only published in 2011! [1]. This trial showed that higher dose of diuretic was superior to low dose diuretic in inducing fluid loss and weight loss and improvement in breathlessness. It also showed that there was no difference in giving the diuretic as a divided dose or as a continuous infusion, so the conclusion was to give patients high dose diuretic in divided doses. However, it was noticed that the high dose of diuretics was more likely to cause a rise in the serum creatinine level, so it is advisable to monitor the creatinine level during therapy. The use of digitalis in heart failure has not shown to confer any survival benefit for heart failure patients but it did reduce the number of hospitalizations for worsening heart failure [2].

At this stage, it is appropriate to add vasodilators especially angiotensin converting enzyme inhibitors (ACE-I). This is because numerous studies have shown that the early addition of ACE-I resulted in a 26% reduction in death and 26% reduction in death or readmissions for heart failure [3]. ACE-I block the angiotensin-renin-aldosterone system which then leads to vasodilation which helps to decongest the heart. The ACE inhibition also leads to reverse remodelling of the heart which may then improve the heart function. The ACE-I should be started at the lowest dose and can be titrated quite aggressively to the maximum tolerable dose within the next 4 -5 days. Attention must be paid to the blood pressure to prevent significant hypotension and a rise in the serum creatinine level. The patient is also encouraged to limit his fluid intake to about 1 liter per day and to avoid adding any salt to his food. He must also weight himself daily once he has achieved his dry weight.

Once the excess fluid has been removed from the patient, the diuretics can be tailed down to a maintenance dose. It is now time to start the beta-blockers. It was always thought that beta-blockers could not be used in heart failure as they have negative inotropic properties which may then exacerbate the heart failure. That is still true but research also shows that in patients with chronic heart failure, there is upregulation of the sympathetic nervous system which leads to an increased mortality. The addition of beta-blockers will then block the sympathetic nervous system which then leads to an increased survival rate. Indeed, the CIBIS 2 study showed that in symptomatic heart failure patients, the addition of bisoprolol reduced all -cause mortality by 34% and sudden cardiac death  by 44% [4]. It was recommended that beta-blockers be started once the patient was out of heart failure and the lowest dose of beta-blocker should be used and the dose of beta-blocker be uptitrated slowly and every two weeks to reach the maximal tolerable dose. This era of studies with ACE-I and beta-blockers led to them becoming the cornerstone of heart failure therapy.

Once our patient was out of fluid congestion, his mortality still remained rather high as the heart function was abnormal. It was noticed from epidemiological data that patients with a heart rate of more than 70 bpm even when they were on beta-blockers had a reduced survival. In fact the mortality increased with an increasing heart rate. The use of a pure heart rate reducer, ivabradine, showed that there was a 26% reduction in admission for heart failure and a 26% reduction in deaths due to heart failure [5]. Once the patient has been maximised on ACE-I and beta-blockers and if their heart rate on the ECG was still above 70 bpm, it is advisable to start ivabradine and aim for a heart rate close to 60 bpm.

The patient with heart failure has an increased mortality from progressive heart failure as well as sudden cardiac death. Sudden cardiac death is usually due to ventricular arrhythmias like ventricular tachycardia or ventricular fibrillation. The survival of patients who have experienced an out of hospital cardiac arrest is dismal. The implantation of an internal defibrillator will help to remove sudden cardiac death. Our patient above has a EF of less than 35% and an infarct which makes him at high risk of sudden cardiac death. The implantation of an implantable defibrillator (ICD) resulted in a 31% reduction in all cause mortality [6]. Heart failure patients with a widened QRS complex of more than 120ms has been shown to benefit from cardiac resynchronization therapy. They are in New York Heart Association functional class II or III, like our patient, and with an ejection fraction of 30% or less. The cardiac resynchronization therapy with a defibrillator (CRT-D) was shown to reduce death by 25% and hospitalization for heart failure by 32% as compared to just implanting a (ICD) alone [7]. So the state of the art has moved and in our patient, he will probably benefit more from having a CRT-D implanted.

Heart failure is a progressive disease. The patients may have had their medications optimised and even a ICD or CRT-D implanted and may be very stable and leading a high quality of life for many years. Invariably, the heart failure will progress and become more and more difficult to treat. This usually occurs about 7 to 8 years after the initial episode of heart failure. At that stage, medications may not be useful anymore. They may have to be considered for a heart transplant if they qualify or a left ventricular assist device if they do not qualify for a heart transplant or are unable to get a donor heart urgently. The left ventricular assist devices (LVAD) have made a remarkable progress over the last 10 years. The early devices were big, noisy and could not last for more than 2 years. The latest device is very small and can fit into the palm of your hand, silent and can last for at least 10 years. In a trial of a permanent implantantion of a left ventricular assist device in severe heart failure patients who were inotrope dependent, the two year survival was 58% versus 8% survival for patients on optimal medical therapy [8]. What is more remarkable was that 83% of the patients with the LVAD were in New York Heart Association class I or II after the therapy and the percentage of patients able to walk jumped from 13% to 89% after the therapy. These amazing results have firmly entrenched LVAD as a treatment of choice for end-stage heart failure patients.

Heart failure is a chronic disease. It requires a good knowledge of the life saving therapies that are available to the patient and the meticulous implementation of these therapies to prolong their life as well as to improve their quality of life.

Dr Kenneth Ng

References

  1. Felker GM, Lee KL, Bull DA et al. Diuretic strategies in patients with acute decompensated heart failure. N Engl J Med 2011;364;797-805.
  2. The Digitalis Investigation Group. The effect of digoxin on mortality and morbidity in patients with heart failure N Engl J Med 1997;336:525-533.
  3. Flather MD, Yusf S, Keber l et al. Long term ACE-inhibitor therapy in patients with heart failure or left ventricular dysfunction. Lancet 2000;355(9215):1575-81.
  4. The cardiac insufficiency bisoprolol study II (CIBIS-II): a randomised trial. Lancet 1999;35399416):9-13.
  5. Swedberg K, Komajda M, Bohm M, Borer JS Ford I et al. Ivabradine and outcomes in chronic heart failure (SHIFT): a randomised placebo-controlled study. Lancet 2010;376(9744):875-885.
  6. Moss AJ, Zareba W, Hall JW et al. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction N Engl J med 2002;346:877-883.
  7. Tang ASL, Wells GA, Talajic M et al. Cardiac-resynchronization therapy for mild to moderate heart failure. N Engl J Med 2010;363:2385-2395.
  8. Slaughter MS, Rogers JG, Milano CA et al. Adavnced heart failure treated with continuous flow left ventricular assist device. N Engl J Med 2009;361:2241-2251.

COFFEE VERSUS TEA SHOOT OUT: WHICH IS BETTER FOR THE HEART?

We all know that wine has been shown in multiple studies to be beneficial in protecting against heart disease which is also known as the French Paradox.

This has spurred investigations into other common beverages like coffee and tea which are consumed by more people and in larger quantities than wine. How do they fare in this respect?

Tea has been drunk for the last 4000 years and has its origins in China. In the early years, it was regarded as a medicinal plant with therapeutic qualities. Tea has been found to contain catechins, caffeine, theanine, saponins, vitamins and many other minor components. The main therapeutic effects must come from the catechins which are polyphenols and have a strong antioxidant effect. The theanine which is an amino acid gives the tea its full bodied taste and has a relaxing effect for which has been famous for relaxation and a good companion to pass time with.

Coffee on the other hand has an image of a stimulant. The major components of coffee include caffeine, antioxidants and diterpenes which is found in the oil of the bean. Coffee cultivation started in the 15th century in Arabia and the custom of drinking this energizing drink with a wonderful aroma quickly established itself in coffee houses in the Middle East and by the 17th century, it had spread to Europe. Many people have to start their day with their dose of coffee and caffeine.

So in the battle between two ancient beverages, which one comes out on top? Modern scientific methods have been employed to study these two all-time favourites. Both beverages have caffeine as their main component and caffeine has been associated with increased blood pressure, abnormal heart rhythms and increased vascular resistance, all which are actually not good for the body system. However, information on how tea or coffee relate to heart events like stroke, heart attacks, cholesterol plaque formation in the heart arteries is sparse.

Recently, researchers from Johns Hopkins Hospital and the National Institutes of Health in the United States embarked on a study to determine just that. They studied a multi-ethnic population of 6814 men and women and determined the consumption of tea, coffee and other food  and caffeine products from a standardised food questionnaire. These people were asked to report the frequency of coffee and tea intake and they were studied for the occurrence of heart events, cardiac diagnoses, hospitalizations, heart procedures and death. Also, many clinical parameters were collected from the participants in this study. The study found that 51% of the participants drank one or more cups of coffee a day and only 13% of them drank one or more cups of tea a day. The participants were followed up for an average of 11 years.

The investigators found that coffee drinkers who drank one or more cups of coffee a day had a higher baseline level of coronary calcium of more than 100. It is well known that the coronary calcium score correlates very strongly with the amount of cholesterol deposits there are in the heart arteries. The higher the score, the more cholesterol there is. The converse was found for tea. In tea drinkers, a lower number of them had a coronary calcium score of 100.

In the follow-up of the participants over time, drinking coffee did not affect the progression of the coronary calcium scores, whilst drinking tea actually helped to reduce coronary calcium score over time, with a 27% reduction in the progression of the score. This means that tea drinking actually retarded the build-up of cholesterol in the heart arteries. This observation is stronger in non-smokers and ex-smokers than in current smokers.

Study participants who drank one or more cups of coffee a day did not have an impact on heart-related events. Those who occasionally drank coffee ie less than one cup a day had a 28% increase in heart related events. Once again, in tea drinkers, those who drank one or more cups of tea a day had a 29% reduction in heart-related events!

In conclusion, from this rather well done study which followed up a group of participants for 11 years found that drinking tea had a beneficial effect in preventing the progression of disease of the heart arteries which then led to a reduction in the occurrence of heart-related events. This is indeed good news for regular tea drinkers and from this shoot-out, it seems that tea has come out on top. The consolation is that regular coffee drinking did not lead to any increase in heart-related events, so it is safe to continue to have your daily coffee fix. The mechanisms of the why this is so is not clear from this study. Tea seems to have a much stronger antioxidant property due to the presence of polyphenols which is also found in wine. Diterpenes in coffee have been found to raise LDL or bad cholesterol levels but depending on the preparation method may not be at significant levels in our cup of coffee. Whatever the underlying cause, I would like to propose a toast to tea drinkers for choosing a superior beverage.

Dr Kenneth Ng

Cholesterol and Supplements

I would recommend that low risk individuals who have high cholesterol levels try taking cholesterol – lowering supplements to lower their bad cholesterol levels. Actually dietary therapy such as vegetables, oats and tofu can lower bad cholesterol levels by at least 10%. By taking supplements, the bad cholesterol level can be lowered by another 10-20%. The rationale for taking cholesterol lowering instead of medications in low risk individuals is that they are not at high risk cardiac events or strokes and can afford to have a less aggressive and slower way of reducing their cholesterol levels.

Supplements have a very low toxicity level and are unlikely to cause harm even if taken at high doses. If the individual already knows that his cholesterol level is high, he may benefit from taking such supplements. If the individual does not know their cholesterol level and is worried, he should go for a check first. By and large, supplements are available over the counter without a need for any prescription. The supplements are unlikely to cause harm and may have some benefit.

There are individuals who refuse to take statins because they are fearful of the possible side effects. I think it boils down to whether the individual is at low or high risk for cardiovascular disease. The evidence is very strong for statins in patients who are in the high risk category. In the low risk category, the guidelines recommend treating the cholesterol level with a statin if the bad cholesterol exceeds 190 mg/dL. In individuals in the low risk category and who have cholesterol levels below 190mg/dL, then they can opt for alternative therapy. Research does support the idea that exercise and dieting helps to lower cholesterol levels through weight loss and a good diet. The cholesterol levels can be reduced by up to 20-30%.

Red yeast rice

Red yeast rice is marketed and found in supplements such as Xuezhikang, cholestin and hypocol. The dose is dependent on the brand of supplement used for example Hypocol dose is up to 2 tablets twice a day.

The active ingredient in red yeast rice is Monacolin K which is also known as lovastatin. Three placebo –controlled studies have shown that red yeast rice can reduce total cholesterol by up to 16% and LDL cholesterol by up to 24%. This degree of reduction is equivalent to lovastatin drug dose of 20-40mg.

Red yeast rice also contains beta-sitosterol and capesterol which inhibits cholesterol absorption of the intestine.

FDA in 2007 warned consumers not to buy certain brands of red yeast rice as they contained lovastatin and banned those products. However, the Hypocol which is available in Singapore has monacolins in the ingredients label and as mentioned above, monacolin K is lovastatin. So I would presume that the red yeast rice sold in Singapore are still effective.

Fish oils contain omega-3 fatty acids which are considered essential. The active components of omega-3 fatty acids are EPA and DHA. They have been shown to have anti-inflammatory and antithrombotic effects. Fish oils are to inhibit the production of triglycerides in the liver.

The main effect of fish oils is that they lower triglyceride levels. However, the lowering of triglyceride levels by drugs or others have not been shown to reduce the risk of cardiac events.

The evidence from clinical trials center mainly on secondary prevention, ie in people who already have heart disease. In two trials of patients who had suffered a previous heart attack, treatment with 850mg of DHA/EPA per day significantly reduced the risk of death by 28%, driven mainly by a 45% risk reduction in sudden cardiac death.

In a trail of patients with heart failure, 850mg pf DHA/EPA reduced the risk of death by 9% and hospitalization for a cardiac cause by 8%.

A very large study from Japan in patients with high cholesterol and a vascular event showed that combined therapy with a statin and 1.8 grams of EPA reduced the combined end-point of death, revascularization, myocardial infarction and unstable angina by 19% compared with statin alone.

There is no toxicity associated with omega-3 fatty acids so there are no real cons except that if you burp after taking one of these capsules, your breathe will smell very fishy.