Never too young to have heart disease

THE caller over the weekend sounded very distressed. It was my patient who was due to have opening of the heart arteries by stenting the following Monday. He was shocked to learn that his nephew, who was 35, had died suddenly of a massive heart attack - without any warning symptoms. Autopsy had shown complete occlusion of two out of three major heart arteries.

In the same week, 35-year-old Mr A came to me for a second opinion. He had gone to a hospital in July last year for chest pain and was suspected to have blockage of the heart arteries (coronary artery disease or CAD). During an elective invasive diagnostic coronary angiogram, where plastic tubes were inserted into the heart arteries to take X-ray images, he was told that he had severe blockage of the heart arteries that required open heart bypass graft surgery immediately. He was whisked off to another hospital where bypass surgery was performed.

Just when he thought that his problem was over, he started feeling chest tightness again three months later in October. He was treated symptomatically but the severity of the chest tightness progressed. A subsequent invasive coronary angiogram confirmed that two of his bypass grafts were occluded, resulting in insufficient blood supply to two out of three major heart arteries. He was given the option of either continuing with his medication or going to another hospital to get a second opinion on another open heart bypass graft surgery.

Men vs women

Sudden death from a heart attack in young adults is tragic and catastrophic as it deprives young children of a parent and leaves elderly parents heartbroken at the sudden loss of a beloved child. In an autopsy study of 760 young (less than 35 years) victims of accidents, suicides, or homicides by McGill published in Circulation journal in 2000, advanced cholesterol deposits causing narrowing and hardening of heart arteries (atherosclerosis) were seen in 2 per cent of men and no women aged 15 to 19 years. Nineteen per cent and 8 per cent of men and women aged 30 to 34 years, respectively, had a >40 per cent narrowing of the left anterior descending artery, the main blood supply to the main heart chamber.

In the Framingham Heart Study, the incidence of a heart attack over a 10-year follow-up was 12.9/1000 in men 30 to 34 years old and 5.2/1000 in women 35 to 44 years old. Hence, in young men, close to 20 per cent have CAD and about 13 out of every 1,000 develop a heart attack.

Risk factors

Last year, my youngest patient with severe CAD was 32 years old and this year, my youngest patient with severe CAD was 25 years old. What these two young men had in common were a family history of CAD, an elevated bad cholesterol (LDL-C or low density lipoprotein cholesterol) >190 mg/dl and chronic smoking.

If your parents had CAD before the age of 50, your risk is increased. Smoking is the worst health decision a young person can make. In the Framingham Heart Study, young smokers had three times the risk of developing CAD compared to non-smokers. In female smokers, the risk is more than five times that of non-smoking women. It gets much worse with the use of oral contraceptives in female smokers - death from CAD increases 13-fold.

Parents should take note that a smoke-filled home is a health hazard for their children. A 2007 study on children aged 11 who had daily exposure to second hand smoke showed that there was significant impairment in the ability of their heart arteries to increase in diameter when there was increased demand for more blood to the tissues. Hence, even passive smoking can have a detrimental impact on heart arteries.

The manner in which the risk factors translate into real world CAD risk is shown in the Coronary Artery Risk Development in Young Adults (CARDIA) study which evaluated 5,115 young adults, aged 18 to 30, from 1986 till present. The study examined the impact of risk factors on atherosclerosis in heart arteries by screening for calcium deposits in the walls of heart arteries using computed tomography X-ray scanning. The more calcification there was, the more extensive the atherosclerosis of the coronary arteries. The study showed that the likelihood of CAD increased as follows: 50 per cent increase in risk by smoking 10 cigarettes a day or with every 30 mg/dL rise in LDL-C; 30 per cent increase in risk by each 10 mm Hg rise in systolic blood pressure; and 20 per cent increase in risk by each 15 mg/dL rise in blood sugar levels.

About 20 per cent of heart attacks in the young are not due to CAD but other causes. About 4 per cent are due to underlying congenital abnormal heart arteries, 5 per cent due to clot formation from underlying abnormalities of the blood clotting system, 5 per cent from blood clots formed elsewhere which travel to the coronary arteries, and 6 per cent due to rare causes such as spasm, spontaneous tear in the coronary arteries, inflammation, chest radiotherapy, chest trauma and drug abuse (especially cocaine and amphetamines).

Most young people assume that they will never get CAD until they are much older and hence they are often unwilling to give up their reckless lifestyle. You may be surprised that, unlike older CAD patients, younger CAD patients are less likely to have symptoms. In three quarters of young CAD patients, the initial presentation of an existing severe CAD is an impending heart attack or a heart attack. About two-thirds of young CAD patients with a heart attack do not have chest pain prior to the infarct. Among those who have preceding chest pain, the first episodes are usually present only in the week preceding the heart attack.

What lies ahead

In a 2003 Journal of the American College of Cardiology publication by Cole, more than 800 young CAD patients diagnosed on coronary angiogram were followed up for 15 years. The mean age for severe CAD was 35 years and 36 years for women and men respectively. After 15 years, 30 per cent of the young CAD patients had died. The 15-year death rate was higher for those who had a previous heart attack (45 per cent), those with underlying diabetes mellitus (65 per cent) and those with more than 50 per cent reduction in heart pump function (83 per cent).

Medication alone was associated with a higher death rate compared to opening of heart arteries by balloon dilatation or open heart artery bypass graft surgery. In another study of men and women who had a heart attack before age 40, 25 per cent died in less than 15 years. Data from the Swedish national heart registry (SwedeHeart registry) showed that almost one in five young CAD patients who underwent open heart bypass graft surgery died 15 years later.

CAD in young adults is associated with a poor long-term outlook. A previous heart attack, the presence of diabetes mellitus, chronic smoking and severely impaired heart pump function are associated with a significantly higher risk of death.

Making the right decisions

As for Mr A, he declined a second bypass graft surgery which can carry a more than 4 per cent risk of death and had successful stenting of his blocked native arteries. Given the grim long-term outcome of young CAD patients, prevention is still the best strategy. Even if you are young, if you have a family history of CAD and high LDL-C, seek medical advice early. Smokers harm their family and friends and smoking cessation is the best gift of health they can give to themselves and loved ones.

There is some light at the end of the tunnel for young CAD patients. Given the availability of absorbable stents, young CAD patients with severe blockage of all three major heart arteries may have an alternative option of opening the heart arteries with polymer stents. These stents eventually get absorbed within three years, giving them a clean slate and "brand new" heart arteries in their natural state.

Finally take heart that the Framingham Heart Study showed that if you are not obese, do not smoke, do not have high blood pressure, do not have high LDL-C, do not have diabetes and do not have low HDL cholesterol, there is only a 5 per cent risk of getting heart disease at the age of 95 years. Hence, investing in risk factor control from young pays off.