As a 35 yr old man with an acute inferior wall myocardial infarction was being shifted out of the cardiac catheterization lab after an emergency primary angioplasty and three stents to alleviate three critical blocks in two of his coronary arteries, one was left pondering about what could possibly be the reasons for such critical triple vessel disease in a very young person. His family was equally concerned about how a young man with no previous traditional risk factors like Diabetes, Hypertension, Dyslipidemia, smoking, obesity could have 2 heart attacks in the past 3 years with triple vessel disease. On further enquiry it was evident that he had “a strong family history of premature Coronary artery disease”
The concept of “Family history of premature Coronary artery disease” was first added as a conventional risk factor for developing Cardiovascular disease along with risk factors like age, smoking, diabetes, Dyslipidemia, low HDL in the ATP set of guidelines, which was basically a tool to guide control of deranged cholesterol and LDL levels with diet, lifestyle changes, statins and other drugs -thereby reducing the 10 year risk of developing Cardiovascular disease. These were initially validated by various population studies conducted in western populations. However various multiethnic and Asian population studies have more or less validated similar findings in our populations as well. So the six pertinent questions that need to be addressed are as follows…
Q1.what does one mean by “family history of premature Coronary artery disease”?
Q 2.How does one evaluate or ascertain this risk?
Q 3. What is the additional risk incurred by having this?
Q 4.Does this have a prognostic effect?
Q 5.What are the reasons for it?
Q 6.And finally what can be done to reduce ones risk?
To address the first query as to what exactly entails a family history of premature CAD- Many times patients quote instances of CAD in cousins, uncles, aunts (second/third degree relatives) as evidence of strong family history. But what is clinically validated by large population cohort studies is CAD in First degree relatives (Father, mother, brother, or sister) only. And by premature meaning in a male less than 55 years and female less than 65 years of age. On the contrary many are unaware of what constitutes CAD. So the question that one needs to ask is “if any first degree relative, male under the age of 55 years or female under age of 65 years has history of angina, heart attack, angioplasty or Coronary artery bye pass surgery.” If yes then there’s a definite risk.
So how and why does a family history of premature CAD portend a risk? Our body is made up millions of cells, with about 25,000 different genes. Genes determine how we look and how our bodies work, and we inherit them from our parents. Genes can pass on high risk conditions such as high blood pressure and high cholesterol levels to name a few. These conditions can also increase your risk of developing heart diseases. There's no single gene that increases your risk - it's likely that several genes play a part.
Are inherited conditions same as family history? Inherited conditions are caused by a fault (or mutation) in one or more of your genes. The most common inherited conditions are cardiomyopathies (heart muscle diseases), channelopathies (inherited life threatening arrhythmias), and familial hypercholesterolemia ( high cholesterol levels). Family history is more complex as it can be the combination of shared genes and shared environments passed down from one generation to the next, that increase the risk of developing a disease rather than a single faulty gene.
The relative risk for CAD in first-degree relatives of affected persons ranges from 2 to 12 times that of the general population. Risk increases with the number of primary relatives affected and at younger ages of onset. Various population based studies have looked at angiographic Coronary artery disease patients and then retrospectively enquired about family history of premature CAD and found prevalence as high as 30% for western populations and 15% for Asians. Coronary artery calcium scoring using CT Coronary angiogram has been used by few studies to show increased CAC (Coronary artery calcium) scores in asymptomatic individuals or advanced coronary atherosclerosis for one’s age and gender. The effect of a reported family history of premature CHD was similar across all ethnic groups. The relationship existed with both a sibling history and a parental history of premature CHD.
The only heartening thing is that the long term prognosis and outcomes seem better for such people who develop a coronary event as they are younger ,have less of left main disease or triple vessel disease, are more likely to be compliant to medical therapy ,adopt healthy lifestyles more diligently, and hence have better long term survival as compared to patients with traditional risk factors.
So finally what’s the solution as one really can’t change ones family history can they? Take care to determine and control the modifiable risk factors which additionally increase your risk of developing cardiovascular diseases. These include not smoking or quitting, being physically active, eating a healthy balanced diet, keeping to a healthy weight and body shape. Consult a doctor to check your blood sugars, lipid profile, and Blood pressures regularly and control with adequate lifestyle changes and medications as prescribed.
A noninvasive test like a Treadmill test (TMT) or CT Coronary angiogram may be required for early disease detection.
To conclude “You can’t change your genes, but you can change your lifestyle and in turn reduce your risk factors. Family history doesn’t have to be your destiny”
Dr. Jay B Pattam
MD-Medicine (PGI-Chd) DM-Cardiology (PGI-Chd)
Consultant Interventional Cardiologist
Renai Medicity, Kochi