Coronary artery disease – overview and risk factors

Coronary artery disease – overview and risk factors

Coronary artery disease (CAD) is known by various names like ischemic heart disease and atherosclerotic coronary heart disease. In general, CAD is due to coronary obstruction as a result of atherosclerotic plaques. Other rare causes of coronary obstruction include coronary dissection and coronary spasm. Manifestation of CAD can vary from asymptomatic to sudden cardiac death as initial manifestation. Sudden cardiac death in a previously asymptomatic person is usually due life threatening ventricular arrhythmia known as ventricular fibrillation which can occur in the early hours of a myocardial infarction (heart attack). Symptomatic CAD is divided into chronic stable angina, now termed chronic coronary syndrome and unstable ischemic syndromes. Unstable ischemic syndromes or acute coronary syndromes can be further divided into unstable angina (without elevation of biomarkers like cardiac troponin) and myocardial infarction. Myocardial infarction includes those with ST segment elevation known as ST elevation myocardial infarction (STEMI) and those without ST segment elevation known as non ST elevation myocardial infarction (NSTEMI). STEMI is usually due to acute thrombotic occlusion of a major coronary artery and will benefit from early removal of the obstruction either by mechanical means (primary coronary angioplasty) or clot lysing medication (thrombolytic therapy) or a combination of the two.

Risk factors for coronary artery disease

 Coronary risk factors can be divided into modifiable and non-modifiable.

Non-modifiable coronary risk factors: The main three non-modifiable coronary risk factors are age, gender and family history. Prevalence of coronary artery disease increases as age advances. Coronary artery disease is more prevalent in males. The more number of close relatives in your family with CAD, the higher the risk of CAD.

Modifiable coronary risk factors: Important modifiable risk factors are hypertension, diabetes mellitus, dyslipidemia, obesity, smoking and sedentary lifestyle. Sitting for more than 5 hours a day is considered to give a risk equivalent to smoking. That is why many workplaces have started implementing standing desks at work. Regular exercise of at least 30 minutes on a minimum of 5 days a week is important in reducing the risk. But if you are above 40 years of age, it is wiser to start the exercise program in a graded pattern after a medical check up to exclude silent CAD, which can become symptomatic with vigorous exercise.

Novel coronary risk factors: The conventional risk factors detailed above do not fully explain the occurrence of coronary artery disease. Hence the search for novel coronary risk factors. More than 100 emerging risk markers have been suggested. The widely discussed ones include C-reactive protein, homocysteine, fibrinogen, adiponectin, plasminogen activator inhibitor-1 and interleukin-6.