Association of major modifiable risk factors among patients with coronary artery disease--a retrospective analysis

The relative importance of various risk factors varies in different regions of India. This was a retrospective study of patients with recently diagnosed coronary artery disease to assess four major risk factors: dyslipidemia, hypertension, smoking and diabetes.

A total of 5748 patients (4952 males, 796 females) with recently diagnosed coronary artery disease were analysed from the records of Heart Hospital along with 8103 controls (6092 males and 2011 females). Absolute lipid levels as well as prevalence of dyslipidemia using the ATP III guidelines were assessed. They were classified into two major groups premature CAD (males < 45 years females < 55 years) and CAD at usual age (males > or = 45 years, females > or = 55 years).

The most common pattern of CAD was chronic stable angina (n=2773, 48.24%). Mean total cholesterol (TC), LDL cholesterol and TC/HDL ratio were significantly higher in subjects with CAD compared to subjects without CAD controls. The mean HDL cholesterol and triglyceride levels were similar in both groups. Elevated LDL cholesterol, decreased HDL cholesterol, elevated total cholesterol and abnormal TC/HDL ratios were more common in CAD patients as compared to controls (38.8% vs. 33.14%, 29.3% vs 18.2%, 36.9% vs 32.5% and 59.05% vs 44.3% respectively). However lipid abnormalities were not significantly different in females > or = 55 in CAD vs non-CAD group. Smoking was significantly more common in subjects with CAD groups (30.97% vs. 12.72%) as compared to subjects without CAD (P < 0.0001). It was most common in males with premature CAD (44.1 % P < 0.0001). Hypertension was found in 1036 patients (18.02%) and diabetes in 763 (13.28%) as compared to 1126 (13.9%) hypertensives in non-CAD group and 639 diabetics (7.89%) (P = 0.001), both were more common in males > or = 45 and females > or = 55 as compared to those with premature CAD (p < 0.01).

Among the risk factors assessed, dyslipidemia (particularly abnormal TC/HDL ratio and elevated LDL cholesterol), smoking hypertension and diabetes were associated with coronary artery disease in decreasing order of prevalence. In premature CAD, dyslipidemia and (in males) smoking are of particular importance.