High Density Lipoprotein Cholesterol in Coronary Artery Disease: When Higher Means Later

Abstract

Although high-density lipoprotein cholesterol (HDL-C) levels are inversely associated with cardiovascular risk, patients with elevated HDL-C also develop coronary artery disease (CAD) and cardiac events. We aimed to draw the clinical profile of CAD patients with elevated HDL-C and to assess the prognostic impact of elevated HDL-C. We prospectively examined 2322 patients (age 67±10 years, 79% male) with chronic CAD, defined by >50% coronary stenosis and/or previous myocardial infarction. HDL-C levels were low (<35 mg/dL) in 736 patients (32%), normal (35-60 mg/dL) in 1464 (63%), and high (>60 mg/dL) in 122 (5%). Patients with elevated HDL-C were less frequently male (p<0.0001), smokers (p<0.0001), diabetic (p<0.0001), and obese (p<0.0015) than those with low or normal HDL-C, but were 3 and 5 years older, respectively (p<0.0001). During follow-up (median, 46 months) 143 patients died from cardiac causes and 80 developed a non-fatal infarction. Cardiac event-free survival was lower in patients with low compared to normal HDL-C (p<0.0001), but was not significantly different from that of patients with elevated HDL-C. The prognostic impact of low HDL-C was independent of age, sex, diabetes, LV function, extent of coronary stenoses, low density lipoprotein cholesterol, triglycerides, complete blood count, thyroid and renal function (p<0.0001). Conversely, the prognostic impact of elevated HDL-C disappeared (p>0.10) after adjustment for age. Patients with elevated HDL-C develop CAD and cardiac events as do those with low or normal HDL, but at a more advanced age.