Lipid risk factor correlates of ischemic heart disease as diagnosed by myocardial perfusion scintigraphy

Patients with known coronary artery disease frequently change their lifestyles (e.g., diet, exercise, and smoking habit) after the diagnosis is made. Such changes can alter lipid risk factor levels and obscure etiologic risk factor associations with the presence of coronary artery disease. It is therefore preferable to determine the contribution of potential risk factors before the diagnosis of coronary artery disease has been established. In this trial, we used stress nuclear myocardial perfusion imaging to diagnose coronary artery disease in patients presenting for evaluation of chest pain. Two groups of age- and sex-matched patients were identified: a normal group (patients with no evidence of coronary artery disease), and an abnormal group (patients whose scans indicated the presence of significant coronary artery disease due to either fixed or reversible perfusion defects). Blood samples were drawn before scanning and analyzed for lipid risk factors. Compared to the normal group, the abnormal group had higher levels of triglycerides (189±91 vs. 135±51 mg/dL, p=0.003), lower levels of high density lipoprotein cholesterol (39±9 vs. 45±14 mg/dL, p=0.037), and higher levels of small, dense low density lipoprotein (LDL₃) (42±18 vs. 32±13 mg/dL, p=0.007). Total cholesterol, low density lipoprotein, and lipoprotein(a) levels were similar between groups. These findings suggest that ischemic heart disease, as assessed by myocardial perfusion scintigrapby, is more closely associated with the low high density lipoprotein/high triglyceride syndrome than with increased low density lipoprotein or total cholesterol levels. (C) 2000 by CHF, Inc.