Plasma lipid concentrations and subsequent coronary occlusion after a first myocardial infarction

This study correlated plasma lipid values with angiographic evidence of progression to complete coronary occlusion. Baseline triglycerides (TGs), total cholesterol (Chol), high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, and HDL/LDL and HDL/Chol ratios were compared with coronary angiograms taken at baseline, 3 and 5 years in a prospective angiographic study. Results were from part of the multicenter trial of plasma lipid reduction in patients after a single myocardial infarction (POSCH). Comparison of patient's baseline lipids in the absence or presence of a new total coronary occlusion at 3 years showed a significant difference (p = 0.01) in TGs of 197 ± 147 versus 250 ± 162 mg/dl (p = 0.02) and VLDL of 30 ± 23 (n = 284) versus 40 ± 30 (n = 49) mg/dl. Stratification by the mean HDL/Chol ratio (16%) demonstrated that baseline TG levels were significantly increased in patients with a new coronary occlusion by 3 years despite a higher HDL/Chol ratio. When measured at the 3-year visit, plasma TG (176 ± 91 versus 212 ± 146 mg/dl; p = 0.02) and VLDL (28 ± 18 versus 35 ± 29 mg/dl; p = 0.04) were significantly elevated in the presence of a new 3-year coronary occlusion. Stratification by the mean HDL/Chol ratio (16%) demonstrated that 3-year TG levels increased significantly in patients with a new 3-year coronary occlusion despite a higher HDL/Chol ratio. A comparison of the baseline lipid results with angiographic evidence of occlusion by 5 years showed a significant difference (p = 0.04) in Chol in patients with a new total coronary occlusion (255 ± 35 mg/dl) versus patients without a new total coronary occlusion (247 ± 30 mg/dl). Both LDL and the HDL/LDL ratio were not significantly different between groups. When measured at 5 years, TGs were higher in patients who did (213 ± 165 mg/dl) than in patients who did not (182 ± 91 mg/dl) occlude by 5 years (p < 0.05). Chol, LDL, and the HDL/LDL ratio were not significantly different between groups. Stratification by the mean HDL/Chol ratio (16%) demonstrated that 5-year TG levels were not significantly increased in patients who developed a new 5-year coronary occlusion despite a higher HDL/Chol ratio. It is suggested that lipid reduction, even within the spectrum of hyperlipidemia with elevated LDL and known coronary artery disease, might decrease the incidence of progression to coronary occlusion.