Propranolol-induced lipid changes and their prognostic significance after a myocardial infarction: the Beta-Blocker...

Beta blockers represent the only documented effective long-term prophylactic treatment for patients after myocardial infarction (MI). Concern continues to be expressed about the lipid-altering effects of their long-term use, especially beta blockers without intrinsic sympathomimetic activity such as propranolol. Data collected for the Beta-Blocker Heart Attack Trial, the largest long-term clinical trial of beta-blocker use in patients after MI, have been analyzed to address the following questions. To what extent does propranolol alter lipid levels at least 6 months after MI and initiation of therapy? How predictive of subsequent coronary events and mortality are lipid levels 6 months after MI? Is there any evidence that altered lipid levels attenuate any of the beneficial effect of propranolol on coronary morbidity and mortality? By the 6-month post-MI visit, propranolol was shown to raise serum triglyceride levels by about 17% (approximately equal to 35 mg/dl) and lower serum high density lipoprotein (HDL) cholesterol by about 6% (approximately equal to 3 mg/dl). There was no effect on total cholesterol or low density lipoprotein cholesterol. In other analyses, no lipid measured 6 months after the MI was strongly predictive of subsequent coronary events or mortality. For example, every 1-mg-lower HDL value was associated with only a 0.7% relative increase in the mortality rate. Theoretically, the estimated relative increase on all-cause mortality associated with propranolol-induced HDL reduction is about 2%. In multivariate analyses adjusting for changes in HDL and serum triglyceride, propranolol-induced beneficial reductions in mortality and morbidity remained on the order of 20%, 10 times the estimated hazard.