Mortality after 16 years for participants randomized to the Multiple Risk Factor Intervention Trial

Abstract

Background: A mortality follow-up of 12,866 men was conducted 16 years after randomization to special intervention (SI) or usual care (UC) groups of the Multiple Risk Factor Intervention Trial to assess the long-term effect of cardiovascular risk factor intervention on coronary heart disease (CHD), cardiovascular death (CVD), and total mortality.

Methods and results: During the 7-year active-intervention phase of the trial, 6428 of the men were given dietary recommendations to lower blood cholesterol, antihypertensive drugs to lower blood pressure, and counseling for cigarette smoking cessation. The remaining 6438 men were referred to their usual source of medical care. After 16 years, 370 SI and 417 UC men had died from CHD, which represents an 11.4% lower mortality rate for SI versus UC men (95% CI, -23% to 1.9%). Results for total mortality followed a similar pattern; 991 SI and 1050 UC men had died by the end of follow-up (relative difference, -5.7%; 95% CI, -13% to 2.8%). For acute myocardial infarction, a subcategory of CHD, the relative difference was -20.4% (95% CI, -34.4% to -3.4%). Differences between SI and UC men in mortality rates from acute myocardial infarction, CHD, and all causes were greater during the posttrial follow-up period than during the trial.

Conclusions: Results of a 7-year multifactor intervention program aimed at lowering blood pressure and serum cholesterol and at cigarette smoking cessation among high-risk men give additional evidence of a long-term, continuing mortality benefit from the program.