Modelling total coronary heart disease burden and long-term benefit of cholesterol lowering in middle aged men with and without a history of cardiovascular disease

Abstract

Aims: Cumulative coronary heart disease (CHD) events over 20 years were examined in men screened for, and in those randomized to, the West of Scotland Coronary Prevention Study.

Methods and results: Record linkage provided CHD-related events and days in hospital for the 80 230 screenees, including the randomized cohort of 6595 men. Risk factors were determined at baseline, and disease burden assessed for groups defined by cholesterol. Effects of cholesterol lowering were modelled from differences between groups, and from the treatment arms of the trial. Over 20 years, those without a history of CHD (n = 61 211) had 23.0 events per 100 subjects in the lowest cholesterol group (mean 4.0 mmol/L) and 65.1 per 100 in the highest (8.8 mmol/L). Corresponding days in hospital were 167.2-435.4 per 100 subjects. Analogous figures for men with a CHD history (n = 8570) were 77.3-141.7 events per 100 and 526.1-936.7 hospital days per 100. Lowering cholesterol by about 1.0 mmol/L in men with average cholesterol and no CHD was predicted to be associated with 8.9 fewer events and a saving of 56.0 hospital days per 100. In those with CHD this difference gave, depending on starting level, 26.8-36.5 fewer events and savings of 158.2-247.3 hospital days per 100 subjects. Comparison of cumulative events in 45-54 vs. 55-64 year olds in the trial revealed greater benefit from intervention in the younger decade.

Conclusion: Long-term, longitudinal data reveal the considerable CHD burden in middle-aged men and indicate substantial clinical benefits from both moderate and aggressive cholesterol lowering.

Keywords: Cholesterol; Clinical trial; Data linkage; Myocardial infarction.