Real-world effectiveness of lipid-lowering therapy in male and female outpatients with coronary heart disease: relation to pre-treatment low-density lipoprotein-cholesterol, pre-treatment coronary heart disease risk, and other factors

Abstract

Background: Determinants of the real-world effectiveness of lipid-lowering therapy have been rarely assessed in an unselected observational coronary heart disease (CHD) community cohort over time.

Design: Randomly drawn patients (n=605) from randomly drawn practices (n=62) were retrospectively followed for a median of 3.6 years (1998-2002) on lipid-lowering therapy (98% statins).

Methods: Coronary heart disease population-averaged estimates and variances accounting for repeated measurements within patients were obtained using generalized estimating equations.

Results: Post-treatment low-density lipoprotein-cholesterol (LDL-C) was 124 mg/dl in men and 141 mg/dl in women and was independently associated (all P<0.05) with pre-treatment LDL-C (+3.7 mg/dl per 10 mg/dl increment), female sex (+14.0 mg/dl), coronary bypass (-9.5 mg/dl), drug-treated diabetes mellitus (-6.8 mg/dl), and era 2002/2001 versus 1999/2000 (-6.4 mg/dl) in age-adjusted multivariate analyses. Holding pre-treatment LDL-C constant post-treatment LDL-C was associated with pre-treatment Framingham CHD risk in men (-13.9 mg/dl per doubling of risk), whereas LDL-C control in women resembled that in low-risk men. The likelihood of attaining LDL-C <100 mg/dl was 0.28 in men and 0.17 in women and was likewise associated with the above factors.

Conclusion: Low-density lipoprotein-cholesterol control remained low despite lipid-lowering therapy across a wide range of pre-treatment LDL-C and pre-treatment CHD risk. Low-density lipoprotein-cholesterol control in women was inferior to that in men, a finding that warrants attention and clarification.