Class effects of statins in elderly patients with congestive heart failure: A population-based analysis

Background Long-term treatment with statins reduces mortality in patients with congestive heart failure (CHF). Whether statin agents exert a class effect is unknown. Methods We analyzed long-term mortality in Canadian patients aged >= 65 years who were discharged from hospital with a diagnosis of CHIF from January 1998 to December 2002. Administrative data from Quebec, Ontario, and British Columbia were merged. We compared patients prescribed with atorvastatin, simvastatin, pravastatin, and lovastatin. Results A total of 15 368 patients hospitalized with a diagnosis of CHF fulfilled the inclusion criteria for this study. In this final dataset, 6670 (43.4%) filled a prescription for atorvastatin, 4261 (27.7%) for simvastatin, 3209 (20.9%) for pravastatin, and 1228 (8.0%) for lovastatin. Clinical characteristics and proportion of days covered with a statin prescription were similar across groups. Drug dosages were relatively low, with 82% of patients who received the agent at a dose of <= 20 mg. Although controlling for time-dependent covariates representing current use and dosage, as well as for age, sex, coronary artery disease, and several other comorbidities, treatment with pravastatin (adjusted hazards ratio [HR] 0.94, 95% Cl 0.83-1.07), lovastatin (adjusted HR 1.02, 95% Cl 0.88-1.17), or simvastatin (adjusted HR 0.92, 95% Cl 0.83-1.01) had a similar effectiveness to prevent mortality compared to atorvastatin (reference in this analysis) in this population with CHIF. Time-dependent exposure to a statin was highly protective against mortality. Conclusions Statins exert a class effect in patients with CHF, when used at a relatively low dose. The favorable effects appear largely independent of drug dosage.