A large observational study of cardiovascular outcomes associated with atorvastatin or simvastatin therapy in hypertensive patients without prior cardiovascular disease

Abstract

The objective of this study was to examine whether differences in effectiveness exist between statins in hypertensive patients seen in clinical practice. We assessed cardiovascular (CV) outcomes in hypertensive patients without cardiovascular disease who began therapy with atorvastatin (10 or 20 mg/d) or simvastatin (20 or 40 mg/d) between January 1, 2003, and September 30, 2005, using claims data from 92 US managed care plans in the PharMetrics database. A total of 98,471 hypertensive patients were identified, comprising 74,685 atorvastatin users (mean dose 13.6 mg/d) and 23,786 simvastatin users (mean dose 28.6 mg/d), and followed a median 1.5 years for the occurrence of a first CV event. The crude CV event rates were 2.81 and 3.92 per 100 person-years for atorvastatin and simvastatin, respectively [unadjusted hazard ratio (HR): 0.73; 95% confidence interval (CI): 0.68-0.78, P < 0.001]. After adjusting for clinical and demographic confounders, use of atorvastatin was associated with fewer CV events compared with simvastatin (HR: 0.91; 95% CI: 0.84-0.98, P = 0.009). However, the lipid-lowering efficacy of the 2 statins could not be assessed as patient lipid data were unavailable. In conclusion, hypertensive patients without cardiovascular disease who initiated atorvastatin (10 or 20 mg/d) had a significantly lower risk of subsequent CV events compared with those who initiated simvastatin at doses of similar potency (20 or 40 mg/d). As with all observational studies, the study is subject to certain limitations, and the findings should be regarded as hypothesis generating.