Effect of Statin Therapy on Mortality in Older Adults Hospitalized With Coronary Artery Disease

A Propensity-Adjusted Analysis

Daniel P. Rothschild, MD; Eric Novak, MS; Michael W. Rich, MD

Disclosures

J Am Geriatr Soc. 2016;64(7):1475-1479. 

In This Article

Results

Baseline characteristics of the participants who did and did not receive statins are summarized in Table 1 . In general, those treated with statins were more likely to be male, to have a primary diagnosis of AMI, to have traditional cardiovascular risk factors (hypertension, diabetes mellitus), and to receive other standard cardiovascular medications in addition to statins. Age, race, length of stay, lipid levels, and hemoglobin did not differ between the groups, but the statin group had modestly better renal function based on estimated glomerular filtration rates.

In unadjusted analysis, the statin group had lower all-cause mortality than the nonstatin group over a median follow-up of 3.1 years (hazard ratio (HR) = 0.83, 95% confidence interval (CI) = 0.71–0.96; Figure S1). As shown in Figure 1, which illustrates standardized differences before and after propensity adjustment for 31 measured covariates, IPTW was successful in reconciling differences between the statin and nonstatin groups. In the propensity-matched cohort, the mortality benefit associated with statin prescription was attenuated by approximately 50% and was no longer statistically significant (HR = 0.91, 95% CI = 0.73–1.14). Similarly, using IPTW, which included all 1,262 subjects, there was no difference in mortality between the statin and nonstatin groups (HR = 0.88, 95% CI = 0.74–1.05, P = .17; Figure 2).

Figure 1.

Standardized differences between statin and nonstatin groups for 31 covariates before and after inverse propensity treatment weighting (IPTW) using first imputed data set.

Figure 2.

Inverse propensity treatment-weighted survival curves.

Subgroup analysis according to age (80–84 vs ≥85) revealed no significant interaction between age, statin therapy, and mortality (P for interaction = .80 in the IPTW-adjusted model). Findings were also similar when calculated at 5-year age intervals (80, 85, 90, 95).

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