Statins and atherosclerotic cardiovascular outcomes in patients on incident dialysis and with atherosclerotic heart disease.

BACKGROUND Statins failed to reduce cardiovascular (CV) events in trials of patients on dialysis. However, trial populations used criteria that often excluded those with atherosclerotic heart disease (ASHD), in whom statins have the greatest benefit, and included outcome composites with high rates of non-atherosclerotic CV events that may not be modified by statins. Here, we study whether statin use associates with lower atherosclerotic CV risk among patients with known ASHD on dialysis, including in those likely to receive a kidney transplant, a group excluded within trials, but with lower competing mortality risks. METHODS Using data from the United States Renal Data System including Medicare claims, we identified adults initiating dialysis with ASHD. We matched statin users 1:1 to statin nonusers with propensity scores incorporating hard matches for age and kidney transplant listing status. Using Cox models, we evaluated associations of statin use with the primary composite of fatal/non-fatal myocardial infarction and stroke (including within pre-specified subgroups of younger age (<50years) and waitlisting status); secondary outcomes included all-cause mortality, and composite of all-cause mortality, non-fatal myocardial infarction or stroke. RESULTS Of 197,716 patients with ASHD, 47,562 (24%) were consistent statin users from which we created 46,186 matched pairs. Over a median 662days, statin users had similar risk of fatal/non-fatal myocardial infarction or stroke overall (HR 1.00, 95% CI 0.97, 1.02), or in subgroups [age<50years (HR=1.05, 95% CI 0.95, 1.17); waitlisted for kidney transplant (HR 0.99, 95% CI 0.97, 1.02)]. Statin use was modestly associated with lower all-cause mortality (HR 0.96, 95% CI 0.94, 0.98; E-value =1.21) and similarly, a modest lower composite risk of all-cause mortality, non-fatal myocardial infarction or stroke over the first two years (HR 0.90, 95% CI 0.88, 0.91), but attenuated thereafter (HR 0.98, 95% CI 0.96, 1.01). CONCLUSIONS Our large observational analyses are consistent with trials in more selected populations and suggest that statins may not meaningfully reduce atherosclerotic CV events even among incident dialysis patients with established ASHD and those likely to receive kidney transplants.