Thienopyridine use after coronary stenting in low income patients enrolled in medicare part D receiving maintenance dialysis

Abstract

Background: Coronary stenting in patients on dialysis has increased by nearly 50% over the past decade, despite heightened risks of associated stent thrombosis and bleeding relative to the general population. We examined clopidogrel, prasugrel or ticlopidine use after percutaneous coronary intervention (PCI) with stenting in patients on dialysis. We conducted 3-, 6-, and 12-month landmark analyses to test the hypothesis that thienopyridine discontinuation prior to those time points would be associated with higher risks of death, myocardial infarction, or repeat revascularization, and a lower risk of major bleeding episodes compared with continued thienopyridine use.

Methods and results: Using the US Renal Data System, we identified 8458 patients on dialysis with Medicare Parts A+B+D undergoing PCI with stenting between July 2007 and December 2010. Ninety-nine percent of all thienopyridine prescriptions were for clopidogrel. At 3 months, 82% of patients who received drug-eluting stents (DES) had evidence of thienopyridine use. These proportions fell to 62% and 40% at 6 and 12 months, respectively. In patients who received a bare-metal stent (BMS), 70%, 34%, and 26% of patients had evidence of thienopyridine use at 3, 6, and 12 months, respectively. In patients who received a DES, there was a suggestion of higher risks of death or myocardial infarction associated with thienopyridine discontinuation in the 3-, 6-, and 12-months landmark analyses, but no higher risk of major bleeding episodes. In patients who received a BMS, there were no differences in death or cardiovascular events, and possibly lower risk of major bleeding with thienopyridine discontinuation in the 3- and 6-month landmark analyses.

Conclusions: The majority of patients on dialysis who undergo PCI discontinue thienopyridines before 1 year regardless of stent type. While not definitive, these data suggest that longer-term thienopyridine use may be of benefit to patients on dialysis who undergo PCI with DES.

Keywords: clopidogrel; end‐stage renal disease; epidemiology; percutaneous coronary intervention; revascularization.

Figure 1.

Cohort assembly. Patients in the USRDS with ESRD on dialysis who underwent PCI with stenting and met the inclusion and exclusion criteria. ESRD indicates end‐stage renal disease; PCI, percutaneous coronary intervention; USRDS, United States Renal Data System.

Figure 2.

Days from PCI discharge to thienopyridine discontinuation in the first year. Patients censored at time of loss of Medicare Part D low‐income subsidy or death. Discontinuation defined as a period of >30 days without thienopyridine supply. Abbreviations: BMS indicates bare metal stent; DES, drug eluting stent; PCI, percutaneous coronary intervention.

Figure 3.

Association of discontinued vs continued thienopyridine use in the 3‐, 6‐, and 12‐month landmark analyses using 3 analytic methods in patients receiving (A) drug‐eluting stents and (B) bare metal stents. Abbreviations: multivariable=multivariable adjusted; IPTW indicates inverse probability of treatment weighting; MI, myocardial infarction; PS, propensity score.