2012 HSR&D/QUERI National Conference Abstract
1093 — Hospital Variation in Premature Clopidogrel Discontinuation Following Drug Eluting Stent Placement and Adverse Cardiovascular Outcomes
Vigen R, Maddox TM, and O'Donnell C, VA Eastern Colorado Healthcare System; Bhatt DL, VA Boston Healthcare System; Tsai TT, Rumsfeld JS, and Ho PM, VA Eastern Colorado Healthcare System;
Clopidogrel is recommended for 1 year following drug eluting stent (DES) placement and premature discontinuation has been associated with adverse outcomes. The extent of variation in premature discontinuation across hospitals within an integrated healthcare system is unknown. Accordingly, we assessed variation in premature clopidogrel discontinuation across all VA sites that perform percutaneous coronary interventions (PCI) and the association between hospitals with higher rates of premature discontinuation and adverse outcomes.
We used the VA CART-CL registry which includes all PCIs with drug eluting stents performed between 10/01/08 and 09/30/09 at 55 VA cath labs. We evaluated the frequency of patients who prematurely discontinue clopidogrel at 6 and 9 months using pharmacy refill data. Multivariable regression assessed the association between premature discontinuation and all-cause mortality and/or myocardial infarction (MI). We then grouped sites into quartiles of premature discontinuation and evaluated the association between hospital-level premature discontinuation and adverse outcomes.
Of the 7,022 patients who received a DES, 6.3% discontinued clopidogrel by 6 months, and 10.2% by 9 months. After risk adjustment, patients who discontinued clopidogrel prematurely had increased risk of adverse events with HR of 5.42 at 6 months (95% CI 4.22 – 6.99), and 6.24 at 9 months (95% CI 4.98 – 7.83). There was a significant trend in the unadjusted rates between quartiles toward increased risk of adverse outcomes among hospitals with greater rates of patients who discontinue prematurely by 6 months (p < 0.01 for trend, OR 1.65 CI 1.07 – 2.62 for comparison between quartile 1 and 4).
Premature discontinuation of clopidogrel is associated with adverse outcomes among patients who receive drug eluting stents. Hospitals with higher rates of premature discontinuation of clopidogrel have higher rates of adverse outcomes. Hospital-level interventions to reduce early discontinuation of clopidogrel therapy have the potential to improve outcomes of patients who receive a DES.
Veterans who discontinue clopidogrel prematurely following DES placement are at increased risk for adverse outcomes. VA hospitals with higher rates of premature discontinuation have higher rates of adverse cardiac outcomes. Hospital-level interventions to increase adherence to clopidogrel therapy are needed to improve care among VA patients who receive a DES.