Mortality after presentation with stent thrombosis is associated with time from index percutaneous coronary intervention: A report from the VA CART program

Background The risk of mortality for patients presenting to the cardiac catheterization laboratory with stent thrombosis (ST) may differ as a function of the timing from initial stent implantation. We hypothesized that the 30-day mortality would differ for angiographically defined early ST (EST), late ST (LST), and very late ST (VLST). Methods All patients undergoing angiography for diagnosis and treatment of ST were identified by the Department of Veterans Affairs (VA) Clinical Assessment, Reporting, and Tracking (CART) Program from 2006 to 2012. Stent thrombosis occurring <= 30 days after stent implantation were defined as EST; 31 to 365 days as LST; and >365 days as VLST. Log-rank test and Cox proportional hazard regression modeling were used to describe unadjusted and adjusted differences in mortality between groups. Results A total of 656 patients were diagnosed with angiographic definite ST with known timing. This cohort consisted of 129 (20%), 138 (21%), and 389 (59%) patients with EST, LST, and VLST, respectively. Over three fourths (76%) of VLST cases occurred >2 years after stent implantation. Stent thrombosis timing was significantly associated with 30-day mortality risk in unadjusted (P < .001) and adjusted (P = .04) analyses. Unadjusted mortality risk was 3% in VLST, 6% in LST, and 13% in EST. After multivariable adjustment, patients with LST had nonsignificantly lower 30-day mortality (hazard ratio [HR] for LST, 0.5; 95% CI, 0.2-1.2), whereas VLST had significantly lower 30-day mortality (HR for VLST, 0.38; 95% CI, 0.18-0.82) when compared with patients with EST. Conclusions Thirty-day mortality after an angiographic definite ST presentation is associated with time from index percutaneous coronary intervention to ST. This relationship potentially reflects the differing mechanisms of ST that are postulated to predominate at different timeframes.