Abstract 17: Exploring Trade-Offs: Post-Discharge Bleeding and Myocardial Infarction are Associated With Similar Increases in Long-Term Mortality after Percutaneous Coronary Intervention
Authors: Kazi Dhruv S , Leong Thomas K , Chang Tara I , Solomon Matthew D , Hlatky Mark A , Go Alan S 
Published: March 2022

Background:
Platelet inhibition after percutaneous coronary intervention (PCI) reduces the risk of myocardial infarction (MI) but increases the risk of bleeding. Periprocedural bleeding is associated with an increased short-term risk of adverse outcomes. However, the prognostic significance of non-periprocedural bleeds (i.e., those occurring after hospital discharge) has not been systematically studied in community-based populations. The relative impact of a non-periprocedural bleed versus a subsequent MI on long-term mortality could help define the net clinical benefit of newer, more potent antiplatelet and antithrombotic strategies.

Methods:
We conducted a retrospective cohort study of all patients ≥ 30 years without known coronary disease who underwent a PCI between 1996-2008 within Kaiser Permanente of Northern California. Patients were followed for subsequent MI or hospitalization for bleeding between 7 to 365 days after discharge from the index hospitalization. The primary outcome was all-cause mortality, which was ascertained from health-plan, state, and Social Security Administration death files. We evaluated the independent prognostic value of post-discharge MI or bleed using a multivariable Cox regression model that adjusted for demographics, clinical history (including hypertension, diabetes, dyslipidemia, and a history of MI or bleed prior to, during, or within 7 days after index hospitalization), kidney function, and longitudinal medication exposure.

Results:
Among 32,906 adults who survived the index PCI, 530 patients had a bleed and 991 had an MI between 7 and 365 days after discharge from the index hospitalization. Patients who suffered a bleed were older and more likely to be female and have hypertension, peripheral artery disease, chronic kidney disease or history of bleeding. They were also more likely to receive warfarin, but antiplatelet therapy use was similar in the two groups. During a mean 4.42 years of follow-up, we observed 4,048 deaths (164 in patients who had a bleed, and 315 in patients who had an MI). Compared with patients who did not have a bleed or an MI, patients who had a hospitalized bleed had a significantly increased risk of death (hazard ratio [HR], 1.65; 95% CI: 1.33-2.04). The increased hazard of long-term mortality associated with bleeding was similar to that associated with an MI during follow-up (HR, 1.87; 95% CI: 1.58-2.22), and persisted after adjustment for antiplatelet and antithrombotic therapy use - suggesting that it could not be fully explained by the differential use of these therapies among patients who bleed.

Conclusions:
In a large, diverse, community-based sample of adults undergoing PCI, non-periprocedural bleeding was associated with a significant increase in long-term mortality, which was similar in magnitude to that associated with an MI, and was not fully explained by the differential use of antiplatelet and antithrombotic drugs. Our results underscore the significant negative prognostic implications of bleeding, and emphasize the careful evaluation of the long-term net clinical benefit of evolving antiplatelet and antithrombotic strategies in the management of coronary disease.