Relationship of cancer and dual antiplatelet duration to long-term risk of ischaemic and bleeding outcomes after percutaneous coronary intervention.

Aims: The long-term cardiovascular (CV) risks after percutaneous coronary intervention (PCI) in cancer patients are unclear. We assessed the risks of adverse events after PCI related to active or inactive cancer and the duration of dual antiplatelet therapy (DAPT). Methods and results: This is a retrospective cohort of all patients having PCI with second-generation drug-eluting stents in the national Veterans Affairs Healthcare System between 2008 and 2016. We compared patients with active cancer (cancer and chemotherapy/radiotherapy), inactive cancer (cancer without chemotherapy/radiotherapy), or no cancer using Cox proportional hazards regression models adjusted by the propensity for cancer. Models estimated hazard ratios (HR) and 95% confidence intervals (95% CI) for myocardial infarction (MI), major bleeding, and death and the relationship to duration of DAPT after PCI. Of 40 677 patients, 791 (2%) had active cancer, 7633 (19%) had inactive cancer, and 32 253 (79%) had no cancer. Over a mean 5.4 (SD 2.8) years, the risks of MI and major bleeding were higher in patients with active cancer (MI: HR = 1.18, 95% CI = 1.00, 1.40; major bleed: HR = 1.73, 95% CI = 1.43, 2.10) and inactive cancer (MI: HR = 1.13 95% CI = 1.07, 1.20; major bleed: HR = 1.30, 95% CI = 1.21, 1.41). Discontinuing DAPT more than 9 months after PCI associated with lower risks of MI (active cancer: HR = 0.91, 95% CI = 0.70, 1.19; inactive cancer: HR = 0.78, 95% CI = 0.70, 0.88) and major bleeding (active cancer: HR = 0.68, 95% CI = 0.49, 0.97; inactive cancer: HR = 0.87, 95% CI = 0.76, 0.99). Conclusion: Patients with cancer have higher risks of ischaemic and bleeding outcomes after PCI. However, we found no evidence that DAPT duration should differ from current guidelines in patients with cancer after PCI.