Long-term mortality after coronary revascularization in Swedish dialysis patients with three-vessel disease: a nationwide retrospective cohort study.

BACKGROUND: Coronary artery disease (CAD) affects approximately 50% of patients aged ≥65 years with end-stage renal disease (ESRD) requiring chronic dialysis, and is a leading cause of mortality. Improved survival among patients on dialysis has led to an increasing number requiring treatment for multivessel CAD. Current guidelines on myocardial revascularization favour coronary artery bypass grafting (CABG) in patients with a life expectancy exceeding 1 year; however, clear recommendations regarding the optimal revascularization strategy are lacking. No prospective randomized trials have compared CABG with percutaneous coronary intervention (PCI), and observational studies have yielded conflicting results. We therefore conducted this nationwide retrospective cohort study to assess short- and long-term all-cause mortality in dialysis patients with ESRD and three-vessel CAD who had undergone CABG or PCI. METHODS: All dialysis patients ≥18 years old with three-vessel disease who underwent a first-time PCI (n=412) or CABG (n=199) in Sweden during 2006-2020 were identified in the SWEDEHEART registry. Individual patient data were merged from three nationwide mandatory registers. The Swedish Cardiac Surgery Registry, which is a part of the SWEDEHEART registry, was used along with the National Patient Register (NPR) to collect data on patients' characteristics, including ESRD requiring dialysis. The Swedish Cause of Death Register was used to obtain mortality. Short- and long-term mortality were assessed using multivariable Cox regression models adjusted for age, sex, and comorbidities, with a sensitivity analysis using a propensity score-matched model. Median follow-up was 1.7 (range, 0.7-3.7) years in the PCI group and 2.5 (range, 1.1-5.0) years in the CABG group. RESULTS: Patients undergoing PCI were older, had longer dialysis duration, and more often had a history of cancer, whereas prior myocardial infarction, hyperlipidaemia, and atrial fibrillation were more common in the CABG group. The crude 30-day mortality was 6.8% and 4.5%, respectively, in the PCI and CABG groups, and the crude mortality at the end of follow-up was 63.8% and 54.8%, respectively. At the end of follow-up, the mortality risk was lower after CABG than after PCI [multi-adjusted hazard ratio (HR): 0.70; 95% confidence interval (CI): 0.55-0.89]. These results were confirmed in the propensity score analysis for both 30-day mortality (multi-adjusted HR: 0.72; 95% CI: 0.29-1.80) and long-term mortality (multi-adjusted HR: 0.68; 95% CI: 0.51-0.91). CONCLUSIONS: Patients who underwent CABG or PCI with three-vessel CAD and ESRD requiring chronic dialysis had a high risk of mortality. The long-term mortality risk was lower after CABG. Treatment should be individualized for each patient through a multidisciplinary discussion that considers potential benefits and risks as well as patient preferences.