Prognostic Impact of Percutaneous Coronary Intervention in Chronic Dialysis Patients with Acute Myocardial Infarction: Findings from the Lombardy Health Database

Background: Patients on chronic dialysis are less likely to be treated with percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). This is due to the lack of evidence from randomized trials, concerns about possible PCI-related side effects, and multimorbidity. Therefore, routine use of PCI for treatment of dialysis patients with AMI remains an unresolved issue. Methods: We analyzed data of patients on chronic dialysis hospitalized with AMI from 2003 to 2018, by using the administrative Lombardy Health Database (Italy). Patients were grouped according to whether they underwent or not PCI during index hospitalization. The primary outcome was in-hospital mortality, 1-year mortality was the secondary endpoint. Results: During the study period, 265,048 patients were hospitalized with AMI. Of them, 3206 (1.2%) were on chronic dialysis (age 71 ± 11; 72% males). Among dialysis patients, 44% underwent PCI, while 54% underwent PCI among non-dialysis patients (p < 0.0001). Dialysis was an independent predictor of treatment with medical therapy only (OR 0.75 [95% CI 0.70–0.81]). In-hospital mortality in the dialysis cohort was 15%, significantly lower in patients treated with PCI than in those not treated with PCI (11% vs. 19%; p < 0.0001). One-year mortality was 47% and it was lower in PCI-treated patients (33% vs. 52%; p < 0.0001). The adjusted risk of the study endpoints was significantly lower in dialysis patients undergoing PCI: OR 0.62 (95% CI 0.50–0.76) for in-hospital mortality; HR 0.63 (95% CI 0.56–0.71) for 1-year mortality. Conclusions: This study showed that in AMI patients on chronic dialysis, PCI is associated with a significant in-hospital and 1-year survival benefit. Yet, they underwent PCI less frequently than patients with preserved renal function.