Bleeding risk and cardiovascular outcomes in acute myocardial infarction patients with multivessel disease: a post-hoc analysis of the Japan AMI registry

Background Patients with acute myocardial infarction (AMI) and multivessel disease require intensive antithrombotic therapy due to their elevated ischemic risk. However, these patients often exhibit characteristics associated with a higher bleeding risk. While achieving optimal revascularization is an important goal in multivessel disease, the bleeding risk associated with this patient population remains insufficiently characterized. Purpose This post-hoc analysis aimed to evaluate the bleeding risk in AMI patients with multivessel disease. Methods Using data from the Japan AMI Registry (JAMIR), a nationwide, multicenter, prospective study, we conducted a post-hoc analysis of 3,242 AMI patients (M/F 2,499/743, mean age 68 years). Patients were categorized based on the presence of single-vessel or multivessel disease. The incidence of major adverse cardiovascular events (MACE) (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke) and Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding events was compared over a 1-year follow-up. Results Among the 3,242 patients, 1,822 had single-vessel disease, and 1,420 had multivessel disease (849 with two-vessel and 571 with three-vessel disease). Patients who experienced bleeding events had a significantly higher risk of all-cause mortality (hazard ratio [HR] 6.95, 95% confidence interval [CI] 5.14–9.40, P<0.001). Compared to those with single-vessel disease, patients with multivessel disease had a significantly higher incidence of MACE (1-year event rate: 3.5% vs. 8.8%, P<0.001) and bleeding events (BARC type 3 or 5) (Figure 1). After adjusting for clinically relevant factors, multivessel disease remained independently associated with an increased bleeding risk (HR 1.42, 95% CI 1.01–2.00, P=0.045). Additionally, post-discharge bleeding events were significantly more frequent in patients with multivessel disease, and this association remained significant after adjusting for the Japan high bleeding risk score (HR 1.79, 95% CI 1.01–3.16, P=0.046) (Figure 2). Conclusion This post-hoc analysis revealed that AMI patients with multivessel disease have both a higher incidence of MACE and an increased risk of bleeding events. These findings highlight the need for a tailored treatment strategy that carefully balances ischemic and bleeding risks, potentially including adjustments in antithrombotic therapy duration and intensity.