Expanding reperfusion to the highest-risk patients: ten-year temporal trends in emergent PCI and 30-day mortality across clinical severity and age from the Mie ACS Registry

Background Over the past decades, emergent percutaneous coronary intervention (PCI) has substantially improved survival in acute myocardial infarction (AMI). However, contemporary long-term regional data examining whether expanding reperfusion strategies have translated into improved short-term outcomes across different clinical severities and age groups remain limited. Purpose To investigate 10-year temporal trends (2013–2022) in patient characteristics, reperfusion strategies, and 30-day mortality in a regional AMI cohort, with specific focus on Killip class and age-stratified outcomes. Methods We analyzed 6,890 consecutive patients with AMI enrolled in the ongoing multicenter Mie ACS Registry between January 2013 and December 2022. Temporal changes in emergent PCI use and reperfusion within 6 hours were evaluated overall and stratified by Killip class (I, II–III, IV) and age (<65, 65–74, 75–84, ≥85 years). The primary endpoint was 30-day mortality. Age-adjusted mortality rates were calculated to account for temporal shifts in population aging. Annual trends were assessed using regression models and expressed as odds ratios (OR) per year with 95% confidence intervals (CI). Results During the study period, the overall rate of emergent PCI use increased significantly from 84.0% to 90.5% (P<0.001). The increase was most pronounced in Killip class IV (68.2% to 86.4%; OR 1.16 per year; P for trend <0.001, Figure 1A), with a significantly steeper rise compared with Killip class I (interaction P=0.039). Reperfusion within 6 hours improved significantly in Killip IV but not in lower Killip classes. Correspondingly, age-adjusted 30-day mortality in Killip IV declined markedly from 46.3% to 28.4% (P=0.03, Figure 1B), whereas the overall reduction in 30-day mortality (8.8% to 6.7%) did not reach statistical significance (P=0.20). Across all age categories, PCI utilization increased significantly (Figure 2A). However, no significant temporal decline in 30-day mortality was observed within any age stratum, including patients aged ≥85 years (OR per year 0.96, 95% CI 0.90–1.02, Figure 2B). Conclusions Over the past decade, reperfusion strategies were increasingly extended to the highest-risk patients with AMI, particularly those with Killip class IV, resulting in substantial improvement in short-term survival in this group. In contrast, despite increased PCI use across all age strata, short-term mortality did not significantly improve among older patients. Optimizing outcomes in the rapidly aging AMI population remains a key challenge for the next decade.Figure 1Figure 2