Renal function-dependent risk of early invasive strategy in patients with non-ST-segment elevation myocardial infarction: insight from KAMIR-NIH and KRAMI-RCC

Abstract

The efficacy of an early invasive strategy (EIS) in NSTEMI patients with renal dysfunction remains unclear. This study assesses the clinical impact of invasive time strategies in NSTEMI patients, stratified by renal function, using data from two major Korean acute myocardial infarction registries. We analyzed a decade-long dataset, combining 5 years each from the Korea Acute Myocardial Infarction-National Institute of Health (KAMIR-NIH) and Registry of Acute Myocardial Infarction for Regional Cardiocerebrovascular Centers (KAMIR-RCC). NSTEMI patients were classified into preserved renal function (PRF, eGFR >= 60 mL/min/1.73 m(2)) and decreased renal function (DRF, eGFR < 60 mL/min/1.73 m(2)). The comparison between early invasive strategy (EIS, <= 24 h) and delayed invasive strategy (DIS, > 24 h) for coronary angiography (CAG) referral was conducted. The baseline characteristics were adjusted using stabilized inverse probability of treatment weighting (IPTW). The primary endpoint was one-year all-cause mortality. Among 11,605 NSTEMI patients undergoing PCI, 75% had PRF and 25% had DRF. In patients with PRF, in-hospital mortality did not differ between EIS and DIS (0.7% vs. 0.4%, p = 0.196). However, in DRF patients, EIS was associated with higher in-hospital mortality compared to DIS (4.9% vs. 3.1%, p = 0.024). Similarly, in PRF patients, one-year mortality was comparable between EIS and DIS (HR 1.068, 95% CI 0.694-1.261, p = 0.664), whereas in DRF patients, EIS was associated with higher one-year mortality (HR 1.405, 95% CI 1.09-1.80, p = 0.007). Stratified by four eGFR groups, no significant differences were found between EIS and DIS in patients with PRF. However, mortality progressively increased with worsening renal function, with significant increases in patients with eGFR < 30 mL/min/1.73 m(2) (Adjusted HR: 1.545, p = 0.022) group. Interaction analysis revealed that the mortality risk associated with EIS increased significantly as renal function declined (p interaction < 0.001). In NSTEMI patients, the impact of EIS progressively diminished with worsening renal function, with significantly higher mortality observed in those with DRF, showing the harmful effects of EIS in this group.