Effects of immediate invasive strategy on occurrence of in-hospital major cardiovascular events in non-STEMI patients

Abstract

Purpose: Current clinical practice guidelines for the management of NSTEMI patients suggest early invasive procedure, within 24h, if GRACE score is >140 and within 72h of admission in patients at lower risk, with GRACE score ≤140. The aim of this study was to investigate if immediate invasive strategy (<2h) is associated with lower in-hospital MACE rates. Methods: We randomized 323 non-STEMI patients into the immediate invasive strategy group (<2h after randomization, n=162) and the late invasive strategy group (2-72h after randomization, n=161). Patients with hemodynamic instability, heart insufficiency and life-threatening ventricular arrhythmia on admission, were excluded from the study. Results: The median time from randomization to angiography in the immediate group was 1.3h and 61.5h in the late group (p < 0.001). Baseline characteristics did not differ significantly between the two study arms, except for diabetes (33% in the late group vs. 22% in the immediate group, p = 0.024). GRACE score was not significantly different between the groups (132 vs. 129, p = 0.3). In-hospital MACE (cardiovascular death, re-infarction or stroke) occurred significantly less frequently in the immediate compared to the late study arm (3.1% vs. 11.8%, p = 0.003). After adjusting for the localization of myocardial infarction, sex, age and diabetes, the calculated odds ratio was 0.269 (95% CI 0.095-0.760, p = 0.013). The observed difference in in-hospital MACE was mainly due to lower rates of re-infarction in the immediate versus late group (1.9% vs. 9.3%, adjusted OR = 0.2, 95% CI 0.056 -0.736, p = 0.015). In-hospital rates of cardiovascular death and stroke were similar between the groups. Conclusion: Immediate invasive strategy in NSTEMI patients is associated with lower rates of in-hospital MACE, irrespective of baseline GRACE score.