Very Low Risk ST-segment Elevation Myocardial Infarction? It exists and may be easily identified

Abstract Background Early discharge protocols have been proposed for ST-segment elevation myocardial infarction (STEMI) low risk patients despite the existence of few but significant cardiovascular events during mid-term follow-up. We aimed to identify a subgroup of patients among those considered low-risk in which prognosis would be particularly good. Methods We analyzed 30-day outcomes and long-term follow-up among 1.111 STEMI patients treated with reperfusion therapy. Results Multivariate analysis identified seven variables as predictors of 30-day outcomes: Femoral approach; Age > 65; Systolic dysfunction; postprocedural TIMI flow < 3; Elevated creatinine level > 1.5 mg/dL; Stenosis of left-main coronary artery; and Two or higher Killip class (FASTEST). A total of 228 patients (20.5%), defined as very low-risk (VLR), had none of these variables on admission. VLR group of patients compared to non-VLR patients had lower in-hospital (0% vs . 5.9%; p < 0.001) and 30-day mortality (0% vs . 6.25%: p < 0.001). They also presented fewer in-hospital complications (6.6% vs . 39.7%; p < 0.001) and 30-day major adverse events (0.9% vs . 4.5%; p = 0.01). Significant mortality differences during a mean follow-up of 23.8 ± 19.4 months were also observed (2.2% vs . 15.2%; p < 0.001). The first VLR subject died 11 months after hospital discharge. No cardiovascular deaths were identified in this subgroup of patients during follow-up. Conclusions About a fifth of STEMI patients have VLR and can be easily identified. They have an excellent prognosis suggesting that 24–48 h in-hospital stay could be a feasible alternative in these patients.