Very low risk ST-segment elevation myocardial infarction? It exists and may be easily identified

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.

We analyzed 30-day outcomes and long-term follow-up among 1.111 STEMI patients treated with reperfusion therapy.

Multivariate analysis identified seven variables as predictors of 30-day outcomes: Femoral approach; age>65; systolic dysfunction; postprocedural TIMI flow<3; elevated creatinine level>1.5mg/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±19.4months were also observed (2.2% vs. 15.2%; p<0.001). The first VLR subject died 11months after hospital discharge. No cardiovascular deaths were identified in this subgroup of patients during follow-up.

About a fifth of STEMI patients have VLR and can be easily identified. They have an excellent prognosis suggesting that 24-48h in-hospital stay could be a feasible alternative in these patients.