TIME AND MORTALITY IN ST ELEVATION MYOCARDIAL INFARCTION: INSIGHTS FROM THE TOTAL TRIAL

Abstract

The effect of thrombus aspiration in patients with ST elevation myocardial infarction (STEMI) may differ based on ischemic time. Patients with short ischemic times have greater viable myocardium and so may derive greater benefit from thrombus aspiration. We sought to determine the effect of thrombus aspiration on mortality in patients presenting with STEMI based on total ischemic time (duration of symptom onset to first medical device time) and first medical contact to first device time. The TOTAL trial was an international multicenter randomized trial of 10,732 patients comparing routine thrombus aspiration plus percutaneous coronary intervention (PCI) vs PCI alone in STEMI patients undergoing primary PCI within 12 hours of symptom onset. We performed a subgroup analysis for total ischemic time and first medical contact to device time for the primary outcome (Cardiovascular death [CV], Myocardial Infarction [MI], cardiogenic shock and heart failure) and CV mortality. In addition, we used a multi-variable analysis to determine the impact on CV mortality at 1 year for total ischemic time (6 hours) and first medical contact to device (120min). In this international multicenter trial, 64% of patients achieved a first medical contact to device time within 120 minutes and 41% within 90 minutes. In terms of total ischemic time, 87% of patients presented within 6 hours of symptom onset. For the randomized comparison of thrombus aspiration, there was no significant benefit on the primary outcome and for CV death irrespective of total ischemic time and medical contact to device time (Figure 1). CV Mortality was higher in patients with longer total ischemic time (2.5%, 3.5%, 5.2% for < 2 hours, 2-6 hours, >6 hours, P=0.0005). Similarly, CV mortality was higher in patients with longer first medical contact to device time (2.4%, 2.9%, 3.5%, 4.7% for 120 min, P= 0.0001). In a step-wise multivariable analysis, both total ischemic time (>3 hours, hazard ratio 1.34; 95% CI 1.09-1.66) and first medical contact to device time (>90 minutes, hazard ratio 1.45; 95% CI 1.16-1.82) were independent predictors of CV mortality at 1 year. Irrespective of first medical contact to device time and total ischemic time, thrombus aspiration was not beneficial for the primary outcome or CV death. In the current STEMI era, both total ischemic time and first medical contact to device times are important and are independent predictors of CV mortality.