P3126Immediate versus delayed revascularization in patients with transient ST-elevation myocardial infarction: 1-year follow-up of the randomized clinical TRANSIENT trial

Abstract Background Up to 24% of acute coronary syndrome patients present with ST-elevation but show complete resolution of ST-elevation and symptoms before revascularization. The current guidelines do not clearly state whether these transient ST-elevation myocardial infarction (TSTEMI) patients should be treated with a ST-elevation myocardial infarction (STEMI)-like or a non-STEMI-like invasive approach. Purpose The aim of the present study is to determine the effect of an immediate versus a delayed invasive strategy on infarct size measured by 4-month cardiac magnetic resonance imaging (CMR) and clinical outcome up to one year. Methods In this multicenter trial, 142 TSTEMI patients were randomized 1:1 to either an immediate or a delayed intervention. CMR was performed at four days and at 4-month follow-up to assess infarct size and myocardial function. Clinical follow-up was performed at four months and one year. Results Both in the immediate (0.4 h) and the delayed invasive group (22.7 h) CMR-derived infarct size at four months was very small and left ventricular function was good. In addition, major adverse cardiac events and all-cause mortality at one year were low and not different between both groups (table 1). CMR and clinical outcomes up to one year Outcome Immediate invasive group (n=70) Delayed invasive group (n=72) p-value Myocardial infarct size (% of LV), median (IQR) 0.4 (0.0–3.5) 0.4 (0.0–2.5) 0.79 LVEF (%), mean ± SD 59.9±5.4 59.3±6.5 0.63 LVEF recovery (%), mean ± SD 2.2±5.4 1.7±5.3 0.66 MVO present, No. (%) 0 (0.0) 1 (1.9) 0.50 MACE (death, reinfarction, target lesion revascularization), No. (%) 3 (4.4) 4 (5.7) 1.00 Death from any cause, No. (%) 0 (0.0) 3 (4.3) 0.24 Reinfarction, No. (%) 2 (3.0) 1 (1.4) 0.62 Target lesion revascularization, No. (%) 2 (3.0) 1 (1.4) 0.62 Definite stent thrombosis, No. (%) 1 (1.5) 1 (1.4) 1.00 Abbreviations: IQR, interquartile range; LV, left ventricle; LVEF, left ventricle ejection fraction; MACE, major adverse cardiac events; MVO, microvascular obstruction; NA, not applicable; SD, standard deviation. Conclusions We demonstrated that patients with TSTEMI have limited infarct size and preserved left ventricular function and that an immediate or delayed approach has no effect on clinical outcome up to one year. Therefore, patients with TSTEMI can be treated with both an immediate or a delayed invasive strategy with similar outcome. These findings extend our current knowledge about the optimal timing of coron