Impact of direct stenting on myocardial injury assessed by cardiac magnetic resonance imaging and prognosis in ST-elevation myocardial infarction.

Background: The results of studies investigating the clinical benefit of a direct stenting (DS) strategy in ST-elevation myocardial infarction (STEMI) are inconsistent and data regarding cardiac magnetic resonance (CMR) parameters of myocardial injury are lacking. The aim of this study was to investigate the effect of DS on myocardial damage in comparison to a conventional stenting technique (CS) with predilation in patients with reperfused STEMI.

Methods: In a subanalysis of the randomized LIPSIA CONDITIONING trial (NCT02158468), STEMI patients were stratified according to the percutaneous coronary intervention technique into the DS (n = 171) or CS (n = 171) group after matching the patients for age (±5 years), gender, and TIMI flow before coronary intervention. Patients underwent CMR imaging within one week after infarction. Clinical outcome (death, reinfarction, hospitalization for heart failure) was assessed within 6 months after the index event.

Results: Patients in the DS group had significantly lower infarct size (16 vs. 19% of left ventricular mass; p = 0.046) and microvascular obstruction with significant improvement of left ventricular parameters, which was associated with favorable clinical outcome with a lower incidence of heart failure hospitalizations (4% vs. 11%, p = 0.011) and mortality (5% vs. 12%, p = 0.034) as compared to patients with CS. In multivariate Cox regression analysis, DS was identified as an independent predictor of reduced mortality (HR 0.30, 95% CI 0.11-0.87, p = 0.026).

Conclusion: In patients with acute reperfused STEMI, DS is safe and feasible with a significant reduction of infarct size compared to CS and subsequent lower incidence of heart failure hospitalizations and mortality.