Comprehensive prognosis assessment by CMR imaging after ST-segment elevation myocardial infarction

Abstract

Background: Although the prognostic value of findings from cardiac magnetic resonance (CMR) imaging has been established in single-center center studies in patients with ST-segment elevation myocardial infarction (STEMI), a large multicenter investigation to evaluate the prognostic significance of myocardial damage and reperfusion injury is lacking.

Objectives: The aim of this study was to assess the prognostic impact of CMR in an adequately powered multicenter study and to evaluate the most potent CMR predictor of hard clinical events in a STEMI population treated by primary percutaneous coronary intervention (PCI).

Methods: We enrolled 738 STEMI patients in this CMR study at 8 centers. The patients were reperfused by primary PCI <12 h after symptom onset. Central core laboratory-masked analyses for quantified left ventricular (LV) function, infarct size (IS), microvascular obstruction (MO), and myocardial salvage were performed. The primary clinical endpoint of the study was the occurrence of major adverse cardiac events.

Results: Patients with cardiovascular events had significantly larger infarcts (p < 0.001), less myocardial salvage (p = 0.01), a larger extent of MO (p = 0.009), and more pronounced LV dysfunction (p < 0.001). In a multivariate model that included clinical and other established prognostic parameters, MO remained the only significant predictor in addition to the TIMI (Thrombolysis In Myocardial Infarction) risk score. IS and MO provided an incremental prognostic value above clinical risk assessment and LV ejection fraction (c-index increase from 0.761 to 0.801; p = 0.036).

Conclusions: In a large, multicenter STEMI population reperfused by primary PCI, CMR markers of myocardial damage (IS and especially MO) provide independent and incremental prognostic information in addition to clinical risk scores and LV ejection fraction. (Abciximab i.v. Versus i.c. in ST-elevation Myocardial Infarction [AIDA STEMI]; NCT00712101).

Keywords: magnetic resonance imaging; myocardial infarction; prognosis.