Right ventricular injury in ST-elevation myocardial infarction: risk stratification by visualization of wall motion, edema, and delayed-enhancement cardiac magnetic resonance.

BACKGROUND Patients with right ventricular injury (RVI) complicating ST-elevation myocardial infarction (STEMI) have impaired prognosis, but it is unclear which patients are at risk of developing RVI. Cardiac magnetic resonance can identify these patients and might add important information on risk stratification, prognosis, and treatment. Aims were to determine the predictors and the prognostic significance of RVI assessed by wall motion abnormalities, edema, myocardial salvage index, and delayed enhancement in acute reperfused STEMI. METHODS AND RESULTS We studied 450 patients 1-4 days after primary angioplasty in STEMI. T2-weighted and delayed-enhancement cardiac magnetic resonance was used for visualizing edema and scar to calculate myocardial salvage index. Cine-imaging was performed to assess wall motion abnormalities, which, in combination with edema, were considered diagnostic for RVI. Patients with RVI were compared with matched patients with isolated left ventricular infarction. The primary end point was the occurrence of a major adverse cardiac event: a composite of death, reinfarction, and congestive heart failure after a median follow-up period of 20.9 months. RVI was present in 69 patients, and 41 of 69 showed myocardial necrosis. In a multivariable stepwise forward logistic regression analysis, a high RV myocardial mass (odds ratio, 2.06; 95% confidence interval, 1.18-3.58; P=0.012) and a low Thrombolysis In Myocardial Infarction flow before angioplasty (odds ratio, 0.50; 95% confidence interval, 0.32-0.76; P=0.011) were associated with RVI. Cox regression analysis revealed RVI as the most statistically significant predictor of time to major adverse cardiac events (hazard-ratio, 3.36; 95% confidence interval, 1.99-5.66; P<0.001). CONCLUSIONS RVI detected by cardiac magnetic resonance is a strong and independent predictor of clinical outcome after acute reperfused STEMI. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01359306.