Rapid cardiac MR predictive of worse outcomes in patients with non–ST-elevation ACS

Rapid cardiac magnetic resonance indentified reversibly injured myocardium resulting from obstructive coronary artery disease and predicted worse outcomes in patients with non-ST–elevation acute coronary syndromes, results from an study indicated.

Researchers from Ohio, Md. and Italy enrolled 100 consecutive patients with non-ST–elevation ACS in the study. Patients underwent 30-minute cardiac MR, which included T2-weighted edema imaging and late gadolinium enhancement prior to coronary angiography. Five patients could not complete cardiac magnetic resonance (CMR) examination due to claustrophobia, while T2 image quality was inadequate in seven patients.

Of the remaining population (n=88), 57 patients showed myocardial edema. Obstructive CAD requiring revascularization was present in 87.7% of edema-positive patients vs. 25.8% of edema-negative patients (P<.001). Following multiple logistic regression analysis after adjusting for late perfusion, gadolinium enhancement and wall motion scores, thrombolysis in MI risk score was not predictive of obstructive CAD. However, an increase in T2 score by one unit increased the odds of coronary revascularization 5.7-fold (95% CI: 2.38 to 13.62, P<.001). After adjusting for peak troponin-I, patients with edema showed a higher hazard of a CV event or death within six months after non-ST–elevation ACS vs. those without edema (HR=4.47; CI 95%, 1.00-20.03).

“This diagnostic strategy does not require stress, and may define a myocardial signature predictive of obstructive CAD requiring revascularization,” wrote the researchers of their findings. “Use of rapid CMR upon admission for non-ST–elevation ACS warrants further evaluation through randomized trials as a tool to optimize selection of an early invasive strategy in these patients.”

Raman SV. J Am Coll Cardiol. 2010; 55:2480-2488

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