Report from SCMR: DE-CMR stratifies risk for dilated cardiomyopathy patients

January 23, 2006

Delayed-enhancement cardiac MR imaging has been widely adopted as a powerful test for predicting the success of revascularization for heart attack patients. DE-MRI can significantly improve risk stratification of dilated cardiomyopathy patients as well, according to results of a prospective trial reported at the ninth annual meeting of the Society for Cardiovascular Magnetic Resonance held in Miami Jan. 20 to 22.

Delayed-enhancement cardiac MR imaging has been widely adopted as a powerful test for predicting the success of revascularization for heart attack patients. DE-MRI can significantly improve risk stratification of dilated cardiomyopathy patients as well, according to results of a prospective trial reported at the ninth annual meeting of the Society for Cardiovascular Magnetic Resonance held in Miami Jan. 20 to 22.

A prospective trial at the Royal Brompton Hospital in London indicates that the evidence of myocardial midwall fibrosis observed with DE-CMR is better than ejection fraction or ventricular volume measures for predicting future death and hospitalization from cardiovascular disease.

The findings were drawn from tracking the deaths and hospitalization of 101 consecutive patients with dilated cardiomyopathy. Consistent with previous reported studies, DE-CMR revealed a midwall pattern of circumferential fiber in 30% of the patients, according to presenter Dr. Ravi Assomull, a clinical research fellow at the National Heart and Lung Institute. Patients with midwall fibrosis had significantly larger end diastolic and end systolic volume and lower left and right ejection fractions than the 70% of patients without evidence of fibrosis.

From follow-up outcome analysis performed an average of 655 days after testing, Assomull found that fibrotic patients were significantly more likely to die or be hospitalized than patients without fibrosis.

"What is most exciting is this finding where we just looked at sudden death and hospitalization. Significant differences were seen despite a relatively few number of events," he said.

The results add to growing evidence about the role of fibrosis as a major cause of death and morbidity from dilated myocardiopathy, according to Dr. Dudley Pennell, director of cardiac MRI at Royal Brompton.

"This supports an overarching hypothesis that fibrosis, especially homogeneously distributed fibrosis, is a predictor of adverse remodeling and arrhythmia, which are the two things that produce all the other events," he said.

The findings could ultimate help physicians decide which cardiomyopathy patients will benefit from a biventricular pacemaker or implantable cardiac defibrillator. Better decision making may help decrease the number of patients who die because of arrhythmia or heart failure despite expensive device implantation.

The question now is whether the presence of midwall fibrosis seen with DE-MRI can select the best candidate for implants. To answer this question, prospective longitudinal trials are needed, Assomull said.

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