Toward clinical risk assessment in hypertrophic cardiomyopathy with gadolinium cardiovascular magnetic resonance.

OBJECTIVES We sought to assess whether hyperenhancement by gadolinium cardiovascular magnetic resonance (CMR) occurs in hypertrophic cardiomyopathy (HCM) and correlates with the risk of heart failure and sudden death. BACKGROUND The myocardial interstitium is abnormal in HCM at post-mortem. Focally increased interstitial myocardial space appears as hyperenhancement with gadolinium CMR. METHODS In a blinded, prospective study, HCM patients were selected for the presence (n = 23) or absence (n = 30) of an increased clinical risk of sudden death and/or progressive adverse left ventricular (LV) remodeling. Gadolinium-enhanced CMR was performed. RESULTS Myocardial hyperenhancement was found in 42 patients (79%), affecting 10.9% (range 0% to 48%) of the LV mass. There was a greater extent of hyperenhancement in patients with progressive disease (28.5% vs. 8.7%, p < 0.001) and in patients with two or more risk factors for sudden death (15.7% vs. 8.6%, p = 0.02). Improved discrimination was seen in patients >40 years old (29.6% vs. 6.7%, p < 0.001) for progressive disease and for patients <40 years old for risk factors for sudden death (15.7% vs. 2.1%, p = 0.002). Patients with diffuse rather than confluent enhancement had two or more risk factors for sudden death (87% vs. 33%, p = 0.01). CONCLUSIONS Gadolinium CMR reveals myocardial hyperenhancement in HCM. The extent of hyperenhancement is associated with progressive ventricular dilation and markers of sudden death.