Usefulness of cardiac magnetic resonance in assessing the risk of ventricular arrhythmias and sudden death in patients with hypertrophic cardiomyopathy.

Aims: To assess the relationship between cardiovascular magnetic resonance (CMR) parameters and both spontaneous ventricular tachycardia (VT) and risk of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) patients.
Methods and Results: One hundred and eight consecutive HCM patients (mean age 42 +/- 15 years, 76% males) underwent CMR evaluation and risk assessment. Delayed contrast enhancement (DCE) was quantified with a specifically designed score. Endpoints were either the presence of clinical VT/ventricular fibrillation (VF) or of acknowledged risk factors for SCD. Compared to patients without arrhythmia, those with VT/VF (n = 33) had a higher DCE score [median 8 (2-13) vs. 11 (6-20); P = 0.01]; DCE score was also the only independent predictor of VT/VF in the multivariable model. DCE score [median 6 (1-10.5) vs. 12 (6-18); P = 0.001], mean and maximal left ventricular (LV) wall thickness (MaxLVWT), as well as LV mass index were significantly greater among patients at risk for SCD (n = 51) compared with the remaining 57 patients at low risk. DCE score and MaxLVWT were independent predictors of SCD risk.
Conclusion: In HCM patients several CMR parameters are associated with risk for SCD. A semi-quantitative index of DCE is a significant multivariable predictor of both clinical VT/VF and of risk for SCD and may contribute to risk assessment in borderline or controversial cases.