Introduction: Myocardial fibrosis is a risk factor for ventricular tachycardia (VT) and the worsening of heart failure in patients with hypertrophic cardiomyopathy (HCM). The present study investigates whether myocardial fibrosis using cardiac magnetic resonance T1 imaging and late gadolinium enhancement (LGE) could be a surrogate marker for VT in patients with HCM.
Methods: A total of 57 patients with HCM (mean age 58±15 years, 84% men)underwent LGE and saturation recovery T1 measurements with 3 Tesla scanner to quantify myocardial fibrosis. The extracellular volume (Septal-ECV, %) for mid-left ventricular septum was calculated by T1 values pre- and post-LGE. LGE volume (cm3) for the whole left ventricle was measured using the cutoff of more than 6 standard deviation of normal myocardial intensity. Comparison of septal-ECV and LGE volume between patients with and without VT was analyzed.
Results: VT was observed in 22 (38%) of 57 patients. Septal-ECV and LGE volume was significantly greater for patients with VT than those without (33±17% vs. 25±11%, 22±11cm3 vs. 14±9cm3, p<0.05). The optimal cutoffs of septal-ECV and LGE volume can predict patient with VT with an area under the curve of 0.63 and 0.7.
Conclusion: Septal-LGE and LGE volume can be used as a surrogate marker for VT in HCM. LGE volume is more precise in the prediction of VT than septal-ECV.