Association between scar quantification and documented history of ventricular tachycardia in patients with hypertrophic cardiomyopathy

Abstract Background Hypertrophic cardiomyopathy (HCM) is a major risk factor for sudden cardiac death, and it is crucial to accurately identify patients who may benefit from implantable cardioverter defibrillator (ICD) implantation. Therefore, accurate risk stratification remains an unmet clinical need for patients with obstructive (HOCM) and non-obstructive (HNCM) hypertrophic cardiomyopathy. Methods and Aim Consecutive HCM patients were enrolled at a tertiary academic center and underwent cardiac magnetic resonance imaging. We aimed to explore risk factors for a documented history of ventricular tachycardia (VT). Results In total 246 HCM (160 HNCM, 86 HOCM) patients were included in the present analysis. Patients with HOCM and HNCM had similar rates of documented VTs (20.0% vs. 23.2%, p=0.61). However, the HCM-risk-score was significantly lower in HNCM patients (4.56% vs. 3.36%, p=0.003). There was no significant difference in age (53 vs. 57 years, p=0.65), sex (female sex 30% vs. 42%, p=0.14), or echocardiographic parameters, including the maximum outflow tract gradient (59 vs. 67 mmHg, p=0.71), the maximum wall thickness (21 vs. 20 mm, p=0.088), and the left atrial diameter (57 vs. 56 mm, p=0.59), in patients with versus without a history of documented VT. Furthermore, NT-proBNP (1040 vs. 1199 pg/mL, p=0.74) and high sensitivity troponin-T levels (22 vs. 19 ng/L, p=0.38) did not differ between groups. Patients with a history of VT were significantly more likely to have late gadolinium enhancement (LGE, 80% vs 50%, p=0.007) and had a higher percentage of LGE in relation to the left ventricular mass (9.2% vs 3.7%, p=0.001). These findings were consistent in patients with HOCM and HNCM (3.32% vs. 5.72% p=0.085). In an adjusted logistic regression model, the percentage of LGE was independently associated with the presence of VT (Odds ratio 1.27 [95%CI 1.08-1.50]). Conclusion These findings suggest that LGE may be a useful imaging marker for risk assessment in patients with HOCM and HNCM.