Late gadolinium enhancement location assessed by magnetic resonance and arrhythmogenic risk in hypertrophic cardiomyopathy

Abstract

Introduction and objectives: Late gadolinium enhancement (LGE) extent has emerged as a predictor of sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM), however little is known about the arrhythmogenic relevance of its specific location in the left ventricle. Our aim was to analyze the influence of LGE location on the occurrence of ventricular arrhythmias (VA) and SCD in patients with HCM.

Methods: We performed a retrospective analysis of clinical and Holter records of HCM patients who underwent cardiac magnetic resonance at our center. LGE extent and distribution were assessed using the American Heart Association 17-segment model. VA was defined as non-sustained or sustained ventricular tachycardia, ventricular fibrillation or SCD.

Results: Sixty-one patients (age 57.0±16.7 years) were included and VA occurred in 24.6% (n=15). Patients with VA showed greater LGE extent than those without (7.40±5.3 vs. 3.52±3.0 segments, p=0.007). Analyzing the distribution of LGE, a set of arrhythmogenic segments (apex/basal inferior/basal anterolateral/mid inferoseptal) was found. The extent of LGE involvement in these segments was also greater in patients with VA (2.07±1.03 vs. 0.65±0.71 segments, p<0.001; area under the curve 0.861 for VA) and this difference remained significant after adjustment for potentially confounding variables.

Conclusions: The extent of LGE involvement of a set of segments with an apparent relation to cardiac areas of increased mechanical stress was significantly and independently associated with the occurrence of VA, suggesting that not only the extent but also the location of LGE is important for the assessment of SCD risk in HCM patients.

Keywords: Cardiac magnetic resonance; Hypertrophic cardiomyopathy; Late gadolinium enhancement; Miocardiopatia hipertrófica; Realce tardio; Ressonância magnética cardíaca.