Left ventricular involvement assessed by LGE-CMR in predicting the risk of adverse outcomes of arrhythmogenic cardiomyopathy with ICDs

Abstract

Background: Arrhythmogenic cardiomyopathy (ACM) is characterized by a high incidence of ventricular tachyarrhythmia and sudden death. Implantable cardioverter-defibrillator (ICD) implantation is the cornerstone of management.

Objective: This study aims to reveal the prognostic value of the contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) amount in predicting varying lethal outcomes among ACM patients with ICDs.

Methods: The 88 patients with definite ACM who were all referred for contrast-enhanced CMR received an ICD and were followed up for a median of 4.0 years.

Results: Fifty-four patients had no left ventricular (LV) involvement and sixteen had an LV LGE amount > 15%. During the follow-up time, appropriate ICD therapy was seen in 57, electrical storm (ES) in 19, and cardiac death in 9 patients. Compared with those without LV involvement, patients with LV LGE amount > 15% had a higher risk of cardiac death (log-rank P = 0.021). LV LGE amount was associated with an increased risk of ICD therapy [adjusted hazard ratio (HR) 1.035, 95% confidence interval (CI) 1.008-1.062, P = 0.010], and cardiac death (adjusted HR 1.082, 95% 1.006-1.164, P = 0.034), independently of LV ejection fraction. LV LGE mass of >15% demonstrated an over 2-fold increase in ICD therapy (adjusted HR 2.180, 95%CI 1.058-4.488, P = 0.035) and an over 7-fold increase in cardiac death (unadjusted HR 7.198, 95%CI 1.399-37.043, P = 0.018) than those without LV involvement, respectively.

Conclusions: The LV LGE-CMR in ACM shows a dose-dependent association with ICD therapy and cardiac death. And LV LGE amount of >15% is a strong predictor.

Keywords: Appropriate ICD therapy; Arrhythmogenic cardiomyopathy; Cardiac death; Electrical storm; Implantable cardioverter defibrillator; Left ventricular involvement.