Left Ventricular Dysfunction in Arrhythmogenic Cardiomyopathy: Association With Exercise Exposure, Genetic Basis, and Prognosis

Figure 1. Left ventricular function in 146 patients with arrhythmogenic cardiomyopathy and known exercise habits at presentation. Slopes are fitted mean linear response with 95% CIs for patients with and without desmoplakin mutations. P values for progression and interaction by linear mixed‐model regression with random effects for families and individuals and exchangeable covariance structure. Exercise during 3 immediate years before presentation expressed as average MET‐hours per week, with dichotomization at median exercise exposure. Patients with exercise exposure above median had GLS 1.0% (interquartile range, 0.1%–1.9%; P=0.02) worse than patients with exercise exposure below median. There was no difference in the progression of left ventricular dysfunction in patients with greater or lesser exercise exposure (illustrated by P for interaction=0.87). See Table 2 for coefficients and continuous exercise variable. GLS indicates global longitudinal strain; and LV, left ventricular.

Figure 2. Left ventricular functional deterioration during follow‐up of 168 patients with arrhythmogenic cardiomyopathy with desmoplakin genotypes (blue curves) and with other genotypes or gene elusive patients (green curves). Slopes are fitted mean linear response with 95% CIs for patients with and without desmoplakin mutations. P values for progression and interaction by linear mixed‐model regression with random effects for families and individuals and exchangeable covariance structure. Patients with desmoplakin genotypes had worse progression of left ventricular dysfunction than patients with other genotypes or gene‐elusive patients (illustrated by P for interaction<0.001 for both EF and GLS). See text for regression coefficients. DSP indicates desmoplakin; EF, ejection fraction; and GLS, global longitudinal strain.

Figure 3. Left ventricular functional deterioration during follow‐up of 168 patients with arrhythmogenic cardiomyopathy predicted subsequent ventricular tachyarrhythmias. Odds ratios for impending ventricular tachyarrhythmias with 1% decline in GLS presented in the lower left panel were calculated by generalized estimating equations of the repeated left ventricular functional assessments with binomial family, logit link, and independent correlation structure, adjusting for the effect of patient relatedness, elapsed time (primary prevention subgroup) and previous ventricular arrhythmia (all patients). GLS indicates global longitudinal strain; ICD, implantable cardioverter defibrillator; OR, odds ratio; and VT, ventricular tachycardia.