Safety and Utility of Cardiopulmonary Exercise Testing in Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia

Abstract

Background Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is characterized by high arrhythmic burden and progressive heart failure, which can prompt referral for heart transplantation. Cardiopulmonary exercise testing (CPET) has an established role in risk stratification for advanced heart failure therapies, but has not been described in ARVC/D. This study sought to determine the safety and prognostic utility of CPET in patients with ARVC/D. Methods and Results Using the Johns Hopkins ARVC/D Registry, we examined patients with ARVC/D undergoing CPET. Baseline characteristics and transplant-free survival were compared on the basis of peak oxygen consumption (pVO2) (≤14 or >14 mL/kg per minute) and ventilatory efficiency (Ve/VCO₂ slope ≤34 or >34). Thirty-eight patients underwent 50 CPETs. There were no sustained arrhythmic events. Twenty-nine patients achieved a maximal test. Patients with pVO2 ≤14 mL/kg per minute were more often men (P=0.042) compared with patients with pVO2 >14 mL/kg per minute. Patients with Ve/VCO₂ slope >34 tended to have more moderate/severe right ventricular dilation (7/9 [78%] versus 10/26 [38%]; P=0.060) and clinical heart failure (8/9 [89%] versus 13/26 [50%]; P=0.056) compared with patients with Ve/VCO₂ slope ≤34. Patients who underwent heart transplantation were more likely to have clinical heart failure (10/10 [100%] versus 13/28 [46%]; P=0.003). Patients with Ve/VCO₂ slope >34 had worse transplant-free survival compared with patients with Ve/VCO₂ slope ≤34 (n=35; hazard ratio, 6.57 [95% CI, 1.28-33.72]; log-rank P=0.010), whereas transplant-free survival was similar on the basis of pVO2 groups (n=29; hazard ratio, 3.38 [95% CI, 0.75-15.19]; log-rank P=0.092). Conclusions CPET is safe to perform in patients with ARVC/D. Ve/VCO₂ slope may be used for risk stratification and guide referral for heart transplantation in ARVC/D.

Keywords: arrhythmias; cardiomyopathy; exercise testing; genetics; heart failure; transplantation.

Figure 1

Transplant‐free survival based on peak oxygen consumption (VO ₂) (A) and ventilatory efficiency (Ve/VCO ₂ slope) (B). Comparison of survival curves for patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia undergoing cardiopulmonary exercise testing based on peak VO ₂ (≤14 vs >14 mL/kg per minute) and Ve/VCO ₂ slope (≤34 vs >34). HR indicates hazard ratio.

Figure 2

Transplant‐free survival based on percentage predicted peak oxygen consumption (pVO ₂) (A) and ventilatory efficiency (Ve/VCO ₂ slope) (B). Comparison of survival curves for patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia undergoing cardiopulmonary exercise testing based on percentage predicted pVO ₂ (<70% vs ≥70%) and Ve/VCO ₂ slope (≤36 vs >36). HR indicates hazard ratio.