Is cardiopulmonary exercise testing essential to indicate ventricular assist device implantation in patients with INTERMACS profile 4-7?

Cardiopulmonary exercise testing (CPXT) is a promising tool for predicting 2-year cardiac death or ventricular assist device (VAD) implantation in patients assigned to INTERMACS profile 4-7. However, CPXT is not available in all hospitals. We evaluated 130 patients <65 years old with advanced heart failure assigned to INTERMACS profile 4-7 who underwent CPXT. CPXT scores (0-8 points), which we created recently, and the Seattle HF Model (SHFM) scores were both significant predictors of 2-year cardiac death or VAD implantation (14 events) by Cox-regression analysis (P < 0.05 for both) and had comparable areas under the curve (AUCs) in receiver operating characteristic analyses (0.811 vs. 0.737, P > 0.05). The combination score: age <46 years and serum sodium concentration <137 mEq/L, both of which were significant predictors of cardiac death or VAD implantation by uni/multivariate Cox-regression analyses, had a significantly higher AUC than did CPXT scores (0.909, P < 0.05). In a validation study, the AUC of the combination score was comparable with that of SHFM among 52 patients <65 years old receiving adaptive servo-ventilator treatment (0.753 vs. 0.794, P > 0.05). In conclusion, VAD indication may be discussed without CPXT in patients <65 years old with INTERMACS profile 4-7 at least in the current Japanese situation.