472 PROGNOSTIC VALUE OF CPET REPETITION DURING FOLLOW-UP OF DILATED CARDIOMYOPATHY

Abstract

Abstract Background although cardiopulmonary exercise testing (CPET) is a recognized tool for prognostic stratification in patients with dilated cardiomyopathy (DCM), there are no data about the prognostic value of its repetition during follow-up in this setting. The aim of this study was to test the prognostic value of repeating CPET during follow-up, among a large cohort of DCM patients. Methods in this multicenter, retrospective study, we analyzed DCM patients who consecutively performed at least two CPET during a clinical stable phase of disease. All patients performed CPET and echocardiogram within 10 days. The study end-point was a composite of death from all causes, heart transplantation, implantation of durable left ventricular assist device, life-threatening ventricular arrhythmias or hospitalization for HF. Results 216 DCM patients were enrolled (52±12 years, 78% male, NYHA I-II 82%, LVEF 32±9%, 94% on ACE inhibitors, 95% on beta-blockers); the duration of the disease at the time of first CPET was 68 months. The interval between the two CPETs was 15 (11;23) months. During a median follow-up of 38 months from the second CPET, 108 (47%) patients went through the end-point. Time-dependent ROC curves revealed that to repeat during a follow-up of 12 months both CPET and echocardiogram gives a more accurate prognostic stratification than basal echocardiography + basal CPET. Despite an higher AUC (0.91 vs 0.85) there were no significant different accuracies (95% CI: 83.6 - 98 vs 75.5–96.5; p-value: 0.2) between the repetition of CPET plus echocardiogram vs. the repetition of the echocardiogram alone. Among patients who experienced the study outcome, there was a substantial stability of echocardiographic values (relative variation of LVEF +2.7%, LVEDV +1.3%) but a significant worsening of functional capacity (relative variation of percentage predicted VO2 peak +6%, p-value: 0.002). Conversely, there were a significant improvement in echocardiographic values and CPET values in events-free patients (LVEF relative variation -8.6% p-value: 0.002; ppVO2 peak relative variation -6.8%, p-value: 0.002). Conclusion in a large population of clinically stable DCM patients, the systematic repetition of echocardiography or both CPET and echocardiography showed no significant prognostic impact, in presence of stable or worsened echocardiogram. Nevertheless, when there is a clinical variation of symptoms or a failing in the reverse remodeling process, 1-year repetition of CPET can identify higher risk patients.