Prognostic value of cardiopulmonary exercise testing in valvular heart disease

Abstract

Abstract Introduction Cardiopulmonary exercise testing (CEPT) is not routinely used for the assessment of valvular heart disease (VHD) patients. The cutoff values of percentage of predicted peak VO2 and ventilatory efficiency parameters that carry out a bad prognosis have been predominantly validated in heart failure. The aim of this study was to analyze the prognostic value of CPET parameters in a broad population of VHD patients. Methods 163 patients (51% female) with moderate or severe VHD who underwent a CEPT (n=197) at their physician's discretion from 2017 until 2019 were included. We calculated the net reclassification index of CPET, compared to the classical clinical or echocardiographic parameters, regarding the need for surgical indication. Also, the predictive value of CPET for death and symptom development during follow-up was estimated using regression analysis. Results At inclusion, all patients were asymptomatic or with minimal equivocal symptoms. Aortic valvular lesions were the most common (47%), followed by mitral valvular disease (44%). There was a predominance of severe valvular heart disease (71%) and most of the CEPTs were performed on a treadmill (74%). The percentage of predicted peak VO2 was 76±18% and at anaerobic threshold was 61±18%. The mean follow-up time was 15±10 months. There were 5 deaths (3%) and 24 patients became symptomatic. The net reclassification index of CPET over either clinical or echocardiographic parameters was 46%. The CEPT parameters that predicted increased risk of death were VE/VCO2 slope (p=0.009), % of predicted peak VO2 (p=0.049) and Eq CO2 at anaerobic threshold (p=0.047). None of the CEPT parameters was predictive of symptom development during follow-up, however, in the subgroup of patients who became clearly symptomatic, the ventilatory efficiency parameters were similar to the cut off values that confer bad prognosis (see Table in Figure). Conclusion In our series, CPET added prognostic mortality value to patients with VHD. The cut off values used for patients with HF can also be applied in a VHD population. In addition, CEPT clearly improved the clinical decision for surgical referral. Nevertheless, these results need to be validated in a broader population. Funding Acknowledgement Type of funding sources: None.