ABC | Volume 114, Nº2, February 2020

Original Article Prognostic Prediction of Cardiopulmonary Exercise Test Parameters in Heart Failure Patients with Atrial Fibrillation António Valentim Gonçalves, 1 T iago Pereira-da-Silva, 1 Rui Soares, 1 Joana Feliciano, 1 Rita Ilhão Moreira, 1 Pedro Rio, 1 Ana Abreu, 1 Rui Cruz Ferreira 1 Centro Hospitalar Universitário Lisboa Central, Hospital de Santa Marta, 1 Lisbon – Portugal Mailing Address: António Valentim Gonçalves • Rua de Santa Marta, 50. 1169-1024, Lisbon - Portugal E-mail: antonio.a.goncalves.14@gmail.com Manuscript received September 05, 2018, revised manuscript March 03, 2019, accepted April 10, 2019 DOI: https://doi.org/10.36660/abc.20180193 Abstract Background: Atrial fibrillation (AF) is associated with increased mortality in heart failure (HF) patients. Objective: To evaluate whether the risk of AF patients can be precisely stratified by relation with cardiopulmonary exercise test (CPET) cut-offs for heart transplantation (HT) selection. Methods: Prospective evaluation of 274 consecutive HF patients with left ventricular ejection fraction ≤ 40%. The primary endpoint was a composite of cardiac death or urgent HT in 1-year follow-up. The primary endpoint was analysed by several CPET parameters for the highest area under the curve and for positive (PPV) and negative predictive value (NPV) in AF and sinus rhythm (SR) patients to detect if the current cut-offs for HT selection can precisely stratify the AF group. Statistical differences with a p-value <0.05 were considered significant. Results: There were 51 patients in the AF group and 223 in the SR group. The primary outcome was higher in the AF group (17.6% vs 8.1%, p = 0.038). The cut-off value of pVO 2 for HT selection showed a PPV of 100% and an NPV of 95.5% for the primary outcome in the AF group, with a PPV of 38.5% and an NPV of 94.3% in the SR group. The cut-off value of VE/VCO 2 slope showed lower values of PPV (33.3%) and similar NPV (92.3%) to pVO 2 results in the AF group. Conclusion: Despite the fact that AF carries a worse prognosis for HF patients, the current cut-off of pVO 2 for HT selection can precisely stratify this high-risk group. (Arq Bras Cardiol. 2020; 114(2):209-218) Keywords: Atrial Fibrillation/mortality; Peak Expiratory Flow Rate; Exercise Test; Oxygen Consumption; Heart Failure; Prognosis. Introduction Heart failure (HF) and atrial fibrillation (AF) often coexist, 1 with AF occurring in some reports in more than 50% of HF patients, and HF in more than one-third of AF patients. 2 Since the burden of each is growing, they have been called the two new epidemics of cardiovascular (CV) disease. 3 The presence of AF in HF patients is associated with adverse hemodynamic consequences, which may exacerbate HF, increasing morbidity and mortality. 4-6 The cardiopulmonary exercise test (CPET) is a powerful predictor of mortality in HF patients and is used as the criterion standard for the need for heart transplantation (HT), 7 with peak O 2 consumption (pVO 2 ) and the relation between ventilation and CO 2 production (VE/VCO 2 slope) as the most used risk assessment tools. 8 However, less information is known about whether HF patients with AF can be precisely stratified with the current CPET cut-offs for HT selection. Since the combination of HF and AF provide a worse prognosis, a timely referral for HT or mechanical circulatory support could be extraordinarily important to reduce the negative prognostic effect of AF in HF patients. The present study seeks to compare the prognostic importance in HF patients of CPET parameters in AF versus sinus rhythm (SR) patients. Methods The investigation conforms to the principles outlined in the Declaration of Helsinki. The institutional ethics committee approved the study protocol. All patients provided written informed consent. Patient population and study protocol The study included a single centre analysis of 274 consecutive HF patients referred to our institution with left ventricular ejection fraction (LVEF) ≤ 40% and New York Heart Association (NYHA) class II or III, from 2009 to 2016. All the patients were referred for evaluation with HF team and possible indication for HT or mechanical circulatory support. Patients with elective HT during the follow-up period (patients who had indication for HT and a heart become available in the first year of follow-up) were excluded from the analysis. 209