ABC | Volume 114, Nº2, February 2020

Original Article Gonçalves et al. Prediction of CPET in HF patients with AF Arq Bras Cardiol. 2020; 114(2):209-218 Table 2 – Adverse events at 12 months follow-up Adverse events at 12 months follow-up SR - n (%) AF - n (%) p Combined endpoint 18 (8.1%) 9 (17.6%) 0.038 Total mortality 14 (6.3%) 9 (17.6%) 0.008 Cardiac mortality 12 (5.4%) 6 (11.8%) 0.097 Sudden cardiac death 5 (2.2%) 4 (7.8%) 0.043 Death for worsening HF 7 (3.1%) 2 (3.9%) 0.777 Urgent HT 6 (2.7%) 3 (5.9%) 0.249 Mechanical circulatory support 0 (0%) 0 (0%) 1.000 AF: atrial fibrillation; HF: heart failure: HT: transplantation; SR: sinus rhythm. Table 3 – Univariate Cox proportional-hazards analysis (non-CPET parameters) Characteristics All SR AF Wald Hazard ratio 95% CI p Wald Hazard ratio 95% CI p Wald Hazard ratio 95% CI p Age 0.092 0.995 0.965-1.026 0.762 0.768 0.984 0.950-1.020 0.381 0.057 1.010 0.933-1.093 0.811 Gender 0.524 0.699 0.265-1.845 0.469 1.041 0.525 0.152-1.812 0.308 1.188 2.397 0.498-11.547 0.276 BMI 1.175 0.947 0.859-1.045 0.278 0.183 0.974 0.863-1.099 0.669 1.906 0.887 0.748-1.052 0.167 Beta-Blocker 5.139 2.469 1.130-5.393 0.023 4.259 2.713 1.051-6.998 0.039 0.877 1.941 0.484-7.779 0.349 Diabetes 0.130 1.197 0.451-3.174 0.718 0.027 0.910 0.297-2.792 0.869 0.691 2.416 0.302-19.326 0.406 Baseline CRT 1.614 1.995 0.687-5.790 0.204 1.047 2.160 0.494-9.446 0.306 1.807 2.940 0.610-14.167 0.179 HFSS 34.893 0.233 0.144-0.378 < 0 .001 22.674 0.233 0 .128-0.424 < 0 .001 8.600 0.243 0 .095-0.626 0.003 Glomerular filtration rate 3.520 0.586 0.971-1.101 0.061 2.578 0.985 0.967-1.003 0.108 0.205 0.994 0.969-1.020 0.650 Sodium 27.303 0.787 0.720-0.861 < 0. 001 14.635 0.766 0. 668-0.878 < 0 .001 7.668 0.839 0 .726-0.947 0.006 NT-proBNP 20.456 8.212 2.234-12.367 < 0 .001 15.171 6.263 1 .894-10.223 < 0 .001 3.187 2.335 1 .285-4.534 0.004 LVEDD 5.670 1.072 1.012-1.135 0.017 3 .001 1.077 0.990-1.171 0.083 1.443 1.049 0.970-1.135 0.230 LVEF 18.934 0.887 0.840-0.936 < 0 .001 13.810 0.884 0 .828-0.943 < 0 .001 3.351 0.912 0 .826-0.998 0.049 RV dysfunction 21.377 3.758 2.144-6.588 < 0 .001 6.160 2.846 1 .246-6.499 0.013 8.346 4.267 1.594-11.419 0.004 SR: sinus rhythm; AF: atrial fibrillation; CI: confidence interval; BMI: body mass index; CRT: cardiac resynchronization therapy; HFSS: Heart Failure Survival Score; LVEDD: left ventricular end-diastolic diameter; LVEF: left ventricular ejection fraction; RV: right ventricular. the two groups were also observed with prognostic measures of CPET, with a worse status in AF group revealed by a lower CPET duration, pVO 2 , oxygen uptake efficiency slope (OUES), time to anaerobic threshold (AT), pVO 2 at AT and a higher VE/ VCO 2 slope (Table 1). Primary and secondary endpoints At 1 year, the primary endpoint (cardiac death or urgent HT) had occurred in 27 (9.9%) patients as represented in Table 2. There were no patients requiring mechanical circulatory support . The AF group had more events regarding the combined endpoint (17.6% vs 8.1%, p = 0.038), with cardiac mortality alone showing a trend for a worse prognosis in the AF group (11.8% vs 5.4%, p = 0.097), with no statistical difference regarding urgent HT (5.9% vs 2.7%, p = 0.249). Secondary endpoints showed higher all-cause mortality (17.6% vs 6.3%, p = 0.008) and a higher sudden cardiac death (7.8% vs 2.2%, p = 0.043) in the AF group, with no difference regarding death for worsening HF (3.9% vs 3.1%, p = 0.777). Complete data of univariable Cox analysis for prediction of the primary endpoint is presented in Table 3 and Table 4. HFSS, Sodium, NT-proBNP, right ventricular dysfunction, LVEF, CPET duration, heart rate recovery in the first minute after finishing CPET (HHR1) and initial and maximal SBP during CPET were predictors of the primary endpoint in both groups. With the exception of HHR1, heart rate (HR) parameters during CPET were only predictors of the primary endpoint in the AF group, as seen with lower values of maximal HR, lower values of maximal (%) predicted HR and a lower variation of the HR during exercise, for patients with AF for whom the primary endpoint occurred and for those for whom it did not, respectively (Table 4). On the other hand, the use of BB was only a predictor of the primary endpoint in the SR group (Table 3). Relationship between CPET prognostic parameters and primary outcome The power to predict the primary outcome by CPET parameters is represented in the supplementary index. Univariate Cox analysis shows that pVO 2 , pVO 2 (%) predicted, pVO 2 at AT, VE/VCO 2 slope and OUES are all predictors of the primary outcome in both groups (p < 0.05 for all). In addition to the Cox analysis, these CPET parameters were analysed for the highest AUC in the 12 months’ follow- up period. In the SR group, VE/VCO 2 slope had the highest 212