RESUMO
Objective:To analyze the value of minute ventilation to carbon dioxide production slope (VE/VCO 2 slope) combined with peak systolic blood pressure (SBP) in predicting prognosis for patients with chronic heart failure (CHF). Methods:A total of 170 patients with CHF who visited the Cardiac Rehabilitation Center of Tongji Hospital Affiliated to Tongji University and completed cardiopulmonary exercise test from March 2007 to December 2018 were enrolled in the study. The clinical data, cardiopulmonary exercise testing results and follow-up information of patients were collected to explore the predictors of all-cause mortality in patients with CHF.Results:The median follow-up time was 647 (182-1 764) days. All-cause death occurred in 34 patients. Compared with surviving patients, the proportion of diabetes and angiotensin-converting enzyme inhibitor/angiotensin Ⅱ receptor blocker (ACEI/ARB) use in fatal patients was significantly higher ( P<0.01). The VE/VCO 2 slope and peak SBP*VE/VCO 2 in the fatal patients were significantly higher, and the peak oxygen consumption (peak VO 2) was lower than those in the surviving patients ( P<0.01). The areas under the receiver operating characteristic curve (AUC) of VE/VCO 2 slope and peak SBP*VE/VCO 2 in predicting all-cause mortality in patients with CHF were 0.648 ( P=0.008) and 0.681 ( P=0.001), respectively; the optimal thresholds were >40.95 ( P=0.008) and > 5 423.50 mmHg (1 mmHg=0.133 kPa, P=0.006), the sensitivity was 0.559 and 0.588, and the specificity was 0.728 and 0.735, respectively. Multivariate Cox regression analysis showed that after adjusting for age, gender, diabetes and ACEI/ARB use, VE/VCO 2 slope ( HR=2.12, P=0.036) and peak SBP*VE/VCO 2 ( HR=2.42, P=0.016) were independent risk factors for all-cause mortality in patients with CHF. Conclusion:Compared to the traditional index VE/VCO 2 slope, a novel index peak SBP* VE/VCO 2 provides a relatively better predictive value for all-cause death of CHF patients.