These results indicate that FIT modifies the relationship between BMI and survival. Thus, assessing the obesity paradox in systolic HF may be misleading unless FIT is considered.

The objective of the study is to assess the role of cardiopulmonary exercise testing (CPX) variables, including peak oxygen consumption (VO(2)), which is the most recognized CPX variable, the minute ventilation/carbon dioxide production (VE/VCO(2)) slope, the oxygen uptake efficiency slope (OUES), and exercise oscillatory ventilation (EOV) in a current meta-analysis investigating the prognostic value of a broader list of CPX-derived variables for major adverse cardiovascular events in patients with HF. A search for relevant CPX articles was performed using standard meta-analysis methods. Of the initial 890 articles found, 30 met our inclusion criteria and were included in the final analysis. The total subject populations included were as follows: peak VO(2) (7,319), VE/VCO(2) slope (5,044), EOV (1,617), and OUES (584). Peak VO(2), the VE/VCO(2) slope and EOV were all highly significant prognostic markers (diagnostic odds ratios ≥ 4.10). The OUES also demonstrated promise as a prognostic marker (diagnostic odds ratio = 8.08) but only in a limited number of studies (n = 2). No other independent variables (including age, ejection fraction, and beta-blockade) had a significant effect on the meta-analysis results for peak VO(2) and the VE/VCO(2) slope. CPX is an important component in the prognostic assessment of patients with HF. The results of this meta-analysis strongly confirm this and support a multivariate approach to the application of CPX in this patient population.

BackgroundThis study aimed to compare the independent and incremental prognostic value of peak oxygen consumption (VO 2) and minute ventilation/carbon dioxide production (VE/VCO 2) in heart failure (HF) with preserved (HFpEF), midrange (HFmEF), and reduced (HFrEF) ejection fraction (LVEF).Methods and ResultsIn 195 HFpEF (LVEF ≥50%), 144 HFmEF (LVEF 40–49%), and 630 HFrEF (LVEF <40%) patients, we assessed the association of cardiopulmonary exercise testing variables with the composite outcome of death, left ventricular assist device implantation, or heart transplantation (256 events; median follow‐up of 4.2 years), and 2‐year incident HF hospitalization (244 events). In multivariable Cox regression analysis, greater association with outcomes in HFpEF than HFrEF were noted with peak VO 2 (HR [95% confidence interval]: 0.76 [0.67–0.87] versus 0.87 [0.83–0.90] for the composite outcome, P interaction=0.052; 0.77 [0.69–0.86] versus 0.92 [0.88–0.95], respectively for HF hospitalization, P interaction=0.003) and VE/VCO 2 slope (1.11 [1.06–1.17] versus 1.04 [1.03–1.06], respectively for the composite outcome, P interaction=0.012; 1.10 [1.05–1.15] versus 1.04 [1.03–1.06], respectively for HF hospitalization, P interaction=0.019). In HFmEF, peak VO 2 and VE/VCO 2 slope were associated with the composite outcome (0.79 [0.70–0.90] and 1.12 [1.05–1.19], respectively), while only peak VO 2 was related to HF hospitalization (0.81 [0.72–0.92]). In HFpEF and HFrEF, peak VO 2 and VE/VCO 2 slope provided incremental prognostic value beyond clinical variables based on the C‐statistic, net reclassification improvement, and integrated diagnostic improvement, with models containing both measures demonstrating the greatest incremental value.ConclusionsBoth peak VO 2 and VE/VCO 2 slope provided incremental value beyond clinical characteristics and LVEF for predicting outcomes in HFpEF. Cardiopulmonary exercise testing variables provided greater risk discrimination in HFpEF than HFrEF.

Background-Peak oxygen consumption (VO 2 ) is routinely assessed in patients with heart failure undergoing cardiopulmonary exercise testing. The purpose of the present investigation was to determine the prognostic ability of several established peak VO 2 prediction equations in a large heart failure cohort. Methods and Results-One thousand one hundred sixty-five subjects (70% males; age, 57.0Ϯ13.8 years; ischemic etiology, 43%) diagnosed with heart failure underwent cardiopulmonary exercise testing. Percent-predicted peak VO 2 was calculated according to normative values proposed by Wasserman and Hansen (equation), Jones et al (equation), the Cooper Clinic (below low fitness threshold), a Veteran's Administration male referral data set (4 equations), and the St James Take Heart Project for women (equation). The prognostic significance of percent-predicted VO 2 values derived from the 2 latter, sex-specific equations were assessed collectively. There were 179 major cardiac events (117 deaths, 44 heart transplantations, and 18 left ventricular assist device implantations) during the 2-year tracking period (annual event rate, 10%). Measured peak VO 2 and all percent-predicted peak VO 2 calculations were significant univariate predictors of adverse events (