Abstract 4002: Prediction of Mortality by VE/VCO2 Slope in Heart Failure: A Metanalysis of the Published Data
Background: The evaluation of maximal oxygen consumption (PeakVO2) and VE/VCO2 slope in a cardiopulmonary stress test are frequently used as prognostic markers in heart failure. Traditionally, PeakVO2 has been considered as the gold standard for prediction of death. However, several studies suggest that VE/VCO2 is at least as good as PeakVO2. Our goal was to systematically review the published papers on VE/VCO2 slope and prognosis in HF and to compare it with PeakVO2.
Methods: We performed a metanalysis of diagnostic studies. We searched PubMed and ISI Web of Science for papers related to VE/VCO2 slope. The end-point for analysis was death. Studies were excluded if we were unable to determine sensibility (Se) and specificity (Sp), duplicated publications, or lack of information about the specified endpoint. We analyzed the selected studies for Se, Sp, diagnostic odds ratio (DOR) and developed a summary ROC curve. We used the Meta-disc 1.4 software.
Results: Our strategy retrieved 478 possible studies and we further selected 92 for analysis. After exclusion criteria, we were left with 13 studies. Total patients enrolled were 3013, with a median age of 57 years (52–59), 80% (72– 87%) were male, 64% in NYHA functional class I–II, 51% (35–58%) with ischemic cardiomyopathy and a median ejection fraction of 29% (27–32%). Cut-off values for prediction of death were >35 (range 32– 45) for VE/VCO2 slope and <14 ml/kg/min (13–16) for PeakVO2. Median follow-up time was 31 months (24 –39). Overall, Se was 0.67 (IC95%: 0.64 – 0.71), and Sp was 0.73 (0.71– 0.75). DOR was 5.09 (4.15– 6.24) and resumed AUC was 0.75 (0.73– 0.78). We selected seven papers with enough information to compare prognostic performance of VE/VCO2 slope and PeakVO2. Total number of patients was 2171. Results are shown in the table⇓.
Conclusion: This metanalysis suggest that VE/VCO2 solpe is at least similar to PeakVO2 in predicting mortality in heart failure.