Journal Article

Beyond the slope: prognostic utility of the VE/VCO2 intercept in chronic heart failure

Emdin, Michele, Sinagra, Gianfranco, Pezzuto, Beatrice, Apostolo, Anna, Contini, Mauro C, Cosimo, Carriere, Campodonico, Jeness, Tricarico, Lucia, Castiglione, Vincenzo, Vignati, Carlo, Senni, Michele, Magrì, Damiano, Mapelli, Massimo, Agostoni, Piergiuseppe, Galotta, Arianna, Baracchini, Nikita, Cattadori, Gaia, Felli, Luca, Sciomer, Susanna, Grosdani, Stefano, Passino, Claudio, Iorio, Annamaria, Willixhofer, Robin, Barbato, Emanuele, Correale, Michele, Mattavelli, Irene, Palermo, Pietro, Salvioni, Elisabetta, Capovilla, Teresa Maria, Rubbo, Filippo Maria, Abete, Raffaele, Fiori, Emiliano

2026

Overview

AimsCardiopulmonary exercise testing (CPET) parameters are used for heart failure (HF) prognostication. While the ventilation to carbon dioxide production (VE/VCO2) slope ≥34 identifies high risk, patients with intermediate values remain heterogeneous. The VE/VCO2 Y-intercept, reflecting dead space ventilation at rest and its changes during effort, may refine prognostication.MethodsWe retrospectively analysed 2642 HF. Follow-up was 26 (9–63) months. The study endpoint was the composite of all-cause death, urgent transplant or left ventricular assist device implantation.ResultsMedian age was 62 (53–70) years and left ventricular ejection fraction (LVEF) 33% (27%–39%). 27% of patients were New York Heart Association class III–IV. During follow-up, 534 events occurred. Both VE/VCO₂ slope and peakVO₂ were associated with outcome in univariable and multivariable models (HR 1.04, 95% CI 1.03 to 1.06; HR 0.90, 95% CI 0.88 to 0.93, p<0.001, respectively). Y-intercept was not prognostic univariately but added independent value in multivariable models (HR 1.08, 95% CI 1.04 to 1.13, p<0.001). Prognosis and clinical profiles improved from group A (VE/VCO2 slope ≥34, n=858) to B (28–34, n=943) to C (<28, n=841). Group A versus C patients had lower LVEF (30% (25%–36%) vs 35% (30%–40%), ptrend<0.001), peakVO₂ (12.7 (10.06–15.3) vs 17.7 (14.6–21.6) mL/kg/min, ptrend<0.001) and higher N-terminal pro-B-type natriuretic peptide (1400 (572–3122) vs 454 (174–1081) pg/mL, ptrend<0.001). Only within group B, a high median Y-intercept (B1≥3.9 L/m) clearly identified patients with higher HF severity and worse survival than B2 (<3.9 L/m, log-rank p<0.001).ConclusionAn increase in the VE/VCO2 slope is associated with a progressive lower survival. Y-intercept enhances risk assessment in HF with intermediate VE/VCO₂ slope values.

• Publisher: British Cardiovascular Society,BMJ Publishing Group LTD,BMJ Publishing Group
• Subject: Anaerobic threshold / Carbon dioxide / Ejection fraction / HEART FAILURE / Heart Failure and Cardiomyopathies / Heart Failure, Systolic / Original Research / Patients / Regression analysis / Risk Factors