{
  "abstract": "Aims Cardiopulmonary exercise testing (CPET) parameters are used for heart failure (HF) prognostication. While the ventilation to carbon dioxide production (VE/VCO 2) 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.Methods We 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.Results Median 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/VCO ₂ 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).Conclusion An increase in the VE/VCO 2 slope is associated with a progressive lower survival. Y-intercept enhances risk assessment in HF with intermediate VE/VCO₂ slope values.",
  "authors": [
    {
      "affiliations": [
        "Centro Cardiologico Monzino Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy"
      ],
      "name": "Piergiuseppe Agostoni"
    },
    {
      "affiliations": [
        "Centro Cardiologico Monzino Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy"
      ],
      "name": "Robin Willixhofer"
    },
    {
      "affiliations": [
        "Centro Cardiologico Monzino Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy"
      ],
      "name": "Arianna Galotta"
    },
    {
      "affiliations": [
        "Monzino Cardiology Centre, Milan, Italy",
        "Treatment of Cardiomyopathies, Cardiovascular Department, University of Trieste, Trieste, Italy"
      ],
      "name": "Filippo Maria Rubbo"
    },
    {
      "affiliations": [
        "Centro Cardiologico Monzino, Monzino Cardiology Centre, Milan, Italy"
      ],
      "name": "Stefano Grosdani"
    },
    {
      "affiliations": [
        "Monzino Cardiology Centre, Milan, Italy"
      ],
      "name": "Luca Felli"
    },
    {
      "affiliations": [
        "Cardiovascular Department, ASST Papa Giovanni XXIII, Bergamo, Italy"
      ],
      "name": "Raffaele Abete"
    },
    {
      "affiliations": [
        "Scuola Superiore Sant’Anna, Pisa, Italy",
        "Fondazione Toscana Gabriele Monasterio, Pisa, Italy"
      ],
      "name": "Vincenzo Castiglione"
    },
    {
      "affiliations": [
        "Centro Cardiologico Monzino, Milano, Italy"
      ],
      "name": "Elisabetta Salvioni"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences and Community Health, Centro Cardiologico Monzino, IRCCS, University of Milan, Milano, Italy"
      ],
      "name": "Massimo Mapelli"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences and Community Health, Centro Cardiologico Monzino, IRCCS, University of Milan, Milano, Italy"
      ],
      "name": "Carlo Vignati"
    },
    {
      "affiliations": [
        "Heart Failure Unit, Monzino Cardiology Centre, Milan, Italy"
      ],
      "name": "Beatrice Pezzuto"
    },
    {
      "affiliations": [
        "Heart Failure Unit, Monzino Cardiology Centre, Milan, Italy"
      ],
      "name": "Irene Mattavelli"
    },
    {
      "affiliations": [
        "Cardiothoracovascular Department, University of Trieste, Trieste, Italy"
      ],
      "name": "Carriere Cosimo"
    },
    {
      "affiliations": [
        "Treatment of Cardiomyopathies, Cardiovascular Department, University of Trieste, Trieste, Italy",
        "University of Trieste, Trieste, Italy"
      ],
      "name": "Nikita Baracchini"
    },
    {
      "affiliations": [
        "Treatment of Cardiomyopathies, Cardiovascular Department, University of Trieste, Trieste, Italy",
        "University of Trieste, Trieste, Italy"
      ],
      "name": "Teresa Maria Capovilla"
    },
    {
      "affiliations": [
        "Fondazione G. Monasterio CNR Regione Toscana, Pisa, Italy"
      ],
      "name": "Claudio Passino"
    },
    {
      "affiliations": [
        "Centro Cardiologico Monzino Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy"
      ],
      "name": "Anna Apostolo"
    },
    {
      "affiliations": [
        "Centro Cardiologico Monzino Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy"
      ],
      "name": "Pietro Palermo"
    },
    {
      "affiliations": [
        "Centro Cardiologico Monzino Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy"
      ],
      "name": "Jeness Campodonico"
    },
    {
      "affiliations": [
        "Centro Cardiologico Monzino, Milano, Italy"
      ],
      "name": "Mauro C Contini"
    },
    {
      "affiliations": [
        "Università degli Studi di Foggia, Foggia, Italy"
      ],
      "name": "Lucia Tricarico"
    },
    {
      "affiliations": [
        "Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy"
      ],
      "name": "Emanuele Barbato"
    },
    {
      "affiliations": [
        "Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy"
      ],
      "name": "Emiliano Fiori"
    },
    {
      "affiliations": [
        "Aziende Socio Sanitarie Territoriale Papa Giovanni XXIII, Bergamo, Italy"
      ],
      "name": "Michele Senni"
    },
    {
      "affiliations": [
        "Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy"
      ],
      "name": "Damiano Magrì"
    },
    {
      "affiliations": [
        "Cardiovascular Department, ASST Papa Giovanni XXIII, Bergamo, Italy"
      ],
      "name": "Annamaria Iorio"
    },
    {
      "affiliations": [
        "Department of Cardiology, La Sapienza University, Roma, Italy"
      ],
      "name": "Susanna Sciomer"
    },
    {
      "affiliations": [
        "Foggia University Hospital, Foggia, Italy"
      ],
      "name": "Michele Correale"
    },
    {
      "affiliations": [
        "Unità Operativa Cardiologia Riabilitativa, Ospedale S.Giuseppe, Multimedica Spa, IRCCS, Milan, Michigan, USA"
      ],
      "name": "Gaia Cattadori"
    },
    {
      "affiliations": [
        "Cardiovascular Medicine Division, Fondazione G. Monasterio CNR Regione Toscana, Pisa, Italy"
      ],
      "name": "Michele Emdin"
    },
    {
      "affiliations": [
        "Cardiovascular Department, University Health Authority Giuliano-Isontina, Trieste, Italy",
        "Department of Integrated Cardiothoracic and Vascular Activity, University Health Authority Giuliano-Isontina, Trieste, Italy"
      ],
      "name": "Gianfranco Sinagra"
    }
  ],
  "title": "Beyond the slope: prognostic utility of the VE/VCO2 intercept in chronic heart failure",
  "uid": "2dfe9e12-2836-524d-ac32-161ccbeee190"
}