Prognostic impact of the addition of peak oxygen consumption to the Seattle Heart Failure Model in a transplant referral population

• Published in: The Journal of heart and lung transplantation Vol. 31; no. 8; pp. 817 - 824
• Main Authors: Levy, Wayne C., MD, Aaronson, Keith D., MD, Dardas, Todd F., MD, Williams, Paula, BS, Haythe, Jennifer, MD, Mancini, Donna, MD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.08.2012; Elsevier
• Subjects: Adult; Biological and medical sciences; Cardiology. Vascular system; Cohort Studies; Female; Heart; heart failure; Heart Failure - diagnosis; Heart Failure - physiopathology; Heart Failure - surgery; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Heart Transplantation; Heart-Assist Devices; Humans; left ventricular assist device; Male; Medical sciences; Middle Aged; Models, Statistical; Multivariate Analysis; Oxygen Consumption - physiology; peak oxygen consumption; Predictive Value of Tests; Prognosis; Referral and Consultation; Seattle Heart Failure Model; Severity of Illness Index; Surgery; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the heart; Survival Rate; transplantation; Washington; Washington; heart failure; Seattle Heart Failure Model; left ventricular assist device; prognosis; peak oxygen consumption; transplantation; Heart; Heart failure; Addition; Prognosis; Cardiovascular disease; Oxygen consumption; Transplantation; Homotransplantation; Phlebology; Treatment; Heart disease; Surgery; Graft; Population; Models; Peak; Circulatory system; Cardiology
• ISSN: 1053-2498; 1557-3117
• DOI: 10.1016/j.healun.2012.04.006

Background In this study we investigated whether the addition of peak oxygen consumption (VO2 ) improves the predictive accuracy of the Seattle Heart Failure Model (SHFM). The SHFM is a validated multivariate risk model that uses NYHA classification to assess functional capacity rather than peak oxygen consumption (VO2 ). Methods Outpatients ( n = 1,240) evaluated for transplant at three centers had their SHFM score calculated and peak VO2 measured. The outcomes assessed were death/LVAD/urgent transplant with censoring at the time of elective transplant. Results Over the course of 4.0 (mean) years of observation, there were 571 events. Both the SHFM score (χ2 = 227) and peak VO2 (χ2 = 88, both p < 0.0001) were highly predictive of outcomes. The SHFM and peak VO2 were modestly correlated ( r = 0.39, p < 0.0001). In a multivariate Cox model, peak VO2 added to the SHFM with a hazard ratio of 0.949 ( p < 0.0001) for each 1-ml/kg/min increase. Peak VO2 improved both the net reclassification improvement and integrated discrimination index (both p ≤ 0.0002). Peak VO2 provided additive prognostic information within each SHFM score ( p < 0.05). The 1-year areas under the receiver-operating characteristic curve were obtained for peak VO2 (0.645, 95% CI 0.606 to 0.684), SHFM (0.758, 95% CI 0.721 to 0.795) and SHFM with peak VO2 (0.766, 95% CI 0.731 to 0.802). The SHFM-predicted vs actual survival free of LVAD/UNOS Status 1 transplant at 1 year (86% vs 83%) and 4 years (63% vs 63%) were similar. Conclusions The multivariate SHFM is a powerful predictor of death/LVAD/urgent transplant. Peak VO2 adds prognostic information across the spectrum of the SHFM, but changes in decision regarding transplant listing occur mainly in moderate-risk patients.