TY - JOUR
T1 - Validation of a cardiopulmonary exercise test score in heart failure
AU - Myers, Jonathan
AU - Oliveira, Ricardo
AU - Dewey, Frederick
AU - Arena, Ross
AU - Guazzi, Marco
AU - Chase, Paul
AU - Bensimhon, Daniel
AU - Peberdy, Mary Ann
AU - Ashley, Euan
AU - West, Erin
AU - Cahalin, Lawrence P.
AU - Forman, Daniel E.
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/3
Y1 - 2013/3
N2 - Background-Cardiopulmonary exercise test (CPX) responses are strong predictors of outcomes in patients with heart failure. We recently developed a CPX score that integrated the additive prognostic information from CPX. The purpose of this study was to validate the score in a larger, independent sample of patients. Methods and Results-A total of 2625 patients with heart failure underwent CPX and were followed for cardiovascular (CV) mortality and major CV events (death, transplantation, left ventricular assist device implantation). Net reclassification improvement (NRI) for the score and each of its components were determined at 3 years. The VE/VCO2 slope was the strongest predictor of risk and was attributed a relative weight of 7, with weighted scores for abnormal heart rate recovery, oxygen uptake efficiency slope, end-tidal CO2 pressure, and peak VO2 having scores of 5, 3, 3, and 2, respectively. A summed score of >15 was associated with an annual mortality rate of 12.2% and a relative risk >9 for total events, whereas a score of <5 was associated with an annual mortality rate of 1.2%. The composite score was the most accurate predictor of CV events among all CPX responses considered (C indexes, 0.70 for CV mortality and 0.72 for the composite outcome). Each component of the score provided significant NRI compared with peak VO2 (category-free NRI, 0.61- 0.77), and the score provided significant NRI above clinical risk factors for both CV events and mortality (NRI, 0.63 and 0.65 for CPX score compared with clinical variables alone). Conclusions-These results validate the application of a simple, integrated multivariable score based on readily available CPX responses.
AB - Background-Cardiopulmonary exercise test (CPX) responses are strong predictors of outcomes in patients with heart failure. We recently developed a CPX score that integrated the additive prognostic information from CPX. The purpose of this study was to validate the score in a larger, independent sample of patients. Methods and Results-A total of 2625 patients with heart failure underwent CPX and were followed for cardiovascular (CV) mortality and major CV events (death, transplantation, left ventricular assist device implantation). Net reclassification improvement (NRI) for the score and each of its components were determined at 3 years. The VE/VCO2 slope was the strongest predictor of risk and was attributed a relative weight of 7, with weighted scores for abnormal heart rate recovery, oxygen uptake efficiency slope, end-tidal CO2 pressure, and peak VO2 having scores of 5, 3, 3, and 2, respectively. A summed score of >15 was associated with an annual mortality rate of 12.2% and a relative risk >9 for total events, whereas a score of <5 was associated with an annual mortality rate of 1.2%. The composite score was the most accurate predictor of CV events among all CPX responses considered (C indexes, 0.70 for CV mortality and 0.72 for the composite outcome). Each component of the score provided significant NRI compared with peak VO2 (category-free NRI, 0.61- 0.77), and the score provided significant NRI above clinical risk factors for both CV events and mortality (NRI, 0.63 and 0.65 for CPX score compared with clinical variables alone). Conclusions-These results validate the application of a simple, integrated multivariable score based on readily available CPX responses.
KW - Epidemiology
KW - Exercise physiology
KW - Exercise testing
KW - Heart failure
KW - Oxygen consumption
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U2 - 10.1161/CIRCHEARTFAILURE.112.000073
DO - 10.1161/CIRCHEARTFAILURE.112.000073
M3 - Article
C2 - 23392791
AN - SCOPUS:84877245905
VL - 6
SP - 211
EP - 218
JO - Circulation. Heart failure
JF - Circulation. Heart failure
SN - 1941-3297
IS - 2
ER -