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A flattening oxygen consumption trajectory phenotypes disease severity and poor prognosis in patients with heart failure with reduced, mid‐range, and preserved ejection fraction
Author(s) -
Popovic Dejana,
Arena Ross,
Guazzi Marco
Publication year - 2018
Publication title -
european journal of heart failure
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.149
H-Index - 133
eISSN - 1879-0844
pISSN - 1388-9842
DOI - 10.1002/ejhf.1140
Subject(s) - medicine , cardiology , ejection fraction , heart failure , cardiac output , flattening , respiratory minute volume , hemodynamics , respiratory system , materials science , composite material
Background In heart failure (HF), a flattening oxygen consumption (VO 2 ) trajectory during cardiopulmonary exercise test (CPET) reflects an acutely compromised cardiac output. We hypothesized that a flattening VO 2 trajectory is helpful in phenotyping disease severity and prognosis in HF with either reduced (HFrEF), mid‐range (HFmrEF), or preserved (HFpEF) ejection fraction. Methods and results Overall, 319 HF patients (198 HFrEF, 80 HFmrEF, and 41 HFpEF) underwent CPET. A flattening VO 2 trajectory was tracked and defined as an inflection of VO 2 linearity as a function of work rate with a second slope downward inflection >35% extent of the first one. Peak VO 2 , the minute ventilation/carbon dioxide production (VE/VCO 2 ) slope, and the presence of exercise oscillatory ventilation (EOV) were also determined. Pulmonary artery systolic pressure (PASP) and tricuspid annular plane systolic excursion (TAPSE) were measured by echocardiography. A flattening VO 2 occurred in 92 patients (28.8%). PASP and TAPSE at rest were significantly higher and lower ( P < 0.001), respectively. The primary outcome was the combination of all‐cause death, heart transplantation and left ventricular assist device implantation. The secondary outcome was the primary outcome plus hospitalization for cardiac reasons. In the multivariate model including peak VO 2 , VE/VCO 2 slope, EOV and VO 2 trajectory, a flattening VO 2 trajectory and EOV were retained in the regression for primary (X 2 = 35.78, and 36.36, respectively; P < 0.001) and secondary (X 2 = 12.45 and 47.91, respectively; P < 0.001) outcomes. Conclusions Results point to a flattening VO 2 trajectory as a likely new and strong predictor of events in HF with any ejection fraction. Given the relation of right‐sided cardiac dysfunction to pulmonary hypertension, this oxygen pattern might suggest a real‐time decrease in pulmonary blood flow to the left heart.