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. 2021 Aug 7;10(16):e019950. doi: 10.1161/JAHA.120.019950

Table 2.

Pulmonary Gas Exchange, Hemodynamics, Lung Diffusing Capacity, and Blood Gas Metrics at Rest, 20‐W, and Symptom‐Limited Maximal Exercise

Rest 20 W Symptom‐Limited Maximal Exercise ANOVA Results, P Value
Control HFpEF Control HFpEF Control HFpEF HF Stage HF*Stage
Pulmonary gas exchange
VO2, mL/min 304±26 316±21 786±42 640±43* 1264±121 877±60* 0.008 <0.001 0.005
VO2, mL/min per kg 3.5±0.2 3.2±0.2 9.1±0.5 6.5±0.4* 14.5±1.1 9.0±0.7* <0.001 <0.001 0.001
VCO2, mL/min 240±17 260±±19 649±51 525±38 1299±141 809±60* 0.002 <0.001 <0.001
RER 0.80±0.02 0.82±0.03 0.82±0.04 0.82±0.01 1.02±0.03 0.92±0.02* 0.161 <0.001 0.035
RPE 7.3±0.7 6.0±0.5 10.8±0.8 11.7±0.9 17.1±0.9 14.6±0.8 0.255 <0.001 0.060
Dyspnea 1.1±0.5 1.1±0.5 2.9±0.8 4.4±0.6 7.6±1.0 7.0±0.5 0.940 <0.001 0.195
VE, L/min 9.4±0.8 9.4±0.7 23.5±3.7 18.5±1.3 45.2±5.8 28.2±2.4* 0.007 <0.001 0.012
fb, breaths per min 15.7±1.5 18.8±1.2 27.9±4.5 26.7±1.4 35.7±4.9 34.1±2.2 0.979 <0.001 0.378
VT, mL 657±77 529±36 892±59 716±48* 1360±170 844±54* 0.003 <0.001 0.009
PETCO2, mm Hg 33.1±1.7 37.4±1.1* 35.2±1.6 35.8±1.3 33.7±1.9 34.9±1.3 0.298 0.061 0.066
PECO2/PETCO2 0.69±0.02 0.66±0.01 0.75±0.01 0.73±0.01 0.79±0.01 0.76±0.01* 0.105 <0.001 0.960
VE/VCO2 39.7±2.3 36.8±1.4 34.9±2.3 36.0±1.6 34.7±2.4 35.3±1.6 0.863 0.073 0.290
VD/VT 0.35±0.03 0.40±0.02 0.28±0.02 0.35±0.02* 0.24±0.02 0.30±0.02 0.025 <0.001 0.889
AaDO2, mm Hg 18.4±3.4 22.1±1.8 19.0±3.3 28.7±4.1 22.2±1.6 28.8±2.3 0.187 0.321 0.633
Hemodynamics
Cardiac output, L/min 6.5±0.6 7.4±0.6 9.3±0.4 7.5±0.6* 11.8±0.8 9.1±0.7* 0.154 <0.001 0.004
Cardiac index, L/min per m2 3.2±0.2 3.4±0.2 4.6±0.2 3.5±0.3* 5.8±0.2 4.2±0.3* 0.026 <0.001 0.001
HR, beats per min 70±5 72±3 91±7 89±4 121±11 98±5* 0.307 <0.001 0.010
% predicted maximal HR 42±8 47±9 55±12 58±12 73±20 63±13 0.847 <0.001 0.003
SV, mL 97±11 103±8 108±10 85±6* 106±12 96±8 0.449 0.586 0.021
MAP, mm Hg 97±5 99±3 113±5 115±5 122±5 116±5 0.958 <0.001 0.166
RAPm, mm Hg 7±1 12±1* 10±1 21±2* 11±1 21±1* <0.001 <0.001 0.003
PAPm, mm Hg 18±1 29±2* 26±1 43±3* 29±1 43±3* <0.001 <0.001 0.007
PCWPm, mm Hg 10±1 18±1* 16±1 30±2* 18±2 30±2* <0.001 <0.001 0.014
TPG, mm Hg 9.1±1.6 11.0±1.6 10.1±1.3 12.9±2.4 10.7±1.8 12.4±2.2 0.474 0.296 0.809
PVR, mm Hg/L per min 1.5±0.3 1.9±0.4 1.1±0.2 2.4±0.9 1.0±0.2 1.6±0.4 0.269 0.200 0.308
PA compliance, mL/mm Hg 7.7±1.3 5.2±0.7 5.7±0.6 2.8±0.3* 5.2±0.8 3.3±0.4* 0.002 0.002 0.243
Lung diffusing capacity
DLCO, mL/min per mm Hg 16.4±2.3 10.4±0.7* 20.3±2.8 13.0±0.9* 23.8±3.6 14.6±1.1* 0.003 <0.001 0.113
DLNO, mL/min per mm Hg 48.0±6.5 29.3±2.4* 62.1±8.5 37.4±2.2* 73.4±10.9 42.8±2.7* 0.001 <0.001 0.081
Dm, mL/min per mm Hg 28.4±3.9 16.8±1.6* 37.9±5.4 21.7±1.2* 45.5±7.4 25.0±1.5* <0.001 <0.001 0.073
Vc, mL 84.9±11.2 69.5±6.0 85.3±9.2 75.6±7.2 100.9±12.6 83.0±8.8 0.263 0.129 0.918
Blood gases
SaO2 97±0.81 95±0.50 96±0.88 94±0.61 98±0.56 95±1.02 0.027 0.196 0.572
PaCO2 36±2.14 42±1.13* 37±2.26 41±1.33 35±2.28 39±1.74 0.471 <0.001 0.003
PaO2 84±4.61 72±3.04* 85±5.50 72±2.81* 90±3.61 75±3.67* 0.011 0.116 0.897

ANOVA results include the P value of between‐patient effect (heart failure [HF]), within‐patient effect (stage), and the interaction between the 2 effects (HF*stage). Data are presented as mean±SEM. AaDO2 indicates alveolar to arterial O2 difference; DLCO, lung diffusing capacity for carbon monoxide; DLNO, lung diffusing capacity for nitric oxide; Dm, alveolar‐capillary membrane conductance; fb, breathing frequency; HFpEF, heart failure with preserved ejection fraction; HR, heart rate; MAP, mean arterial pressure; PA, pulmonary artery, PAPm, mean pulmonary artery pressure; PCWPm, mean pulmonary capillary wedge pressure; PECO2, expired partial pressure of carbon dioxide; PETCO2, end‐tidal partial pressure of carbon dioxide; PVR, pulmonary vascular resistance; RAPm, mean right atrial pressure; RER, respiratory exchange ratio; RPE, rate of perceived exertion; SaO2, arterial O2 saturation; SV, stroke volume; TPG, transpulmonary gradient; Vc, pulmonary capillary blood volume; VCO2, carbon dioxide production; VD/VT, ratio of dead space to tidal volume; VE, minute ventilation; VO2, O2 consumption; and VT, tidal volume.

*

Indicates post hoc difference between groups.