Table 3.
Baseline Characteristics and Exercise Measurements when Heart Failure Patients are Stratified by the Median VO2 Recovery Delay
| Characteristic | HF | HFpEF | HFrEF | |||
|---|---|---|---|---|---|---|
| VO2RD < 25s | VO2RD ≥ 25s | VO2RD < 25s | VO2RD ≥ 25s | VO2RD < 25s | VO2RD ≥ 25s | |
| Baseline | ||||||
| n | 25 | 25 | 15 | 15 | 10 | 10 |
| Age, years | 62±9 | 65±11 | 62±9 | 66±11 | 62±10 | 63±12 |
| Male sex, % | 68 | 64 | 53 | 47 | 90 | 90 |
| Body mass index, kg/m2 | 31.9±6.8 | 28.5±6.2 | 33.9±7.5 | 29.1±4.5† | 28.8±4.3 | 27.7±8.4 |
| Hemoglobin, g/dl | 12.9±1.7 | 13.1±1.8 | 12.9±1.6 | 13.5±2.1 | 12.8±1.9 | 12.6±1.2 |
| HFpEF, % | 60 | 60 | NA | NA | NA | NA |
| Comorbidities, % | ||||||
| Hypertension | 56 | 76 | 60 | 87 | 50 | 60 |
| Diabetes mellitus | 24 | 36 | 27 | 40 | 20 | 30 |
| Hyperlipidemia | 52 | 84* | 60 | 87 | 40 | 80 |
| Pharmacotherapies, % | ||||||
| Diuretics | 68 | 60 | 67 | 60 | 70 | 60 |
| ACE inhibitor or ARB | 48 | 48 | 20 | 33 | 90 | 70 |
| β-adrenergic blocker | 68 | 76 | 60 | 73 | 80 | 80 |
| Aldosterone blockade | 24 | 28 | 13 | 13 | 40 | 50 |
| Rest Hemodynamics | ||||||
| Supine PAWP, mmHg | 21±6 | 19±4 | 21±5 | 18±3 | 20±8 | 20±6 |
| Supine mPAP, mmHg | 27±7 | 25±6 | 28±7 | 25±5 | 26±8 | 26±6 |
| Cardiac index, l/min/m2 | 2.3±0.6 | 2.3±0.5 | 2.6±0.6 | 2.2±0.5 | 2.0±0.3 | 2.3±0.7 |
| Peak Exercise | ||||||
| Respiratory exchange ratio | 1.15±0.13 | 1.17±0.08 | 1.11±0.09 | 1.17±0.10 | 1.22±0.16 | 1.18±0.06 |
| Maximum workload, watts | 101±34 | 78±16* | 99±34 | 77±19† | 105±35 | 78±9‡ |
| VO2, % predicted | 72±21* | 57±15* | 81±23 | 62±12† | 60±5 | 49±17 |
| VO2, ml/kg/min | 14.5±2.7 | 12.0±2.2* | 14.5±2.7 | 12.2±2.5† | 14.5±3.0 | 11.9±1.8‡ |
| C(a−v)O2, ml/dl | 12.2±1.9 | 13.2±2.3 | 11.8±2.2 | 12.6±2.4 | 12.8±1.3 | 14.2±1.9 |
| Cardiac output, L/min | 11.4(9.2,14.0) | 7.1(5.9,8.7)* | 12.6(9.4,14.2) | 7.3(6.8,9.1)† | 10.7(8.1,12.9) | 6.7(5.9,7.0)‡ |
| Heart rate, BPM | 119±22 | 112±28 | 122±21 | 112±29 | 114±24 | 112±26 |
| Stroke volume, ml | 98±27 | 69±17* | 103±33 | 73±18† | 90±12 | 65±16‡ |
| VO2/work slope, ml/min/watt | 9.5±1.9 | 7.4±1.5* | 9.4±2.1 | 7.3±1.3† | 9.6±1.4 | 7.7±1.9‡ |
| VE/VCO2 slope | 36.4±9.3 | 42.6±12.1* | 35.6±9.4 | 38.5±9.1 | 37.6±9.5 | 48.8±13.9 |
| O2 Saturation, % | 97(96,99) | 98(97,99) | 97(95,97) | 97(95,99) | 99(98,100) | 99(98,99) |
| PAWP, mmHg | 28±6 | 30±8 | 28±5 | 30±7 | 28±9 | 30±10 |
| mPAP, mmHg | 46±10 | 46±8 | 47±11 | 47±9 | 45±9 | 44±7 |
| VO2RD, seconds | 7 (0,17) | 43 (34,56)* | 10 (5, 19) | 37 (33,50)† | 4 (0, 7) | 49 (39,58)‡ |
| T1/2, seconds | 94±25 | 119±26 | 94±21 | 110±19† | 95±31 | 133±30‡ |
| HR recovery @ 2min, BPM | 24±15 | 22±17 | 26±16 | 21±18 | 22±15 | 26±16 |
HF indicates heart failure; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction; ACE, angiotensin-converting enzyme; ARB, angiotensin receptor blocker; PAWP, pulmonary arterial wedge pressure; mPAP, mean pulmonary arterial pressure; VO2RD, VO2 recovery delay; and HR, heart rate
*
p<0.05 for comparison of HF ≥ 25s and HF < 25s,
†
p<0.05 for comparison of HFpEF ≥ 25s and HFpEF < 25s,
‡
p<0.05 for comparison of HFrEF ≥ 25s and HFrEF < 25s