Table 3.
Comparison of Patient Characteristics Based on Normalized pVO2 Category
| Characteristic | pVO2 ≤14 mL/kg per min (n=4) | pVO2 >14 mL/kg per min (n=25) | P Valuea |
|---|---|---|---|
| Men | 4 (100) | 10 (40) | 0.042 |
| White | 4 (100) | 24 (96) | 0.862 |
| Age at CPET, y | 42.1 (14.4) | 38.2 (23.8) | 0.343 |
| Proband | 3 (75) | 23 (92) | 0.371 |
| Pathogenic mutation, any | 1 (25) | 17 (68) | 0.139 |
| Age at presentation, y | 41.0 (22.0) | 25.8 (21.2) | 0.312 |
| Age at meeting task force criteria, y | 41.0 (22.0) | 30.8 (20.1) | 0.487 |
| No. of major criteria met | 3.5 (2.0) | 3.0 (2.0) | 0.897 |
| No. of minor criteria met | 3.0 (1.5) | 3.0 (3.0) | 0.846 |
| Total No. of criteria met | 6.0 (3.5) | 6.0 (3.0) | 0.749 |
| Type of presentation | 1.000 | ||
| Sudden cardiac arrest | 0 (0) | 1 (4) | |
| Symptomatic | 4 (100) | 19 (76) | |
| Asymptomatic | 0 (0) | 5 (20) | |
| β Blocker | 2 (50) | 22 (88) | 0.127 |
| ACEi/ARB | 3 (75) | 11 (44) | 0.330 |
| Aldosterone receptor blocker | 0 (0) | 6 (24) | 0.553 |
| Antiarrhythmic | 1 (25) | 13 (52) | 0.598 |
| ICD | 3 (75) | 20 (80) | 1.000 |
| Clinical heart failure | 4 (100) | 13 (52) | 0.121 |
| LVEF, % | 47.5 (22.5) | 55.0 (5.0) | 0.255 |
| LVEF <45% | 2 (50) | 4 (16) | 0.180 |
| Left ventricular end diastolic diameter, cm | 4.9 (0.1) | 4.94 (0.7) | 0.824 |
| Moderate/severe RV dysfunction | 3 (75) | 11 (44) | 0.330 |
| Moderate/severe RV dilation | 4 (100) | 11 (44) | 0.100 |
| Absolute pVO2, mL/min | 877 (301) | 1911 (594) | |
| Normalized pVO2, mL/kg per min | 11.7 (0.7) | 22.8 (8.4) | |
| Predicted VO2 (n=27), % | 30.5 (17) | 83.2 (38) | |
| Ve/VCO2 slope (n=26) | 51.0 (26.4) | 29.6 (6.1) | 0.009 |
| VO2 at AT (n=26), mL/kg per min | 8.4 (1.6) | 15.0 (6.2) | 0.006 |
| Respiratory exchange ratio | 1.17 (0.16) | 1.16 (0.10) | 0.727 |
| Peak heart rate, beats per min | 130 (24) | 150 (37) | 0.311 |
| Predicted heart rate, % | 75.5 (18.6) | 82 (19) | 0.569 |
Categorical variables are expressed as number (percentage). Continuous variables are expressed as median (interquartile range). ACEi indicates angiotensin‐converting enzyme inhibitor; ARB, angiotensin receptor blocker; AT, anabolic threshold; CPET, cardiopulmonary exercise testing; ICD, implantable cardioverter‐defibrillator; LVEF, left ventricular ejection fraction; pVO2, peak VO2; RV, right ventricle; Ve/VCO2 slope, ventilatory efficiency; VO2, oxygen consumption.
a
Continuous variables were analyzed using Wilcoxon rank‐sum test (Mann‐Whitney U test), and categorical data were analyzed using Fisher exact test.