Table 5.
Comparison of Patient Characteristics Based on Ve/VCO2 Slope Category
| Characteristic | Ve/VCO2 Slope ≤34 (n=26) | Ve/VCO2 Slope >34 (n=9) | P Valuea |
|---|---|---|---|
| Men | 13 (50) | 6 (67) | 0.460 |
| White | 25 (96) | 9 (100) | 0.740 |
| Age at CPET, y | 38.8 (24.3) | 42.9 (14.0) | 0.706 |
| Proband | 23 (88) | 8 (89) | 1.000 |
| Pathogenic mutation, any | 19 (73) | 6 (67) | 0.694 |
| Age at presentation, y | 26.1 (21.1) | 26.2 (18.8) | 0.678 |
| Age at meeting task force criteria, y | 33.3 (23.4) | 26.2 (20.4) | 0.850 |
| No. of major criteria met | 3.0 (2.0) | 3.0 (1.0) | 0.110 |
| No. of minor criteria met | 3.0 (3.0) | 3.0 (1.0) | 0.427 |
| Total No. of criteria met | 6.0 (3.0) | 6.0 (4.0) | 0.717 |
| Type of presentation | 0.410 | ||
| Sudden cardiac arrest | 2 (8) | 1 (11) | |
| Symptomatic | 18 (69) | 8 (89) | |
| Asymptomatic | 6 (23) | 0 (0) | |
| β Blocker | 23 (88) | 7 (78) | 0.586 |
| ACEi/ARB | 16 (62) | 4 (44) | 0.451 |
| Aldosterone receptor blocker | 6 (23) | 2 922) | 1.000 |
| Antiarrhythmic | 12 (46) | 6 (67) | 0.443 |
| ICD | 22 (85) | 9 (100) | 0.553 |
| Clinical heart failure | 13 (50) | 8 (89) | 0.056 |
| LVEF, % | 55 (15) | 55 (10) | 0.847 |
| LVEF <45% | 6 (23) | 2 (22) | 1.000 |
| Left ventricle end diastolic diameter, cm | 5.1 (0.8) | 4.8 (0.6) | 0.059 |
| Moderate/severe RV dysfunction | 13 (50) | 4 (44) | 1.000 |
| Moderate/severe RV dilation | 10 (38) | 7 (78) | 0.060 |
| Absolute pVO2, mL/min | 1743 (740) | 1255 (344) | 0.006 |
| Normalized pVO2, mL/kg per min | 21.8 (12.0) | 15.9 (10.6) | 0.025 |
| Predicted peak VO2, % | 73 (35) | 60 (36) | 0.071 |
| VO2 at AT (n=32), mL/kg per min | 13.5 (5.4) | 10.2 (6.1) | 0.041 |
| Respiratory exchange ratio | 1.10 (0.16) | 1.11 (0.11) | 0.692 |
| Peak heart rate, beats per min | 152 (52) | 121 (20) | 0.395 |
| Predicted heart rate, % | 82 (25) | 68 (17) | 0.282 |
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.