Table 1 Characteristics of patients and controls.
| Characteristic | Patients | Controls (n = 118) | p Value between patient groups | |
|---|---|---|---|---|
| With β blocker (n = 164) | Without β blocker (n = 73) | |||
| Age (years) | 66 (10) | 68 (11) | 65 (12) | 0.11 |
| Height (cm) | 171 (8) | 168 (11) | 169 (10) | 0.09 |
| Weight (kg) | 80.5 (15.9) | 76.0 (17.3) | 74.2 (12.9)* | <0.05 |
| Men/women | 123/41 | 55/18 | 62/56 | |
| LVEDD (cm) | 6.5 (0.9) | 6.3 (1.2) | 4.9 (0.7)† | 0.12 |
| LVEF (%) | 32.0 (7.0) | 33.3 (9.8) | 59.3 (8.0)† | 0.40 |
| Aetiology | ||||
| Dilated cardiomyopathy | 29 | 21 | ||
| Hypertensive HF | 10 | 2 | ||
| Ischaemic heart disease | 121 | 50 | ||
| IDDM | 4% | 4% | 0 | |
| NIDDM | 12% | 10% | ||
| Hypertension | 38% | 21% | 19% | |
| Drugs | ||||
| Furosemide (mg)‡ | 68 (46) | 72 (38) | 0 | 0.45 |
| ACEI/AIIA | 84% | 78% | 2% | |
| Amiodarone (currently) | 5% | 7% | 0 | |
| Amiodarone (last 6 months) | 2% | 0% | ||
| Digoxin | 7% | 14% | 0 | |
| Aspirin | 70% | 68% | 7/0 | |
| Warfarin | 29% | 33% | ||
| NYHA class | ||||
| I | 6% | 5% | ||
| II | 74% | 72% | ||
| III | 19% | 23% | ||
| RHR (beats/min) | 72 (15) | 80 (17) | 71 (11) | 0.0002 |
| PHR (beats/min) | 123 (25) | 133 (26) | 157 (21)† | 0.0045 |
| Predicted PHR (beats/min) | 154 (9.6) | 153 (10.8) | 155 (12) | 0.23 |
| %Max‐PPHR | 80 (15) | 87 (17) | 102 (11)† | 0.0005 |
| HRR | 31 (23) | 19 (25) | −3 (17)† | 0.0004 |
| %HRR | 63 (26) | 73 (32) | 104 (21)† | 0.017 |
| pVo2 (ml/kg/min) | 20.4 (5.7) | 19.5 (5.3) | 34.4 (9.4)† | 0.35 |
| Ve/Vco2 slope | 36.0 (8.2) | 36.6 (6.7) | 28.3 (3.9)† | 0.55 |
| Exercise time (s) | 498 (198) | 435 (218) | 788 (290)† | 0.02 |
| RER | 1.02 (0.1) | 1.02 (0.1) | 1.02 (0.1) | 0.31 |
| pVo2/PHR ratio | 0.13 (0.03) | 0.13 (0.03) | 0.22 (0.05)† | 0.34 |
| Follow up (days alive) | 1032 (337) | 898 (410) | 909 (326) | 0.029 |
Values are mean (SD).
*p<0.05 for the difference between all patients and controls; †p<0.0001 for the difference between all patients and controls; ‡mean daily dose of furosemide (or furosemide equivalent).
ACEI, angiotensin converting enzyme inhibitor; AIIA, angiotensin II inhibitor; HF, heart failure; HRR, heart rate reserve; HR/Vo2 slope, slope relating heart rate to oxygen consumption; IDDM, insulin dependent diabetes mellitus; LVEDD, left ventricular end diastolic dimension from M mode echocardiography; LVEF, left ventricular ejection fraction; NIDDM, non‐insulin dependent diabetes mellitus; NYHA, New York Heart Association; PHR, peak heart rate; pVo2, peak oxygen consumption; %HRR, percentage heart rate reserve; %Max‐PPHR, percentage maximum age predicted peak heart rate; RER, respiratory exchange ratio (Vco2/Vo2); RHR, resting heart rate; Ve/Vco2 slope, slope relating ventilation to carbon dioxide production.