Table 2.
Baseline characteristics of the intention-to-treat population
| All patients (n = 433) | Study group | ||
|---|---|---|---|
| Active (n = 221) | Control (n = 212) | ||
| Age, years | 61.6 ± 12.5 | 62.0 ± 13.0 | 61.2 ± 12.0 |
| Men/women | 382 (88.2)/51 (11.8) | 193 (87.3)/28 (12.7) | 189 (89.2)/23 (10.8) |
| Left-ventricular ejection fraction, % | 34.9 ± 13.3 | 34.7 ± 13.0 | 35.1 ± 13.6 |
| Indication for implantable cardioverter defibrillator | |||
| Primary prevention | 232 (53.6) | 119 (53.8) | 113 (53.3) |
| Secondary prevention | 201 (46.4) | 102 (46.2) | 99 (46.7) |
| Implanted device | |||
| Single chamber | 302 (69.7) | 161 (72.9) | 141 (66.5) |
| Dual chamber | 131 (30.3) | 60 (27.1) | 71 (33.5) |
| Device implant | |||
| First implantation | 369 (85.2) | 186 (84.2) | 183 (86.3) |
| Replacement | 64 (14.8) | 35 (15.8) | 29 (13.7) |
| New York Heart Association functional class | |||
| I | 113 (26.1) | 60 (27.1) | 53 (25.0) |
| II | 268 (61.9) | 139 (62.9) | 129 (60.8) |
| III | 38 (8.8) | 15 (6.4) | 25 (11.8) |
| Underlying heart disease | |||
| Coronary heart disease | 283 (65.4) | 143 (64.7) | 140 (66.5) |
| Non-ischaemic dilated cardiomyopathy | 76 (17.6) | 39 (17.6) | 37 (17.5) |
| Primary electric diseasea | 21 (4.8) | 11 (4.7) | 10 (4.7) |
| Hypertrophic cardiomyopathy | 15 (3.5) | 5 (2.3) | 10 (4.7) |
| Valvular heart disease | 12 (2.8) | 3 (1.4) | 9 (4.2) |
| Hypertension | 6 (1.4) | 3 (1.4) | 3 (1.4) |
| Other cardiomyopathy | 11 (2.5) | 8 (3.6) | 3 (1.4) |
| Undetermined | 8 (1.8) | 4 (1.8) | 4 (1.9) |
| None | 16 (3.7) | 11 (5.0) | 5 (2.6) |
| History of | |||
| Sustained ventricular tachycardia | 109 (25.2) | 54 (24.4) | 55 (25.9) |
| Ventricular fibrillation | 57 (13.2) | 30 (13.6) | 27 (12.7) |
| Torsade de pointes | 4 (0.9) | 2 (0.9) | 2 (0.9) |
| Atrial arrhythmia | 68 (15.7) | 38 (17.2) | 30 (14.2) |
Values are means ± SD, or numbers (%) of observations. Between-groups differences are all statistically non-significant.
aBrugada syndrome, long-QT syndrome.