Table 1. Baseline characteristics stratified by study of origin.
Bloomfield et al. 21 n=472 | Klingenheben et al. 26 n=107 | ALPHA 25 n=415 | Ikeda et al. 23 n=834 | Ikeda et al. 24 n=1041 | Chan et al. 22 n=486 | |
---|---|---|---|---|---|---|
Age (years) | 55.3 ± 12.9 | 54.2 ± 10.1 | 58.6 ± 12.6 | 62.8 ± 10.8 | 63.9 ± 9.0 | 65.9 ± 12.5 |
Male gender (n) | 328 (70%) | 86 (80%) | 349 (78%) | 696 (83%) | 824 (79%) | 366 (75%) |
Ischemic cardiomyopathy (n) | 215 (46%) | 67 (63%) | 0 | 834 (100%) | 1041 (100%) | 375 (77%) |
LV ejection fraction (%) | 25.2 ± 8.5 | 28.2 ± 7.5 | 29.5 ± 7.1 | 50.3 ± 13.4 | 54.6 ± 10.4 | 27.8 ± 6.4 |
Beta blocker therapy at enrollment (n) | 367 (78%) | 45 (42%) | 357 (80%) | 232 (28%) | 216 (21%) | 399 (82%) |
MTWA results (n) | ||||||
positive | 140 | 52 | 175 | 302 | 176 | 151 |
negative | 163 | 33 | 151 | 4343 | 773 | 236 |
indeterminate | 169 | 22 | 89 | 98 | 92 | 99 |
Duration of follow-up (months) | 20.3 ± 5.9 | 14.6 ± 9.6 | 31.2 ± 16.2 | 24.7 ± 13.3 | 31.8 ± 14.0 | 36.9 ± 18.5 |
Definition of SCD endpoint | Unwitnessed deaths, witnessed instantaneous deaths nonsudden deaths due to incessant tachycardia, deaths considered to be sequelae of cardiac arrest | Sudden death, resuscitated VF or sustained VT | Unwitnessed deaths, witnessed instantaneous deaths nonsudden deaths due to incessant tachycardia, deaths considered to be sequelae of cardiac arrest | Instantaneous, unexpected death or death within one hour of symptom on-set not related to circulatory failure or resuscitated VF | Instantaneous, unexpected death or death within one hour of symptom on-set not related to circulatory failure or resuscitated VF | Unwitnessed death (if observed to be stable within 24 hrs before death), witnessed instantaneous death or sequelae of cardiac arrest |
HR for SCD endpoint | Not reported | ∞** | 4.01* | 11.4** | 23.5** | Not reported |
Data are presented as mean ± standard deviation or n (%).
LV=left ventricle; MTWA=microvolt T-wave alternans; MI=myocardial infarction; SCD=sudden cardiac death; VF=ventricular fibrillation; VT=ventricular tachycardia; HR=hazard ratio.
for non-negative MTWA (positive and indeterminate) vs. negative MTWA
for positive MTWA vs. negative MTWA