Study designs of evaluations included in the review
Prospective studies were eligible for inclusion. Case reports were excluded. The designs of the included studies were not reported.
Specific interventions included in the review
Studies of MTWA, performed according to stress protocol with a commercially available device, were eligible for inclusion. No further details were provided.
Reference standard test against which the new test was compared
There were no inclusion criteria relating to the reference standards. The authors discussed the reference standards available; these included invasive electrophysiology, signal averaged electrocardiogram, heart rate variability, baroreflex sensitivity and Holter monitoring. However, the reference standards used in the individual included studies were not reported.
Participants included in the review
Studies of patients who might be considered for ICD therapy were eligible for inclusion. The populations recruited into the included studies comprised patients with coronary artery disease, idiopathic dilated cardiomyopathy, acute myocardial infarction, electrophysiology, congested cardiac failure and Brugada syndrome, and Multicenter Automatic Defibrillator Implantation Trial II-like patients.
Outcomes assessed in the review
The studies had to report event rates stratified by MTWA results, the sensitivity and/or specificity of MTWA, or a Kaplan-Meier analysis. The main outcomes of interest were morbidity, mortality and quality of life. The outcomes reported in the included studies were ventricular tachycardiac events (VTE), death (cardiac, sudden cardiac, non-sudden cardiac, all-cause) and cardiac arrest.
How were decisions on the relevance of primary studies made?
The authors did not state how the studies were selected for the review, or how many reviewers performed the selection.