Study designs of evaluations included in the review
1. Cohort studies of mortality after CABG, with follow-up periods ranging from 1 to 6 years, and case series studies of change in functional status after CABG.
2. Case series and case reports of outcomes and risks in angioplasty. Studies dealing with aneurysm resection, simultaneous repair of valvular congenital heart disease or mechanical assist devices were excluded, as were technical reviews of surgical techniques and articles dealing solely with determinants of operative mortality rates.
Specific interventions included in the review
1. Coronary artery bypass grafting (CABG).
2. Percutaneous coronary angioplasty.
Participants included in the review
Patients with moderate-to-severe left ventricular dysfunction (ejection fraction less than 0.04).
In the 7 included studies of survival after CABG, the proportion of male participants ranged from 87 to 93, and all the patients suffered from angina.
In the 17 studies of the impact of CABG on functional status, the proportion of male participants ranged from 81 to 100%, and the majority of participants suffered from angina.
Outcomes assessed in the review
1. Operative mortality, total mortality, change in functional status (changes in ejection fraction, change in New York Heart Association (NYHA) class, and symptom improvement) and risk of procedure-related complications.
2. Relief of angina, improvement in ventricular function and risk of procedure-related complications.
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the authors performed the selection.