Summary of findings for the main comparison. Carvedilol compared with placebo for heart failure in patients with Chagas cardiomyopathy.
| Carvedilol compared with placebo for heart failure in patients with Chagas cardiomyopathy | ||||||
| Patient or population: heart failure in patients with Chagas cardiomyopathy Settings: outpatients Intervention: carvedilol Comparison: placebo | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Placebo | Carvedilol | |||||
| All‐cause mortality Follow‐up: 4 to 6 months | 86 per 1000 | 59 per 1000 (10 to 333) | RR 0.69 (0.12 to 3.88) | 69 (2 studies) | ⊕⊝⊝⊝ very low1,2 | |
| Cardiac mortality at 30 days | See comment | See comment | Not estimable | 69 (2 studies) | See comment | No trials reported this outcome |
| Time‐to‐heart decompensation | See comment | See comment | Not estimable | 69 (2 studies) | See comment | No trials reported this outcome |
| Disease‐free period (at 30, 60, and 90 days) | See comment | See comment | Not estimable | 69 (2 studies) | See comment | No trials reported this outcome. |
| Overall survival | See comment | See comment | Not estimable | 39 (1 study) | ⊕⊝⊝⊝ very low1,3 | Diniz 2004 only reported P = 0.525 |
| Quality of life assessed with the Minnesota Living With Heart Failure Questionnaire (MLHFQ). The total score for the 21 items ranges between 0 and 105. A lower MLHFQ score indicates less effect of heart failure on a patient’s quality of life. Follow‐up: 6 months | The mean quality of life in the intervention group was 14.74 lower (24.75 to 4.73 lower) | 30 (1 study) | ⊕⊝⊝⊝ very low1,3 | |||
| Adverse events Follow‐up: 6 months | 867 per 1000 | 797 per 1000 (581 to 1000) | RR 0.92 (0.67 to 1.27) | 30 (1 study) | ⊕⊝⊝⊝ very low1,4 | |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio; | ||||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
1 Downgraded one level due to limitations in design and execution: random sequence generation, allocation concealment and blinding at any level: unclear risk of bias. 2 Downgraded two levels due to imprecision. The sample size was very small (N = 69) and the number of events was very low (N = 5).
3 Downgraded two levels due to imprecision. The sample size was very small (N = 30) with wide confidence interval for the QoL outcome.
4 Downgraded two levels due to imprecision. The sample size was very small (N = 30) and the number of events was very low (N = 25).