Summary of findings 5. Metoprolol compared to placebo or no treatment for maintaining sinus rhythm after cardioversion of atrial fibrillation.
| Metoprolol compared to placebo or no treatment for maintaining sinus rhythm after cardioversion of atrial fibrillation | ||||||
| Patient or population: adults in sinus rhythm after cardioversion of atrial fibrillation Setting: hospital/community Intervention: metoprolol Comparison: placebo or no treatment | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo or no treatment | Risk with Metoprolol | |||||
| All‐cause mortality follow‐up: mean 6 months | Study population | RR 2.02 (0.37 to 11.1) | 562 (2 RCTs) | ⊕⊕⊕⊝ Moderatea | — | |
| 4 per 1000 | 7 per 1000 (1 to 39) | |||||
| Withdrawals due to adverse effects follow‐up: mean 6 months | Study population | RR 3.47 (1.48 to 8.1) | 562 (2 RCTs) | ⊕⊕⊕⊕ High | — | |
| 21 per 1000 | 74 per 1000 (31 to 173) | |||||
| Proarrhythmia follow‐up: mean 6 months | Study population | RR 18.14 (2.42 to 135.6) | 562 (2 RCTs) | ⊕⊕⊕⊕ High | Anticipated absolute effects per 1000 could not be calculated because there were no events in the control group. Risks are the data from the RCTs. | |
| 0 / 282 | 17 / 280 | |||||
| Stroke | — | — | — | — | — | Not reported |
| Recurrence of atrial fibrillation follow‐up: mean 6 months | Study population | RR 0.83 (0.68 to 1.02) | 562 (2 RCTs) | ⊕⊕⊕⊝ Moderateb | — | |
| 72.0 per 100 | 59.7 per 100 (49.0 to 73.4) | |||||
| *The risk in the intervention group (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; RCT: randomised controlled trial; RR: risk ratio. | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
aDowngraded one level for imprecision. Confidence intervals included both possible harm and possible benefit. bDowngraded one level for inconsistency: high I2 statistic (59%) indicated heterogeneity and this could not be explored in subgroup analysis due to only two studies being included.