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.