Prophylactic Oral Amiodarone for the Prevention of Arrhythmias That Begin Early After Revascularization, Valve Replacement, or Repair
Bibliographic record
Abstract
CONTEXT: Atrial tachyarrhythmias after cardiac surgery are associated with adverse outcomes and increased costs. Previous trials of amiodarone prophylaxis, while promising, were relatively small and yielded conflicting results. OBJECTIVE: To determine whether a brief perioperative course of oral amiodarone is an effective and safe prophylaxis for atrial tachyarrhythmias after cardiac surgery overall and in important subgroups. DESIGN, SETTING, AND PATIENTS: Double-blind randomized controlled trial of 601 patients listed for nonemergent coronary artery bypass graft (CABG) surgery and/or valve replacement/repair surgery between February 1, 1999, and September 26, 2003, at a tertiary care hospital. The patients were followed up for 1 year. INTERVENTION: Oral amiodarone (10 mg/kg daily) or placebo administered 6 days prior to surgery through 6 days after surgery (13 days). Randomization was stratified for subgroups defined by age, type of surgery, and use of preoperative beta-blockers. MAIN OUTCOME MEASURE: Incidence of atrial tachyarrhythmias lasting 5 minutes or longer that prompted therapy by the sixth postoperative day. RESULTS: Atrial tachyarrhythmias occurred in fewer amiodarone patients (48/299; 16.1%) than in placebo patients (89/302; 29.5%) overall (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.34-0.69; P<.001); in patients younger than 65 years (19 [11.2%] vs 36 [21.1%]; HR, 0.51 [95% CI, 0.28-0.94]; P = .02); in patients aged 65 years or older (28 [21.7%] vs 54 [41.2%]; HR, 0.45 [95% CI, 0.27-0.75]; P<.001); in patients who had CABG surgery only (22 [11.3%] vs 46 [23.6%]; HR, 0.45 [95% CI, 0.26-0.79]; P = .002); in patients who had valve replacement/repair surgery with or without CABG surgery (25 [23.8%] vs 44 [44.1%]; HR, 0.51 [95% CI, 0.31-0.84; P = .008); in patients who received preoperative beta-blocker therapy (27 [15.3%] vs 42 [25.0%]; HR, 0.58 [95% CI, 0.34-0.99]; P = .03); and in patients who did not receive preoperative beta-blocker therapy (20 [16.3%] vs 48 [35.8%]; HR, 0.40 [95% CI, 0.22-0.71]; P<.001), respectively. Postoperative sustained ventricular tachyarrhythmias occurred less frequently in amiodarone patients (1/299; 0.3%) than in placebo patients (8/302; 2.6%) (P = .04). Dosage reductions of blinded therapy were more common in amiodarone patients (34/299; 11.4%) than in placebo patients (16/302; 5.3%) (P = .008). There were no differences in serious postoperative complications, in-hospital mortality, or readmission to the hospital within 6 months of discharge or in 1-year mortality. CONCLUSION: Oral amiodarone prophylaxis of atrial tachyarrhythmias after cardiac surgery is effective and may be safe overall and in important patient subgroups. Clinical Trials Registration ClinicalTrials.gov Identifier: NCT00251706.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".