Atrial fibrillation: calcium-channel blocker, beta-blockers and digoxin can control the ventricular rate

Clinical bottom line (level 1a)

  1. Calcium-channel blockers and beta-blockers can control ventricular rate better than placebo at rest and during exercise in patients with atrial fibrillation. Beta-blockers however can reduce exercise tolerance.
  2. Digoxin can control ventricular rate at rest, but not during exercise.
  3. Adding a calcium-channel blocker or beta-blocker to digoxin is more effective than using digoxin alone.
Segal et al: Journal of Family Practice 2000; 49 : 47-59
McNamara et al: AHRQ Evidence Report 2001; 12 : -
Expires November 2003

The study

Systematic review of all randomised controlled trials of
  • Patients: previous episodes of paroxsymal or persistent (lasting > 48 hours and not terminating spontaneously) atrial fibrillation
  • Intervention: rate-control drugs: diltiazem, verapamil, atenolol, xamoterol, timolol, nadolol, celiprolol, pindolol, propranolol, labetolol, clonidine, propafenone, sotaolol, digoxin, betaxolol, magnesium sulfate, metoprolol, disopyramide, flecainide, quinidine, amiodarone compared with another anti-arrhythmic agent
  • Outcome: ventricular rate control

    Articles found in all languages - though only English ones were included using CENTRAL (consisting of Medline, Embase and hand-searching of 100 journals), 1948 to May 1998 (search terms: detailed in text ) and searching Pubmed for related articles, Cardiovascular Randomized Controlled Trial Registery. Reference lists of relevant meta-analyses, recent review articles and major clinical trials were searched. Investigators in the field and search co-ordinators of relevant Cochrane Review groups were contacted to identify unpublished studies. Abstracts of major cardiology conference meetings for 1997-1998 were also checked and recent contents of journals frequently cited in the search results database.

    Selection criteria: selected by 3 clinicians
    Appraisal criteria: detailed in text - included study population, bias, confounding, outcomes, follow-up, statistical quality: by 2 independent reviewers
    Articles excluded if:
    • article did not address management of AF or atrial flutter
    • no human data
    • included post-operative AF data that could not be separated out
    • adults not part of study population
    • no original data in study
    • no randomisation
    • unable to separate out AF or flutter from other arrhythmias


    45 studies found on 17 different drugs and drug combinations: 10 comparing calcium-channel blockers and placebo; 12 comparing beta-blockers and placebo; 7 comparing digoxin and placebo; 6 comparing calcium-channel blockers and digoxin; 4 comparing beta-blockers and digoxin; 9 comparing other drugs
    Results were too heterogeneous for formal meta-analysis.

    The evidence

    • Calcium channel blockers reduce heart rate both at rest and during exercise compared with placebo.
    • Beta-blockers reduce heart rate at rest and during exercise compared with placebo, but may reduce exercise tolerance. Atenolol and nadolol appeared most effective.
    • Digoxin reduces heart rate at rest compared with placebo, but is not clearly effective at control heart rate during exercise.
    • Neither calcium-channel blockers nor beta-blockers were clearly better than digoxin at controlling heart rate at rest, though beta-blockers were more effective during exercise.
    • Adding a calcium-channel blocker or a beta-blocker to digoxin was more effective than using digoxin alone.
    • Other drug comparisons had too few patients to draw reliable conclusions.

    Comments

    1. 8 non-English language articles were found, but full articles were not retrieved or combined in the meta-analysis.
    2. Most studies were small (< 50 patients), and study populations, drug administration, and length of follow-up varied greatly.
    3. Few studies reported improvement in symptoms or quality-of-life measures.

    Citation

    1. Segal JB, McNamara RL, Miller MR, et al: the evidence regarding the drugs used for ventricular rate control. Journal of Family Practice 2000; 49 : 47-59
    2. McNamara RL, Bass EB, Miller MR, et al: Management of New Onset Atrial Fibrillation. Evidence Report/Technology Assessment No. 12 (prepared by the Johns Hopkins University Evidence-based Practice Center in Baltimore, MD, under Contract No. 290-97-0006). AHRQ Publication Number 01-E026. Rockville, MD: Agency for Healthcare Research and Quality.. AHRQ Evidence Report 2001; 12 : -
    Search Terms: from AHRQ website
    Contributor: Chris Ball, November 2001
    Reviewer:

    Clinical Question.
    Patient atrial fibrillation
    Intervention or Exposure rate-control drug
    Comparison placebo or another rate-control drug
    Outcome control of heart rate
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