Question of the Week #483

BACKGROUND:

Beta-blockers reduce mortality in patients who have chronic heart failure, systolic dysfunction, and are on background treatment with diuretics and angiotensin-converting enzyme inhibitors. We aimed to compare the effects of carvedilol and metoprolol on clinical outcome.

METHODS:

In a multicenter, double blind, and randomized parallel group trial, we assigned 1511 patients with chronic heart failure to treatment with carvedilol (target dose 25 mg twice daily) and 1518 to metoprolol (metoprolol tartrate, target dose 50 mg twice daily). Patients were required to have chronic heart failure (NYHA II-IV), previous admission for a cardiovascular reason, an ejection fraction of less than 0.35, and to have been treated optimally with diuretics and angiotensin-converting enzyme inhibitors unless not tolerated. The primary endpoints were all-cause mortality and the composite endpoint of all-cause mortality or all-cause admission. Analysis was done by intention to treat.

FINDINGS:

The mean study duration was 58 months (SD 6). The mean ejection fraction was 0.26 (0.07) and the mean age 62 years (11). The all-cause mortality was 34% (512 of 1511) for carvedilol and 40% (600 of 1518) for metoprolol (hazard ratio 0.83 [95% CI 0.74-0.93], p=0.0017). The reduction of all-cause mortality was consistent across predefined subgroups. Incidence of side effects and drug withdrawals did not differ by much between the two study groups.

 

  1. To which of the following patients are the results of this clinical trial applicable?
    1. A 62-year-old male with primarily diastolic congestive heart failure.
    2. A 75-year-old female with systolic dysfunction and an EF of 45%.
    3. A 56-year-old male with NYHA class I systolic heart failure.
    4. A newly diagnosed 66-year-old male who has yet to begin treatment for his NYHA class II systolic heart failure.
    5. A 68-year-old male with NYHA class II systolic heart failure and EF 30%.

 

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