Forty-one studies (1,785 patients), encompassing 29 studies that were placebo-controlled, were included. This included 2 of the authors' studies using carvedilol in patients with left ventricular dysfunction and hypertension. Four hundred and fifty-eight patients were treated with metoprolol (16 studies), 1,030 with carvedilol (13 studies), 199 with bucindolol (7 studies), 10 with atenolol (1 study), 44 with nebivolol (2 studies) and 44 with propranolol (2 studies). Eleven studies examined 361 patients with idiopathic dilated cardiomyopathy, and 11 studies looked at 269 patients with ischaemic cardiomyopathy.
For patients treated with metoprolol, there was a weighted mean follow-up of 9.5 months and a mean increase in LVEF units of 7.4% (range: 3 to 16).
For patients treated with carvedilol, there was a weighted mean follow-up of 7 months and a mean increase in LVEF units of 5.7% (range: 3 to 11).
For patients treated with bucindolol, there was a weighted mean follow-up of 4 months and a mean increase in LVEF units of 4.6% (range: 0 to 8).
For patients treated with nebivolol, atenolol and propranolol combined, there was a weighted mean follow-up of 13 months and a mean increase in LVEF units of 8.6% (range: 4 to 15).
When patients with idiopathic and ischaemic cardiomyopathies were compared, the average increases in LVEF units were 8.5% (range: 3 to 16) and 6.0% (range: 3 to 11), respectively.
Information about the etiology of LVF was available for 630 patients.