Combined alpha-beta blockade ( doxazosin plus metoprolol) compared with beta blockade alone in chronic congestive heart failure

• Published in: The American journal of cardiology Vol. 77; no. 7; pp. 486 - 491
• Main Authors: Kukin, Marrick L., Kalman, Jill, Mannino, Michael, Freudenberger, Ronald, Buchholz, Cathleen, Ocampo, Ofelia
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-03-1996; Elsevier; Elsevier Limited
• Subjects: Adrenergic alpha-Antagonists - therapeutic use; Adrenergic beta-Antagonists - therapeutic use; Adult; Aged; Biological and medical sciences; Cardiovascular system; Chronic Disease; Doxazosin - therapeutic use; Drug therapy; Drug Therapy, Combination; Exercise; Female; Heart failure; Heart Failure - drug therapy; Heart Failure - physiopathology; Hemodynamics - drug effects; Humans; Male; Medical sciences; Metoprolol - therapeutic use; Middle Aged; Pharmacology. Drug treatments; Treatment Outcome; Vasodilator agents. Cerebral vasodilators; Human; Heart failure; Chemotherapy; Chronic; Alpha blocking agent; Vasodilator agent; Heart disease; Cardiovascular disease; Exploration; Combined treatment; Comparative study; Beta blocking agent
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/S0002-9149(97)89342-3

There has been growing evidence for the benefits of β blockers, but α blockers have not shown sustained benefits in chronic congestive heart failure (CHF). Thirty patients with moderate to severe CHF (New York Heart Association class II to IV) were sequentially assigned to receive metoprolol 6.25 mg with the α-1 antagonist doxazosin 4 mg/day or metoprolol alone. The dose of metoprolol was gradually increased to a target dose of 50 mg orally twice daily. Hemodynamic measurements were obtained before drug therapy, 2 hours after the first dose of combined α-β therapy or metoprolol alone, and after 3 months of continuous treatment. Nucleur ejection fraction, plasma norepinephrine, and submaximal and maximal exercise capacity were also measured before and after chronic therapy. With initial combined drug administration, mean arterial pressure, left ventricular filling pressure, and systemic vascular resistance decreased significantly compared with results after metoprolol alone. However, after 3 months of continuous therapy, both treatment groups showed similar and significant reductions in systemic vascular resistance and heart rate, with significant increases in cardiac index, stroke volume index, stroke work index, ejection fraction, and exercise capacity. Furthermore, the next dose of chronic combined medication no longer showed vasodilating effects. Chronic therapy with fixed-dose doxazosin and increasing doses or metoprolol produced identical effects as those seen in patients receiving metoprolol alone.