Efficacy, safety and tolerability of metoprolol CR/XL in patients with diabetes and chronic heart failure: experiences from MERIT-HF.
BACKGROUND
The objective of the current study was to examine the efficacy and tolerability of the beta-blocker metoprolol succinate controlled release/extended release (CR/XL) in patients with diabetes in the Metoprolol CR/XL Randomized Intervention Trial in Chronic Heart Failure (MERIT-HF).


METHODS
The Cox proportional hazards model was used to calculate hazard ratios (HR) for convenience expressed as relative risks (risk reduction = 1-HR), and 95% confidence intervals (CI).


RESULTS
The risk of hospitalization for heart failure was 76% higher in diabetics compared to non-diabetics (95% CI 38% to 123%). Metoprolol CR/XL was well tolerated and reduced the risk of hospitalization for heart failure by 37% in the diabetic group (95% CI 53% to 15%), and by 35% in the non-diabetic group (95% CI 48% to 19%). Pooling of mortality data from the Cardiac Insufficiency Bisoprolol Study II (CIBIS II), MERIT-HF, and the Carvedilol Prospective Randomized Cumulative Survival Study (COPERNICUS) showed similar survival benefits in patients with diabetes (25%; 95% CI 40% to 4%) and without diabetes (36%; 95% CI 44% to 27%); test of diabetes by treatment interaction was non-significant. Adverse events were reported more often on placebo than on metoprolol CR/XL.


CONCLUSIONS
Patients with heart failure and diabetes have a much higher risk of hospitalization than patients without diabetes. Regardless of diabetic status, a highly significant reduction in hospitalizations for heart failure was observed with metoprolol CR/XL therapy, which was very well tolerated also by patients with diabetes. Furthermore, the pooled data showed a statistically significant survival benefit in patients with diabetes.
Deedwania
Prakash C
PC
Department of Veterans Affairs Medical Center, Fresno, Calif, USA. deed@ucsfresno.edu
Giles
Thomas D
TD
Klibaner
Michael
M
Ghali
Jalal K
JK
Herlitz
Johan
J
Hildebrandt
Per
P
Kjekshus
John
J
Spinar
Jindrich
J
Vitovec
Jiri
J
Stanbrook
Hilary
H
Wikstrand
John
J
D000319:Adrenergic beta-Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D003692:Delayed-Action Preparations; D048909:Diabetes Complications / Q000188:drug therapy* / Q000401:mortality; D003920:Diabetes Mellitus / Q000401:mortality; D004311:Double-Blind Method; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000188:drug therapy*; D006760:Hospitalization; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D008875:Middle Aged; D016016:Proportional Hazards Models; D012306:Risk; D016019:Survival Analysis
D000319:Adrenergic beta-Antagonists; D003692:Delayed-Action Preparations; D008790:Metoprolol