Effects of long-term treatment with carvedilol on myocardial blood flow in idiopathic dilated cardiomyopathy
- Danilo Neglia1,
- Renata De Maria1,
- Stefano Masi2,
- Michela Gallopin3,
- Patrizia Pisani1,
- Silvia Pardini1,
- Antonello Gavazzi4,
- Antonio L’Abbate5,
- Oberdan Parodi1
- 1CNR Institute of Clinical Physiology, Pisa, Italy
- 2Dipartimento di Medicina Interna, Universita’ di Pisa, Pisa, Italy
- 3Cardiologia–Ospedale di Prato, Prato, Italy
- 4Dipartimento Cardiovascolare, Ospedali Riuniti di Bergamo, Bergamo, Italy
- 5Scuola Superiore Sant’Anna, Pisa, Italy
- Correspondence to:
Dr D Neglia
CNR Institute of Clinical Physiology, Via G Moruzzi, 1, 56126 Pisa, Italy;
- Accepted 31 October 2006
- Published Online First 19 January 2007
Objective: To assess whether chronic treatment with carvedilol can increase myocardial blood flow (MBF) and MBF reserve in idiopathic dilated cardiomyopathy (IDC).
Study design: In a double-blind, placebo-controlled trial, 16 consecutive patients with IDC were randomised to treatment with either carvedilol up to 25 mg twice a day (n = 8, 7 men, mean (SD) age 60 (9) years, mean (SD) left ventricular ejection fraction (LVEF) 30% (5%)), or placebo (n = 8, 6 men, mean (SD) age 62 (9) years, mean (SD) LVEF 28% (6%), NS vs carvedilol group). Before and 6 months after treatment, regional MBF was measured at rest and after intravenous injection of dipyridamole (Dip; 0.56 mg/kg in 4 min) by positron emission tomography and using 13N-ammonia as a flow tracer. Exercise capacity was assessed as the time duration in a maximal bicycle exercise stress test.
Results: Carvedilol induced a significant decrease in heart rate at rest and during maximal exercise, and an increase in exercise capacity. Absolute MBF values did not significantly change after carvedilol or placebo treatment, either at rest or during Dip injection, although Dip-MBF tended to improve after treatment. Coronary flow reserve significantly increased following carvedilol treatment (from 1.67 (0.63) to 2.58 (1.04), p<0.001), whereas it remained unchanged following the placebo treatment (from 1.80 (0.84) to 1.77 (0.60), NS). Stress-induced regional perfusion defects decreased after carvedilol treatment (from 38% to 15%).
Conclusions: Long-term treatment with carvedilol can significantly increase coronary flow reserve and reduce the occurrence of stress-induced perfusion defects, suggesting a favourable effect of the drug on coronary microvascular function in patients with IDC.
- CFR, coronary flow reserve
- Dip, dipyridamole
- Dip+, region with Dip-induced regional perfusion defect
- Dip−, region without Dip-induced regional perfusion defect
- IDC, idiopathic dilated cardiomyopathy
- LV, left ventricular
- LVEF, left ventricular ejection fraction
- MBF, myocardial blood flow
- nMBF, normalised resting myocardial blood flow
- PET, positron emission tomography
- RPP, rate pressure product
Published Online First 18 January 2007
This is a substudy of a multicentre trial (CAR-01) sponsored by Roche. Roche did not specifically fund the substudy, and had no role in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication.
Competing interests: None declared.