DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more



Attenuation of adenosine-induced myocardial perfusion heterogeneity by atenolol and other cardioselective beta-adrenoceptor blockers: a crossover myocardial perfusion imaging study.

Author(s): Reyes E, Stirrup J, Roughton M, D'Souza S, Underwood SR, Anagnostopoulos C

Affiliation(s): National Heart and Lung Institute, Imperial College London, London, United Kingdom. e.reyes@rbht.nhs.uk

Publication date & source: 2010-07, J Nucl Med., 51(7):1036-43. Epub 2010 Jun 16.

Publication type: Randomized Controlled Trial; Research Support, Non-U.S. Gov't

Little is known about the effect of chronic beta-blockade on adenosine actions. We sought to investigate the effect of oral beta-blockers on the presence, extent, and severity of myocardial perfusion abnormality induced by adenosine in patients with coronary artery disease. METHODS: In this crossover study, 45 male patients with coronary artery disease on beta-blocker therapy with atenolol, bisoprolol, or metoprolol underwent adenosine myocardial perfusion imaging both on and off beta-blockade in a random order on separate days. Myocardial perfusion was assessed both qualitatively and quantitatively. Hemodynamic response, image analysis, and sensitivity for the detection of coronary stenosis (>or=50% luminal diameter reduction on x-ray coronary angiography) were compared between the on and off beta-blocker studies. RESULTS: Rate pressure product both at baseline and at peak adenosine infusion decreased by 23% +/- 15% and 21% +/- 18%, respectively, after beta-blockade (P < 0.001 for all). The median (interquartile range) summed difference score, a measure of defect reversibility, and quantitative defect size were both significantly lower after beta-blockade (median, 7.0 [interquartile range, 2.0-9.5] vs. median, 5.0 [interquartile range, 0-8.0], P = 0.002; and quantitative defect size, 18% [interquartile range, 9%-34%] vs. quantitative defect size, 6% [interquartile range, 0%-19%], P < 0.001, respectively). The overall sensitivity for the detection of coronary stenosis decreased from 0.76 (95% confidence interval, 0.65-0.88) to 0.58 (95% confidence interval, 0.45-0.71) after beta-blockade (P = 0.03). CONCLUSION: beta-blockade causes a small but significant reduction in the extent and severity of perfusion abnormality by adenosine. This may reduce the diagnostic sensitivity of adenosine myocardial perfusion imaging for the detection of flow-limiting coronary stenosis.

Page last updated: 2010-10-05

-- advertisement -- The American Red Cross
 
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017