Acute beta-blockade reduces the extent and severity of myocardial perfusion defects with dipyridamole Tc-99m sestamibi SPECT imaging.

Abstract

OBJECTIVES:

The goal of this study was to examine the effect of acute beta-blockade on dipyridamole Tc-99m sestamibi myocardial perfusion imaging (DMPI).

BACKGROUND:

Studies suggest that antianginal drugs may reduce the presence and severity of myocardial perfusion defects with dipyridamole stress. However, there are no data regarding specific drugs.

METHODS:

Patients with catheterization-proven coronary artery disease (CAD) were enrolled in this prospective, double-blind, placebo-controlled study and randomly assigned to DMPI after placebo, low-dose metoprolol (up to 10 mg), and high-dose metoprolol (up to 20 mg). Patients underwent one Tc-99m sestamibi study at rest on a separate day. The interval between DMPI studies was <or=14 days. Images were interpreted by three observers blinded to clinical data using a 17-segment, five-point model. For each image, a summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) were calculated (SDS = SSS - SRS). Images with an SSS <4 were considered normal.

RESULTS:

Twenty-one patients completed all four Tc-99m sestamibi studies. The sensitivity of DMPI for detection of CAD was 85.7% with placebo versus 71.4% with low- and high-dose metoprolol. In comparison with placebo, the SSS was significantly lower (p < 0.05) with low- and high-dose metoprolol (12.0 +/- 10.1 vs. 8.7 +/- 9.0 and 9.3 +/- 10.6, respectively). The SDS also was significantly lower (8.4 +/- 8.8 with placebo vs. 5.0 +/- 6.7 [p < 0.001] and 5.4 +/- 7.9 [p < 0.01] with low- and high-dose metoprolol, respectively).

CONCLUSIONS:

The presence and severity of CAD may be underestimated in patients receiving beta-blocker therapy undergoing dipyridamole stress myocardial perfusion imaging.

• Authors: Raymond Taillefer, Alan W Ahlberg, Yasmin Masood, C Michael White, Isabella Lamargese, Jeffrey F Mather, Carol C McGill, Gary V Heller
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 42 Issue 8 Pg. 1475-83 (Oct 15 2003) ISSN: 0735-1097 [Print] United States
• PMID: 14563595 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)

Chemical References

• Adrenergic beta-Antagonists
• Radiopharmaceuticals
• Vasodilator Agents
• Dipyridamole
• Technetium Tc 99m Sestamibi
• Metoprolol

Topics

• Adrenergic beta-Antagonists (administration & dosage, pharmacology)
• Coronary Disease (diagnostic imaging, physiopathology)
• Dipyridamole
• Double-Blind Method
• Exercise Test
• Female
• Hemodynamics (drug effects)
• Humans
• Male
• Metoprolol (administration & dosage, pharmacology)
• Middle Aged
• Prospective Studies
• Radiopharmaceuticals
• Technetium Tc 99m Sestamibi
• Tomography, Emission-Computed, Single-Photon
• Vasodilator Agents