Metoprolol does not effect myocardial fractional flow reserve in patients with intermediate coronary stenoses.
OBJECTIVE
Myocardial fractional flow reserve (FFR) is utilized to determine the hemodynamic significance of coronary stenoses. We sought to determine the effect, if any, of metoprolol on FFR in patients with coronary stenoses of intermediate severity.


RESULTS
Eighteen patients (10 males, mean age, 59.4 +/- 7.7 years) with isolated, intermediate (30% to 70% narrowing on coronary angiogram) lesions on the proximal LAD and a preserved ejection fraction, underwent FFR measurement using a 0.014 inch pressurewire and intracoronary adenosine injection before and after intravenous metoprolol at a dose that achieved at least a 10% decrease in the heart rate. Heart rate dropped significantly with metoprolol. At the premetoprolol measurement, aortic pressure (Pa) remained essentially the same (105.7 +/- 11.5 versus 105.6 +/- 11.6 mmHg, P > 0.05) and distal coronary pressure (Pd) dropped significantly by 9% from 96.3 +/- 12.7 to 87.4 +/- 13.4 mmHg (P < 0.001) after adenosine injection yielding an FFR(1) of 0.83 +/- 0.07. At the postmetoprolol phase, Pa dropped nonsignificantly by 2% from 104.4 +/- 12.8 to 102.4 +/- 14.3 mmHg (P = 0.09) and Pd dropped significantly by 11% from 95.7 +/- 14.4 to 85.3 +/- 16.4 mmHg (P < 0.001) after adenosine injection, yielding an FFR(2) of 0.83 +/- 0.08, which was almost exactly the same as FFR(1) (P > 0.05).


CONCLUSIONS
In this study, FFR was found not to be influenced by metoprolol treatment in patients with intermediate coronary stenoses and a preserved ejection fraction.
Ozdemir
Murat
M
Department of Cardiology, Gazi University School of Medicine, Ankara, Turkey.
Yazici
Guliz Erdem
GE
Turkoglu
Sedat
S
Timurkaynak
Timur
T
Cengel
Atiye
A
D000241:Adenosine / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D023921:Coronary Stenosis / Q000503:physiopathology*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage / Q000494:pharmacology*; D008875:Middle Aged