title: The effect of aortic valve replacement on coronary flow reserve in patients with a normal coronary angiogram.
abstract: BACKGROUND
  In patients with aortic stenosis and a normal coronary angiogram, a coronary flow reserve (CFR) is impaired. The aim of the present study was to examine the effect of aortic valve replacement (AVR) on the CFR after a long-term follow-up.
  
  
  METHODS
  30 patients with aortic stenosis and a normal coronary angiogram were enrolled in the study. CFR measurements were made on 21 patients 123 +/- 137 days before and 497 +/- 167 days after AVR. CFR measurements were carried out according to a standard protocol, with a vasodilator stimulus dipyridamole (0.56 mg/kg for 4 min) and peak diastolic velocity measurements at 6 min.
  
  
  RESULTS
  Initially, the average peak gradient of aortic stenosis was 89.5 +/- 22.4 mm Hg. After AVR, it decreased to 26.2 +/- 9 mm Hg. Left ventricular mass was significantly lower after AVR: 354.9 +/- 107.9 g versus 223.8 +/- 73.6 g (p < 0.001). The average baseline diastolic velocity measured by pulsed Doppler in the left anterior descending coronary artery amounted to 62.2 +/- 25.5 cm/s before and 40.1 +/- 13.6 cm/s after AVR. The difference was statistically significant (p < 0.01). The average diastolic velocity at maximum stress equaled 117 +/- 42.8 cm/s pre- and 91.5 +/- 34 cm/s postoperatively (p < 0.005). The calculated CFR before AVR amounted to 1.96 +/- 0.5 and increased to 2.37 +/- 0.8 postoperatively. The difference was statistically significant (p < 0.05).
  
  
  CONCLUSIONS
  Prosthetic AVR is of considerable benefit concerning the CFR in patients with a normal coronary angiogram after a long-term follow-up.
authors.affiliation: 2nd Department of Medicine and Cardiology Center, Albert Szent-Györgyi Medical and Pharmaceutical Center, University of Szeged, Hungary. nemes@in2nd.szote.u-szeged.hu
authors.forename: Attila
authors.initials: A
authors.lastname: Nemes
authors.forename: Tamás
authors.initials: T
authors.lastname: Forster
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Kovács
authors.forename: Attila
authors.initials: A
authors.lastname: Thury
authors.forename: Imre
authors.initials: I
authors.lastname: Ungi
authors.forename: Miklós
authors.initials: M
authors.lastname: Csanády
mesh_terms: D000368:Aged; D001024:Aortic Valve Stenosis / Q000503:physiopathology / Q000601:surgery*; D001783:Blood Flow Velocity / Q000502:physiology; D002306:Cardiac Volume / Q000502:physiology; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology*; D004176:Dipyridamole; D018619:Echocardiography, Doppler, Pulsed; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000503:physiopathology*
chemical_list: D004176:Dipyridamole