COMPARATIVE REST AND EXERCISE HEMODYNAMICS OF ALLOGRAFT AND PROSTHETIC VALVES IN THE AORTIC POSITION

Background. Allograft aortic valve replacement has gained widespread a cceptance. However, there is little information about in vivo allograf t valve function at rest and during exercise. Methods. Cardiac cathete rization was performed to measure hemodynamic variables at rest and du ring supine bicycle exercise in 44 patients who had had aortic valve r eplacement using allograft valves or Bicer or St. Jude Medical prosthe tic valves 19 to 27 mm in diameter. Sixteen patients received an allog raft valve; 17, a Bicer valve; and 11, a St. Jude Medical valve. There were no significant differences between the three groups in age, body surface area, left ventricular end-systolic and end-diastolic volume indices, exercise cardiac index, exercise heart rate, or work load ach ieved. Left ventricular and ascending aortic pressures were measured s imultaneously according to the transseptal method. Results. The mean p ressure gradient was generally higher for the Bicer and St. Jude Medic al valves than for the allograft valves, both at rest and during exerc ise. Significant differences were obtained in patients with small-size d valves (21 and 23 mm); pressure gradients were higher in the prosthe tic valve groups. In patients with large-sized prosthetic valves (25 m m), there were no significant differences between the three groups at rest and during exercise. However, there was no pressure gradient at a ll for allograft valves. Conclusions. Exercise cardiac catheterization confirms that the allograft aortic valve is an ideal substitute from the hemodynamic aspect, particularly in patients with a small aortic r oot and in those who perform strenuous exercise. (C) 1997 by The Socie ty of Thoracic Surgeons.