Haemodynamic performance of aortic pericardial bioprostheses and bileafletprostheses at rest and during exercise: implications for the surgical management of patients with small aortic roots

Objective-To determine the haemodynamic behaviour, at rest and during exerc ise, of aortic valve pericardial bioprostheses and different sizes of bilea flet prosthesis. Design-Observational study. Setting-Tertiary medical centre. Patients and interventions-74 patients (33 women, 41 men; mean age 64 years ) in whom 40 pericardial bioprostheses and 34 bileaflet prostheses sized 19 , 21, or 23 mm had been implanted to replace aortic valves. Main outcome measures-Doppler echocardiography at rest and at peak exercise , between 12 and 47 months after surgery. Results-All patients achieved a significant increase in heart rate, systoli c blood pressure, and cardiac output with exercise. Transvalvar pressure fa ll, valve area, and left ventricular systolic and diastolic function indice s also underwent significant changes with exercise. Reductions in peak and mean transvalvar pressure, at rest and at peak exercise, were greater in pa tients with small valves (p < 0.05).Valve areas and effective area index we re greater in the patients with larger valves (p < 0.001). There were no si gnificant differences between patients with mechanical and biological prost heses with regard to transvalvar pressure fall and valve areas at rest and at peak exercise. Conclusions-19 mm and 21 mm aortic prostheses and bioprostheses continue to create significant obstruction, particularly with exercise.