Hemodynamic performance and leaflet kinematics of porcine versus pericardial aortic valve prostheses

Introduction: Opening and closing characteristics differ between porcine and pericardial valve substitutes. The following in vitro study investigates, how these differences affect hemodynamic performance and leaflet movements in different simulated clinical situations.

Methods: Edwards Perimount Magna (n=5) and Medtronic Mosaic Ultra (n=5) aortic valves (23mm diameter) were investigated in a pulse duplicator. Leaflet kinematics were visualized with a high-speed camera (3000 frames/s) at normal cardiac output (CO) (5 l/min, 70 beats/min (BPM), in an exercise state (CO 8 l/min, 150 BPM) and a low output situation (CO 2.5 l/min, 130 BPM).

Results: Table 1 summarizes the results. Transvalvular pressure gradients were lower, but closure volume significantly larger for pericardial valves leading to an equivalent total energy loss. Leaflet opening and closing times were shorter for porcine valves especially with low stroke volume.

	Perimount	Mosaic	Perimount	Mosaic	Perimount	Mosaic
	70 BPM, 5l/min		150 BPM, 8l/min		130 BPM, 2.5l/min
Gradient (mmHg)	10.7±1.2	14.3±1.1	8.5±1.3	11±1.2	2.4±0.5	3.4±0.4
Closure Volume (% of stroke volume)	7.2±1.4	1.8±0.4	5.3±1.2	1.3±0.2	13±3	5.7±1.2
Total Energy Loss (%)	8.9±1.4	9.0±1.5	8.0±1.3	8.2±1.2	7.7±1.2	6.7±1.3
Opening Time (msec)	48±10	27±6	38±11	27±5	54±12	30±8
Closure Time (msec)	111±12	74±10	68±11	48±8	86±15	53±9

Conclusion: Perimount Magna pericardial valves demonstrated lower transvalvular pressure gradients compared to the Mosaic porcine prosthesis. However, opening and closure was prolonged in the pericardial valves leading to an increase in closing volume especially in the hemodynamically critical low output situation with a small stroke volume.