Prospective study of hemodynamic performances of standard ATS and AP-ATS valves.

Background And Aim Of The Study: Following aortic valve replacement (AVR), a residual transprosthetic gradient can develop which has detrimental long-term effects, especially with regard to left ventricular mass regression and subsequent mortality. The Advanced Performance-ATS valve (AP-ATS) was developed to overcome this potential patient-prosthesis mismatch. In the present study, the early postoperative transprosthetic gradient was determined after AVR with ATS valves 18 to 25, to confirm the promise of superior hemodynamic performance of the AP series and to define respective indications.

Methods: This prospective study included 302 consecutive patients operated on for AVR between December 1997 and December 2000. In all patients, body surface area (BSA), associated with mean transprosthetic gradient and paravalvular leaks (measured echocardiographically) was monitored, between the 5th and 8th postoperative days.

Results: A significantly lower mean transprosthetic gradient was found for size 22 and 24 valves, compared with size 23 and 25 valves. Results for size 18 and 20 valves were in concordance with those obtained for size 22 and 24 valves. For size 23 valves the mean gradient was significantly higher when the BSA was >1.9 m2, but the use of size 22 valves in these patients overcame this potential patient-prosthesis mismatch. No patient was reoperated on for paravalvular leakage, and no greater degree of paravalvular leakage was found with AP-ATS than with Standard ATS valves.

Conclusion: These results confirm the global good hemodynamic performances of Standard ATS and especially of the AP-ATS valves. However, the significantly lower mean gradient found in the AP-ATS valves recommends their use in patients with larger BSA.