Hemodynamic performance and clinical consequences of aortic valve replacement with 21mm-size pericardial bioprosthesis

Objective: Aortic valve replacement with a 21mm-size bioprosthesis is still discussed controversially. Since better results have been reported on pericardial valves, we wanted to analyze hemodynamic performance and clinical parameters in our patients.

Material and Methods: 342 patients underwent AVR with a bioprosthesis between 1987 and 2000. A 21mm prosthesis was used in 39 patients (group S), whereas 301 patients received at least a 23mm-size valve (group L). Group S included 19 patients with a pericardial valve (group S1) and 20 patients with a standard porcine valve (group S2).

Results: Before discharge the peak- and mean transprosthetic gradients were significantly lower in the pericardial group than in the porcine group, particularly between patients with 21mm valves (peak/mean: S1: 24±9 / 20.8±6.5mm Hg vs. S2: 38±15 / 33±9mm Hg, p<0.05). We could also find that the peak transprosthetic gradient 7 days postoperatively was not significantly higher in patients with 21mm pericardial valves than in group L.

Furthermore there were significantly more cerebral ischemic events (S1: 5.3%, S2: 10%), a prolonged mechanical ventilation (S1: 11.3±1.7 hours, S2: 17.2±4.3 hours), a higher mortality (S1: 5.3%, S2: 10%), and a longer stay in hospital in group S2 compared to S1 (p<0.05).

Conclusions: Our study reveals good performance of pericardial valves, particularly in patients with small aortic roots. As the outcome of patients with a 21mm pericardial valve was even not worse than of patients with greater valves, enlarging procedures for the aortic root did not seem to be necessary in these patients.