Freedom SOLO valve: early- and intermediate-term results of a single centre's first 100 cases

A European Multicenter Study of 616 Patients Receiving the Freedom Solo Stentless Bioprosthesis

BACKGROUND

The purpose of this study was to evaluate the safety and performance of the Freedom Solo valve in aortic valve replacement by clinical and hemodynamic outcomes.

METHODS

Six hundred sixteen patients underwent aortic valve replacement in 18 European centers; mean age was 74.5 ± 5.9 years, 54.1% of the patients were male, and concomitant procedures were performed in 43.2% of the patients. The majority (69%) of the implanted sizes were 23 mm and 25 mm.

RESULTS

At 1 year, overall survival was 94.0%, whereas freedom from valve-related death was 98.6%. There were 9 (1.5%) early (≤ 30 days) and 27 (4.4%) late (>30 days) deaths. Early and late valve-related mortality was 0.3% (n = 2) and 1.1% (n = 7), respectively. Freedom from explant was 97.6%; 10 valves were explanted for endocarditis and 4 for paravalvular leak. There were 10 (1.6%) early and 5 (0.8%) late strokes. Atrioventricular block requiring pacemaker implant occurred in 8 (1.3%) and 1 (0.2%) patients in the early and late postoperative period, respectively. Thrombocytopenia was seen in 27 cases (4.4%) in the early postoperative period. Preoperatively, 93.8% of patients were in New York Heart Association functional classes II through IV, whereas at 1 year 96.9% of patients were in New York Heart Association functional classes I and II. At 1-year follow-up, mean and peak pressure gradients were 7.2 and 14.6 mm Hg, respectively. Indexed left ventricular mass decreased by 12% from 138 g/m(2) at discharge to 122 g/m(2) at 1 year.

CONCLUSIONS

At 1-year follow-up after Freedom Solo implantation, we found acceptable clinical results with low mortality and morbidity and good hemodynamic performance, confirming safety and effectiveness in this multicenter experience.

Partial aortic valve replacement: a new and simple approach for endocarditis

We describe the replacement of a single cusp in two patients with severe aortic regurgitation due to endocarditis with a one third stentless bioprosthesis, with excellent results in both.

Influence of type of aortic valve prosthesis on coronary blood flow velocity

BACKGROUND

Severe aortic valve stenosis is associated with high resting and reduced hyperemic coronary blood flow. Coronary blood flow increases after aortic valve replacement (AVR); however, the increase depends on the type of prosthesis used. The present study investigates the influence of type of aortic valve prosthesis on coronary blood flow velocity.

METHODS

The blood flow velocity in the left anterior descending coronary artery (LAD) and the right coronary artery (RCA) was measured intraoperatively before and after AVR with a stentless bioprosthesis (Sorin Freedom Solo; n = 11) or a bileaflet mechanical prosthesis (St. Jude Medical Regent; n = 11). Measurements were made with an X-Plore epicardial Doppler probe (Medistim, Oslo, Norway) following induction of hyperemia with an adenosine infusion. Preoperative and postoperative echocardiography evaluations were used to assess valvular and ventricular function. Velocity time integrals (VTI) were measured from the Doppler signals and used to calculate the proportion of systolic VTI (SF), diastolic VTI (DF), and normalized systolic coronary blood flow velocities (NSF) and normalized diastolic coronary blood flow velocities (NDF).

RESULTS

The systolic proportion of the LAD VTI increased after AVR with the St. Jude Medical Regent prosthesis, which produced higher LAD SF and NSF values than the Sorin Freedom Solo prosthesis (SF, 0.41 ± 0.09 versus 0.29 ± 0.13 [P = .04]; NSF, 0.88 ± 0.24 versus 0.55 ± 0.17 [P = .01]). No significant changes in the LAD velocity profile were noted after valve replacement with the Sorin Freedom Solo, despite a significant reduction in transvalvular gradient and an increase in the effective orifice area. AVR had no effect on the RCA flow velocity profile.

CONCLUSION

The coronary flow velocity profile in the LAD was significantly influenced by the type of aortic valve prosthesis used. The differences in the LAD velocity profile probably reflect differences in valve design and the systolic transvalvular flow pattern.

Evaluation of platelet count after isolated biological aortic valve replacement with Freedom Solo bioprosthesis

OBJECTIVE

The risk of thrombocytopenia in patients undergoing aortic valve replacement (AVR) with the Freedom Solo (FS) bioprosthesis is controversial. The aim of our study was to evaluate the postoperative evolution of platelet count and function after AVR in patients undergoing isolated biological AVR with FS.

METHODS

Between May 2005 and June 2010, 322 patients underwent isolated biological AVR. Of these, 116 patients received FS and were compared with 206 patients who received biological valves. Platelet count, mean platelet volume (MPV), and platelet distribution width (PDW) were evaluated at baseline (T0), first (T1), second (T2), and fifth (T3) postoperative days, respectively.

RESULTS

Overall in-hospital mortality was 1.5% with no difference between the two groups. Thirty-seven (11.5%) patients developed thrombocytopenia. FS implantation was associated with a higher incidence of thrombocytopenia compared with the control group (24.1% vs 4.4%, p<0.0001). Patients in the FS group showed a lower platelet count than the control group at T1 (99.4±38×10(3) μl(-1) vs 122.5±41.6×10(3) μl(-1), p<0.001), T2 (79.7±36.3×10(3) μl(-1) vs 122.5±43.3×10(3) μl(-1), p<0.001) and T3 (86.6±57.4×10(3) μl(-1) vs 158.4±55.8×10(3) μl(-1), p<0.001). Moreover, the FS group also had a higher MPV (11.6±0.9 fl vs 11±1 fl, p<0.001) and higher PDW (15.1±2.3 fl vs 13.9±2.1 fl, p<0.001) at T3. In a multivariable analysis, FS (p<0.0001), body surface area (p<0.0001), cardiopulmonary bypass time (p=0.003), and lower preoperative platelet counts (p=0.006) were independent predictors of thrombocytopenia.

CONCLUSIONS

The FS valve might increase the risk of thrombocytopenia and platelet activation, in the absence of adverse clinical events. Prospective randomized studies on platelet function need to confirm our data.