Clinical and haemodynamic outcomes in 804 patients receiving the Freedom SOLO stentless aortic valve: results from an international prospective multicentre study.

OBJECTIVES

The Freedom SOLO™ valve (Sorin Group, Italy) is a stentless aortic bioprosthesis designed for simplified implantation. The present multicentre study is the largest prospective evaluation of this prosthesis. Herein, we report on outcomes at 3-year follow-up.

METHODS

From March 2009 to February 2013, a total of 804 consecutive patients (mean age 74.9 ± 6.3 years; 45.1% females) underwent aortic valve replacement with the Freedom SOLO™ valve at 33 centres. Concomitant procedures (70.2% coronary artery bypass grafting) were performed in 376 patients. The cumulative follow-up included 1100 patient-years (mean 16.5 ± 10.8 months; range: 0-40.5 months).

RESULTS

Sixty-four patients died (14 early, 50 late); 12 deaths (1 early, 11 late) were valve-related. Operative mortality (30 days) was 1.7%. At 3 years, overall survival was 82.6% [95% confidence interval (CI) 75.5-87.8%] and freedom from valve-related death was 95.5% (95% CI 89.2-98.2%). Linearized late event rates were 0.82%/patient-years for non-structural valve dysfunction, 0.55%/patient-years for structural valve deterioration, 1.55%/patient-years for endocarditis, 3.64%/patient-years for thromboembolism and 3.18%/patient-years for bleeding. In total, there were 22 reinterventions [19 valve explants, 2 refixations, 1 transcatheter aortic valve intervention (TAVI)] for endocarditis (11), non-structural dysfunction (9) and structural valve deterioration (2). Freedom from reintervention was 95.2% (95% CI 91.2-97.4%) at 3 years. There were no instances of valve thrombosis or haemolysis. At 1, 2 and 3 years, 97.0, 95.5 and 91.4% of patients were in NYHA class I or II. Between discharge and 3 years after surgery, mean transvalvular gradients exhibited a non-significant increase (6.5 ± 4.3 vs 8.7 ± 6.5 mmHg), whereas effective orifice area index remained stable (0.9 ± 0.2 vs 0.8 ± 0.3 cm(2)/m(2)). At 3 years, no patient presented with more than mild aortic regurgitation. Left ventricular mass index decreased significantly between discharge and 1 year after surgery (139.4 ± 40.9 vs 122.4 ± 35.3 g/m(2), P < 0.001) and remained unchanged thereafter. Left ventricular size and function did not change over time.

CONCLUSIONS

The Freedom SOLO™ valve is a unique stentless pericardial bioprosthesis whose design favours haemodynamic performance and thus facilitates left ventricular reverse remodelling. In terms of survival, morbidity and functional status, it is associated with beneficial outcomes up to 3 years after surgery. Ongoing follow-up will assess the valve at the long-term course.