The Toronto SPV: hemodynamic data at 1 and 5 years' postimplantation

The Toronto-SPV (T-SPV) bioprosthesis has been used for aortic valve replacement (AVR) since July 1991. There is no published data on its mid-term hemodynamic performance. This study compares the hemodynamic data of a consecutive series of patients at 1 and 5 years after AVR. The first 109 consecutive patients who had AVR with a T-SPV have been monitored for a minimum of 5 years and have had annual Doppler echocardiographic studies. There were 80 men and 29 women in the study; mean age was 62 years (range 34 to 80 years). Concomitant coronary artery bypass surgery was done in 35 patients. One operative and nine late deaths occurred. The mean systolic gradient across the T-SPV in all patients was 3.9+/-2.4 mm Hg at 1 year and 4.1+/-3.3 mm Hg at 5 years (P = .27). The mean aortic valve area was 2.2+/-0.6 cm2 at 1 year and 2.3+/-0.7 cm2 at 5 years (P = .43). The mean left ventricular mass index (LVMI) was 104+/-31 g/m2 at 1 year and 97+/-24 g/m2 at 5 years (P = .08). Multivariate linear regression analysis showed that preoperative coronary artery disease (P<.0001) and hypertension (P<.01) were independent predictors of higher LVMI over time. Aortic insufficiency was none/trivial in 94% of patients and mild in 6% at 1 year. At 5 years, aortic insufficiency was none/trivial in 88% of patients, mild in 10%, and moderate in 2%. The aortic leaflets remained thin and pliable in all patients as assessed by echocardiography. Most patients (85%) were in New York Heart Association functional class I. The hemodynamic performance of the T-SPV remained unchanged during the first 5 years after implantation. The LVMI continued to decrease after the first year and tended to normalize in most patients. The aortic valve remained competent, and the leaflets did not change their thickness or show evidence of calcification.