Results
711 Perimount and 453 Trifecta valves were implanted in the study period. Patient demographics are summarized in Table 1. Average follow-up times were 2.48 ± 1.70 years for Perimount and 2.51 ± 1.51 years for Trifecta. No significant differences in patient characteristics and co-morbidities were found between Perimount and Trifecta groups (Table 1).
Reoperation rates were 0.8% for Perimount and 2.2% for Trifecta (p = 0.07) for the entire patient cohort over the 6-year study period (Table 2). However, significant differences were found among patients undergoing reoperation in age and smoking history subgroups. Reoperation rates were 1.4% for Perimount and 7.6% for Trifecta (p = 0.04) in the age < 60 years subgroup. Reoperation rates were 0% for Perimount and 10.2% for Trifecta (p < 0.01) in the smoking history subgroup. All other subgroups demonstrated non-significant differences in event rates (Table 2).
Reoperation hazards were 1.64% for Perimount and 3.93% for Trifecta (p = 0.06) for the entire patient cohort at the 6-year study period end point (Table 3, Fig. 1). However, significant differences were found in the age and smoker subgroups (Fig. 2). Reoperation hazards were 2.44% for Perimount and 13.1% (p = 0.02) in the age < 60 years subgroup. Reoperation hazards were 0% for Perimount and 18.0% for Trifecta (p < 0.01) in the smoker subgroup. All other subgroups demonstrated non-significant differences in event hazards. Interestingly, Trifecta demonstrated noticeable high rate of reoperations at < 6 months of the study period in subgroups of age < 60 years, males, and smokers (Fig. 2).
The Cox-proportional Hazards Model showed Hazard Ratios (HR) for age: 0.96 (0.92-0.99, p=0.02), female (vs male): 0.35 (0.08-1.53, p=0.16), smoker (vs non-smoker): 2.44 (0.85-7.02, p=0.1), and Trifecta (vs Perimount): 2.68 (0.97-7.39, p=0.06).