Short-term outcomes of the Tiara bioprosthesis and the Ozaki procedure comparison: a multicenter retrospective study with propensity score analysis
Authors: Enginoev S. T. , Chernov I. I. , Kolesnikov V. N. , Kadyraliev B. K. , Belov V. A. , Arutyunyan V. B. , Komarov R. N. , Semagin A. P. , Kuznetsov D. V. , Zybin A. A. , Gamzaev A. B. , Tlisov B. M. , Dzhambieva M. N. , Kolosova K. A. , Kdralieva N. V. 
Published: July 2024

Cardiac surgery research shows that isolated aortic valve (AV) procedures account for 9% of all cardiac surgeries, with a surgery mortality rate of 2.3% and the predominance of bioprosthese use. Despite the widespread use of these methods, there is a high rate of patient-prosthesis mismatch affecting long-term survival. In this context, new technologies are emerging, such as Tiara bioprostheses and Ozaki neocuspidization of AV, but their comparative analysis is currently lacking.

Aim: to compare short-term outcomes of the Tiara bioprosthesis implantation and the Ozaki procedure.

Methodology and Research Methods. Retrospective analysis of 387 patients who underwent Ozaki procedure or the Tiara bioprosthesis implantation was performed. Inclusion criteria are patient age 18 years or older, Ozaki procedure performed or the Tiara bioprosthesis implantation. Exclusion criteria are use of a mini-access, the presence of infective endocarditis and repeated cardiac surgery. Ultimately, 352 patients were selected. Given the statistically significant differences in clinical and demographic characteristics between the groups, a propensity score matching was used in a 1 : 1 ratio. As a result two balanced groups of 58 patients each were formed.

Results. In the group, where the Tiara bioprosthesis was implanted, the average age was 69 ± 5 years. In the group, where the Ozaki procedure was performed, the average age was 68 ± 6 years (p = 0.3). There were 14 men and 44 women in the Tiara group and 21 men and 37 women in the Ozaki group (p = 0.1). The median diameter of the annulus in the Tiara group was 20 (20–22) mm, while in the Ozaki group it was 21 (20–22) mm (p = 0.2). Statistically significant differences were noted in the duration of the surgery, cardiopulmonary bypass and cross-clamp time, which were statistically less in the Tiara group compared to the Ozaki group: surgery duration – 160 (145–199) minutes versus 250 (220–295) minutes (p < 0.001 ), cardiopulmonary bypass time – 72 (60–97) minutes versus 112 (92–133) minutes (p < 0.001), cross-clamp time – 55 (46–70) minutes versus 81 (71–100) minutes (p < 0.001). There was no statistically significant difference between the groups in terms of postoperative complications and hospital mortality. In-hospital mortality was 0% versus 2 (3.4%) cases (p = 0.4). Resternotomy due to bleeding was performed in 1 patient (1.7%) in the Tiara group and in 4 patients (6.9%) in the Ozaki group (p = 0.3). Pacemaker implantation was required in 2 patients (3.4%) in the Tiara group, whereas such a need did not arise in the Ozaki group (p = 0.4). Stroke occurred in 4 patients (6.9%) in the Tiara group and in 1 patient (1.7%) in the Ozaki group (p = 0.3). Acute kidney injury was recorded only in 1 patient in the Ozaki group (1.7%) (p = 1). Both groups had similar rates of patient-prosthesis mismatch; moderate discrepancy was noted in only one patient (1.7%) in the Tiara group; no such cases were recorded in the Ozaki group. However, significant differences were found in peak and mean gradients on AV. In the Tiara group, the peak gradient was 32 ± 12 mmHg, and the average was 17 (11–20) mmHg. In comparison, in the Ozaki group the average values were significantly lower: peak gradient – 11 ± 5 mmHg, average – 5 (3–8) mmHg. (p < 0.001 for both comparisons).

Conclusion. The study showed that the surgery duration, cardiopulmonary bypass, and myocardial ischemia period was statistically significantly shorter in the Tiara group compared with the Ozaki group. Despite this, transvalvular gradients on the AV were smaller in the Ozaki group.