Degenerative aortic valve disease represents the most prevalent valvular condition in our setting, with aortic valve replacement being the treatment of choice for severe cases. In recent years, new valve replacement techniques have emerged, blending traditional surgical aortic valve replacement (SAVR) principles with transcatheter aortic valve implantation (TAVI) approaches. This development has led to the advent of sutureless (SS) and rapid-deployment (RD) bioprostheses. 

The aim of this study is to determine whether the need for permanent pacemaker implantation is genuinely higher in SS and RD prostheses, to investigate underlying mechanisms, and to clarify potential confounding factors. 

This investigation is based on data from the SURD-IR international multicenter registry, involving 19 centers. A total of 4166 patients undergoing SAVR between January 2008 and April 2019 were included and divided into two cohorts for subgroup analysis due to structural differences between the prosthesis types: sutureless (SS) and rapid-deployment (RD). The incidence of permanent pacemaker implantation during hospitalization was analyzed. A reduction in implantation rates from 8.1% to 5.9% across the study population was observed starting in 2017, leading to the division of each cohort into early and late groups based on this finding. 

Patients in the late group were significantly younger and had lower EuroSCORE II values in both cohorts. In the SS cohort, the late group showed not only younger age but also a significantly higher incidence of aortic regurgitation. Although smaller prostheses were increasingly used, the reduction in pacemaker implantation rates was also significant with the use of larger prostheses (L and XL). The incidence of concomitant procedures (mainly revascularization and myectomies) also decreased significantly in the late group compared to the early group. 

In patients receiving an RD prosthesis, the incidence of concomitant procedures, particularly septal myectomy, increased from 1.9% to 3.8% in the late group, with a nonsignificant increase in pacemaker implantation rates observed in this group as well. 

This study indicates a decrease in pacemaker implantation in SS prostheses while remaining stable in RD prostheses. However, significant temporal differences, such as the reduction in mean age or lower incidence of pure stenosis, should be considered. Appropriate patient selection and greater precision in prosthesis sizing may explain these findings. 

Limitations of this study may include variations in data collection as it is a multicenter, retrospective study. Additionally, the main focus is conduction disturbances, yet preoperative electrocardiographic data are not provided. 

COMMENTARY:
In recent years, significant changes have occurred in the treatment of aortic valve disease, and the introduction of transcatheter prostheses has revitalized valve replacement techniques. The emergence of sutureless and rapid-deployment bioprostheses offers advantages such as reduced ischemia and extracorporeal circulation times. However, concerns about potentially higher complication rates compared to conventional SAVR have limited their use. 

One such complication is the need for permanent pacemaker implantation, traditionally higher than with conventional SAVR and comparable to TAVI. This study aims to clarify some of the mechanisms underlying the increased pacemaker incidence, using a well-divided cohort design. Although both types of bioprostheses (SS and RD) share common characteristics, they are structurally distinct, potentially explaining differing incidence rates. However, the real differentiating factor in the results is that the temporal subgroups in the SS cohort are not comparable, given the significant differences in baseline patient characteristics. 

It is in these differences that we should perhaps focus, as it is among younger patients with a lower incidence of severe stenosis that sutureless prosthesis outcomes improve substantially. This finding echoes an established lesson: appropriate patient selection often yields better outcomes. 

Consequently, innovations initially designed to meet the needs of older patients requiring shorter surgical times may also be suitable solutions for lower-risk patients, allowing them to benefit from the same advantages without incurring higher complication rates. 

REFERENCE:

Pollari F, Berretta P, Albertini A, Carrel T, Teoh K, Meuris B, et al. Pacemaker after Sutureless and Rapid-Deployment Prostheses: A Progress Report from the SURD-IR. Thorac Cardiovasc Surg. 2023 Oct;71(7):557-565. doi: 10.1055/s-0042-1757778.