Reduced Permanent Pacemaker Implantation in Patients With Stentless Freedom SOLO Compared With Stented Perimount Magna Aortic Bioprostheses: A Propensity Score Weighted Analysis

Abstract

Postoperative permanent pacemaker implantation (PPI) after conventional aortic valve replacement (AVR), due to new-onset severe conduction system disorders, is required in approximately 7% of patients. This study investigated the need for PPI after AVR with conventional stented Perimount Magna compared with the Freedom SOLO (FS) stentless valve (Sorin Group, Saluggia, Italy), now LivaNova plc (London, UK) that uses a strictly supra-annular, subcoronary running suture implantation technique, sparing the vulnerable interleaflet triangles in the region of the septum membranaceum. A total of 413 consecutive patients (71.4±9.2 yrs, 178 [43.1%] female) underwent isolated AVR using the stented Perimount Magna (n=264) or the stentless FS (n=149) bioprosthesis. Propensity score weighted analysis was used to account for patient-specific and procedural-specific variables, and to identify the prosthesis-specific need for early postoperative PPI within 30 days of AVR. Twenty (20) patients required PPI, which was associated with longer intensive care unit (2.1±1.7 vs 1.5±3.0 days, p<0.001) and overall hospital stays (13.8±5.2 vs 10.7±5.3 days, p<0.001) compared with no PPI. Propensity weighted logistic regression including cross-clamp times identified that use of the stented Perimount Magna was associated with increased need for PPI, as compared with the FS, with an odds ratio 5.8 (95% CI, 1.09-30.76; p=0.039). After corrections for all plausible confounders, AVR with the stented Perimount valve was associated with an odds ratio of almost 6 for an increased early postoperative need for pacemaker implantation compared with the FS stentless valve. This finding can be explained by the conventional implantation technique, which is potentially associated with mechanical trauma to the conducting system.