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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Adding vancomycin to perioperative prophylaxis decreases deep sternal wound infections in high-risk cardiac surgery patients.

OBJECTIVES: Perioperative prophylaxis with cephalosporins reduces sternal wound infections (SWIs) after cardiac surgery. However, more than 50% of coagulase-negative staphylococci, an important pathogen, are cephalosporin resistant. The aim of this study was to determine the impact of adjunctive vancomycin on SWIs in high-risk patients. METHODS: We conducted a pre- and postintervention study in an academic hospital. Preintervention (2010-2011), all patients received prophylaxis with 1.5 g of cefuroxime for 48 h. During the intervention period (2012-2013), high-risk patients additionally received 1 g of vancomycin. High-risk status was defined as body mass index ≤18 or ≥ 30 kg/m2, reoperation, renal failure, diabetes mellitus, chronic obstructive pulmonary disease or immunosuppressive medication. Time series analysis was performed to study SWI trends and logistic regression to determine the effect of adding vancomycin adjusting for high-risk status. RESULTS: A total of 3902 consecutive patients (n = 1915 preintervention and n = 1987 postintervention) were included, of which 1493 (38%) patients were high-risk patients. In the high-risk group, 61 of 711 (8.6%) patients had SWI before and 30 of 782 (3.8%) patients after the intervention. Focusing on deep SWI (DSWI), 33 of 711 (4.6%) patients had DSWI before and 13 of 782 (1.7%) patients afterwards; the absolute risk difference of 2.9% yielded a number-needed-to-treat of 34 to prevent 1 DSWI. Corrected for high-risk status, adding vancomycin significantly reduced the overall SWI rate (odds ratio 0.42, 95% confidence interval 0.26-0.67; P < 0.001) and the subset of DSWI (odds ratio 0.30, 95% confidence interval 0.14-0.62; P = 0.001). The rate of SWI in low-risk patients remained unchanged. CONCLUSIONS: Adding vancomycin to standard antibiotic prophylaxis in high-risk patients significantly reduced DSWI after cardiac surgery.

Pitfalls and premature failure of the Freedom SOLO stentless valve.

OBJECTIVES: This study reports a series of pitfalls, premature failures and explantation of the third-generation Freedom SOLO (FS) bovine pericardial stentless valve. METHODS: A total of 149 patients underwent aortic valve replacement using the FS. Follow-up was 100% complete with an average observation time of 5.5 ± 2.3 years (maximum 8.7 years) and a total of 825 patient-years. Following intraoperative documentation, all explanted valve prostheses underwent histological examination. RESULTS: Freedom from structural valve deterioration (SVD) at 5, 6, 7, 8 and 9 years was 92, 88, 80, 70 and 62%, respectively. Fourteen prostheses required explantation due to valve-independent dysfunction (n = 5; i.e. thrombus formation, oversizing, aortic dilatation, endocarditis and suture dehiscence) or valve-dependent failure (acute leaflet tears, n = 4 and severe stenosis, n = 5). Thus, freedom from explantation at 5, 6, 7, 8 and 9 years was 95, 94, 91, 81 and 72%, respectively. An acute vertical tear along the non-coronary/right coronary commissure to the base occurred at a mean of 6.0 years (range 4.3-7.3 years) and affected size 25 and 27 prostheses exclusively. Four FS required explantation after a mean of 7.5 years (range 7.0-8.3 years) due to severe functional stenosis and gross calcification that included the entire aortic root. CONCLUSIONS: The FS stentless valve is safe to implant and shows satisfying mid-term results in our single institution experience. Freedom from SVD and explantation decreased markedly after only 6-7 years, so that patients with FS require close observation and follow-up. Exact sizing, symmetric positioning and observing patient limitations are crucial for optimal outcome.

The Freedom Solo pericardial stentless valve: Single-center experience, outcomes, and long-term durability.

OBJECTIVES: To report our institutional experience and long-term results with the Freedom Solo bovine pericardial stentless bioprosthesis (Sorin Group, Saluggia, Italy). METHODS: Between January 2005 and November 2009, 149 patients (mean age, 73.6 ± 8.7 years; 68 [45.6%] female) underwent isolated (n = 75) or combined (n = 74) aortic valve replacement (AVR) using the Solo in our institution. Follow-up was 100% complete with an average follow-up time of 5.9 ± 2.6 years (maximum, 9.6 years) and a total of 885.3 patient years. RESULTS: Operative (30-day) mortality was 2.7% (1.3% for isolated AVR [n = 1] and 4.0% for combined procedures [n = 3]). All causes of death were not valve-related. Preoperative peak (mean) gradients of 74.2 ± 23.0 mm Hg (48.6 ± 16.3 mm Hg) decreased to 15.6 ± 5.4 mm Hg (8.8 ± 3.0 mm Hg) after AVR, and remained low for up to 9 years. The postoperative effective orifice area was 1.6 ± 0.57 cm(2), 1.90 ± 0.45 cm(2), 2.12 ± 0.48 cm(2), and 2.20 ± 0.66 cm(2) for the valve sizes 21, 23, 25, and 27, respectively, with absence of severe prosthesis-patient mismatch and 0.7% (n = 1) experienced moderate prosthesis-patient mismatch. During follow-up, 26 patients experienced structural valve deterioration (SVD) and 14 patients underwent explantation. Kaplan-Meier estimates for freedom from death, explantation, and SVD at 9 years averaged 0.57 (range, 0.47-0.66), 0.82 (range, 0.69-0.90), and 0.70 (range, 0.57-0.79), respectively. CONCLUSIONS: The Freedom Solo stentless aortic valve is safe to implant and shows excellent early and midterm hemodynamic performance. However, SVD was observed in a substantial number of patients after only 5-6 years and the need for explantation increased markedly, suggesting low durability.