Long-term survival after xenograft versus homograft aortic root replacement: Results from a prospective randomized trial

The Surgical Treatment of Infective Endocarditis: A Comprehensive Review

Infective endocarditis (IE) is a severe cardiac complication with high mortality rates, especially when surgical intervention is delayed or absent. This review addresses the expanding role of surgery in managing IE, focusing on the variation in surgical treatment rates, the impact of patient demographics, and the effectiveness of different surgical approaches. Despite varying global data, a notable increase in surgical interventions for IE is evident, with over 50% of patients undergoing surgery in tertiary centres. This review synthesizes information from focused literature searches up to July 2023, covering preoperative to postoperative considerations and surgical strategies for IE. Key preoperative concerns include accurate diagnosis, appropriate antimicrobial treatment, and the timing of surgery, which is particularly crucial for patients with heart failure or at risk of embolism. Surgical approaches vary based on valve involvement, with mitral valve repair showing promising outcomes compared to replacement. Aortic valve surgery, traditionally favouring replacement, now includes repair as a viable option. Emerging techniques such as sutureless valves and aortic homografts are explored, highlighting their potential advantages in specific IE cases. The review also delves into high-risk groups like intravenous drug users and the elderly, emphasizing the need for tailored surgical strategies. With an increasing number of patients presenting with prosthetic valve endocarditis and device-related IE, the review underscores the importance of comprehensive management strategies encompassing surgical and medical interventions. Overall, this review provides a comprehensive overview of current evidence in the surgical management of IE, highlighting the necessity of a multidisciplinary approach and ongoing research to optimize patient outcomes.

Valve-sparing aortic root replacement-for all patients?

BACKGROUND

Valve-sparing root replacement (VSRR) has been associated with good survival and low rates of valve-related complications (VRCs). Whether these advantages are present irrespective of patient comorbidity or age is unclear. The aim of this study was to analyze survival and frequency of VRCs in relation to patient comorbidity and age.

METHODS

Between October 1995 and December 2021, 1156 patients with a bicuspid or tricuspid aortic valve were treated by root remodeling. The mean patient age was 53.3 ± 14 years, and 973 (84%) were male. The mean duration of follow-up was 6.7 ± 5.5 years (median, 5.9 years), and follow-up was 95% complete (7746 patient-years). We analyzed the population according to comorbidity and age at surgery. A discriminating cutoff for the effect of age was determined using receiver operating characteristic curve (ROC) analysis.

RESULTS

Mean survival at 15 years was 74.7 ± 2.5%. Deceased patients were older (mean, 65.3 ± 12 years vs 51.6 ± 14.1 years; P < .001) at the time of surgery and had more comorbidities (coronary artery disease [CAD], 28.4% vs 9.8%; P < .001). The sole significant adjusted predictor was age (P < .001). By ROC analysis (area under the curve, 0.780), the optimal cutoff for age was 61 years. Survival was 87.1 ± 2.8% at 15 years in patients age <61 years, compared to 55.3 ± 4.3% in patients age >61 years (P < .0001). Using competing risk analysis, VRC-free survival at 15 years was 66.8% at 15 years, including 76.7% in patients age <61 years and 52.4% in those age >61 years (P < .0001).

CONCLUSIONS

VSRR is associated with a low incidence of VRC and excellent durability. Survival is decreased in the presence of comorbidities, mainly CAD, and patient age >61 years. Despite lower survival, freedom from VRC is good.

An In Vitro Model to Study Endothelialization of Cardiac Graft Tissues Under Flow

Pulmonary valve replacement is performed with excellent resultant hemodynamics in patients that have underlying congenital or acquired heart valve defects. Despite recent advancements in right ventricular outflow tract reconstruction, an increased risk of developing infective endocarditis remains, which has a more common occurrence for conduits of bovine jugular vein (BJV) origin compared with cryopreserved homografts. The reason for this is unclear although it is hypothesized to be associated with an aberrant phenotypic state of cells that reendothelialize the graft tissue postimplantation. The aim of this study was to develop an in vitro model that enables the analysis of endothelial cell (EC) attachment to cardiac graft tissues under flow. In the experiments, EC attachment was optimized on bovine pericardium (BP) patch using human umbilical vein ECs. Different biological coatings, namely gelatin, fibronectin, plasma, or a combination of fibronectin and plasma were tested. After cell adaptation, graft tissues were exposed to laminar flow in a parallel-plate flow chamber. Cell retention to the tissue was analyzed after nuclear staining with YO-PRO-1 and a membranous localization of VE-cadherin. Experiments showed that combined coating with fibronectin and blood plasma together with a two-phased shear pattern resulted in a relevant cell monolayer on BP patch and cryopreserved homograft. For BJV tissue, no adherent cells under both static and shear conditions were initially observed. In conclusion, having established the new flow chamber system we could obtain EC layers on the surface of BP patch and cryopreserved pulmonary homograft tissues. The presented in vitro system can serve as a competent model to study cell phenotypes on cardiac grafts in the close-to-physiologic environment. Moreover, this approach allows broad applications and enables further development by testing more complex conditions.

Long-term Outcomes of Aortic Valve Replacement With Aortic Homograft: 27 Years Experience

BACKGROUND

Aortic homografts have been used in young patients requiring aortic valve replacement. Currently, these grafts are generally reserved for aortic valve endocarditis with or without root abscess; however, longitudinal data are lacking. Our aim was to assess the long-term safety and durability of homograft implantation.

METHODS

All adult patients undergoing aortic homograft implantation at a single institution from 1992 to 2019 were included. Outcomes of interest included all-cause mortality and aortic valve reoperation, studied over a median follow-up duration of 19 years.

RESULTS

In all, 252 patients with a mean age of 49 years were included. Infective endocarditis was the primary indication for surgery in 95 patients (38%). The endocarditis group, compared with the no-endocarditis group, had a higher prevalence of New York Heart Association class III-IV (56% vs 26%), chronic kidney disease (22% vs 1%), prior cardiac surgery (40% vs 10%), and emergency status (7% vs 0%; all P < .001). Operative mortality was higher among endocarditis patients (16% vs 0.6%, P < .001), which persisted after risk adjustment. Among patients who survived to discharge, however, there was no difference in long-term survival between the endocarditis group and no-endocarditis group. Overall survival and freedom from reoperation were 88.3% and 80% at 15 years and 87.2% and 78% at 25 years, respectively. Indications for reoperation included structural valve deterioration (83%), endocarditis (12%), and mitral valve disease (5%). Reoperative mortality occurred in 2 patients (4.9%).

CONCLUSIONS

Aortic homografts are associated with good long-term survival and admissible freedom from reoperation. Operative mortality is high among patients with endocarditis; however, for those who survive to discharge, long-term survival and durability are the same as for patients without endocarditis.