Aortic valve repair--current status, indications, and outcomes

Contemporary Evaluation and Clinical Treatment Options for Aortic Regurgitation

Aortic regurgitation (AR) is the third most frequent form of valvular disease and has increasing prevalence with age. This will be of increasing clinical importance with the advancing age of populations around the globe. An understanding of the various etiologies and mechanisms leading to AR requires a detailed understanding of the structure of the aortic valve and aortic root. While acute and chronic AR may share a similar etiology, their hemodynamic impact on the left ventricle (LV) and management are very different. Recent studies suggest current guideline recommendations for chronic disease may result in late intervention and suboptimal outcomes. Accurate quantitation of ventricular size and function, as well as grading of the severity of regurgitation, requires a multiparametric and multimodality imaging approach with an understanding of the strengths and weaknesses of each metric. Echocardiography remains the primary imaging modality for diagnosis with supplemental information provided by computed tomography (CT) and cardiac magnetic resonance imaging (CMR). Emerging transcatheter therapies may allow the treatment of patients at high risk for surgery, although novel methods to assess AR severity and its impact on LV size and function may improve the timing and outcomes of surgical intervention.

Aortic valve repair decreases risks of VRE in AI at 10 years: a propensity score-matched analysis

BACKGROUND

Aortic valve repair(AVr) has emerged as a feasible and effective alternative to replacement(AVR) in patients with aortic insufficiency(AI), however, little data exists comparing outcomes. Thus, the objective of this study was to compare early and long-term valve related complications between AVr and AVR in the treatment of AI.

METHODS

Single centre, retrospective study of all patients(n=417) undergoing AVr (n=264) or AVR (n=153) for primary AI. Propensity-matching using a 1:1 greedy matching algorithm identified 140 patients using six covariates (age, gender, LV function, size, presence of aortopathy, and urgency of operation) for comparison. The primary outcome was a composite of all valve-related events(VRE), including: endocarditis, myocardial infarction(MI), stroke, transient ischemic attack(TIA), thromboembolisms, bleeding, and aortic valve(AV) reoperation. VRE were defined as per published guidelines. Survival and freedom from VRE were reported using the Kaplan-Meier method.

RESULTS

Propensity-matching identified 70 well matched pairs with no major differences in baseline demographics, comorbidities, or AI severity(p=0.57). Perioperative outcomes showed no significant differences in VRE (AVR 8 vs AVr 7,p=0.78) or mortality (AVR 3 vs AVr 1,p=0.62). Event-free survival from the primary outcome at 10-years was significantly better after AVr than after AVR (82%vs68%,p=0.024), with no significant differences in 10-year overall survival between groups(82%vs72%,p=0.29). No significant differences in AI severity(p=0.07) or reoperation rate(p=0.44) were detected between groups.

CONCLUSIONS

This study demonstrated a lower long-term risk of VRE with repair compared to replacement, with low mortality and comparable durability. Further prospective randomized control trials are necessary to formally compare outcomes and determine superiority.

The American Association for Thoracic Surgery consensus guidelines on bicuspid aortic valve-related aortopathy: Full online-only version

Bicuspid aortic valve disease is the most common congenital cardiac disorder, being present in 1% to 2% of the general population. Associated aortopathy is a common finding in patients with bicuspid aortic valve disease, with thoracic aortic dilation noted in approximately 40% of patients in referral centers. Several previous consensus statements and guidelines have addressed the management of bicuspid aortic valve-associated aortopathy, but none focused entirely on this disease process. The current guidelines cover all major aspects of bicuspid aortic valve aortopathy, including natural history, phenotypic expression, histology and molecular pathomechanisms, imaging, indications for surgery, surveillance, and follow-up, and recommendations for future research. It is intended to provide clinicians with a current and comprehensive review of bicuspid aortic valve aortopathy and to guide the daily management of these complex patients.

Changing trends in aortic valve procedures over the past ten years-from mechanical prosthesis via stented bioprosthesis to TAVI procedures-analysis of 50,846 aortic valve cases based on a Polish National Cardiac Surgery Database

Background

Aortic valve replacement (AVR) is one of the most common surgeries performed in cardiac surgery operating rooms. We present actual, real life trends from the last 10 years for AVR interventions based on a multicentre National Registry of Cardiac Surgery Database.

Methods

The study population consisted of all 50,846 consecutive adult patients who underwent AVR between January 2006 and August 2016 in all cardiac surgery units in Poland. The main outcome measures were changes in the number of valves, characteristics of valves, operative details, and in-hospital mortality. Analysis consisted of all aortic valve (AV) procedures, including isolated AV surgery, combination procedures and patients who had a prior valve operation.

Results

In last 10 years, the number of procedures increased by 46%. Isolated surgical AVR was performed in 61.2%, AVR + coronary artery bypass grafting (CABG) in 23.9%, AVR + mitral valve replacement (MVR) in 7%, and transcatheter aortic valve implantation (TAVI) in 2.3% of patients. The mean patient age increased significantly from 61.4 years in 2006 to 66.1 years in 2016. Aortic stenosis was diagnosed in 73.4%, severe aortic insufficiency in 15.8% of cases. The most common valve pathology was calcification. Congenital valve dysfunction was diagnosed in 3.7% of cases. There was a 33.7% increase of bioprosthesis, and the most common implanted bioprosthesis was the Hancock II. The most common implanted mechanical prosthesis was the St. Jude Medical Mechanical Valve. In-hospital mortality decreased significantly over the 10-year period in all AV procedures from 10.9% in 2006 to 8.3% in 2016. Mean in-hospital mortality was: 4.0% in isolated surgical AVR, 5.4% in TAVI, 6.8% in AVR + CABG, 9.8% in AVR + MVR, 17.2% in AVR + MVR + CABG.

Conclusions

In the last ten years, the number of AV procedure has doubled. Mortality was significantly lower with all types of AV procedure despite very rapid aging of AVR patients. TAVI procedure rapidly grew in popularity. There is significant increase in the use of bioprosthesis.

Bicuspid aortic valve disease: systematic review and meta-analysis of surgical aortic valve repair

Aortic valve repair is still emerging, and its role in the treatment of bicuspid aortic valve disease (BAVD) is not yet fully understood. Our objective is to synthesise available evidence on outcomes after surgical aortic valve repair in patients with BAVD. We conducted a systematic review of clinical studies using prespecified methods for searching, identifying and selecting eligible studies in 4 databases, and synthesising results (PROSPERO 2014:CRD42014014415). 2 researchers independently reviewed full-text articles and extracted data. The results of included studies were quantitatively synthesised in frequentist meta-analyses. We included 11 aortic valve repair studies or study arms with a total of 2010 participants. Pooled estimates for the proportion of patients surviving at 30 days, 1 year, 5 years and 10 years were 0.995 (95% CI 0.991 to 0.995), 0.994 (0.989 to 0.999), 0.945 (0.898 to 0.993) and 0.912 (0.845 to 0.979), respectively. The pooled proportion of late deaths from valve-related causes was 0.008 (0.000 to 0.019) at a mean follow-up of 3.5 years. Proportion of patients with valve-related reinterventions was 0.075 (0.037 to 0.113) at a mean follow-up of 3.9 years, and the linearised reintervention rate was 1.3 (0.7 to 1.9) per 100 patient-years. Outcome reporting was insufficient to pool the results for a number of predefined outcomes. In conclusion, existing evidence on aortic valve repair in BAVD is limited to mostly small case series, case-control and small retrospective cohort studies. Despite the low quality, available evidence suggests favourable survival outcomes after aortic valve repair in selected patients with BAVD. Valve-related reinterventions at follow-up are common in all patients undergoing repair surgery.

Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering

Major challenge in heart valve tissue engineering for paediatric patients is the development of an autologous valve with regenerative capacity. Hybrid tissue engineering approach is recently gaining popularity to design scaffolds with desired biological and mechanical properties that can remodel post implantation. In this study, we fabricated aligned nanofibrous Bio-Hybrid scaffold made of decellularized bovine pericardium: polycaprolactone-chitosan with optimized polymer thickness to yield the desired biological and mechanical properties. CD44⁺, αSMA⁺, Vimentin⁺ and CD105^- human valve interstitial cells were isolated and seeded on these Bio-Hybrid scaffolds. Subsequent biological evaluation revealed interstitial cell proliferation with dense extra cellular matrix deposition that indicated the viability for growth and proliferation of seeded cells on the scaffolds. Uniaxial mechanical tests along axial direction showed that the Bio-Hybrid scaffolds has at least 20 times the strength of the native valves and its stiffness is nearly 3 times more than that of native valves. Biaxial and uniaxial mechanical studies on valve interstitial cells cultured Bio-Hybrid scaffolds revealed that the response along the axial and circumferential direction was different, similar to native valves. Overall, our findings suggest that Bio-Hybrid scaffold is a promising material for future development of regenerative heart valve constructs in children.

Cusp repair during aortic valve-sparing operation: technical aspects and impact on results

AIMS

Aortic valve-sparing operations are nowadays considered safe and reliable procedures in terms of mid-term and long-term results. Although surgical techniques regarding the modality of grafts' implantation have been properly addressed, the modality of cusp repair, when needed, is still open to debate. We sought to review the literature to try to shed light on when the cusp repair is required and how it should be performed.

METHODS

We searched the PubMed database using the keywords aortic valve-sparing operation, aortic valve-sparing reimplantation, valve-sparing aortic root replacement, aortic valve repair, and aortic cusp repair. Only studies that included and described in detail the technique of cusp repairs in adjunct to aortic valve-sparing operation were considered.

RESULTS

Bicuspid aortic valve more often requires correction when compared with tricuspid valve. The range of the techniques varies from the 'simple' free margin plication to the more complex triangular resection with patch repair. Results in the literature seem to be encouraging, showing that, in most of the cases, cusp repair does not affect valve competence in the mid-term and long-term.

CONCLUSION

Correction of the cusp is a delicate balance between undercorrection that could lead to residual prolapse and overcorrection that could lead to cusp restriction. Although complex repair of the aortic valve in addition to root replacement provided satisfactory results, it should be reserved for experienced centers with a large volume of patients.