Treatment options for isolated aortic valve insufficiency: a review

Aortic insufficiency (AI) is a valvular disease with increasing prevalence in older patients. The modern era provides numerous options for the management of AI which is explored here. Traditional interventions included aortic valve replacement with either mechanical or bioprosthetic aortic valves. While the former is known for its durability, it has grown out of favor due to the potential complications of anticoagulation. The preference for bioprosthetic valves is thus on the rise, especially with the advancements of transcatheter technology and the use of valve-in-valve therapy. Surgical options are also no longer limited to replacement but include complex techniques such as those required for aortic valve repair, Ozaki neocuspidization, Ross procedure and valve-sparring aortic root repair. Transcatheter options for the management of AI are not commercially available currently; however, preliminary data from ad-hoc trials, showed promising results and potential use of transcatheter technology in a variety of patients with pure AI.

Aortic root enlargement in patients undergoing mitral and aortic replacement: early outcomes in a sub-Saharan population

Introduction

Aortic root enlargement (ARE) is often required to avoid patient-prosthesis mismatch (PPM) in young patients undergoing aortic surgery, including those undergoing combined mitral and aortic valve replacement (double valve replacement, DVR). Adding ARE to DVR may increase the operative risk by extending the surgical time. Herein, we review our experience with ARE in patients who underwent DVR.

Materials and methods

The medical records of 69 patients who underwent DVR at our institution between February 2008 and November 2021 were retrospectively reviewed. The patients were divided into two groups according to the ARE procedure (ARE-DVR: 25 patients; DVR: 44 patients). Descriptive and comparative analyses of demographic, clinical, and surgical data were performed.

Results

Among the 69 patients who underwent DVR, 35 were women (sex ratio, 0.97). The mean age at surgery was 26.7  ±  13.9 years (range: 7-62 years). Among the 47 patients aged ≤30 years, 40.4% (19/47) were aged between 10 and 20 years, and 6.3% (3/47) were aged <10 years. Patients in the ARE-DVR group were younger (23.3 ± 12.9 years vs. 28.5 ± 14.2 years, p < 0.05). The New York Heart Association Class ≥III dyspnea was the most common symptom (89.9%), with no differences between the two groups. Of all the patients, 84.1% had sinus rhythm. Rheumatic disease was the most common etiology in the entire cohort (91.3%). The mean aortic annulus diameter was 20.54 mm, with smaller sizes found in the ARE-DVR group (18.00 ± 1.47 mm vs. 22.50 ± 2.35 mm, p < 0.05). The aortic cross-clamping duration was greater in the ARE-DVR group (177.6 ± 37.9 min vs. 148.3 ± 66.3 min, p = 0.047). The operative mortality rate was 5.6% for the entire cohort (ARE-DVR: 8% vs. DVR: 4.5%, p = 0.46). Among the patients who underwent echocardiographic control at follow-up, the mean aortic gradient was 19.6 ± 7.2 mmHg (range: 6.14-33 mmHg), with no differences among the groups.

Conclusion

The association between ARE and DVR did not significantly affect operative mortality. ARE can be safely used whenever indications arise to reduce the occurrence of PPM, especially in young patients with growth potential.

Prosthesis-Patient Mismatch and Aortic Root Enlargement: Indications, Techniques and Outcomes

Prosthesis-patient mismatch (PPM) is defined as implanting a prosthetic that is insufficiently sized for the patient receiving it. PPM leads to high residual transvalvular gradients post-aortic valve replacement and consequently results in left ventricular dysfunction, morbidity and mortality in both the short and long term. Younger patients and patients with poor preoperative left ventricular function are more vulnerable to increased mortality secondary to PPM. There is debate over the measurement of valvular effective orifice area (EOA) and variation exists in how manufacturers report the EOA. The most reliable technique is using in vivo echocardiographic measurements to create tables of predicted EOAs for different valve sizes. PPM can be prevented surgically in patients at risk through aortic root enlargement (ARE). Established techniques include the posterior enlargement through Nicks and Manouguian procedures, and aortico-ventriculoplasty with the Konno-Rastan procedure, which allows for a greater enlargement but carries increased surgical risk. A contemporary development is the Yang procedure, which uses a Y-shaped incision created through the non- and left-coronary cusp commissure, undermining the nadirs of the non- and left-coronary cusps. Early results are promising and demonstrate an ability to safely increase the aortic root by up to two to three sizes. Aortic root enlargement thus remains a valuable and safe tool in addressing PPM, and should be considered during surgical planning.

Effect of Prosthesis-Patient Mismatch on Long-Term Clinical Outcomes After Bioprosthetic Aortic Valve Replacement

BACKGROUND

Prosthesis-patient mismatch (PPM) is common following surgical aortic valve replacement (SAVR).

OBJECTIVES

The purpose of this study was to quantify the impact of PPM on all-cause mortality, heart failure hospitalization, and reintervention following bioprosthetic SAVR.

METHODS

This observational nationwide cohort study from SWEDEHEART (Swedish Web system for Enhancement and Development of Evidence based care in Heart disease Evaluated According to Recommended Therapies) and other national registers included all patients who underwent primary bioprosthetic SAVR in Sweden from 2003 to 2018. PPM was defined according to the Valve Academic Research Consortium 3 criteria. Outcomes were all-cause mortality, heart failure hospitalization, and aortic valve reintervention. Regression standardization was used to account for intergroup differences and to estimate cumulative incidence differences.

RESULTS

We included 16,423 patients (no PPM: 7,377 [45%]; moderate PPM: 8,502 [52%]; and severe PPM: 544 [3%]). After regression standardization, the cumulative incidence of all-cause mortality at 10 years was 43% (95% CI: 24%-44%) in the no PPM group compared with 45% (95% CI: 43%-46%) and 48% (95% CI: 44%-51%) in the moderate and severe PPM groups, respectively. The survival difference at 10 years was 4.6% (95% CI: 0.7%-8.5%) and 1.7% (95% CI: 0.1%-3.3%) in no vs severe PPM and no vs moderate PPM, respectively. The difference in heart failure hospitalization at 10 years was 6.0% (95% CI: 2.2%-9.7%) in severe vs no PPM. There was no difference in aortic valve reintervention in patients with or without PPM.

CONCLUSIONS

Increasing grades of PPM were associated with long-term mortality, and severe PPM was associated with increased heart failure. Moderate PPM was common, but the clinical significance may be negligible because the absolute risk differences in clinical outcomes were small.

Impact of Aortic Root Enlargement on Patients Undergoing Aortic Valve Replacement

BACKGROUND

Aortic root enlargement (ARE) can be an important adjunct for aortic valve replacement (AVR). This study compared outcomes of AVR with or without ARE.

METHODS

This was an observational study using an institutional database of AVRs from 2010 to 2020 comparing patients who underwent isolated AVR vs AVR with ARE (AVR+ARE). Kaplan-Meier survival estimation and Cox regression were performed.

RESULTS

Of 2371 patients, 2240 (94.5%) underwent isolated AVR and 131 (5.5%) underwent AVR+ARE. Patients who underwent AVR+ARE were more likely to be women and to be younger than those who underwent isolated AVR. Prosthesis size was smaller in patients undergoing AVR+ARE (23 mm [interquartile range {IQR}, 21-25] vs 25 mm [IQR, 23-25], P < .001), but indexed effective orifice area did not differ between the 2 groups. Operative mortality was comparable for AVR (2.3%) and AVR+ARE (3.8%, P = .28). Patients who underwent AVR+ARE had a longer length of stay (7 days [IQR, 6-13] vs 6 days [IQR 5-10], P < .001), were more likely to have acute kidney injury (6.1% vs 2.5%, P = .01), were more likely to require blood product transfusions (40.5% vs 27.6%, P < .001), and were more likely to require prolonged ventilation > 24 hours (16.0% vs 6.8%, P < .001). Rates of stroke, atrial fibrillation, permanent pacemaker, and reoperation were comparable between groups. Kaplan-Meier survival estimates were similar, and on multivariable regression AVR+ARE was not associated with an increased hazard of death as compared with AVR (hazard ratio, 1.09; 95% confidence interval, 0.81-1.46; P = .59).

CONCLUSIONS

ARE can be safely performed with isolated AVR and should be considered for patients with small annuli to avoid prosthesis-patient mismatch.

Bioprosthetic Aortic Valve Hemodynamics: Definitions, Outcomes, and Evidence Gaps: JACC State-of-the-Art Review

A virtual workshop was organized by the Heart Valve Collaboratory to identify areas of expert consensus, areas of disagreement, and evidence gaps related to bioprosthetic aortic valve hemodynamics. Impaired functional performance of bioprosthetic aortic valve replacement is associated with adverse patient outcomes; however, this assessment is complicated by the lack of standardization for labelling, definitions, and measurement techniques, both after surgical and transcatheter valve replacement. Echocardiography remains the standard assessment methodology because of its ease of performance, widespread availability, ability to do serial measurements over time, and correlation with outcomes. Management of a high gradient after replacement requires integration of the patient's clinical status, physical examination, and multimodality imaging in addition to shared patient decisions regarding treatment options. Future priorities that are underway include efforts to standardize prosthesis sizing and labelling for both surgical and transcatheter valves as well as trials to characterize the consequences of adverse hemodynamics.

Modified Manouguian technique for aortic root enlargement: A case series

BACKGROUND

Manouguian aortic root enlargement (ARE) has been a standard root enlargement procedure to assist in patients with a small annular size. We describe a modification to the Manouguian ARE similar to Yang et al. This approach could serve as an alternate technique for performing ARE; to date only case reports have defined this approach and no studies have evaluated its efficacy or safety.

METHODS

A retrospective case series was performed on patients who underwent ARE for surgical aortic valve replacement via the modified Manouguian procedure at a single institution. Thirteen patients were identified between 2015 and 2021, and all surgeries were performed by a single operator. Data were collected via the Society of Thoracic Surgeons database and chart review. The primary outcome was difference in valve size after the procedure.

RESULTS

The most common indication for surgery was aortic stenosis (12, 92%), with the most common etiology being degenerative calcification (7, 54%). Congenital bicuspid or unicuspid valves were identified in five (38%) patients. The majority (10, 77%) of patients received a mechanical valve. This procedure was successfully performed in all 13 of the patients. Additionally, 13 of the 13 patients (100%) were upsized to a satisfactory valve size based on preoperative echocardiography sizing.

CONCLUSIONS

The modified Manouguian aortic enlargement technique can be safely and effectively used as an aortic enlargement procedure in a broad sample of patients.

Transcatheter Aortic Valve Replacement in Asia: Present Status and Future Perspectives

Over the last decade, based on evidence from multiple randomized clinical trials, transcatheter aortic valve replacement (TAVR) has become the established treatment for patients with symptomatic severe aortic stenosis. Despite the overwhelming expansion of TAVR in Western countries, the initial uptake and widespread adoption of this procedure have been relatively delayed in Asian countries, owing to the high cost of devices; limited local health and reimbursement policies; and lack of specific training/proctoring program, specialized heart team, or dedicated infrastructure. Furthermore, it has not yet been determined whether there are substantial interracial and ethnic differences in the clinical characteristics, comorbidities, and anatomic features, as well as procedural and long-term outcomes, in patients receiving TAVR. In this review, we provide not only a comprehensive look at the current status and outcomes of TAVR in Asian populations compared with those of Western populations but also a perspective on the future of TAVR in Asia.

Aortic valve neocuspidisation using xenologous pericardium versus bioprosthetic valve replacement

BACKGROUND

Surgical aortic valve replacement (SAVR) for aortic valve stenosis (AS) patients with small aortic root is associated with a higher rate of prosthesis-patient mismatch and suboptimal clinical outcomes. Aortic valve neocuspidisation using xenologous pericardium (xAVNeo) has shown favorable hemodynamic performance. The aim was to compare 6-year clinical outcomes of xAVNeo with SAVR.

METHODS

Between 2003-2018, 412 patients with severe AS and small aortic root received either xAVNeo (N=114) or bioprosthesis (N=298). After propensity matching, the cohort included 222 patients. The primary endpoints were early-, 6-year mortality and freedom from reoperation. Mean follow-up averaged 3.4±3.1 years and was 95% complete.

RESULTS

Early mortality was 8.1% for the SAVR group vs 9.9% for the xAVNeo group, OR 1.25 [CI95% 0.51-2.89]. The estimated survival probabilities at 6 years for the SAVR and xAVNeo cohorts were 89.9% and 88.8%, respectively, OR 1.07 [0.49-2.34]. Progressive degeneration of the neo-cusps resulted in mean gradients increase from 6.1±2.3 mmHg to 22.7±11.5 mmHg ( p<0.0001 ); cusp sclerosis was the most common indication for reoperation in the xAVNeo group with a linearised rate of 1.92% vs. 0.26% per patient-year, rate ratio = 7.41 [CI95% 0.95-333.7]. The freedom from reoperation was 84.8% at 6 years, inferior to that of the SAVR group (100%).

CONCLUSIONS

Early clinical outcome and 6-year survival following xAVNeo and SAVR was comparable. However, xAVNeo using bovine pericardium was associated with a higher rate of structural valve deterioration and inferior freedom from reoperation when compared to SAVR.

Aortic root widening: “pro et contra”

In patients with a small aortic annulus, the clinical benefits of aortic valve replacement depend on avoidance of patient-prosthesis mismatch as it is associated with reduced overall survival. Aortic root widening or enlargement is a useful technique to implant larger valve prosthesis to prevent patient-prosthesis mismatch. Posterior annular enlargement is the commonest technique used for aortic root enlargement. Consistent enlargement of the aortic root requires more extensive procedures like Manouguian or Konno-Rastan techniques. The patients commonly selected are younger patients with good life expectancy. However, caution is advised in applying this procedure in elderly patients, patients with heavily calcified annulus and when performing concomitant procedures. There is no definitive conclusion on the best material to use for the reconstruction of aortic annulus and aorta in aortic root enlargement procedures.

Analysis of various techniques of aortic root enlargement

Prosthesis-patient mismatch after aortic valve replacement is associated with increased morbidity and mortality. A myriad of techniques have been described for aortic root enlargement to circumvent this problem. We review the salient techniques with their merits, demerits, and results.

Aortic root enlargement: When and how

Aortic valve replacement is the definitive management for severe aortic stenosis. Intraoperatively, an aortic root enlargement (ARE) may be used to facilitate the implementation of a suitably sized prosthetic valve. This is to prevent patient prosthesis mismatch (PPM), a condition that causes a left ventricular outflow obstruction. There are four main techniques that are used to perform ARE, namely, Nicks, Manouguian, Nunez (modified Manouguian), and Kanno-Rastan procedures. They each involve incisions through different anatomical structures and allow a variety of valve sizes to be implanted. Studies prove that ARE effectively reduces the incidence of PPM. In addition, they show that there is no definitive link between ARE and perioperative mortality or other complications. There is a scarcity of literature exploring the comparative outcomes of each surgical technique. Therefore, further research is warranted for these procedures to be compared adequately. This review aims to summarise the available literature surrounding ARE with respect to three main questions. (1) What are the indications for ARE, (2) what surgical techniques exist to facilitate ARE, and (3) are there significant differences in patient outcomes when these surgical techniques are employed?

Immediate Outcomes of Aortic Valve Neocuspidization with Glutaraldehyde-treated Autologous Pericardium: a Multicenter Study

Objective

To determine the feasibility of aortic valve neocuspidization (AVNeo) with glutaraldehyde-treated autologous pericardium.

Methods

One hundred and seventy (170) AVNeo (84 males/86 females) were performed from January 2017 through March 2019 in three centers. All the records were prospectively collected and retrospectively reviewed.

Results

Most of the patients were older than 60 years and over 95% were operated for aortic stenosis. Preoperatively, pressure gradients were 69.9±21.3 mmHg for patients with aortic stenosis, and the surgical annular diameter was 21.0±2.0 mm for all patients. Effective orifice area (EOA) and indexed EOA (iEOA) averaged 0.7±0.3 cm² and 0.4±0.2 cm²/m² for patients with aortic stenosis before surgery, respectively. There was no conversion to prosthetic aortic valve replacement. Eight patients needed reoperation for bleeding, but no patient needed reoperation due to early infective endocarditis. There were five in-hospital deaths due to noncardiac cause. Compared to preoperative echocardiographic measurements, postoperative peak pressure gradient decreased significantly (-58.7±1.7 mmHg; P<0.001) and reached 11.2±5.6 mmHg, and mean pressure gradient also decreased significantly (-36.8±1.1 mmHg; P<0.001) and reached 6.0±3.5 mmHg. Accordingly, EOA and iEOA increased significantly 2.0 cm² and 1.0 cm²/m² (both P<0.001) to reach 2.7±0.6 cm² and 1.4±0.3 cm²/m² after surgery, respectively, with minimal significant aortic regurgitation (0.6% > mild).

Conclusion

AVNeo is feasible and reproducible with good clinical results. Hemodynamically, AVNeo produces immediate postoperative low-pressure gradients, large EOA, and minimal regurgitation of the aortic valve. Further studies are necessary to evaluate mid- and long-term evolution.

Impact of Prosthesis-Patient Mismatch on 1-Year Outcomes after Transcatheter Aortic Valve Implantation: Meta-analysis of 71,106 Patients

OBJECTIVES

This study sought to evaluate the impact of prosthesis-patient mismatch (PPM) on the risk of early-term mortality after transcatheter aortic valve implantation (TAVI).

METHODS

Databases (Medical Literature Analysis and Retrieval System Online [MEDLINE], Excerpta Medica dataBASE [EMBASE], Cochrane Controlled Trials Register [CENTRAL/CCTR], ClinicalTrials.gov, Scientific Electronic Library Online [SciELO], Latin American and Caribbean Literature on Health Sciences [LILACS], and Google Scholar) were searched for studies published until February 2019. PPM after TAVI was defined as moderate if the indexed effective orifice area (iEOA) was between 0.85 cm2/m2 and 0.65 cm2/m2 and as severe if iEOA ≤ 0.65 cm2/m2.

RESULTS

The search yielded 1,092 studies for inclusion. Of these, 18 articles were analyzed, and their data extracted. The total number of patients included who underwent TAVI was 71,106. The incidence of PPM after TAVI was 36.3% (25,846 with PPM and 45,260 without PPM). One-year mortality was not increased in patients with any PPM (odds ratio [OR] 1.021, 95% confidence interval [CI] 0.979-1.065, P=0.338) neither in those with moderate PPM (OR 0.980, 95% CI 0.933-1.029, P=0.423). Severe PPM was separately associated with high risk (OR 1.109, 95% CI 1.041-1.181, P=0.001).

CONCLUSION

The presence of severe PPM after TAVI increased early-term mortality. Although moderate PPM seemed harmless, the findings of this study cannot not rule out the possibility of it being detrimental, since there are other registries that did not address this issue yet.

Prosthesis-Patient Mismatch after Surgical Aortic Valve Replacement: Neither Uncommon nor Harmless

Prosthesis-patient mismatch (PPM) after surgical aortic valve replacement (SAVR) is an issue that has been overlooked (not to say neglected). Cardiac surgeons must bear in mind that this is a real problem that we must tackle. The purpose of this paper is to be a wake-up call to the surgical community by giving a brief overview of what PPM is, its incidence and impact on the outcomes. We also discuss the increasing role played by imaging for predicting and assessing PPM after SAVR (with which surgeons must become more acquainted) and, finally, we present some options to avoid PPM after the surgical procedure.