Stented versus Stentless Aortic Valve Replacement in Patients with Small Aortic Root: A Systematic Review and Meta-Analysis

Sutureless Aortic Valve Replacement vs. Transcatheter Aortic Valve Implantation in Patients with Small Aortic Annulus: Clinical and Hemodynamic Outcomes from a Multi-Institutional Study

OBJECTIVE

This study aimed to compare hemodynamic performances and clinical outcomes of patients with small aortic annulus (SAA) who underwent aortic valve replacement by means of sutureless aortic valve replacement (SUAVR) or transcatheter aortic valve implantation (TAVI).

METHODS

From 2015 to 2020, 622 consecutive patients with SAA underwent either SUAVR or TAVI. Through a 1:1 propensity score matching analysis, two homogeneous groups of 146 patients were formed. Primary endpoint: all cause-death at 36 months. Secondary endpoints: incidence of moderate to severe patient-prosthesis mismatch (PPM) and incidence of major adverse cardiovascular and cerebrovascular events (MACCEs).

RESULTS

All-cause death at three years was higher in the TAVI group (SUAVR 12.2% vs. TAVI 21.0%, P=0.058). Perioperatively, comparable hemodynamic performances were recorded in terms of indexed effective orifice area (SUAVR 1.12 ± 0.23 cm2/m2 vs. TAVI 1.17 ± 0.28 cm2/m2, P=0.265), mean transvalvular gradients (SUAVR 12.9 ± 5.3 mmHg vs. TAVI 12.2 ± 6.2 mmHg, P=0.332), and moderate-to-severe PPM (SUAVR 4.1% vs. TAVI 8.9%, P=0.096). TAVI group showed a higher cumulative incidence of MACCEs at 36 months (SUAVR 18.1% vs. TAVI 32.6%, P<0.001). Pacemaker implantation (PMI) and perivalvular leak ≥ 2 were significantly higher in TAVI group and identified as independent predictors of mortality (PMI: hazard ratio [HR] 3.05, 95% confidence interval [CI] 1.34-6.94, P=0.008; PPM: HR 2.72, 95% CI 1.25-5.94, P=0.012).

CONCLUSION

In patients with SAA, SUAVR and TAVI showed comparable hemodynamic performances. Moreover, all-cause death and incidence of MACCEs at follow-up were significantly higher in TAVI group.

Comparative analysis of early postoperative results of transcatheter aortic valve implantation and surgical aortic valve replacement with a biological prosthesis

OBJECTIVE

. Aim: The choice of aortic valve stenosis correction method is determined by a number of clinical and technical parameters. The task was to compare early postoperative outcomes in patients after correction of aortic valve stenosis using TAVI and surgical aortic valve replacement with a biological prosthesis.

PATIENTS AND METHODS

Materials and Methods: This retrospective study analyzed the medical records of adult patients (18 years of age and older) who had transcatheter aortic valve implantation or surgical aortic valve replacement with a biological prosthesis at the State Institution "Heart Institute of the Ministry of Health" in the period from 2018 to 2022.

RESULTS

Results: In 47 (47.5%) cases, TAVI was performed and in 52 (52.5%) cases, SAVR with a biological prosthesis was performed. Patients who underwent TAVI were significantly older (p=0.002) and had a higher EuroSCORE II operative risk score (p<0.001). In patients with TAVI, larger diameter aortic valve prostheses were significantly more often used compared with the SAVR group with biological prosthesis (27.5±2.74 vs. 22.5±1.84, p<0.001). The early postoperative period in patients with TAVI was characterized by an 11.4% (p=0.046) and 15.4% (p=0.006). The length of stay in the ICU (p=0.024), as well as the duration of hospitalization in general (p=0.005), was also significantly lower in patients with TAVI compared with patients with biological prosthesis SAVR.

CONCLUSION

Conclusions: Despite the higher surgical risk of surgery according to EuroSCORE II, TAVI was characterized by a lower incidence of postoperative complications, with shorter duration of stay in ICU and hospitalization in general in comparison with patients undergoing SAVR with a biological prosthesis.

Structural abnormalities after aortic root replacement with stentless xenograft

OBJECTIVE

In complex and high-risk aortic root disease, the porcine Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, Minn) is an important surgical treatment option. We aimed to determine prevalence and clinical effect of structural and functional abnormalities after full-root Freestyle implantation.

METHODS

Our cross-sectional 2-center study combined with clinical follow-up included 253 patients with full-root Freestyle bioprostheses implanted from 1999 to 2017. Patients underwent transthoracic echocardiography (TTE) and contrast-enhanced, electrocardiogram-gated 4-dimensional cardiac computed tomography (4DCT) at median age 70 (interquartile range, 62-75) years. After 4DCT, clinical follow-up continued throughout 2018. Median follow-up was 3.3 years before 4DCT and 1.4 years after.

RESULTS

We identified abnormalities in 46% of patients, including pseudoaneurysms (n = 32; 13%), moderate or severe coronary ostial stenosis (n = 54; 21%), and moderate-severe leaflet thickening or reduced leaflet motion (n = 51; 20%). TTE only identified 1 patient with pseudoaneurysm. After 4DCT, the unadjusted hazard ratio for surgical reintervention among patients with abnormal 4DCT was 4.2 (95% confidence interval, 1.2-15.3), in all, 10% required a reintervention. 4DCT abnormalities were associated with a statistically nonsignificant increased risk of death, stroke, or myocardial infarction (hazard ratio obtained using Cox proportional hazards regression analysis, 2.4; 95% confidence interval, 0.7-7.6). In all, 4.0% died, 3.6% had a myocardial infarction, and 2.0% had a stroke.

CONCLUSIONS

Structural and functional abnormalities of the aortic root are frequent after Freestyle implantation and TTE appears to be insufficient for follow-up. Abnormalities might be associated with increased risk of reintervention and potentially adverse clinical outcomes. Longer follow-up and larger study populations are needed to further clarify the clinical implications of abnormalities identified with 4DCT.

Outcomes of bovine versus porcine surgical aortic valve replacement

INTRODUCTION

There are no guidelines regarding the use of bovine pericardial or porcine valves for aortic valve replacement, and prior studies have yielded conflicting results. The current study sought to compare short- and long-term outcomes in propensity-matched cohorts of patients undergoing isolated aortic valve replacement (AVR) with bovine versus porcine valves.

METHODS

This was a retrospective study utilizing an institutional database of all isolated bioprosthetic surgical aortic valve replacements performed at our center from 2010 to 2020. Patients were stratified according to type of bioprosthetic valve (bovine pericardial or porcine), and 1:1 propensity-score matching was applied. Kaplan-Meier survival estimation and multivariable Cox regression for mortality were performed. Cumulative incidence functions were generated for all-cause readmissions and aortic valve reinterventions.

RESULTS

A total of 1502 patients were identified, 1090 (72.6%) of whom received a bovine prosthesis and 412 (27.4%) of whom received a porcine prosthesis. Propensity-score matching resulted in 412 risk-adjusted pairs. There were no significant differences in clinical or echocardiographic postoperative outcomes in the matched cohorts. Kaplan-Meier survival estimates were comparable, and, on multivariable Cox regression, valve type was not significantly associated with long-term mortality (hazard ratio: 1.02, 95% confidence interval: 0.74, 1.40, p = .924). Additionally, there were no significant differences in competing-risk cumulative incidence estimates for all-cause readmissions (p = .68) or aortic valve reinterventions (p = .25) in the matched cohorts.

CONCLUSION

The use of either bovine or porcine bioprosthetic aortic valves yields comparable postoperative outcomes, long-term survival, freedom from reintervention, and freedom from readmission.

Stentless Versus Stented Aortic Valve Replacement for Aortic Stenosis

BACKGROUND

The differences in long-term outcomes of aortic valve replacement for aortic stenosis between stentless and stented bioprostheses are controversial.

METHODS

Between 2007 and 2018, 1173 patients underwent aortic valve replacement for aortic stenosis, including 559 treated with a stentless valve and 614 with a stented valve. A propensity score matched cohort with 348 pairs was generated by matching for age, sex, body surface area, bicuspid aortic valve, chronic lung disease, previous cardiac surgery, coronary artery disease, renal failure on dialysis, valve size, concomitant procedures, and surgeon. The primary endpoints of the study were long-term survival and incidence of reoperation.

RESULTS

Immediate postoperative outcomes were similar between the stentless and stented groups with an overall operative mortality of 2.9% (P = .19). Kaplan-Meier estimation for long-term survival was comparable between the stentless and stented valves in both the whole cohort and the propensity score matched cohort (10-year survival 59% vs 55%, P = .20). The hazard ratio of stentless vs stented valve for risk of long-term mortality was 1.12 (P = .33). The 10-year cumulative incidence of reoperation due to valve degeneration was 5.5% in the stentless group and 4.7% in the stented group (P = .25). The transvalvular pressure gradient at 5-year follow-up was significantly lower in the stentless group (7 vs 11 mm Hg, P < .001).

CONCLUSIONS

Both stented and stentless valves could be used in aortic valve replacement for aortic stenosis. We recommend stented valves for aortic valve replacement in patients with aortic stenosis for their simplicity of implantation.

Examination of the most cited studies on transcatheter aortic valve replacement with bibliometric analysis

AIM

The aim of this study is to analyze the studies on TAVI with the bibliometric method and to perform a scientiometric analysis of the top 100 most cited articles for researchers.

METHODS

The Thomson Reuters Web of Science database was searched for all relevant articles using the terms "TAVR" and "TAVI". The results were ordered according to the number of citations. We also analyzed the 100 most cited articles (T100) by annual average citation count (ACpY), years, research methods, author, institution, journal, funding agencies, and keywords. Analyses were also performed between the total number of citations, ACpY, impact factors, and publication time.

RESULTS

The article titled "Transcatheter Aortic-Valve Implantation for Aortic Stenosis in Patients Who Cannot Undergo Surgery" was the most cited article (n = 4616). The article titled "Transcatheter Aortic-Valve Replacement with a Balloon-Expandable Valve in Low-Risk Patients" had the highest ACpY count (n = 497). The United States was the country that contributed the most to the T100 list. While the journal that contributed the most with 32 articles was "Journal of the American College Of Cardiology", the journal in which the top 10 most cited articles were published most frequently was the "New England Journal of Medicine". In addition, the most publications were made in 2012.

CONCLUSION

Although this bibliometric analysis study has some limitations, it allows the most cited publications on TAVI to be analyzed systematically and provides scientific contributions.

Survival after aortic root replacement with a stentless xenograft is determined by patient characteristics

OBJECTIVES

Our objective was to examine intermediate-term survival and reinterventions in unselected patients, stratified according to indication, who received a Freestyle (Medtronic Inc, Minneapolis, Minn) bioprosthesis as a full aortic root replacement.

METHODS

Data from medical records were retrospectively collected for patients who had aortic root replacement using Freestyle bioprostheses between 1999 and 2018 at 6 North-Atlantic centers. Survival status was extracted from national registries and results stratified according to indication for surgery.

RESULTS

We included 1030 implantations in 1008 patients with elective indications for surgery: aneurysm (39.8%), small root (8.3%), and other (13.8%), and urgent/emergent indications: endocarditis (26.7%) and Stanford type A aortic dissection (11.4%). Across indications, 46.3% were nonelective cases and 34.0% were reoperations. Median age was 66.0 (interquartile range, 58.0-71.8) years and median follow-up was 5.0 (interquartile range, 2.6-7.9) years. Thirty-day mortality varied from 2.9% to 27.4% depending on indication. Intermediate survival for 90-day survivors with elective indications were not different from the general population standardized for age and sex (P = .95, .83, and .16 for aneurysms, small roots, and other, respectively). In contrast, patients with endocarditis and type A dissection had excess mortality (P < .001). Freedom from valve reinterventions was 95.0% and 94.4% at 5 and 8 years, respectively. In all, 52 patients (5.2%) underwent reinterventions, most because of endocarditis.

CONCLUSIONS

At intermediate term follow-up this retrospective study provides further support for the use of the Freestyle bioprosthesis in the real-world setting of diverse, complex, and often high-risk aortic root replacement and suggests that outcome is determined by patient and disease, rather than by prosthesis, characteristics.

Surgical aortic valve replacement in small aortic annulus

BACKGROUND

Although aortic valve replacement (AVR) has been the standard of treatment for severe aortic stenosis, a small aortic annulus (SAA) poses significant challenges. Improvements in valve designs and evolution in surgical techniques have led to improved outcomes, however, the ideal prosthetic valve remains elusive.

METHODS

We performed a comprehensive literature review to discuss the surgical management of aortic stenosis, with a special focus on patients with SAA.

RESULTS

Stentless valves and root replacement techniques have been shown to overcome the hemodynamic challenges associated with conventional stented bioprostheses, but are technically challenging and require longer cross-clamp times. Sutureless and rapid deployment valves mitigate the long operative time while maintaining the hemodynamic advantages. The use of transcatheter AVR has emerged as another reasonable alternative and has shown promise among patients with SAA, however, long-term outcomes are awaited.

CONCLUSION

There is no consensus regarding the type of valve prosthesis or replacement technique among patients with SAA. Consideration of patient comorbidities and valvular anatomy is paramount in planning the optimal strategy for AVR. Further long-term clinical trials are necessary to assess outcomes and achieve progress toward the development of the ideal prosthesis.

Bioprosthetic Aortic Valve Replacement in <50 Years Old Patients - Where is the Evidence?

Aortic valve disease is one of the most common valvular heart diseases in the cardiovascular category. Surgical replacement of the diseased aortic valve remains the definitive intervention for most diseases.

There is a clear consensus that in young patients who require aortic valve replacement, a mechanical prosthesis is the preferred choice due to its durable prosthesis without fear of wear and tear over time. However, this comes at the expense of increased risk of bleeding and thromboembolic events; in addition, there is a lack of strict evidence in using bioprosthesis in patients younger than 50 years. The objective of this review article is to assess the current evidence behind using bioprosthetic aortic valve in this young cohort.

TAVI and the future of aortic valve replacement

Aortic valve stenosis (AS) is the most common valvular pathology and has traditionally been managed using surgical aortic valve replacement (SAVR). A large proportion of affected patient demographics, however, are unfit to undergo major surgery given underlying comorbidities. Since its introduction in 2002, transcatheter aortic valve implantation (TAVI) has gained popularity and transformed the care available to different-risk group patients with severe symptomatic AS. Specific qualifying criteria and refinement of TAVI techniques are fundamental in determining successful outcomes for intervention. Given the successful applicability in high-risk patients, TAVI has been further developed and trialed in intermediate and low-risk patients. Within intermediate-risk patient groups, TAVI was shown to be noninferior to SAVR evaluating 30-d mortality and secondary endpoints such as the risk of bleeding, development of acute kidney injury, and length of admission. The feasibility of expanding TAVI procedures into low-risk patients is still a controversial topic in the literature. A number of trials have recently been published which demonstrate TAVI as noninferior and even superior over SAVR for primary study endpoints.