Long-term Fate of Dilated Ascending Aorta after Aortic Valve Replacement for Bicuspid Versus Tricuspid Aortic Valve Disease

Ascending Aortic Progression After Isolated Aortic Valve Replacement Among Patients with Bicuspid and Tricuspid Aortic Valves

OBJECTIVES

The aims of the present study were to compare the long-term outcomes for ascending aortic dilatation and adverse aortic events after isolated aortic valve replacement between patients with bicuspid aortic valve (BAV) and tricuspid aortic valve ( TAV).

METHODS

This retrospective study included 310 patients who had undergone isolated aortic valve replacement with an ascending aorta diameter ≤ 45 mm between January 2010 and September 2021. The patients were divided into BAV group (n=90) and TAV group (n=220). The differences in the dilation rate of the ascending aorta and long-term outcomes were analyzed.

RESULTS

Overall survival was 89 ± 4% in the BAV group vs. 75 ± 6% in the TAV group at 10 years postoperatively (P=0.007), yet this difference disappeared after adjusting exclusively for age (P=0.343). The mean annual growth rate of the ascending aorta was similar between the two groups during follow-up (0.5 ± 0.6 mm/year vs. 0.4 ± 0.5 mm/year; P=0.498). Ten-year freedom from adverse aortic events was 98.1% in the BAV group vs. 95.0% in the TAV group (P=0.636). Multivariable analysis revealed preoperative ascending aorta diameter to be a significant predictor of adverse aortic events (hazard ratio: 1.76; 95% confidence interval: 1.33 to 2.38; P<0.001).

CONCLUSION

Our study revealed that the long-term survival and the risks of adverse aortic events between BAV and TAV patients were similar after isolated aortic valve replacement. BAV was not a risk factor of adverse aortic events.

From Biomechanical Properties to Morphological Variations: Exploring the Interplay between Aortic Valve Cuspidity and Ascending Aortic Aneurysm

Background: This research explores the biomechanical and structural characteristics of ascending thoracic aortic aneurysms (ATAAs), focusing on the differences between bicuspid aortic valve aneurysms (BAV-As) and tricuspid aortic valve aneurysms (TAV-As) with non-dilated aortas to identify specific traits of ATAAs. Methods: Clinical characteristics, laboratory indices, and imaging data from 26 adult patients operated on for aneurysms (BAV-A: n = 12; TAV-A: n = 14) and 13 controls were analyzed. Biomechanical parameters (maximal aortic diameter, strain, and stress) and structural analyses (collagen fiber organization, density, fragmentation, adipocyte deposits, and immune cell infiltration) were assessed. Results: Significant differences in biomechanical parameters were observed. Median maximal strain was 40.0% (control), 63.4% (BAV-A), and 45.3% (TAV-A); median maximal stress was 0.59 MPa (control), 0.78 MPa (BAV-A), and 0.48 MPa (TAV-A). BAV-A showed higher tangential modulus and smaller diameter, with substantial collagen fragmentation (p < 0.001 vs. TAV and controls). TAV-A exhibited increased collagen density (p = 0.025), thickening between media and adventitia layers, and disorganized fibers (p = 0.036). BAV-A patients had elevated adipocyte deposits and immune cell infiltration. Conclusions: This study highlights distinct pathological profiles associated with different valve anatomies. BAV-A is characterized by smaller diameters, higher biomechanical stress, and significant collagen deterioration, underscoring the necessity for tailored clinical strategies for effective management of thoracic aortic aneurysm.

Progression of the ascending aorta diameter after surgical or transcatheter bicuspid aortic valve replacement

OBJECTIVES

Ascending aorta (AA) dilatation in patients with bicuspid aortic valve (AV) is related both to genetic and haemodynamic factors. The aim of this study is to compare late progression of AA dilatation in bicuspid AV patients undergoing surgical aortic valve replacement (SAVR) versus transcatheter aortic valve implantation (TAVI).

METHODS

Data of 189 consecutive patients who underwent AV replacement for severe bicuspid AV stenosis were prospectively collected. Patients who underwent SAVR were compared to patients who underwent TAVI. Indication to the procedure was validated by the institutional Heart Team. Aortic diameters were evaluated by transthoracic echocardiogram. Differences between preoperative and long-term follow-up AA diameters were compared in the 2 groups.

RESULTS

Between January 2015 and December 2021, 143 (76%) patients underwent SAVR and 46 (24%) patients underwent TAVI. At 4.6 (standard deviation 1.7) years follow-up, patients in the TAVI group showed significantly lower survival (P = 0.00013) and event-free survival (P < 0.0001). AA diameter progression was lower in surgical compared to transcatheter patients, 0.95 (0.60, 1.30) vs 1.65 (0.67, 2.63) mm, P = 0.02. AA diameter progression indexed for body surface area and height was lower in the surgical group: 0.72 (0.38, 1.05) vs 1.05 (0.39, 1.71) mm/m2, P = 0.02, and 0.59 (0.36, 0.81) vs 1.11 (0.44, 1.78) mm/m, P = 0.001, respectively. At multivariable linear regression analysis transcatheter procedure, baseline aortic diameter and paravalvular leak were significantly associated with increased postoperative AA dilatation.

CONCLUSIONS

Bicuspid AV patients who underwent SAVR, showed significantly less long-term AA diameter progression than patients who underwent transcatheter procedure.

Effect of transcatheter aortic valve replacement on ascending aorta dilatation rate in patients with tricuspid and bicuspid aortic stenosis

Objectives

The aim of the present study was to assess the differences between BAV and TAV patients with chronic moderate to severe or severe AS regarding presentation, incidence of TAVR, survival, ascending aorta diameter and dilatation rate before and after TAVR.

Methods

The study included 667 consecutive patients with chronic moderate to severe or severe AS from January 2012 and December 2022. Outcomes included all-cause mortality, incidence of TAVR, and ascending aorta diameter and dilatation rate.

Results

There were 185 BAV-AS and 482 TAV-AS patients, and BAV-AS patients were younger (67 vs 78 years, P = 0.027). Total follow-up was 4.5 years (IQR: 2.7-8.9 years), 290 patients underwent TAVR, and 165 patients died. The 8-year TAVR incidence was higher in BAV-AS (55% ± 4%) vs TAV-AS (41% ± 5%; P = 0.02). The 8-year survival was higher in BAV-AS (85% ± 6%) vs TAV-AS (71% ± 6%; P < 0.0001) and became insignificant after age adjustment (P = 0.33). The dilatation rate of ascending aorta was significantly faster in BAV-AS patients compared with TAV-AS patients before TAVR. However, the ascending aorta dilatation rate for BAV-AS and TAV-AS patients was not significantly different after TAVR.

Conclusions

Compared with TAV-AS, BAV-AS patients were younger and underwent TAVR more frequently, resulting in a considerable survival advantage. After TAVR, ascending aorta dilatation rates were similar in BAV-AS and TAV-AS patients, suggesting an important role of hemodynamics on ascending aorta dilatation in BAV-AS.

Aortic root replacement in the setting of a mildly dilated nonsyndromic ascending aorta

OBJECTIVE

There is controversy on how to address mild aortic root dilation during concomitant aortic valve replacement: composite aortic valve conduit replacement or separate ascending aorta and aortic valve replacement. We reviewed our experience to address the issue.

METHODS

We retrospectively reviewed 778 adult nonsyndromic patients with aortic root diameter 55 mm or less who received replacement of the ascending aorta and aortic valve from January 1994 to June 2017. Patients were divided into 2 groups based on the type of aortic root intervention: composite aortic valve conduit replacement in 406 patients (52%) and separate ascending aorta and aortic valve replacement in 372 patients (48%). Propensity matching was used to mitigate differences in baseline patient characteristics and produced 188 matched pairs.

RESULTS

Sinus of Valsalva diameter was 43 mm (39-47). Operative mortality occurred in 3 patients (2%) in the composite aortic valve conduit replacement group and in 5 patients (3%) in the separate ascending aorta and aortic valve replacement group (P = .470). Median follow-up was 9.6 years (8.4-10.1). Long-term mortality was similar in the 2 groups (P = .083). Repeat operation was performed in 13 patients (7%) in the composite aortic valve conduit replacement group and in 19 patients (10%) in the separate ascending aorta and aortic valve replacement group (P = .365). Sinus of Valsalva diameter decreased 2 mm (-4-0; median follow-up 41 months) in the propensity-matched separate ascending aorta and aortic valve replacement group.

CONCLUSIONS

In patients with mild aortic root dilation, separate ascending aorta and aortic valve replacement results in a similar risk of repeat operation and mortality in comparison with composite aortic valve replacement. Separate ascending aorta and aortic valve replacement is not associated with subsequent aortic root dilation on medium-term echocardiography follow-up.

Comparison of patients with bicuspid and tricuspid aortic valve in transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has emerged as a safe and effective alternative to surgery for aortic stenosis (AS). However, there are still differences in the procedural process and outcome of bicuspid aortic valve (BAV) treated with TAVI compared with tricuspid aortic valve.

AREAS COVERED

This review paper aims to summarize the main characteristics and clinical evidence of TAVI in patients with bicuspid and tricuspid aortic valves and compare the outcomes of TAVI procedure.

EXPERT OPINION

The use of TAVI in patients with BAV has shown similar clinical outcomes compared with tricuspid aortic valve. The efficacy of TAVI for challenging BAV anatomies remains a concern due to the lack of randomized trials. Detailed preprocedural planning is of great importance in low-surgical-risk BAV patients. A better understanding of which subtypes of BAV anatomy are at greater risk for adverse outcomes can potentially benefit the selection of TAVI or open-heart surgery in low surgical risk AS patients.

The Presence of Ascending Aortic Dilatation in Patients Undergoing Transcatheter Aortic Valve Replacement Is Negatively Correlated with the Presence of Diabetes Mellitus and Does Not Impair Post-Procedural Outcomes

Both relevant aortic valve stenosis (AS) and aortic valve insufficiency significantly contribute to structural changes in the ascending aorta (AA) and thus to its dilatation. In patients with severe AS undergoing transcatheter aortic valve replacement (TAVR), survival data regarding aortic changes and laboratory biomarker analyses are scarce.

METHODS

A total of 179 patients with severe AS and an available computed tomography were included in this retrospective study. AA was measured, and dilatation was defined as a diameter ≥ 40 mm. Thirty-two patients had dilatation of the AA. A further 32 patients from the present population with a normal AA were matched to the aortic dilatation group with respect to gender, age, body mass index and body surface area, and the resulting study groups were compared with each other. In addition to echocardiographic and clinical characteristics, the expression of cardiovascular biomarkers such as brain natriuretic peptide (BNP), soluble suppression of tumorigenicity-2 (sST2), growth/differentiation of factor-15 (GDF-15), heart-type fatty-acid binding protein (H-FABP), insulin-like growth factor binding protein 2 (IGF-BP2) and soluble urokinase-type plasminogen activator receptor (suPAR) was analyzed. Kaplan-Meier curves for short- and long-term survival were obtained, and Pearson's and Spearman's correlations were calculated to identify the predictors between the diameter of the AA and clinical parameters.

RESULTS

A total of 19% of the total cohort had dilatation of the AA. The study group with an AA diameter ≥ 40 mm showed a significantly low comorbidity with respect to diabetes mellitus in contrast to the comparison cohort with an AA diameter < 40 mm (p = 0.010). This result continued in the correlation analyses performed, as the presence of diabetes mellitus correlated negatively not only with the diameter of the AA (r = -0.404; p = 0.001) but also with the presence of aortic dilatation (r = -0.320; p = 0.010). In addition, the presence of AA dilatation after TAVR was shown to have no differences in terms of patient survival at 1, 3 and 5 years. There were no relevant differences in the cardiovascular biomarkers studied between the patients with dilated and normal AAs.

CONCLUSION

The presence of AA dilatation before successful TAVR was not associated with a survival disadvantage at the respective follow-up intervals of 1, 3 and 5 years. Diabetes mellitus in general seemed to have a protective effect against the development of AA dilatation or aneurysm in patients with severe AS.

Aortic Root Anatomy Is Related to the Bicuspid Aortic Valve Phenotype

BACKGROUND

Bicuspid aortic valve (BAV) is associated with an asymmetric (not circular) aortic root, resulting in variability in the aortic root diameter measurements obtained using different techniques. The objective of this study was to describe aortic root asymmetry, including its orientation in the thorax, in relation to the various phenotypes of BAV and its impact on aortic root diameter measurements obtained using transthoracic echocardiography.

METHODS

Aortic root asymmetry, orientation of the largest root diameter, and orientation of the valve opening were studied using computed tomographic scans of patients with BAV without significant aortic valve dysfunction referred for evaluation of a thoracic aortic aneurysm. Eighty-five patients with BAV were evaluated; BAV with fusion of the left and the right coronary cusps (L-R BAV), with or without raphe (n = 63), was compared with BAV with fusion of the right coronary and noncoronary cusps (N-R BAV), with or without raphe (n = 22).

RESULTS

Asymmetry of the aortic root and its orientation in the thorax can be predicted from BAV phenotype: orientation of the valve opening differed from orientation of the largest root diameter by nearly 75° in both groups. The angle of the largest root diameter with the reference sagittal plane was 64.3° in the L-R BAV group versus 143.1° in the N-R BAV group (P < .0001). Therefore, using the parasternal long-axis view on transthoracic echocardiography, in N-R BAV, the ultrasound beam is roughly parallel to the valve opening orientation and almost orthogonal to the maximum diameter of the root. On the contrary, in L-R BAV, the ultrasound beam is roughly perpendicular to the valve opening orientation and almost parallel to the maximum diameter of the root. Consequently, the parasternal long-axis view on transthoracic echocardiography significantly underestimates maximal aortic root diameter in N-R BAV and modestly underestimates root diameter in L-R BAV (-6.1 ± 0.96 vs -2.3 ± 0.47 mm, P = .0008).

CONCLUSIONS

Aortic root morphology in patients with BAV can be predicted by BAV phenotype: the largest root diameter is roughly perpendicular to the orientation of the valve opening. Therefore, echocardiographic measurements according to present recommendations (parasternal long-axis view) underestimate maximal diameter in patients with N-R BAV.

Prognostic effect of increased left ventricular wall thickness in severe aortic stenosis

Background

It is unclear whether increased left ventricular (LV) thickness is associated with worse clinical outcomes in severe aortic stenosis (AS). The aim of this study was to determine the effect of increased LV wall thickness (LVWT) on major clinical outcomes in patients with severe AS.

Methods and results

This study included 290 severe AS patients (mean age 69.4 ± 11.0 years; 136 females) between January 2008 and December 2018. For outcome assessment, the endpoint was defined as death from all causes, cardiovascular death, and the aortic valve replacement (AVR) surgery rate. During follow-up (48.7 ± 39.0 months), 157 patients had AVR, 43 patients died, and 28 patients died from cardiovascular causes. Patients with increased LVWT underwent AVR surgery much more than those without LVWT (60.0% vs. 39.0%, p < 0.001). Furthermore, in patients with increased LVWT, the all-cause and cardiovascular death rates were significantly lower in the AVR group than in the non-AVR group (8.8% vs. 27.3%, p < 0.001, 4.8%, vs. 21.0%, p < 0.001). Multivariate analysis revealed that increased LVWT, age, dyspnea, and AVR surgery were significantly correlated with cardiovascular death.

Conclusions

In patients with severe AS, increased LVWT was associated with a higher AVR surgery rate and an increased rate of cardiovascular death independent of other well-known prognostic variates. Thus, these findings suggest that increased LVWT might be used as a potential prognostic factor in severe AS patients.