Contemporary differences between bicuspid and tricuspid aortic valve in chronic aortic regurgitation

Left ventricular reverse remodeling after aortic valve replacement or repair in bicuspid aortic valve with moderate or greater aortic regurgitation

Objective

Bicuspid aortic valve (AV) patients with aortic regurgitation (AR) differ from tricuspid AV patients given younger age, greater left ventricle (LV) compliance, and more prevalent aortic stenosis (AS). Bicuspid AV-specific data to guide timing of AV replacement or repair are lacking.

Methods

Adults with bicuspid AV and moderate or greater AR who underwent aortic valve replacement or repair at our center were studied. The presurgical echocardiogram, and echocardiograms within 3 years postoperatively were evaluated for LV geometry/function, and AV function. Semiquantitative AS/AR assessment was performed in all patients with adequate imaging.

Results

One hundred thirty-five patients (85% men, aged 44.5 ± 15.9 years) were studied (63% pure AR, 37% mixed AS/AR). Following aortic valve replacement or repair, change in LV end-diastolic dimension and change in LV end-diastolic volume were associated with preoperative LV end-diastolic dimension (β = 0.62 Δcm/cm; 95% CI, 0.43-0.73 Δcm/cm; P < .001), and LV end-diastolic volume (β = 0.6 ΔmL/mL; 95% CI, 0.4-0.7 ΔmL/mL; P < .001), respectively, each independent of AR/AS severity (P = not significant). Baseline LV size predicted postoperative normalization (LV end-diastolic dimension: odds ratio, 3.75/cm; 95% CI, 1.61-8.75/cm, LV end-diastolic volume: odds ratio, 1.01/mL; 95% CI, 1.004-1.019/mL, both P values < .01) whereas AR/AS severity did not (P = not significant). Indexed LV end diastolic volume outperformed LV end-diastolic dimension in predicting postoperative LV normalization (area under the curve = 0.74 vs 0.61) with optimal diagnostic cutoffs of 99 mL/m2 and 6.1 cm, respectively. Postoperative indexed LV end diastolic volume dilatation was associated with increased risk of death, transplant/ventricular assist device, ventricular arrhythmia, and reoperation (hazard ratio, 6.1; 95% CI, 1.7-21.5; P < .01).

Conclusions

Remodeling extent following surgery in patients with bicuspid AV and AR relates to preoperative LV size independent of valve disease phenotype or severity. Many patients with LV end-diastolic dimension below current surgical thresholds did not normalize LV size. LV volumetric assessment offered superior diagnostic performance for predicting residual LV dilatation, and postoperative indexed LV end diastolic volume dilatation was associated with adverse prognosis.

Imaging Methods for Evaluation of Chronic Aortic Regurgitation in Adults: JACC State-of-the-Art Review

A global multidisciplinary workshop was convened to discuss the multimodality diagnostic evaluation of aortic regurgitation (AR). Specifically, the focus was on assessment tools for AR severity and analyzing evolving data on the optimal timing of aortic valve intervention. The key concepts from this expert panel are summarized as: 1) echocardiography is the primary imaging modality for assessment of AR severity; however, when data is incongruent or incomplete, cardiac magnetic resonance may be helpful; 2) assessment of left ventricular size and function is crucial in determining the timing of intervention; 3) recent evidence suggests current cutpoints for intervention in asymptomatic severe AR patients requires further scrutiny; 4) left ventricular end-systolic volume index has emerged as an additional parameter that has promise in guiding timing of intervention; and 5) the role of additional factors (including global longitudinal strain, regurgitant fraction, and myocardial extracellular volume) is worthy of future investigation.

Magnetic resonance analysis of ventricular volumes in bicuspid and trileaflet aortic regurgitation

OBJECTIVE

To identify differences in left ventricular (LV) remodelling between patients with bicuspid aortic valve (BAV) and trileaflet aortic valve (TAV) with chronic aortic regurgitation (AR).

METHODS

Retrospective cohort study of 210 consecutive patients undergoing cardiac magnetic resonance for AR evaluation. We divided the study population according to valvular morphology. Independent predictors of LV enlargement AR were evaluated.

RESULTS

There were 110 patients with BAV and 100 patients with TAV. Patients with BAV were younger (mean age BAV vs TAV: 41±16 years vs 67±11 years; p<0.01), mostly male (% male BAV vs TAV: 84.5% vs 65%, p=0.01) and presented milder degrees of AR (median regurgitant fraction BAV vs TAV: 14 (6-28)% vs 22 (12-35)%, p=0.002). Both groups presented similar indexed LV volumes and ejection fraction. According to the degree of AR, at mild AR, patients with BAV presented larger LV volumes (BAV vs TAV: indexed end diastolic left ventricular volumes (iEDV): 96.5±19.7 vs 82.1±19.3 mL, p<0.01; indexed end systolic left ventricular volumes (iESV): 39.4±10.3 mL vs 33.2±10.5 mL, p=0.01). These differences disappeared at higher degrees of AR. Independent predictors of LV enlargement were regurgitant fraction (EDV: OR 1.118 (1.081-1.156), p<0.001; ESV: OR 1.067 (1.042-1.092), p<0.001), age (EDV: OR 0.940 (0.917-0.964), p<0.001, ESV: OR 0.962 (0.945-0.979), p<0.001) and weight (EDV: OR 1.054 (1.025-1.083), p<0.001).

CONCLUSIONS

In chronic AR, LV enlargement is an early finding. LV volumes display a direct correlation with regurgitant fraction and an inverse association with age. Patients with BAV present larger ventricular volumes, especially at mild AR. However, these differences are attributable to demographic disparities; valve type is not independently associated with LV size.

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.

Mechanisms of Aortic Dilation in Patients With Bicuspid Aortic Valve: JACC State-of-the-Art Review

Bicuspid aortic valve is the most common congenital heart disease and exposes patients to an increased risk of aortic dilation and dissection. Aortic dilation is a slow, silent process, leading to a greater risk of aortic dissection. The prevention of adverse events together with optimization of the frequency of the required lifelong imaging surveillance are important for both clinicians and patients and motivated extensive research to shed light on the physiopathologic processes involved in bicuspid aortic valve aortopathy. Two main research hypotheses have been consolidated in the last decade: one supports a genetic basis for the increased prevalence of dilation, in particular for the aortic root, and the second supports the damaging impact on the aortic wall of altered flow dynamics associated with these structurally abnormal valves, particularly significant in the ascending aorta. Current opinion tends to rule out mutually excluding causative mechanisms, recognizing both as important and potentially clinically relevant.

Comparison Between Bicuspid and Tricuspid Aortic Regurgitation

Background

Although the Asian population is growing globally, data in Asian subjects regarding differences between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) in aortic regurgitation (AR) remain unexplored.

Objectives

The aim of this study was to examine differences between Asian BAV-AR and TAV-AR in significant AR, including aorta complications.

Methods

The study included 711 consecutive patients with chronic moderate to severe and severe AR from 2008 to 2020. Outcomes included all-cause death, aortic valve surgery (AVS), and incidence of aortic dissection (AD).

Results

There were 149 BAV-AR (mean age: 48 ± 16 years) and 562 TAV-AR (mean age: 68 ± 15 years; P < 0.0001) patients; baseline indexed left ventricle and indexed aorta size were larger in TAV-AR. Total follow-up was 4.8 years (IQR: 2.0-8.4 years), 252 underwent AVS, and 185 died during follow-up; 18 cases (only 1 BAV) of AD occurred, with a mean maximal aorta size of 60 ± 9 mm. The 10-year AVS incidence was higher in TAV-AR (51% ± 4%) vs BAV-AR (40% ± 5%) even after adjustment for covariates (P < 0.0001). The 10-year survival was higher in BAV-AR (86% ± 4%) vs TAV-AR (57% ± 3%; P < 0.0001) and became insignificant after age adjustment (P = 0.33). Post-AVS 10-year survival was 93% ± 5% in BAV-AR and 78% ± 5% in TAV-AR, respectively (P = 0.08). The 10-year incidence of AD was higher in TAV-AR (4.8% ± 1.5%) than in BAV-AR (0.9% ± 0.9%) and was determined by aorta size ≥45 mm (P ≤ 0.015). Compared with an age- and sex-matched population in Taiwan, TAV-AR (HR: 3.1) had reduced survival (P < 0.0001).

Conclusions

Our findings suggest that TAV-AR patients were at a later stage of AR course and had a high AD rate as opposed to BAV-AR patients in Taiwan, emphasizing the importance of early referral for timely management. Surgery on the aorta with a lower threshold in TAV-AR should be considered.

Automated Global Longitudinal Strain Exhibits a Robust Association with Death in Asymptomatic Chronic Aortic Regurgitation

BACKGROUND

Whether automated left ventricular global longitudinal strain (LVGLS) is associated with outcomes in asymptomatic aortic regurgitation (AR) is unknown.

OBJECTIVE

To explore the impact of automated LVGLS on survival and compare it with conventional LV parameters in chronic asymptomatic AR.

METHODS

LVGLS (presented as absolute value) was measured using fully-automated two-dimensional strain software in consecutive patients with isolated chronic ≥moderate-severe AR between 2004 and 2020; incremental value of LVGLS was assessed. Limited correction of endocardial border tracking was performed if needed.

RESULTS

Of 550 asymptomatic patients (age 60±17 years; 86% men), average LVGLS was 17±3% (1^st and 2^nd tertile, 15.8% and 18.5%). In 16% cases, tracking border was partially corrected; average time for analysis was 25±5 seconds. At a median (interquartile range) of 4.8(1.5-9.9) years, 87 patients had died (19 died after aortic-valve surgery [AVS]). Separate multivariable models adjusted for age, sex, Charlson index, AR severity and time-dependent AVS demonstrated that LVEF(hazard ratio[HR] per 10%: 0.9), LV end-systolic volume index(LVESVi; HR per 5ml/m²: 1.08) and LVGLS(HR per unit: 0.87) were independently associated with death(all p≤0.018); however, LVGLS remained statistically significant (HR: 0.86-0.9; P≤0.007) as compared head-to-head to LVEF, LVESVi and LV end-systolic dimension index(LVESDi). The association of LVGLS and mortality was consistent across all subgroups (P for interaction all≥0.08). Spline curves showed that continuous risk of death rose at LVGLS <15%. Those with LVGLS <15% had 2.6-fold risk of death [95% CI 1.54-4.23] while those with LVGLS <15% plus LVESVi≥45ml/m² had 3.96-fold risk[95% CI 1.94-8.03].

CONCLUSION

In this large cohort of asymptomatic patients with ≥moderate-severe AR, automated LVGLS was feasible, efficient, and independently associated with death on head-to-head comparison with conventional LVEF, LVESDi, and LVESVi. The automated-LVGLS threshold of <15% alone or combined with LVESVi≥45ml/m², was significantly associated with increased mortality risk and may be considered in early surgery decision-making.

Bicuspid Aortic Valve Disease from Infancy to Older Age: A 25-Year Experience from an Italian Referral Center

Aim:

Bicuspid aortic valve (BAV) is the most common congenital heart defect, with considerable risk of morbidity and mortality. The purpose of the study was to analyze clinical and echocardiographic presentation of BAV in a large-volume tertiary Italian center and to test their interaction with full age span, sex, and first diagnosis versus second referral.

Methods:

Consecutive patients of all ages diagnosed with BAV at our center from January 1988 to December 2012 were retrospectively included. Exclusion criteria were as follows: associated complex congenital cardiac disease, systemic syndrome, and previous cardiac surgery.

Results:

Eligible patients were 790, divided by age quartiles. Seventy-two percent of patients had any grade BAV dysfunction. Aortic valve stenosis was more frequent in the first (24%) and fourth (24%) quartiles. This corresponds to a double-peak stenosis severity curve, being more severe at a very young age and in the elderly. Aortic valve regurgitation was more prevalent in each quartile than stenosis, with a prevalence of 72% in the second quartile and 77% in the third quartile. This corresponds to a single-peak regurgitation severity curve, being more severe in the fourth and fifth decades of life. Patients with previously diagnosed BAV had more significant valve dysfunction in comparison to patients with first diagnosis of BAV, either stenosis (15% vs. 21%, P = 0.024) or regurgitation (58% vs. 68%, P = 0.006).

Conclusion:

The dominant BAV dysfunction in this large Northern Italian community is regurgitation, with higher severity of disease in the fourth and fifth decades of life.