Management of Patients With Bicuspid Aortic Valve Disease

Conotruncal Heart Defects: A Narrative Review of Molecular Genetics, Genomics Research and Innovation

Congenital heart defects (CHDs) are most prevalent cardiac defects that occur at birth, leading to significant neonatal mortality and morbidity, especially in the developing nations. Among the CHDs, conotruncal heart defects (CTDs) are particularly noteworthy, comprising a significant portion of congenital cardiac anomalies. While advances in imaging and surgical techniques have improved the diagnosis, prognosis, and management of CTDs, their molecular genetics and genomic substrates remain incompletely understood. This expert review covers the recent advances from January 2016 onward and examines the complexities surrounding the genetic etiologies, prevalence, embryology, diagnosis, and clinical management of CTDs. We also emphasize the known copy number variants and single nucleotide variants associated with CTDs, along with the current planetary health research efforts aimed at CTDs in large cohort studies. In all, this comprehensive narrative review of molecular genetics and genomics research and innovation on CTDs draws from and highlights selected works from around the world and offers new ideas for advances in CTD diagnosis, precision medicine interventions, and accurate assessment of prognosis and recurrence risks.

Navigating the challenges of bicuspid aortic valve-aortopathy

Bicuspid aortic valve (BAV) is a congenital heart defect that affects 0.5-2% of the general population with familial predominance. The modifications in hemodynamics and structure change at cellular level contribute to the dilation of aorta, resulting in bicuspid aortopathy, which can result in catastrophic aortic events. The American Heart Association recommends screening first-degree relatives of patients with bicuspid aortic valve and aortic root disease. BAV may or may not be associated with a syndrome, with the non-syndromic variety having a higher chance of predisposition to congenital and vascular abnormalities. Many genes have been implicated in the etiology of non-syndromic aortic aneurysm such as ACTA2, MYH11, FLNA, and SMAD3. Common diagnostic modalities include transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), multi system computer tomography (MSCT), and cardiac MRI. Medical management reduces the rate of disease progression and surgical management is indicated based on the diameter of the ascending aorta, which differs in American and European guidelines. Our article aims to explore the current understanding of the pathophysiology, clinical aspects, and surgical management of bicuspid aortic valve disease. Additionally, we have included a discussion on the management of this condition in special populations, such as athletes and pregnant women, who require distinct treatment recommendations.

Aortic strain in bicuspid aortic valve: an analysis

Bicuspid aortic valve (BAV) is monitored by transthoracic echocardiography and computed tomography (CT) angiography. However, it does not have any early marker of disease progression. This study evaluated speckle-tracking echocardiography (STE) aortic and left ventricular (LV) strain prognostic values, their discriminative power, and their correlation with the degree of valvular regurgitation. We conducted a retrospective analysis of a prospectively enrolled cohort of 45 diagnosed with BAV and 20 gender and age matched controls. We performed 2D-STE aortic and LV strain analysis of the selected population. The cohort was followed-up during a median period of 19.9 months (IQR 12.9-25.2), and outcomes (hospital admission for heart failure (HF), aortic valve replacement (AVR), and death) were determined. The mean patient age was 46.6 ± 15.5 years and 80 % were male. LV indexed volumes and aortic diameter were higher in BAV patients. LV global longitudinal strain (GLS) was impaired (p < 0.001) and aortic GLS was significantly augmented (p = 0.027) in BAV patients. Aortic global circumferential strain (GCS) did not vary between groups. Aortic diameter was the best parameter related to BAV (AUC 0.92) and aortic GLS was best correlated with significant AR (AUC 0.76). AVR was the only outcome observed and its only predictor was indexed LV end-diastolic volume. BAV had impaired LV-GLS values. Aortic GLS was abnormally augmented in BAV patients, which might reflect higher aortic diameters that distorted strain calculations. STE aortic strain is related to AR but does not appear to be a reliable predictor of surgery in BAV patients, at 19 months.

Transcatheter aortic valve replacement for patients with severe bicuspid aortic stenosis

BACKGROUND

Patients with bicuspid aortic valve stenosis (BAV) were excluded from all the trileaflet aortic valve stenosis (TAV) pivotal trials, and therefore, their outcomes are not clearly defined. The aim of the study was to evaluate the outcomes of transcatheter aortic valve replacement (TAVR) in patients with BAV and compared them with those of TAV.

METHODS

We evaluated the outcomes following TAVR of patients with BAV at our institution between April 2011 and November 2016 and compared them with the outcomes of patients with TAV treated with TAVR. The χ² and the Mann-Whitney U tests were used to compare the groups, and a Kaplan-Meier analysis was performed to estimate long-term survival.

RESULTS

TAVR was performed in a total of 567 patients, from which 50 (8.8%) had BAV and 517 (91.2%) had TAV. Patients with BAV were younger and had higher prevalence of chronic obstructive pulmonary disease, lower prevalence of coronary artery disease, higher body mass index, and lower Society of Thoracic Surgeons score (STS PROM). Patients with BAV had a slightly higher mean aortic valve gradient postoperatively (median 12 mm Hg [10-15] vs 10 [7-13], P < .001), but paravalvular aortic regurgitation was not different between the groups (> mild 4.0% vs 3.5%, P = .541). Clinical outcomes were not different between the groups, including stroke (2.0% vs 1.5, P = .567) and the 30-day all-cause mortality (6.0% vs 1.5, P = .064). The 2-year survival (82.0% vs 83.4, P = .476) was similar between the groups.

CONCLUSIONS

This initial experience suggests that TAVR can be safely performed in patients with BAV, achieving similar short-term procedural and clinical outcomes when compared with patients with TAV.

Perioperative Echocardiography in the Adult With Congenital Heart Disease

Survival of patients with congenital heart disease has significantly improved over the last 2 decades, confronting interventionalists, surgeons, anesthesiologists, cardiologists, and intensivists with often unfamiliar complex pathophysiology in the perioperative setting. Aside from cardiac catheterization, echocardiography has become the main imaging modality in the hospitalized adult with congenital heart disease. The great variety of congenital lesions and their prior surgical management challenges practitioners to generate optimal imaging, reporting, and interpretation of these complex anatomic structures. Standardization of echocardiographic studies can not only provide significant benefits in the surveillance of these patients, but also facilitate understanding of pathophysiologic mechanism and assist clinical management in the perioperative setting. Knowledge in obtaining and interpreting uniform imaging protocols is essential for the perioperative clinician. In this publication, the authors review current international consensus recommendations on echocardiographic imaging of adults with congenital heart disease and describe the fundamental components by specific lesion. The authors will emphasize key aspects pertinent to the clinical management when imaging these patients in the perioperative setting. The goal of this review is to familiarize the perioperative physician on how to structure and standardize echocardiographic image acquisition of congenital heart disease anatomy for optimal clinical management.

Balloon valvuloplasty in a dog with congenital bicuspid aortic valve and supravalvar aortic stenosis (atypical Shone's complex)

An 8-month-old intact female pug was presented for evaluation and possible balloon valvuloplasty (BV) for severe aortic stenosis. A bicuspid, severely stenotic aortic valve of type 3 morphology with a supravalvar stenosis component was diagnosed, consistent with the diagnosis of atypical Shone's complex. There was severe concentric hypertrophy of the left ventricle, with increased echogenicity of the myocardium nearest to the endocardial border. Mild left atrial enlargement was observed. Selective angiography and transesophageal echocardiography revealed an enlarged and relatively tortuous ascending aorta. The changes to the ascending aorta and the anatomy of the lesion made retrograde access to the left ventricle challenging. Ultimately, BV was successful using a pediatric valvuloplasty balloon catheter and rapid right ventricular pacing, and the pressure gradient across the aortic valve was decreased by more than 50% compared with preoperative measurements. Although valvar aortic stenosis is rare in veterinary medicine, this report highlights the potential challenges and feasibility of BV for this disease.

Comparison of aortic annulus size by transesophageal echocardiography and computed tomography angiography with direct surgical measurement

This study sought to compare the accuracy of 2-dimensional transesophageal echocardiography (TEE) and computed tomography angiography (CTA) for noninvasive aortic annular sizing as required for transcatheter aortic valve implantation (TAVI). Direct intraoperative (OR) sizing is the gold standard for aortic annular measurement in surgical aortic valve replacement. Unlike surgical aortic valve replacement, TAVI requires noninvasive assessment of aortic annular dimensions for determining the size of prosthesis to be implanted and controversy exists regarding the best imaging technique for TAVI sizing. Preoperative CTA and OR TEE images of the aortic annulus in 227 patients who underwent proximal aortic surgery with OR annular sizing at the Duke University Medical Center were reviewed. Both imaging techniques were compared with direct OR measurements of aortic annulus diameter using metric sizers as the gold standard. CTA overestimated aortic annulus diameter in 72.2% of cases, with 46.3% >1 TAVI valve-size (>3 mm) overestimations, whereas TEE underestimated aortic annulus diameter in 51.1% of cases, with 16.7% >1 valve-size underestimations. Combining both techniques improved the estimation of aortic annular size. In conclusion, there are limitations to current imaging techniques for noninvasive determination of aortic annular dimensions compared with direct OR sizing. Undersizing by TEE and oversizing by CTA are common and may be related to differences in methods for sizing an elliptical structure. Combining measurements from both techniques would decrease the false exclusion rate for TAVI eligibility because of size mismatch.

Aortic valve reconstruction with use of pericardial leaflets in adults with bicuspid aortic valve disease: early and midterm outcomes

In this study, we retrospectively analyzed the outcomes of adults with bicuspid aortic valve (BAV) disease who underwent aortic valve reconstructive surgery (AVRS), consisting of replacement of the diseased BAV with 2 or 3 pericardial leaflets plus fixation of the sinotubular junction for accurate and constant leaflet coaptation. From December 2007 through April 2013, 135 consecutive patients (mean age, 49.2 ± 13.1 yr; 73.3% men) with symptomatic BAV disease underwent AVRS. Raphe was observed in 84 patients (62.2%), and the remaining 51 patients had pure BAV without raphe. A total of 122 patients (90.4%) underwent 3-leaflet reconstruction, and 13 (9.6%) underwent 2-leaflet reconstruction. Concomitant aortic wrapping with an artificial graft was performed in 63 patients (46.7%). There were no in-hospital deaths and 2 late deaths (1.5%); 6 patients (4.4%) needed valve-related reoperation. The 5-year cumulative survival rate was 98% ± 1.5%, and freedom from valve-related reoperation at 5 years was 92.7% ± 3.6%. In the last available echocardiograms, aortic regurgitation was absent or trivial in 116 patients (85.9%), mild in 16 (11.9%), moderate in 2 (1.5%), and severe in one (0.7%). The mean aortic valve gradient was 10.2 ± 4.5 mmHg, and the mean aortic valve orifice area index was 1.3 ± 0.3 cm(2)/m(2). The 3-leaflet technique resulted in lower valve gradients and greater valve areas than did the 2-leaflet technique. Thus, in patients with BAV, AVRS yielded satisfactory early and midterm results with low mortality rates and low reoperation risk after the initial procedure.

Subtypes of bicuspid aortic valves in coarctation of the aorta

Bicuspid aortic valves (BAVs) represent a wide morphologic and functional spectrum. In coarctation of the aorta, BAVs are common, but the proportion of BAV subtypes and their relation to aortic dimensions and development of late valve dysfunction are unknown. Sixty-two cardiovascular magnetic resonance investigations of patients with coarctation of the aorta were reviewed with respect to aortic valve morphology, aortic valve function, and aortic dimensions. BAVs were identified in 45 patients (72.6%), of which 13 (20.9%) were type-0 (two commissures), 28 (45.1%) type-1 (three commissures but fusion of one commissure with a raphe) and 4 (6.5%) valves were bicuspid but not possible to classify further. Patients with BAVs type-0 had larger dimensions in their sinus of Valsalva (35.5 ± 6.8 vs. 29.7 ± 2.7 mm, p = 0.002), ascending aorta (33.1 ± 6.2 vs. 26.0 ± 4.3 mm, p = 0.005) and sino-tubular junction (29.3 ± 7.4 vs. 24.2 ± 3.5 mm, p = 0.040) compared with tricuspid aortic valves (TAVs). Moderate and severe aortic valve disease was more common in BAV type-0 compared with BAV type-1 (p = 0.030) and TAV (p = 0.016). In a multivariate linear regression model BAV type-0 (p = 0.005), BAV type-1 (p = 0.011), age (p < 0.001), patient height (p = 0.009), and aortic valve disease (p = 0.035) were independently associated with increased diameter of the ascending aorta (R (2) of the model 0.54, p < 0.001). BAV type-0 is relatively common in coarctation of the aorta. Both BAV type-0 and type-1 are associated with increased diameter of the ascending aorta but this association is stronger for BAV type-0. Development of aortic valve disease is more common in BAV type-0 than in BAV type-1. Discrimination between BAV subtypes may potentially provide clinical and prognostic information in patients with coarctation of the aorta.