Surgical Thresholds for Bicuspid Aortic Valve Associated Aortopathy

Bicuspid Aortic Valve Disease With Early Onset Complications: Characteristics And Aortic Outcomes

Bicuspid aortic valve (BAV) is the most common congenital heart malformation in adults but can also cause childhood-onset complications. In multicenter study, we found that adults who experience significant complications of BAV disease before age 30 are distinguished from the majority of BAV cases that manifest after age 50 by a relatively severe clinical course, with higher rates of surgical interventions, more frequent second interventions, and a greater burden of congenital heart malformations. These observations highlight the need for prompt recognition, regular lifelong surveillance, and targeted interventions to address the significant health burdens of patients with early onset BAV complications.

The role of transforming growth factor beta in bicuspid aortic valve aortopathy

A bicuspid aortic valve (BAV) is the most prevalent congenital cardiac deformity, which is associated with an increased risk to develop a thoracic aortic aneurysm and/or an aortic dissection as compared to persons with a tricuspid aortic valve. Due to the high prevalence of a BAV in the general population and the associated life-long increased risk for adverse vascular events, BAV disease places a considerable burden on the public health. The aim of the present review is to discuss the role of transforming growth factor beta (TGF-β) signaling in the development of the vascular wall and on how this complex signaling pathway may be involved in thoracic aortic aneurysm formation in tricuspid and BAV patients.

Unlocking insights in bicuspid aortic valve management in adult patients: the vital role of cardiac imaging

The bicuspid aortic valve (BAV) presents a multifaceted clinical challenge due to its diverse morphologies and associated complications. This review aims to elucidate the critical role of cardiac imaging in guiding optimal management strategies for BAV patients. BAV, with a prevalence of 1-2%, has genetic underpinnings linked to the NOTCH1 gene mutation. Variability in BAV morphology necessitates tailored surgical approaches. The three primary types of BAV morphology - right-left cusp fusion, right-noncoronary cusp fusion, and left-noncoronary cusp fusion - demand nuanced considerations due to their distinct implications. Valvular dysfunction results in aortic stenosis or regurgitation, attributed to altered valve structure and turbulent hemodynamics. Cardiac imaging modalities, including echocardiography, magnetic resonance imaging, and computerized tomography, are instrumental in assessing valve function, aortic dimensions, and associated complications. Imaging helps predict potential complications, enabling informed treatment decisions. Regular follow-up is crucial to detecting alterations early and intervening promptly. Surgical management options encompass aortic valve repair or replacement, with patient-specific factors guiding the choice. Post-surgical surveillance plays a vital role in preventing complications and optimizing patient outcomes. The review underscores the significance of advanced cardiac imaging techniques in understanding BAV's complexities, facilitating personalized management strategies, and improving patient care. By harnessing the power of multimodal imaging, clinicians can tailor interventions, monitor disease progression, and ultimately enhance the prognosis and quality of life for individuals with BAV.

Bicuspid aortic valve with associated aortopathy, significant left ventricular hypertrophy or concomitant hypertrophic cardiomyopathy: A diagnostic and therapeutic challenge

Due to its prevalence of 0.5% to 2% in the general population, with a 75% predominance among men, bicuspid aortic valve is the most common congenital heart defect. It is frequently accompanied by other cardiac congenital anomalies, and clinical presentation can vary significantly, with stenosis being the most common manifestation, often resulting in mild to moderate concentric hypertrophy of the left ventricle. Echocardiography is the primary diagnostic modality utilized for establishing the diagnosis, and it is often the sole diagnostic tool relied upon by clinicians. However, due to the heterogeneous clinical presentation and possible associated anomalies (which are often overlooked in clinical practice), it is necessary to employ various diagnostic methods and persist in finding the accurate diagnosis if multiple inconsistencies exist. By employing this approach, we can effectively manage these patients and provide them with appropriate treatment. Through a clinical case from our practice, we provide an overview of the literature on bicuspid aortic valve with aortophaty and the possible association with hypertrophic cardiomyopathy, diagnostic methods, and treatment options. This review article highlights the critical significance of achieving an accurate diagnosis in patients with bicuspid aortic valve and significant left ventricular hypertrophy. It is crucial to exclude other possible causes of left ventricular outflow tract obstruction, such as sub- or supra-aortic obstructions, and hypertrophic cardiomyopathy.

Interventions in Adults With Repaired Coarctation of the Aorta

Background

Coarctation of the aorta coexists with other cardiac anomalies and has long‐term complications, including recoarctation, which may require intervention after the primary coarctation repair. This study aims to clarify the prevalence of and risk factors for interventions related to the coarctation complex as well as late mortality in a large contemporary patient population.

Methods and Results

The Swedish National Register of Congenital Heart Disease was used, which comprised 683 adults with repaired coarctation of the aorta. Analysis was performed on freedom from intervention thereafter at the coarctation site, aortic valve, left ventricular outflow tract, or ascending aorta. One hundred ninety‐six (29%) patients had at least 1 of these interventions. Estimated freedom from either of these interventions was 60% after 50 years. The risk of undergoing such an intervention was higher among men (hazard ratio, 1.6 [95% CI, 1.2–2.2]). Estimated freedom from another intervention at the coarctation site was 75% after 50 years. In women, there was an increase in interventions at the coarctation site after 45 years. Patients who underwent one of the previously mentioned interventions after the primary coarctation repair had poorer left ventricular function. Eighteen patients (3%) died during follow‐up in the register. The standardized mortality ratio was 2.9 (95% CI, 1.7–4.3).

Conclusions

Interventions are common after coarctation repair. The risk for and time of interventions are affected by sex. Our results have implications for planning follow‐up and giving appropriate medical advice to the growing population of adults with repaired coarctation of the aorta.

Outcomes After Isolated Aortic Valve Replacement in Patients with Bicuspid vs Tricuspid Aortic Valve

To compare the outcomes in patients undergoing isolated aortic valve replacement with bicuspid (BAV) vs tricuspid aortic valves (TAV). A total of 1204 consecutive patients (BAV, n = 454; TAV, n = 750) underwent isolated aortic valve replacement (AVR) between 2002 and 2009 at a single institution. Adverse aortic events were defined as the occurrence of aortic dissection or the ascending aorta diameter greater than 50 mm or sudden death during follow-up. Propensity score matching yielded 318 patient pairs. Follow-up was obtained on 1156 patients. The mean length of follow up was 10.4 ± 3.9 years. A total of 155 (13.4%) patients died, and adverse aortic events occurred in 44 (3.8%) patients. After propensity score matching, the 12-year survivals was 85.5% in the BAV group and 89.2% in the TAV group; hazard ratio (HR) 1.6; 95% confidence interval (CI) 1.0-2.5; P = 0.057. The 12-year cumulative incidence of late adverse aortic events was 14.6% in the BAV group and 10.8% in the TAV group; subdistribution hazard ratio (sHR) 1.1; 95% CI 0.6-2.0; P = 0.758. In the isolated aortic regurgitation subgroup, the rate of adverse aortic events was significantly higher in the BAV group than in the TAV group (sHR, 2.1; 95% CI, 1.1-4.0; P = 0.021). The long-term survival after isolated AVR was similar in both BAV and TAV patients. BAV does not increase the adverse aortic events after isolated AVR compared with the TAV.

Cost-effectiveness analysis of screening for first-degree relatives of patients with bicuspid aortic valve

AIMS

Bicuspid aortic valve (BAV) is the commonest congenital heart valve malformation, and is associated with life-threatening complications. Given the high heritability index of BAV, many experts recommend echocardiography screening for first-degree relatives (FDRs) of an index case. Here we aim to evaluate the cost-effectiveness of such cascade screening for BAV.

METHODS

Using a decision-analytic model, we performed a cost-effectiveness analysis of echocardiographic screening for FDRs of BAV index case. Data on BAV probabilities and complications among FDRs were derived from our institution's BAV familial cohort and from the literature on population-based BAV cohorts with long-term follow-up. Health gain was measured as quality-adjusted life years (QALYs). Cost inputs were based on list prices and literature data. One-way and probabilistic sensitivity analyses were performed to account for uncertainty in the model's variables.

RESULTS

Screening of FDRs was found to be the dominant strategy, being more effective and less costly than no screening, with savings of €644 and gains of 0.3 QALYs. Results were sensitive throughout the rang of the model's variables, including the full range of reported BAV rates among FDRs across the literature. A gradual decrease of the incremental effect was found with the increase in screening age.

CONCLUSIONS

This economic evaluation model found that echocardiographic screening of FDRs of BAV index case is not only clinically important but also cost-effective and cost-saving. Sensitivity analysis supported the model's robustness, suggesting its generalization.

Does the 45 mm Size Cutoff for Ascending Aortic Replacement Predict Better Early Outcomes in Bicuspid Aortic Valve?

BACKGROUND

 The aim of this study is to test if the newly proposed 45 mm size criterion for ascending aortic replacement (AAR) in bicuspid aortic valve (BAV) patients undergoing aortic valve replacement (AVR) is predictive of improved early outcomes.

METHODS

 Data of 306 BAV patients with an aortic diameter of ≥45 mm undergoing AVR alone or with AAR were retrospectively analyzed. Patients were divided into groups of AVR + AAR (n = 220) and AVR only (n = 86) based on if surgery was performed according to the 45 mm criterion. End point was early adverse events, including 30-day and in-hospital mortality, cardiac events, acute renal failure, stroke, and reoperation for bleeding. Cox regression was used to assess if conformance to 45 mm criterion could predict fewer early adverse events.

RESULTS

 AVR + AAR group had significantly higher postoperative left ventricular ejection fraction (LVEF) (0.59 ± 0.09 vs. 0.55 ± 0.11, p = 0.006) and longer cardiopulmonary bypass (CPB) time (128 vs. 111 minutes, p = 0.002). Early adverse events occurred in 45 patients (14.7%), which was more prevalent in the AVR-only group (22.1% vs. 11.8%, p = 0.020). Conformance to the 45 mm criterion predicted lower rate of early adverse events (hazard ratio [HR]: 0.53, 95% confidence interval [CI]: 0.28-0.98, p = 0.042). After adjustment for gender, age, AAo diameter, sinuses of Valsalva diameter, preoperative LVEF, Sievers subtypes, BAV valvulopathy, and CPB and cross-clamp times, conformance to the 45 mm size criterion still predicted lower incidence of early adverse events (HR: 0.37, 95% CI: 0.15-0.90, p = 0.028).

CONCLUSIONS

 This study shows that conformance to 45 mm size cutoff for preemptive AAR during aortic valve replacement in patients with BAV was not associated with increased risk for adverse events and may improve early surgical outcomes.

Surgical repair of bicuspid aortopathy at small diameters: Clinical and institutional factors

OBJECTIVE

Bicuspid aortic valve is a common risk factor for thoracic aortic aneurysm and dissection. Guidelines for elective ascending aortic intervention (AAI) in bicuspid aortic valve are derived from limited evidence, and the extent of practice variation due to patient and provider characteristics is unknown. Using data from 2 large cardiovascular registries, we investigated factors that influence decisions for AAI.

METHODS

All bicuspid aortic valve cases with known aortic diameters and surgical status were included. We used multivariable logistic regression to profile predictors of isolated aortic valve replacement (AVR) or AVR+AAI, stratified by patient characteristics, surgical indications, and institution.

RESULTS

We studied 2861 subjects at 18 institutions from 1996 to 2015. The median aortic diameter of patients who underwent AVR+AAI varied widely across institutions (39-52 mm). Aortic diameters were <45 mm in 38% of patients undergoing AVR+AAI. Patients who underwent AAI at <45 mm, compared with those managed nonoperatively, were younger (54 ± 13 vs 61 ± 15 years; P < .001) with more frequent aortic stenosis (53% vs 28%; P < .001) and regurgitation (52% vs 18%; P < .001).

CONCLUSIONS

Clinical and institutional factors influence the timing of AAI and are associated with significant variability in ascending aortic diameter at AAI across institutions. More than one third of patients with a bicuspid aortic valve undergo AAI at aortic diameters <45 mm. Long-term outcomes of this subgroup of patients, who may manifest earlier and more severe disease, are needed to determine the risk-benefit ratio of routine aortic interventions at smaller diameters.

Risk Stratification in Bicuspid Aortic Valve Aortopathy: Emerging Evidence and Future Perspectives

The current management of aortic dilatation associated with congenital bicuspid aortic valve (bicuspid aortic valve aortopathy) is based on dimensional parameters (diameter of the aneurysm, growth of the diameter over time) and few other criteria. The disease is however heterogeneous in terms of natural and clinical history and risk of acute complications, ie aortic dissection. Dimensional criteria are now admitted to have limited value as predictors of such complications. Thus, novel principles for risk stratification have been recently investigated, including phenotypic criteria, flow-related metrics, and circulating biomarkers. A systematization of the typical anatomoclinical forms that the aortopathy can assume has led to the identification of the more severe root phenotype, associated with higher risk of progression of the aneurysm and possible higher aortic dissection risk. Four-dimensional-flow magnetic resonance imaging studies are searching for potentially clinically significant metrics of flow derangement, based on the recognized association of local abnormal shear stress with wall pathology. Other research initiatives are addressing the question whether circulating molecules could predict the presence or, more importantly, the future development of aortopathy. The present review summarizes the latest progresses in the knowledge on risk stratification of bicuspid aortic valve aortopathy, focusing on critical aspects and debated points.

microRNAs in bicuspid aortic valve associated aortopathy: Recent advances and future perspectives

The risk of acute aortic events in patients with bicuspid aortic valve (BAV) constitutes a medical concern in terms of timing and surgical decision. During the past years, there has been a growing interest in the potential of microRNAs (miRNAs) as crucial epigenetic factors in multiple cellular processes associated with BAV aortopathy. Nevertheless, there are still challenges that need to be overcome before miRNAs could enter clinical practice, and further validation studies in larger and well-defined BAV cohorts are now required. This review aims at providing a comprehensive overview of the available data on the expression profiles and function of specific miRNAs in BAV aortopathy, evaluating miRNA signatures as potential molecular markers of disease. We also discuss the role of other novel classes of non-coding RNAs, including long non-coding RNAs and circular RNAs, in BAV-associated aortopathy, mainly regarding their possible implementation as diagnostic and prognostic markers.

Threshold for intervention upon ascending aortic aneurysms: an evolving target and implication of bicuspid aortic valve

With the proliferation of non-invasive thoracic imaging modalities, the question of when to operate on asymptomatic ascending aortic aneurysms for non-syndromic patients is becoming increasingly relevant. Operation is extensive, often involves circulatory arrest, and subjects the patient to significant risk of mortality and morbidity. Surgery is performed to avert fatal aortic adverse events, which carry a markedly poor prognosis. The question of when the balance is tipped toward preemptive surgical repair is challenging and is centered around predicting the risk of an acute aortic syndrome. Size of the aneurysm has been the traditional guide for decision-making but how this is measured, what risks it truly predicts, the influence of the patient's size, valve morphology, genetic profile, and other risk factors for non-syndromic patients are poorly understood. We here review this issue in detail.

An economic analysis of medical and surgical management of aortopathy associated with bicuspid aortic valve

Aims

To develop a cost-effectiveness model to address the outcome and economic implications of different thresholds for surgery in the management of aortopathy associated with bicuspid aortic valve disease.

Methods and results

A model was created from the perspective of an Australian healthcare funding agency. The index case was a 65-year-old with bicuspid aortic valve (BAV) and ascending aorta diameter of 5.0 cm. Health states were defined as: pre-operative with dilated aorta, post-operative without complications, post-complication, and death. The mean and variance of risks and transition probabilities were taken from a local surgical database and local costs and utilities of elective and urgent thoracic aortic surgery (AoS) with or without aortic valve replacement, with a sensitivity analysis based on a systematic review. Scenario analyses were provided for other aortic dimensions. Implications for survival, quality-adjusted life years (QALYs), and costs were calculated from healthcare delivery and economic perspectives. After 10 000 simulations for the reference case, the utility of watchful waiting (WW) exceeded that of elective AoS (13 ± 4 vs. 10 ± 5 QALY). The net monetary benefit was A$351 063 ± 304 965 with immediate AoS vs. 534 797 ± 198 570 with WW surveillance. The most important variables affecting effectiveness were utility value of survivors, rate of aortic growth, and probability of acute aortic event during WW.

Conclusions

This decision-analytic model informed by our practice, as well as a systematic analysis, shows that AoS in a BAV patient with aorta <5 cm diameter is costlier and less effective than WW.

Evolving Surgical Approaches to Bicuspid Aortic Valve Associated Aortopathy

Bicuspid aortic valve (BAV) is the most common congenital cardiac pathology which results from the fusion of two adjacent aortic valve cusps. It is associated with dilatation of the aorta, known as bicuspid valve-associated aortopathy or bicuspid aortopathy. Bicuspid aortopathy is progressive and is linked with adverse clinical events. Hence, frequent monitoring and early intervention with prophylactic surgical resection of the proximal aorta is often recommended. Over the past two decades resection strategies and surgical interventions have mainly been directed by surgeon and institution preferences. These practices have ranged from conservative to aggressive approaches based on aortic size and growth criteria. This strategy, however, may not best reflect the risks of important aortic events. A new set of guidelines was proposed for the treatment of bicuspid aortopathy. Herein, we will highlight the most recent findings pertinent to bicuspid aortopathy and its management in the context of a case presentation.

Misclassification of bicuspid aortic valves is common and varies by imaging modality and patient characteristics

BACKGROUND

Bicuspid aortic valve (BAV) is the most prevalent adult congenital heart defect. BAV causes lifelong progressive disease that can be prevented by early diagnosis and long-term surveillance, but may be compromised by misclassification of valve morphology.

METHODS

The study population was derived from the UTHealth Bicuspid Aortic Valve Registry, which includes serial images on more than 200 participants over a mean follow-up interval of 2.8 years. We abstracted descriptions of aortic valve morphology from transthoracic or transesophageal echocardiography, computed tomography angiography, and magnetic resonance angiography reports. We used chi-square and t tests to determine associations between reported valve morphologies (definitely bicuspid, possibly bicuspid, tricuspid, or uncertain) and clinical characteristics and assessed image quality using a validated tool.

RESULTS

About 40% of participants were misclassified in at least one imaging report. The mean interval between misclassification and correct diagnosis was 22 months. TEE, MR and CT were more sensitive than TTE and successfully reclassified 20% of participants, but were only used in 14% of patients. Misclassification was associated with age, the extent of valve calcification and image quality, but was not significantly associated with aortic regurgitation, gender, or cusp configuration.

CONCLUSION

Misclassification of BAV is prevalent, frequently leads to delayed diagnosis, and is more likely to occur in the most severely affected cases. TEE, CT and MR may increase diagnostic accuracy in up to half of BAV cases but are underutilized. Additional studies are needed to determine if misclassification of BAV patients leads to increased long-term morbidity and mortality.

Abnormal aortic stiffness in patients with bicuspid aortic valve: phenotypic variation determined by magnetic resonance imaging

The aim of this study was to assess aortic stiffness in patients with bicuspid aortic valve (BAV), and to determine if differences exist among the BAV phenotypes. Stiffness was measured by pulse wave velocity (PWV) determined using velocity-encoded magnetic resonance imaging (VENC-MRI). VENC-MRI was performed in 100 BAV patients and 45 normal controls. PWV was determined between the mid ascending and mid descending aorta. The BAV phenotypes were characterized using steady-state free precession (SSFP) images acquired across the face of the aortic valve, and classified as follows: right-left cusp (R-L) fusion, right and non-coronary cusp (R-NC) fusion, and left and non-coronary cusp (L-NC) fusion. The following BAV phenotypes were identified: 76 R-L, 23 R-NC, and 1 L-NC fusion. BAV patients demonstrated significantly greater PWV compared to normal controls, after adjusting for age (9.16 vs. 3.83 m/s; p < 0.0001). Furthermore, PWV was significantly greater in patients with R-NC fusion than those with R-L fusion phenotype (12.27 vs. 7.97 m/s; p < 0.001). There was significantly increased PWV from VENC-MRI in BAV patients compared to normal controls. Thisis the first to demonstrate the association of different BAV phenotypes and aortic stiffness. VENC-MRI PWV assessment potentially represents a novel parameter for enhanced surveillance and may alter surgical triage of aorta in this high risk group.

MR Imaging of Thoracic Aortic Disease

A number of congenital defects and acquired disease processes affect the thoracic aorta, and traditionally, computed tomography (CT) has been the mainstay of imaging, especially in evaluation of the acute aorta. However, recent advances in magnetic resonance (MR) imaging such as electrocardiographically (ECG) triggered breath-hold sequences and ultrafast 3-dimensional MR angiography (MRA) are bringing MR imaging to the forefront of imaging of the thoracic aorta. By providing high-resolution morphological imaging and sophisticated vascular flow analysis for functional data, this modality can provide a comprehensive, reproducible evaluation of the thoracic aorta. In this review, we discuss the role of MR imaging in the evaluation of thoracic aorta pathology along with pertinent examples of aortic abnormalities.

Distribution of blood flow velocity in the normal aorta: Effect of age and gender

PURPOSE

To apply flow distribution analysis in the entire aorta across a wide age range from pediatric to adult subjects.

MATERIAL AND METHODS

In all, 98 healthy subjects (age 9-78 years, 41 women) underwent 4D flow MRI at 1.5T and 3T for the assessment of 3D blood flow in the thoracic aorta. Subjects were categorized into age groups: group 1 (n = 9, 5 women): 9-15 years; group 2 (n = 13, 8 women): 16-20 years; group 3 (n = 27, 14 women): 21-39 years; group 4 (n = 40, 11 women): 40-59 years; group 5 (n = 9, 3 women): >60 years. Data analysis included the 3D segmentation of the aorta, aortic valve peak velocity, mid-ascending aortic diameter, and calculation of flow velocity distribution descriptors (mean, median, standard deviation, incidence of velocities >1 m/s, skewness, and kurtosis of aortic velocity magnitude). Ascending aortic diameter was normalized by body surface area.

RESULTS

Age was significantly associated with normalized aortic diameter (R = 0.73, P < 0.001), skewness (R = 0.76, P < 0.001), and kurtosis (R = 0.74, P < 0.001), all adjusted by heart rate. Aortic peak velocity and velocity distribution descriptors, adjusted by heart rate, were significantly different between age groups (P < 0.001, analysis of covariance). Skewness and kurtosis significantly increased (P < 0.001) during adulthood (>40 years) as compared with childhood (<21 years). Men and women revealed significant differences (P ≤ 0.05) for peak velocity, incidence, mean, median, standard deviation, and skewness, all adjusted by heart rate.

CONCLUSION

Aortic hemodynamics significantly change with age and gender, indicating the importance of age- and gender-matched control cohorts for the assessment of the impact of cardiovascular disease on aortic blood flow.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;47:487-498.

A Possible Early Biomarker for Bicuspid Aortopathy: Circulating Transforming Growth Factor β-1 to Soluble Endoglin Ratio

RATIONALE

The pathogenesis of bicuspid aortic valve (BAV)-associated aortopathy is poorly understood, and no prognostic biomarker is currently available.

OBJECTIVE

We aimed to identify putative circulating biomarkers pathogenetically and prognostically linked to bicuspid aortopathy.

METHODS AND RESULTS

By reverse transcription polymerase chain reaction, we evaluated gene expression variations (versus normal aorta) of transforming growth factor-β1 (TGF-β1), connective tissue growth factor, matrix metalloproteinase-2 (MMP-2), MMP-14, endoglin (ENG), and superoxide dismutase 3 in ascending aorta samples from 50 tricuspid and 70 patients with BAV undergoing surgery for aortic stenosis (aorta diameter ≤45 mm: BAV_non-dil or >45 mm: BAV_dil). Expression changes of the TGF-β1 active dimer and ENG were analyzed also by Western blot in ascending aorta samples from other 10 tricuspid aortic valve, 10 BAV_non-dil, and 10 BAV_dil patients. The serum concentration of study targets was assessed through ELISA and the ratio of serum TGF-β1/ENG (T/E) was evaluated. All BAV_non-dil patients underwent follow-up echocardiography to assess aortic growth rate. In BAV_non-dil patients, TGF-β1 and MMP-2 gene expression increased significantly, whereas MMP-14 and ENG expression decreased versus controls. Expression changes were confirmed at protein level for TGF-β1 and ENG. TGF-β1 serum concentration significantly decreased in tricuspid aortic valve and BAV_non-dil patients versus healthy subjects. ENG serum concentration decreased in all patients, more markedly in BAV_dil. A significant increase of the T/E ratio versus healthy subjects was unique of patients with BAV. In BAV_non-dil patients, a T/E ≥9 was independently associated in multivariable analysis with higher MMP-2 and lower superoxide dismutase 3 gene expression, independent of age and aortic diameter. A significant correlation was observed between baseline T/E ratio and aortic diameter growth rate in BAV_non-dil patients (r=0.66, P<0.001).

CONCLUSIONS

The novel evidence of a possible value of the T/E ratio as a biomarker of BAV aortopathy was presented: further validation studies are warranted.

Elective primary aortic root replacement with and without hemiarch repair in patients with no previous cardiac surgery

OBJECTIVE

Excellent outcomes have been established for elective aortic root replacement (ARR). It is less clear whether extending the repair into the proximal aortic arch with hypothermic circulatory arrest increases risk. We examined the early outcomes of elective, primary ARR, with and without hemiarch replacement, in patients without previous cardiac surgery.

METHODS

Over a 4-year period, 140 non-redo patients (median age, 54 years) underwent elective, primary ARR for root aneurysms; 119 patients (85%) had hemiarch replacement, and 21 (15%) had only ascending aortic replacement. Valve-sparing ARR was performed in 41 cases (29.3%) and valve-replacing ARR in 99 (70.7%). Moderate hypothermic circulatory arrest and antegrade cerebral perfusion were used in 118 (99%) hemiarch repairs.

RESULTS

There were no operative deaths or permanent strokes. Complications included temporary renal dialysis (n = 1; 4.8%), transient neurologic deficit (n = 2; 9.5%), and tracheostomy (n = 2; 9.5%) after ascending aortic repair and bleeding requiring reoperation (n = 4; 3.4%), pericardial effusion requiring drainage (n = 9; 7.6%), and tracheostomy (n = 2; 1.7%) after hemiarch replacement. No stroke was observed in the hemiarch group (P = .022; univariate analysis). The extent of the repair into the proximal arch did not appear to be associated with any adverse effect.

CONCLUSIONS

In non-redo patients, elective primary ARR has excellent early outcomes, regardless of whether repair extends into the proximal arch. Additional elective hemiarch replacement with moderate hypothermic circulatory arrest and antegrade cerebral perfusion has a low risk of neurologic complications and should be performed if necessary. Long-term data are needed to compare the rates of reintervention in the aortic arch in patients with or without proximal arch replacement.

Functional Aortic Root Parameters and Expression of Aortopathy in Bicuspid Versus Tricuspid Aortic Valve Stenosis

BACKGROUND

The correlation between bicuspid aortic valve (BAV) disease and aortopathy is not fully defined.

OBJECTIVES

This study aimed to prospectively analyze the correlation between functional parameters of the aortic root and expression of aortopathy in patients undergoing surgery for BAV versus tricuspid aortic valve (TAV) stenosis.

METHODS

From January 1, 2012 through December 31, 2014, 190 consecutive patients (63 ± 8 years, 67% male) underwent aortic valve replacement ± proximal aortic surgery for BAV stenosis (n = 137, BAV group) and TAV stenosis (n = 53, TAV group). All patients underwent pre-operative cardiac magnetic resonance imaging to evaluate morphological/functional parameters of the aortic root. Aortic tissue was sampled during surgery on the basis of the location of eccentric blood flow contact with the aortic wall, as determined by cardiac magnetic resonance (i.e., jet sample and control sample). Aortic wall lesions were graded using a histological sum score (0 to 21).

RESULTS

The largest cross-sectional aortic diameters were at the mid-ascending level in both groups and were larger in BAV patients (40.2 ± 7.2 mm vs. 36.6 ± 3.3 mm, respectively, p < 0.001). The histological sum score was 2.9 ± 1.4 in the BAV group versus 3.4 ± 2.6 in the TAV group (p = 0.4). The correlation was linear and comparable between the maximum indexed aortic diameter and the angle between the left ventricular outflow axis and aortic root (left ventricle/aorta angle) in both groups (BAV group: r = 0.6, p < 0.001 vs. TAV group r = 0.45, p = 0.03, z = 1.26, p = 0.2). Logistic regression identified the left ventricle/aorta angle as an indicator of indexed aortic diameter >22 mm/m(2) (odds ratio: 1.2; p < 0.001).

CONCLUSIONS

Comparable correlation patterns between functional aortic root parameters and expression of aortopathy are found in patients with BAV versus TAV stenosis.

Bicuspid aortic valve: unresolved issues and role of imaging specialists

Bicuspid aortic valve (BAV) is the most common congenital heart disease with marked heterogeneity in many aspects. Fusion patterns of the aortic cusp are quite variable with different type and severity of valvular dysfunction. Moreover, non-valvular cardiovascular abnormalities are associated with BAV. Among them, aortic aneurysm/dissection is the most serious clinical condition with variable patterns of segmental aortic dilatation. Potential association between BAV phenotype and valvulopathy or aortopathy has been suggested, but needs to be tested further. A lack of long-term outcome data at this moment is responsible for unresolved debate regarding appropriate management of patients with BAV, specifically to prevent development of aortic dissection. Long-term follow-up data of a well-characterized cohort or registry based on standardized classification of BAV phenotype and aortopathy are necessary for evidence-based medical practice. Advanced imaging techniques such as computed tomography or magnetic resonance imaging offer better opportunities for accurate phenotype classification and imaging specialists should play a central role to establish a collaborative multicenter cohort or registry.

Assessment of altered three-dimensional blood characteristics in aortic disease by velocity distribution analysis

PURPOSE

To test the feasibility of velocity distribution analysis for identifying altered three-dimensional (3D) flow characteristics in patients with aortic disease based on 4D flow MRI volumetric analysis.

METHODS

Forty patients with aortic (Ao) dilation (mid ascending aortic diameter MAA = 40 ± 7 mm, age = 56 ± 17 years, 11 females) underwent cardiovascular MRI. Four groups were retrospectively defined: mild Ao dilation (n = 10; MAA < 35 mm); moderate Ao dilation (n = 10; 35 < MAA < 45 mm); severe Ao dilation (n = 10; MAA > 45 mm); Ao dilation+aortic stenosis AS (n = 10; MAA > 35 mm and peak velocity > 2.5 m/s). The 3D PC-MR angiograms were computed and used to obtain a 3D segmentation of the aorta which was divided into four segments: root, ascending aorta, arch, descending aorta. Radial chart displays were used to visualize multiple parameters representing segmental changes in the 3D velocity distribution associated with aortic disease.

RESULTS

Changes in the velocity field and geometry between cohorts resulted in distinct hemodynamic patterns for each aortic segment. Disease progression from mild to Ao dilation + AS resulted in significant differences (P < 0.05) in flow parameters across cohorts and increased radial chart size for root and ascending aorta segments by 146% and 99%, respectively.

CONCLUSION

Volumetric 4D velocity distribution analysis has the potential to identify characteristic changes in regional blood flow patterns in patients with aortic disease.

Effect of aortic aneurysm replacement on outcomes after bicuspid aortic valve surgery: validation of contemporary guidelines

OBJECTIVE

Bicuspid aortic valve (BAV) disease is associated with aortic dilatation and aneurysm (AN) formation. The American College of Cardiology/American Heart Association (ACC/AHA) 2006 guidelines recommend replacement of the ascending aorta for an aortic diameter (AD)> 45 mm in patients undergoing aortic valve replacement (AVR). We evaluated the outcomes of AVR and AVR with aortic replacement (AVR/AN).

METHODS

We retrospectively reviewed (2004-2011) the data from 456 patients with BAV and compared the morbidity and mortality between the AVR and AVR/AN groups and 3 subgroups: AVR with an AD<45 mm; AVR/AN with an AD of 45 to 49 mm; and AVR/AN with an AD of ≥50 mm. Propensity score matching was used to reduce bias.

RESULTS

Of the 456 patients, 250 (55%) underwent AVR and 206 (45%) AVR/AN, with 98% compliance with the current guidelines. The overall 30-day mortality was 0.9%. The AVR AD<45-mm group had adjusted short- and medium-term survival similar to that of the AVR/AN AD 45- to 49-mm and AVR/AN AD≥50-mm groups, with a 30-day mortality of 0.8%, 0%, and 1.9%, respectively (P=.41). The propensity score-matched AVR/AN AD≥50-mm group had significantly greater rates of reintubation than either the AVR AD<45-mm (P=.012) or AVR/AN AD 45- to 49-mm (P=.04) group and greater rates of prolonged ventilation (P=.022) than the AVR AD<45-mm group. No significant differences were found in reoperation or myocardial infarction among the subgroups.

CONCLUSIONS

In patients with undergoing AVR, no increase was seen in morbidity or mortality when adding aortic replacement with an AD of 45 to 49 mm, in accordance with the 2006 ACC/AHA guidelines, although the AVR/AN AD≥50-mm group had a greater risk of respiratory complications. Our findings indicate that compliance with the ACC/AHA guidelines is safe in select centers.