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

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Bicuspid aortic valve disease - the influence of valve morphotype on age at and types of surgical treatment

Background

Patients with bicuspid aortic valve (BAV) with zero or two raphes have been under-represented in previous studies. Whether these patients have unique clinical courses remains unclear. We describe the indications for and types of surgery in patients with BAV, and describe differences between valve morphotypes.

Methods

Adults who had undergone aortic and/or aortic valve surgery for BAV disease at our centres were identified and classified according to the Sievers definitions.

Results

317 patients were included (74.4% male, median age at surgery 62 years). Of these, 187 (59.0%) had aortic valve surgery, 7 (2.2%) aortic surgery, 120 (37.9%) combined valve and aortic surgery and 3 had a Ross procedure. Most patients had aortic stenosis (71.9%), followed by aortic regurgitation (16.7%). 30-day mortality was low (1.6%).

The commonest valve morphology was type-1 (one raphe) in 89.6%; type-0 (no raphes) occurred in 7.9% and type-2 (two raphes) in 2.5%. Patients with type-2 valves were substantially younger at time of surgery than type-1 patients (median 36 vs 63 years, p = 0.008). A higher proportion of patients with type-0 valves required aortic surgery than those with type-1 (68.0% vs 37.3%, p = 0.007). There were no differences between groups for the indication for surgery, valvular abnormality or 30-day mortality.

Conclusions

The number of BAV raphes was independently and significantly associated with age at surgery and the need for aortic intervention. Patients with type 0 and type 2 valves are a small but important proportion of the BAV population, potentially requiring different clinical surveillance and management.

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 management of the aorta in BAV patients

Patients with a bicuspid aortic valve (BAV) frequently develop aneurysms of the aortic root and tubular ascending aorta. Aneurysms of the aortic arch, in the absence of concomitant aortopathies, are much less common. According to the 2018 American Association of Thoracic Surgery consensus guidelines on BAV-related aortopathy, prophylactic surgical aortic repair / replacement is recommended starting at a maximum aortic diameter of 50 mm in patients with risk factors. Concomitant aortic surgery is also recommended at an aortic diameter of 45 mm in those patients with other indications for cardiac surgery (most commonly aortic valve procedures). The ultimate goal of prophylactic aortic surgery is the prevention of aortic catastrophes, e.g. aortic rupture or acute aortic dissection, which are associated with high morbidity and mortality. The surgical technique used - in elective and emergency cases - depends on the involvement and nature of the aortic valve disease, as well as the extent of aortic aneurysm formation. The current review focusses on the surgical management of the aortic root, tubular ascending aorta, and proximal aortic arch in BAV patients. Despite the abovementioned recommendations, many BAV patients develop acute aortic syndromes below the recommended aortic diameter thresholds. Further research is therefore required in order to identify high-risk BAV subgroups that would benefit from earlier surgical repair.

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.

Applications of a Specialty Bicuspid Aortic Valve Program: Clinical Continuity and Translational Collaboration

Bicuspid aortic valve (BAV) is a common congenital heart diagnosis and is associated with aortopathy. Current guidelines for aortic resection have been validated but are based on aortic diameter, which is insufficient to predict acute aortic events. Clinical and translational collaboration is necessary to identify biomarkers that can individualize the timing of prophylactic surgery for BAV aortopathy. We describe our multidisciplinary BAV program, including research protocols aimed at biomarker discovery and results from our longitudinal clinical registry. From 2012–2018, 887 patients enrolled in our clinical BAV registry with the option to undergo four dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR) and donate serum plasma or tissue samples. Of 887 patients, 388 (44%) had an elective BAV-related procedure after initial presentation, while 499 (56%) continued with medical management. Of medical patients, 44 (9%) had elective surgery after 2.3 ± 1.4 years. Surgery patients’ biobank donations include 198 (46%) aorta, 374 (86%) aortic valve, and 314 (73%) plasma samples. The 4D flow CMR was completed for 215 (50%) surgery patients and 243 (49%) medical patients. Patients with BAV aortopathy can be safely followed by a multidisciplinary team to detect indications for surgery. Paired tissue and hemodynamic analysis holds opportunity for biomarker development in BAV aortopathy.

Management of Adults With Normally Functioning Congenitally Bicuspid Aortic Valves and Dilated Ascending Aortas

We describe herein a 65-year-old woman who underwent resection of a dilated (5.1 cm) ascending aorta associated with a normally functioning congenitally bicuspid aortic valve. The patient provided the framework to discuss proper management-operative versus nonoperative-of the dilated ascending aorta associated with a normally functioning bicuspid aortic valve. Unfortunately, there is inadequate data to provide an unequivocal answer to this dilemma. Operative intervention requires that the short-term risk of the prophylactic procedure be considerably lower than the long-term risk of aortic dissection/rupture without operative intervention. Because there is no proof that operative intervention provides less morbidity and lower mortality, nonoperative management at this time seems to be the better approach.

Open hemiarch versus clamped ascending aorta replacement for aortopathy during initial bicuspid aortic valve replacement

BACKGROUND

There is controversy regarding the extent of aortic resection necessary in patients with aortopathy related to bicuspid aortic valve disease. To address this issue, we reviewed our experience in patients undergoing ascending aorta replacement during bicuspid aortic valve replacement.

METHODS

We reviewed 702 patients who underwent ascending aorta replacement at the time of initial nonemergent native bicuspid aortic valve replacement at our institution between January 2000 and June 2017. Treatment cohorts included an open hemiarch replacement group (n = 225; 32%) and a clamped ascending aorta replacement group (n = 477; 68%).

RESULTS

Median patient age was 60 years (interquartile range [IQR], 51-67 years), female sex was present in 113 patients 16%, ejection fraction was 62% (IQR, 56%-66%), and aortic arch diameter was 33 mm (IQR, 29-36 mm). Cardiopulmonary bypass time was longer in the hemiarch replacement group (188 minutes vs 97 minutes; P < .001). Procedure-related complications (36%) and mortality (<1%) were similar in the 2 groups; however, the hemiarch group had an increased odds of blood transfusion (odds ratio, 1.62; 95% confidence interval [CI], 1.15-2.28; P = .006). The median duration of follow-up was 6.0 years (95% CI, 5.3-6.8 years). Overall survival was 94 ± 1% at 5 years and 80 ± 2% at 10 years. Multivariable analysis demonstrated similar survival in the 2 groups (hazard ratio, 0.83; 95% CI, 0.51-1.33; P = .439). No repeat aortic arch operations were done for aortopathy over the duration of clinical follow-up.

CONCLUSIONS

Compared with patients in the clamped ascending aorta replacement group, patients in the hemi-arch replacement group had longer cardiopulmonary bypass and aortic cross-clamp times, along with an increased risk of blood transfusion, but similar freedom from repeat aortic arch operation and survival. We identified no advantage of performing hemiarch replacement in the absence of aortic arch dilation.

The American Association for Thoracic Surgery consensus guidelines on bicuspid aortic valve-related aortopathy: Full online-only version

Bicuspid aortic valve disease is the most common congenital cardiac disorder, being present in 1% to 2% of the general population. Associated aortopathy is a common finding in patients with bicuspid aortic valve disease, with thoracic aortic dilation noted in approximately 40% of patients in referral centers. Several previous consensus statements and guidelines have addressed the management of bicuspid aortic valve-associated aortopathy, but none focused entirely on this disease process. The current guidelines cover all major aspects of bicuspid aortic valve aortopathy, including natural history, phenotypic expression, histology and molecular pathomechanisms, imaging, indications for surgery, surveillance, and follow-up, and recommendations for future research. It is intended to provide clinicians with a current and comprehensive review of bicuspid aortic valve aortopathy and to guide the daily management of these complex patients.

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.

Should sinus of Valsalva be preserved in patients with bicuspid aortic valve and aortic dilation?

BACKGROUND

It is recommended that dilated ascending aortas (≥45 mm) should be replaced at the time of aortic valve replacement (AVR) for bicuspid aortic valve (BAV). The risk of progressive sinus of Valsalva dilatation after AVR and ascending aorta replacement is less clear.

METHODS

We identified 156 patients (age 56.2±10.8 years, 46 females) who underwent AVR and ascending aorta replacement in our institution from 2010-2014, 124 (79%) of whom had BAV. Aortic root and ascending aorta sizes were determined from preoperative and the most recent echocardiograms. The mean follow-up time was 34.4±22.3 months, and 97% of patients completed the follow-up.

RESULTS

The operative mortality rate was 1.3%. During a follow-up of up to 75.2 months, there were no late reoperations for aortic root dissection or rupture. The mean preoperative aortic root diameters in the tricuspid aortic valve (TAV) and BAV groups were 42.2±5.4 and 37.5±5.4 mm, respectively (P=0.69). After operation, most of the patients had reduced aortic root sizes, as the mean postoperative root diameters in the TAV and BAV groups were 39.6±5.2 and 35.7±5.1 mm, respectively (P=0.99).

CONCLUSIONS

To avoid the risks associated with aortic root replacement, it is reasonable to spare the aortic roots in the setting of AVR and ascending aorta replacement for BAV with a dilated ascending aorta and relatively normal sinuses of Valsalva.

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.

Year in review: bicuspid aortopathy

PURPOSE OF REVIEW

This article outlines the key research contribution to bicuspid aortic valve (BAV) aortopathy over the past 18 months.

RECENT FINDINGS

Investigators have further defined the current gaps in knowledge and the scope of the clinical problem of BAV aortopathy. Support for aggressive resection strategies is waning as evidence mounts to suggest that BAV is not similar to genetic connective tissue disorders with respect to aortic risks. The role of cusp fusion patterns and valve-mediated hemodynamics in disease progression is a major area of discovery. Molecular and cellular mechanisms remain elusive and contradictory.

SUMMARY

BAV aortopathy is a major public health problem that remains poorly understood. New insights on valve-mediated hemodynamics using novel imaging modalities may lead to more individualized resection strategies and improved clinical guidelines.

The Aortic Root: Natural History After Root-Sparing Ascending Replacement in Nonsyndromic Aneurysmal Patients

BACKGROUND

Leaving native aortic tissue in situ in root-sparing ascending aortic replacement raises concern regarding potential later need for root reoperation or for the potential occurrence of localized dissections or rupture in the residual root. The purpose of this study was to evaluate the natural growth of the aortic root after root-sparing aortic replacement.

METHODS

In all, 102 consecutive patients (mean age 61.8 ± 12.5 years; 60% male) who had undergone root-sparing aortic replacement had sufficient retrievable information regarding their aortic root diameter at postoperative baseline and follow-up imaging by computed tomography or echocardiography. The annual growth rate was evaluated and also compared according to the influence of valve morphology and concomitant aortic valve replacement. Furthermore, the years of natural history that would require for root enlargement to meet a 50 mm threshold of the root diameter were calculated.

RESULTS

The estimated growth rate of the aortic root after root-sparing aortic replacement is between 0.27 and 0.51 mm per year (mean 0.41 mm, varying according to the underlying diameter) and therefore fivefold less than other aortic regions. Accordingly, a root aneurysm indicating reoperation would not be expected for 29.1 years on average. Only patients with a diameter of 45 mm or more are at risk for reoperation, and not until at least after 10.4 years have passed. Neither the valve morphology (p = 0.62) nor concomitant aortic valve replacement (p = 0.86) influenced rate of root dilation.

CONCLUSIONS

In nonsyndromic patients, the aortic root is the slowest growing portion of the thoracic aorta. Leaving the native root, as in root-sparing ascending aortic replacement, is a safe approach regarding secondary root intervention for aortic root diameters of 45 mm or less.

Aortic valve disease with ascending aortic aneurysm: Impact of concomitant root-sparing (supracoronary) aortic replacement in nonsyndromic patients

OBJECTIVE

The purpose of the study was to assess the anticipated incremental risk of a concomitant aortic resection performed with an aortic valve replacement.

METHODS

Patients who underwent aortic valve replacement with root-sparing ascending replacement were compared with those who underwent isolated aortic valve replacement using propensity score matching (81 pairs; mean age, 63 ± 11 years [root-sparing ascending replacement] vs 64 ± 14 years). To evaluate the impact of the technique at distal site, 71 pairs of those undergoing root-sparing ascending replacement also were matched by propensity score according to distal anastomosis performed clamped and open under deep hypothermic circulatory arrest.

RESULTS

Operative mortality was equal between the root-sparing ascending replacement and isolated aortic valve replacement groups. No significant difference was found regarding postoperative morbidities, such as bleeding, renal failure, stroke, and length of stay, except prolonged ventilation was found after root-sparing procedures (P = .028). Survival estimation showed no difference between the groups. Comparing the patients undergoing root-sparing ascending replacement with clamped and opened distal anastomosis revealed a prolonged ventilation requirement (7% vs 3%; P = not significant) in the open group. Operative mortality was 0% in both groups, and midterm survival was comparable.

CONCLUSIONS

The concomitant replacement of the aorta in root-sparing fashion is associated with an excellent operative outcome and adds no additional risk to aortic valve replacement in elective and non-high-risk patients. If the distal anastomosis is performed in an open fashion, while the operative mortality is still very low, morbidities are slightly higher, but midterm survival remains comparable.

Valve-Related Hemodynamics Mediate Human Bicuspid Aortopathy: Insights From Wall Shear Stress Mapping

BACKGROUND

Suspected genetic causes for extracellular matrix (ECM) dysregulation in the ascending aorta in patients with bicuspid aortic valves (BAV) have influenced strategies and thresholds for surgical resection of BAV aortopathy. Using 4-dimensional (4D) flow cardiac magnetic resonance imaging (CMR), we have documented increased regional wall shear stress (WSS) in the ascending aorta of BAV patients.

OBJECTIVES

This study assessed the relationship between WSS and regional aortic tissue remodeling in BAV patients to determine the influence of regional WSS on the expression of ECM dysregulation.

METHODS

BAV patients (n = 20) undergoing ascending aortic resection underwent pre-operative 4D flow CMR to regionally map WSS. Paired aortic wall samples (i.e., within-patient samples obtained from regions of elevated and normal WSS) were collected and compared for medial elastin degeneration by histology and ECM regulation by protein expression.

RESULTS

Regions of increased WSS showed greater medial elastin degradation compared to adjacent areas with normal WSS: decreased total elastin (p = 0.01) with thinner fibers (p = 0.00007) that were farther apart (p = 0.001). Multiplex protein analyses of ECM regulatory molecules revealed an increase in transforming growth factor β-1 (p = 0.04), matrix metalloproteinase (MMP)-1 (p = 0.03), MMP-2 (p = 0.06), MMP-3 (p = 0.02), and tissue inhibitor of metalloproteinase-1 (p = 0.04) in elevated WSS regions, indicating ECM dysregulation in regions of high WSS.

CONCLUSIONS

Regions of increased WSS correspond with ECM dysregulation and elastic fiber degeneration in the ascending aorta of BAV patients, implicating valve-related hemodynamics as a contributing factor in the development of aortopathy. Further study to validate the use of 4D flow CMR as a noninvasive biomarker of disease progression and its ability to individualize resection strategies is warranted.

Aortic Dissection in Patients With Bicuspid Aortic Valve-Associated Aneurysms

BACKGROUND

Data regarding the risk of aortic dissection in patients with bicuspid aortic valve and large ascending aortic diameter are limited, and appropriate timing of prophylactic ascending aortic replacement lacks consensus. Thus our objectives were to determine the risk of aortic dissection based on initial cross-sectional imaging data and clinical variables and to isolate predictors of aortic intervention in those initially prescribed serial surveillance imaging.

METHODS

From January 1995 to January 2014, 1,181 patients with bicuspid aortic valve underwent cross-sectional computed tomography (CT) or magnetic resonance imaging (MRI) to ascertain sinus or tubular ascending aortic diameter greater than or equal to 4.7 cm. Random Forest classification was used to identify risk factors for aortic dissection, and among patients undergoing surveillance, time-related analysis was used to identify risk factors for aortic intervention.

RESULTS

Prevalence of type A dissection that was detected by imaging or was found at operation or on follow-up was 5.3% (n = 63). Probability of type A dissection increased gradually at a sinus diameter of 5.0 cm--from 4.1% to 13% at 7.2 cm--and then increased steeply at an ascending aortic diameter of 5.3 cm--from 3.8% to 35% at 8.4 cm--corresponding to a cross-sectional area to height ratio of 10 cm(2)/m for sinuses of Valsalva and 13 cm(2)/m for the tubular ascending aorta. Cross-sectional area to height ratio was the best predictor of type A dissection (area under the curve [AUC] = 0.73).

CONCLUSIONS

Early prophylactic ascending aortic replacement in patients with bicuspid aortic valve should be considered at high-volume aortic centers to reduce the high risk of preventable type A dissection in those with aortas larger than approximately 5.0 cm or with a cross-sectional area to height ratio greater than approximately 10 cm(2)/m.

The addition of hemiarch replacement to aortic root surgery does not affect safety

OBJECTIVES

A hemiarch reconstruction, using deep hypothermic circulatory arrest, is the conventional approach for proximal aortic arch reconstruction, but it carries risks of neurologic events and coagulopathy. The addition of a hemiarch reconstruction to an aortic root replacement may prevent future aortic arch pathology. Outcomes of this approach at a tertiary care institution were examined to determine whether the addition of a hemiarch reconstruction to an aortic root replacement conferred any additional risk.

METHODS

A total of 384 patients underwent an aortic root replacement between April 2004 and June 2012. Of them, 177 (46%) had hemiarch replacement. Propensity score matching yielded 133 pairs of patients receiving hemiarch and non-hemiarch.

RESULTS

Sinus segment diameter was similar between groups; ascending aortic diameter was greater in the hemiarch group (median 50 vs 44 mm; P < .001). The hemiarch group had longer perfusion (median 186 vs 120.5 minutes; P < .001) and crossclamp times (median 140 vs 104 minutes; P < .001); median circulatory arrest was 13 minutes. There was no difference, hemiarch versus no hemiarch, in 30-day mortality (3.0% vs 1.5%; P = .41), stroke (2.3% vs 4.5%; P = .31), reoperation for bleeding (11% vs 10%; P = .84), or overall survival (5-year 88.0% [95% confidence interval, 81.9-94.0] vs 91.4% [95% confidence interval, 85.8-96.9], P = .24).

CONCLUSIONS

In this series, aortic root replacement ± hemiarch reconstruction had low mortality. Addition of hemiarch replacement extended perfusion times but not at the expense of safety. Hemiarch reconstruction should be performed when the aortic root aneurysm extends into the distal ascending aorta.