Impact of Non-Diameter Aortic Indices on Surgical Eligibility: Results from the TITAN: SvS Randomized Controlled Trial.

OBJECTIVES: Traditional criteria for intervention on an asymptomatic ascending aortic aneurysm has been a maximal aortic diameter of ⩾5.5cm. The 2022 ACC/AHA aortic guidelines adopted cross-sectional aortic area/height ratio, aortic size index (ASI) and aortic height index (AHI) as alternate parameters for surgical intervention. The objective of this study was to evaluate the impact of using these newer indices on patient eligibility for surgical intervention in a prospective, multicenter cohort with moderate sized ascending aortic aneurysms between 5.0-5.4 cm. METHODS: Patients enrolled from 2018 to 2023 in the randomization or registry arms of the multicenter trial, TITAN: SvS, were included in the study. Clinical data was captured prospectively in an online database. Imaging data were derived from a core CT lab. RESULTS: Among the 329 included patients, 20% were female. Mean age was 65.0 ± 11.6 years and mean maximal aortic diameter was 50.8 ±3.9 mm. In the one third of all patients (n=109) who met any one of the three criteria (i.e., ASI ⩾ 3.08 cm/m2, AHI ⩾ 3.21 cm/m or cross-sectional aortic area/height ⩾ 10 cm2/m), their mean maximal aortic diameter was 52.5 ±0.52 mm. Alternate criteria were most commonly met in females compared to males: 20% versus 2% for ASI (p<0.001), 39% versus 5% for AHI (p<0.001) and 39% versus 21% for cross-sectional aortic area/height (p=0.002), respectively. CONCLUSIONS: One third of patients in Titan:SvS would meet criteria for surgical intervention based on novel parameters vs. the classic definition of diameter⩾5.5cm. Surgical thresholds for ASI, AHI or cross-sectional aortic area/height ratio are more likely to be met in female patients compared to male patients.

Permanent Pacemaker Implantation and Long-Term Outcomes of Patients Undergoing Concomitant Mitral and Tricuspid Valve Surgery.

BACKGROUND: Tricuspid valve annuloplasty (TA) during mitral valve repair (MVr) is associated with increased risk of permanent pacemaker (PPM) implantation, but the magnitude of risk and long-term clinical consequences have not been firmly established. OBJECTIVES: This study assesses the incidence rates of PPM implantation after isolated MVr and following MVr with TA as well as the associated long-term clinical consequences of PPM implantation. METHODS: State-mandated hospital discharge databases of New York and California were queried for patients undergoing MVr (isolated or with concomitant TA) between 2004 and 2019. Patients were stratified by whether or not they received a PPM within 90 days of index surgery. After weighting by propensity score, survival, heart failure hospitalizations (HFHs), endocarditis, stroke, and reoperation were compared between patients with or without PPM. RESULTS: A total of 32,736 patients underwent isolated MVr (n = 28,003) or MVr + TA (n = 4,733). Annual MVr + TA volumes increased throughout the study period (P < 0.001, trend), and PPM rates decreased (P < 0.001, trend). The incidence of PPM implantation <90 days after surgery was 7.7% for MVr and 14.0% for MVr + TA. In 90-day conditional landmark-weighted analyses, PPMs were associated with reduced long-term survival among MVr (HR: 1.96; 95% CI: 1.75-2.19; P < 0.001) and MVr + TA recipients (HR: 1.65; 95% CI: 1.28-2.14; P < 0.001). In both surgical groups, PPMs were also associated with an increased risk of HFH (HR: 1.56; 95% CI: 1.27-1.90; P < 0.001) and endocarditis (HR: 1.95; 95% CI: 1.52-2.51; P < 0.001), but not with stroke or reoperation. CONCLUSIONS: Compared to isolated MVr, adding TA to MVr was associated with a higher risk of 90-day PPM implantation. In both surgical groups, PPM implantation was associated with an increase in mortality, HFH, and endocarditis.

Quality of Life 5 Years Following Transfemoral TAVR or SAVR in Intermediate Risk Patients.

BACKGROUND: Symptomatic patients with severe aortic stenosis (AS) at high risk for surgical aortic valve replacement (SAVR) sustain comparable improvements in health status over 5 years after transcatheter aortic valve replacement (TAVR) or SAVR. Whether a similar long-term benefit is observed among intermediate-risk AS patients is unknown. OBJECTIVES: The purpose of this study was to assess health status outcomes through 5 years in intermediate risk patients treated with a self-expanding TAVR prosthesis or SAVR using data from the SURTAVI (Surgical Replacement and Transcatheter Aortic Valve Implantation) trial. METHODS: Intermediate-risk patients randomized to transfemoral TAVR or SAVR in the SURTAVI trial had disease-specific health status assessed at baseline, 30 days, and annually to 5 years using the Kansas City Cardiomyopathy Questionnaire (KCCQ). Health status was compared between groups using fixed effects repeated measures modelling. RESULTS: Of the 1,584 patients (TAVR, n = 805; SAVR, n = 779) included in the analysis, health status improved more rapidly after TAVR compared with SAVR. However, by 1 year, both groups experienced large health status benefits (mean change in KCCQ-Overall Summary Score (KCCQ-OS) from baseline: TAVR: 20.5 ± 22.4; SAVR: 20.5 ± 22.2). This benefit was sustained, albeit modestly attenuated, at 5 years (mean change in KCCQ-OS from baseline: TAVR: 15.4 ± 25.1; SAVR: 14.3 ± 24.2). There were no significant differences in health status between the cohorts at 1 year or beyond. Similar findings were observed in the KCCQ subscales, although a substantial attenuation of benefit was noted in the physical limitation subscale over time in both groups. CONCLUSIONS: In intermediate-risk AS patients, both transfemoral TAVR and SAVR resulted in comparable and durable health status benefits to 5 years. Further research is necessary to elucidate the mechanisms for the small decline in health status noted at 5 years compared with 1 year in both groups. (Safety and Efficacy Study of the Medtronic CoreValve® System in the Treatment of Severe, Symptomatic Aortic Stenosis in Intermediate Risk Subjects Who Need Aortic Valve Replacement [SURTAVI]; NCT01586910).

Outcomes of Total Aortic Arch Replacement in a Canadian Nationwide Registry.

BACKGROUND: Accurate benchmarking of outcomes after elective open total arch replacement is important for surgical decision making and for comparisons with emerging endovascular technologies. METHODS: A multicentre registry of consecutive aortic arch procedures in 9 centres across Canada contained 250 elective total arch replacements from 2010 to 2021. A total of 728 patients undergoing elective hemiarch replacement over the same time period was used as a comparator group. Propensity score matching was used to construct 202 well matched pairs. RESULTS: Patients undergoing total arch replacement were 63.2 ± 13.6 years old, and 34% were female. These patients were more likely to have connective tissue disorders compared with patients undergoing hemiarch replacement. When under hypothermic circulatory arrest, the total arch group uniformly used antegrade cerebral perfusion with median nadir temperature of 24°C (interquartile range [IQR] 21-25°C), and median duration 33 minutes (IQR 23-51 minutes). Before matching, in-hospital mortality and stroke rates were 5.2% and 10%, respectively, for the total arch group. After matching, the total arch group had in-hospital mortality similar to the hemiarch group (P = 0.58). Rates of stroke were also not statistically different (P = 0.11). The total arch group was more likely to experience delirium, prolonged intubation, increased intensive care unit length of stay, and transfusions. CONCLUSIONS: Elective total arch replacement is performed with good in-hospital mortality rates that are similar to rates after elective hemiarch repairs. However, total arch replacement was associated with significantly higher rates of other morbidities, including delirium and prolonged intubation.

Mapping microarchitectural degeneration in the dilated ascending aorta with ex vivo diffusion tensor imaging.

Aims: Thoracic aortic aneurysms (TAAs) carry a risk of catastrophic dissection. Current strategies to evaluate this risk entail measuring aortic diameter but do not image medial degeneration, the cause of TAAs. We sought to determine if the advanced magnetic resonance imaging (MRI) acquisition strategy, diffusion tensor imaging (DTI), could delineate medial degeneration in the ascending thoracic aorta. Methods and results: Porcine ascending aortas were subjected to enzyme microinjection, which yielded local aortic medial degeneration. These lesions were detected by DTI, using a 9.4 T MRI scanner, based on tensor disorientation, disrupted diffusion tracts, and altered DTI metrics. High-resolution spatial analysis revealed that fractional anisotropy positively correlated, and mean and radial diffusivity inversely correlated, with smooth muscle cell (SMC) and elastin content (P < 0.001 for all). Ten operatively harvested human ascending aorta samples (mean subject age 61.6 ± 13.3 years, diameter range 29-64 mm) showed medial pathology that was more diffuse and more complex. Nonetheless, DTI metrics within an aorta spatially correlated with SMC, elastin, and, especially, glycosaminoglycan (GAG) content. Moreover, there were inter-individual differences in slice-averaged DTI metrics. Glycosaminoglycan accumulation and elastin degradation were captured by reduced fractional anisotropy (R2 = 0.47, P = 0.043; R2 = 0.76, P = 0.002), with GAG accumulation also captured by increased mean diffusivity (R2 = 0.46, P = 0.045) and increased radial diffusivity (R2 = 0.60, P = 0.015). Conclusion: Ex vivo high-field DTI can detect ascending aorta medial degeneration and can differentiate TAAs in accordance with their histopathology, especially elastin and GAG changes. This non-destructive window into aortic medial microstructure raises prospects for probing the risks of TAAs beyond lumen dimensions.

Hemiarch versus extended arch repair for acute type A dissection: Results from a multicenter national registry.

OBJECTIVE: We compared perioperative outcomes of patients with acute type A aortic dissection undergoing hemiarch (HA) versus extended arch (EA) repair with or without descending aortic intervention. METHODS: Nine hundred twenty-nine patients underwent acute type A aortic dissection repair (2002-2021, 9 centers) including open distal repair (HA) with or without additional EA repair. EA with intervention on the descending aorta (EAD) included elephant trunk, antegrade thoracic endovascular aortic replacement, or uncovered dissection stent. EA with no descending intervention (EAND), included unstented suture-only methods. Primary outcomes were in-hospital mortality, permanent neurologic deficit, computed tomography malperfusion resolution, and a composite. Multivariable logistic regression was also performed. RESULTS: Mean age was 66 ± 18 years, 30% (278 out of 929) were women, and HA was performed more frequently (75% [n = 695]) than EA (25% [n = 234]). EAD techniques included: dissection stent (39 out of 234 [17%]), thoracic endovascular aortic replacement (18 out of 234 [7.7%]), and elephant trunk (87 out of 234 [37%]). In-hospital mortality (EA: n = 49 [21%] and HA: n = 129 [19%]; P = .42), and neurological deficit (EA: n = 43 [18%] and HA: n = 121 [17%]; P = .74) were similar. EA was not independently associated with death (EA vs HA odds ratio, 1.09; 95% CI, 0.77-1.54; P = .63) or neurologic deficit (EA vs HA odds ratio, 0.85; 95% CI, 0.47-1.55; P = .59). Composite adverse events differed significantly (EA vs HA odds ratio, 1.47; 95% CI, 1.16-1.87; P = .001). Malperfusion resolved more frequently after EAD (EAD: n = 32 [80%], EAND: n = 18 [56%], HA: n = 71 [50%]; P = .004), although multivariable analysis was not significant (EAD vs HA odds ratio, 2.17; 95% CI, 0.83-5.66; P = .10). CONCLUSIONS: Extended arch interventions pose similar perioperative mortality and neurologic risks as Hemiarch. Descending aortic reinforcement may promote malperfusion restoration. Extended techniques should be approached with caution in acute dissection due to increased risk of adverse events.

Association of Cerebral Oximetry With Brain Ischemic Lesions and Functional Outcomes in Arch Repair.

BACKGROUND: This exploratory analysis of the randomized controlled Aortic Surgery Cerebral Protection Evaluation CardioLink-3 trial sought to determine if cerebral oximetry desaturation during elective proximal arch repair is associated with detrimental postoperative neuroradiologic and neurofunctional outcomes. METHODS: Cerebral oximetry and pre- and postoperative brain magnetic resonance imaging data from 101 participants were analyzed. Oximetry data from the trial allocation groups were compared; the relationships between cerebral oximetry indices and new ischemic cerebral lesions on magnetic resonance imaging and neurologic outcomes were also evaluated. RESULTS: Total cerebral desaturation events (>20% decrease from baseline) on the left (median [interquartile range], 1 [1-3] vs 1.5 [0.5-3] with innominate and axillary cannulation; P = .80) were comparable to those on the right (1 [1-3] vs 1 [0-3]; P = .75) as were the total area under the curve of desaturation (left, P = .61; right, P = .84). Seventy patients had new ischemic lesions, among whom 36 had new severe lesions. Total desaturation events and area under the curve of desaturation were similar in patients with and without new ischemic lesions or severe lesions. The nadir regional cerebral saturation was lower on the left (49% [41-56]) than the right (53% [44-59]); left desaturation episodes were associated with lower postoperative cognitive test scores (P = .004). CONCLUSIONS: The innominate and axillary cannulation techniques for elective proximal arch repair with unilateral antegrade cerebral perfusion were associated with similar occurrences of cerebral oximetry desaturation and neither were associated with new ischemic lesions.

Trends in sex-specific differences following aortic arch repair: results from the Canadian Thoracic Aortic Collaborative.

Background: Previous data have shown that sex-related differences exist in aortic arch surgery, with female patients experiencing worse outcomes. Over time, as surgical techniques and strategies have improved, these improvements have benefitted female patients. Using a multicenter national aortic registry from the Canadian Thoracic Aortic Collaborative (CTAC), we aimed to determine the relationship between sex and outcomes following aortic arch repair and to examine how these have changed over time. Methods: The multicenter prospective CTAC database of all aortic procedures performed under circulatory arrest from participating centers across Canada (n=9) was used. Patients were included who underwent elective or urgent/emergency arch reconstruction under circulatory arrest from 2002 to 2021. The primary composite endpoint was defined as the occurrence of one of the following endpoints: in-hospital mortality, stroke, dialysis-dependent renal failure, deep sternal wound infection, reoperation, or prolonged ventilation of >40 hours. Secondary endpoints included in-hospital mortality, in-hospital stroke, and a modified version of the Society of Thoracic Surgeons-defined composite endpoint for mortality and major morbidity (MMOM). Results: A total of 2,592 patients who underwent aortic arch repair between 2002 and 2021 (31.4% female and 68.6% male patients). Operative mortality decreased through the study period for female patients. No change in operative mortality was observed in male patients or following elective repair. The composite endpoint improved for female patients over time in both elective and urgent surgery, while for male patients, rates improved for elective surgery and remained stable for urgent. Ultimately, female sex was not an independent predictor of adverse outcomes following aortic arch repair. Conclusions: Our results are congruent with existing data and are highly encouraging. It shows that multilevel improvements in our approach to aortic arch surgery have helped to serve female patients who were previously disadvantaged.

Sex differences in long-term outcomes following surgery for acute type A aortic dissection: a systematic review and meta-analysis.

Background: Recent reports on sex differences in long-term outcomes after surgery for acute type A aortic dissection (ATAAD) are conflicting. We aimed to aggregate updated data on long-term survival and reoperation stratified by sex. Methods: A literature search was conducted using Medline, Embase, and Cochrane Central. Studies reporting sex-stratified long-term survival and/or reoperation following surgery for ATAAD between January 1, 2000, to March 15, 2023 were included. Preoperative characteristics, intraoperative variables, and early perioperative outcomes were meta-analyzed using a random effects model and pooled risk ratio (RR) with men as the reference group. Individual patient-level data for long-term outcomes was reconstructed to generate sex-specific pooled Kaplan-Meier curves to assess long-term survival and freedom from reoperation. Results: A total of 15 studies with 7,608 male and 3,989 female patients were included in this analysis. Female patients were older, had higher rates of hypertension, and had less previous cardiac surgery. Intraoperatively, women received less extensive repairs with lower rates of aortic valve replacement and total arch replacement, and higher rates of hemiarch replacement. There were no sex differences for in-hospital/30-day mortality [risk ratio (RR), 1.18; 95% confidence interval (CI): 0.96, 1.45; P=0.12], stroke (RR, 1.07; 95% CI: 0.90, 1.28; P=0.46), and early reoperation (RR, 0.90; 95% CI: 0.75, 1.09; P=0.28). Female patients had lower long-term survival overall (P<0.001) and amongst survivors at 1-year (P=0.014). Overall survival at 5-year was 82.4% in men and 78.1% in women, and at 10-year was 68.1% for men and 63.4% in women. Male patients had higher rates of long-term reoperation (P<0.001). Freedom for reoperation at 5-year was 88.4% in men vs. 93.1% in women. Conclusions: Though perioperative early outcomes have equalized between the sexes following surgery for ATAAD, differences remain in long-term survival and reoperation.

Bio-Bentall and hybrid arch frozen elephant trunk repair for acute type A aortic dissection with malperfusion.

The extent of repair in patients with acute type A aortic dissection is often determined by factors such as entry tear location, aortic anatomy, malperfusion and team expertise. The hybrid arch frozen elephant trunk, which has become an established technique to extend the distal acute type A aortic dissection repair, is particularly useful in malperfusion; however, it remains technically challenging and is associated with increased duration of circulatory arrest and risks of spinal cord ischaemia. Proximal dissection flap extension often determines repairability versus replacement of the aortic root. We present a case report highlighting the proximal and distal extent of repair in a patient with a known ascending aortic aneurysm presenting with an acute type A aortic dissection, with malperfusion, undergoing a successful bio-Bentall procedure and hybrid arch frozen elephant trunk repair.

The Aortic Team Model and Collaborative Decision Pathways for the Management of Complex Aortic Disease: Clinical Practice Update From the Canadian Cardiovascular Society/Canadian Society of Cardiac Surgeons/Canadian Society for Vascular Surgery/Canadian Association for Interventional Radiology.

Disease of the aortic arch, descending thoracic, or thoracoabdominal aorta necessitates dedicated expertise across medical, endovascular, and surgical specialties. Cardiologists, cardiac surgeons, vascular surgeons, interventional radiologists, and others have expertise and skills that aid in the management of patients with complex aortic disease. No specialty is uniformly expert in all aspects of required care. Because of this dispersion of expertise across specialties, an aortic team model approach to decision-making and treatment is advocated. A nonhierarchical partnership across specialties within an interdisciplinary aortic clinic ensures that all treatment options are considered and promotes shared decision-making between the patient and all aortic experts. Furthermore, regionalization of care for aortic disease of increased complexity assures that the breadth of treatment options is available and that favourable volume-outcome ratios for high-risk procedures are maintained. An awareness of best practice care pathways for patient referrals for preventative management, acute care scenarios, chronic care scenarios, and pregnancy might facilitate a more organized management schema for aortic disease across Canada and improve lifelong surveillance initiatives.

Machine learning and decision making in aortic arch repair.

BACKGROUND: Decision making during aortic arch surgery regarding cannulation strategy and nadir temperature are important in reducing risk, and there is a need to determine the best individualized strategy in a data-driven fashion. Using machine learning (ML), we modeled the risk of death or stroke in elective aortic arch surgery based on patient characteristics and intraoperative decisions. METHODS: The study cohort comprised 1323 patients from 9 institutions who underwent an elective aortic arch procedure between 2002 and 2021. A total of 69 variables were used in developing a logistic regression and XGBoost ML model trained for binary classification of mortality and stroke. Shapely additive explanations (SHAP) values were studied to determine the importance of intraoperative decisions. RESULTS: During the study period, 3.9% of patients died and 5.4% experienced stroke. XGBoost (area under the curve [AUC], 0.77 for death, 0.87 for stroke) demonstrated better discrimination than logistic regression (AUC, 0.65 for death, 0.75 for stroke). From SHAP analysis, intraoperative decisions are 3 of the top 20 predictors of death and 6 of the top 20 predictors of stroke. Predictor weights are patient-specific and reflect the patient's preoperative characteristics and other intraoperative decisions. Patient-level simulation also demonstrates the variable contribution of each decision in the context of the other choices that are made. CONCLUSIONS: Using ML, we can more accurately identify patients at risk of death and stroke, as well as the strategy that better reduces the risk of adverse events compared to traditional prediction models. Operative decisions made may be tailored based on a patient's specific characteristics, allowing for maximized, personalized benefit.

Diagnostic Accuracy of Transesophageal Echocardiographic Commissural-Biplane Approach in Identifying Mitral Valve Anatomy.

BACKGROUND: Transesophageal echocardiography (TEE) conventional multiplane approach (MPA) and the newly proposed commissural-biplane approach (CBA) are the recommended algorithms for identifying the affected mitral valve (MV) segments in the setting of mitral regurgitation. To date, there are no reports to address the diagnostic performance of CBA. In this study we aim to analyze the diagnostic accuracy of CBA and MPA in comparison with three-dimensional echocardiographic findings in patients with severe mitral regurgitation. METHODS: We prospectively enrolled 102 patients with severe mitral regurgitation. All patients underwent systematic TEE assessment of MV before surgical intervention to define the affected MV segments/scallops. The standard MPA includes 4-chamber, 2-chamber, long-axis, and commissural views; CBA was performed by obtaining the bicommissural view and simultaneous biplane imaging of the medial, middle, and lateral MV aspects. The findings of both TEE approaches were compared with three-dimensional TEE data to assess the diagnostic accuracy of MPA and CBA. RESULTS: The mean patient age was (65 ± 11) years, and 37 (36.3%) were female. We found that CBA had an overall diagnostic accuracy between 88% and 97% in identifying the abnormal MV scallops; in contrast, MPA accuracy ranged between 82% and 95%. The CBA and MPA were the least accurate in identifying the P3 scallop-88% and 82% respectively; however, both were the most accurate in assessing the A2 segment-95% and 97%, respectively. The sensitivity of identifying commissural abnormalities was 80% with CBA and 30% with MPA. Three-dimensional TEE was found to have a strong agreement with CBA (averaged kappa of 0.81, P < .0001) and a modest agreement with MPA (averaged kappa of 0.61, P < .0001) in identifying abnormal anterior or posterior segments. On the other hand, three-dimensional TEE had a weak agreement with CBA (kappa of 0.43, P < .0001) and no agreement with MPA (kappa of 0.14, P = .153) in the assessment of commissural involvements. CONCLUSION: The CBA is more accurate than the MPA in the assessment of MV commissural involvement. Given the accuracy differences of the 2 approaches for specific leaflet/scallops, a comprehensive evaluation using both approaches is recommended for all MV scallop assessments.