Anomalous Aortic Origin of a Coronary Artery.

BACKGROUND: Although anomalous aortic origin of a coronary artery (AAOCA) is associated with risk of sudden cardiac arrest (SCA), there is a spectrum of disease, with the appropriate management for many remaining unclear. Increasing data warrant review for an updated perspective on management. METHODS: A panel of congenital cardiac surgeons, cardiologists, and imaging practitioners reviewed the current literature related to AAOCA and its management. Survey of relevant publications from 2010 to the present in PubMed was performed. RESULTS: The prevalence of AAOCA is 0.4% to 0.8%. Anomalous left coronary artery is 3 to 8 times less common than anomalous right coronary, but carries a much higher risk of SCA. Nevertheless, anomalous right coronary is not completely benign; 10% demonstrate ischemia, and it remains an important cause of SCA. Decision-making regarding which patients should be recommended for surgical intervention includes determining anatomic features associated with ischemia, evidence of ischemia on provocative testing, and concerning cardiovascular symptoms. Ischemia testing continues to prove challenging with low sensitivity and specificity, but the utility of new modalities is an active area of research. Surgical interventions focus on creating an unobstructed path for blood flow and choosing the appropriate surgical technique given the anatomy to accomplish this. Nontrivial morbidity has been reported with surgery, including new-onset ischemia. CONCLUSIONS: A proportion of patients with AAOCA demonstrate features and ischemia that warrant surgical intervention. Continued work remains to improve the ability to detect inducible ischemia, to risk stratify these patients, and to provide guidance in terms of which patients warrant surgical intervention.

Contemporary Applications and Outcomes of Pulmonary Artery Banding: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database.

BACKGROUND: Pulmonary artery banding (PAB) in isolation or combined with a congenital cardiac surgical procedure is common and has important mortality. We aimed to determine patient characteristics, clinical outcomes, variation in clinical outcomes by diagnoses, and center variation in PAB use. METHODS: Using The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS CHSD), this study evaluated outcomes of patients undergoing PAB across diagnoses, participating centers, and additional procedures. Patients were identified by procedure and diagnosis codes from 2016 to 2019. We separated patients into groups of main and bilateral PAB and described their outcomes, focusing on patients with main PAB. RESULTS: This study identified 3367 PAB procedures from 2016 to 2019 (3% of all STS CHSD cardiovascular cases during this period): 2677 main PAB, 690 bilateral PAB. Operative mortality was 8% after main PAB and 26% after bilateral PAB. There was significant variation in use of main PAB by center, with 115 centers performing at least 1 main PAB procedure (range, 1-134; Q1-Q3, 8-33). For patients with main PAB, there were substantial differences in mortality, depending on timing of main PAB relative to other procedures. The highest operative mortality (25%; P < .0001) was in patients who underwent main PAB after another separate procedure during their admission, with extracorporeal membrane oxygenation being the most frequent preceding procedure. CONCLUSIONS: PAB is a frequently used congenital cardiac procedure with high mortality and variation in use across centers. Outcomes vary widely by banding type and patient diagnosis. Main PAB after cardiac surgical procedures, especially extracorporeal membrane oxygenation, is associated with very high operative mortality.

Outcomes After Hybrid Palliation for Infants With Critical Left Heart Obstruction.

BACKGROUND: Hybrid palliation (bilateral pulmonary artery banding with or without ductal stenting) is an initial management strategy for infants with critical left heart obstruction and serves as palliation until subsequent operations are pursued. OBJECTIVES: This study sought to determine patient characteristics and factors associated with subsequent outcomes for infants who underwent hybrid palliation. METHODS: From 2005 to 2019, 214 of 1,236 prospectively enrolled infants within the Congenital Heart Surgeons' Society's critical left heart obstruction cohort underwent hybrid palliation across 24 institutions. Multivariable hazard modeling with competing risk methodology was performed to determine risk and factors associated with outcomes of biventricular repair, Fontan procedure, transplantation, or death. RESULTS: Preoperative comorbidities (eg, prematurity, low birth weight, genetic syndrome) were identified in 70% of infants (150 of 214). Median follow-up was 7 years, ranging up to 17 years. Overall 12-year survival was 55%. At 5 years after hybrid palliation, 9% had biventricular repair, 36% had Fontan procedure, 12% had transplantation, 35% died without surgical endpoints, and 8% were alive without an endpoint. Factors associated with transplantation were absence of ductal stent, older age, absent interatrial communication, smaller aortic root size, larger tricuspid valve area z-score, and larger left ventricular volume. Factors associated with death were low birth weight, concomitant genetic syndrome, cardiopulmonary bypass use during hybrid palliation, moderate to severe tricuspid valve regurgitation, and smaller ascending aortic size. CONCLUSIONS: Mortality remains high after hybrid palliation for infants with critical left heart obstruction. Nonetheless, hybrid palliation may facilitate biventricular repair for some infants and for others may serve as stabilization for intended functional univentricular palliation or primary transplantation.

The Academic Impact of Congenital Heart Surgeons' Society (CHSS) Studies.

PURPOSE: We reviewed all 64 articles ever published by The Congenital Heart Surgeons' Society (CHSS) Data Center to estimate the academic impact of these peer-reviewed articles. MATERIALS AND METHODS: The Congenital Heart Surgeons' Society has performed research based on 12 Diagnostic Inception Cohorts. The first cohort (Transposition) began enrolling patients on January 1, 1985. We queried PubMed to determine the number of publications that referenced each of the 64 journal articles generated by the datasets of the 12 Diagnostic Inception Cohorts that comprise the CHSS Database. Descriptive summaries of the data were tabulated using mean with standard deviation and median with range. RESULTS: Sixty-four peer-reviewed papers have been published based on the CHSS Database. Fifty-nine peer-reviewed articles have been published based on the 12 Diagnostic Inception Cohorts, and five additional articles have been published based on Data Science. Excluding the recently established Diagnostic Inception Cohort for patients with Ebstein malformation of tricuspid valve, the number of papers published per cohort ranged from 1 for coarctation to 11 for transposition of the great arteries. The 11 articles generated from the CHSS Transposition Cohort were referenced by a total of 111 articles (median number of references per journal article = 9 [range = 0-22, mean = 10.1]). Overall, individual articles were cited by an average of 11 (mean), and a maximum of 41 PubMed-listed publications. Overall, these 64 peer-reviewed articles based on the CHSS Database were cited 692 times in PubMed-listed publications. The first CHSS peer-reviewed article was published in 1987, and during the 35 years from 1987 to 2022, inclusive, the annual number of CHSS publications has ranged from 0 to 7, with a mean of 1.8 publications per year (median = 1, mode = 1). CONCLUSION: Congenital Heart Surgeons' Society studies are widely referenced in the pediatric cardiac surgical literature, with over 10 citations per published article. These cohorts provide unique information unavailable in other sources of data. A tool to access this analysis is available at: [https://data-center.chss.org/multimedia/files/2022/CAI.pdf].

The Congenital Heart Surgeons' Society Kirklin/Ashburn Fellowship: The Fellows' Perspective.

Since its establishment in 2001, the Congenital Heart Surgeons' Society John W. Kirklin/David Ashburn Fellowship has contributed substantially to the field of congenital heart surgery research while simultaneously training the next generation of surgeon- scientists. To date, ten fellows (and counting) have successfully completed this rigorous training, producing over 40 published articles focused on longitudinal outcomes from the various Congenital Heart Surgeons' Society cohorts. As the Kirklin/Ashburn Fellowship expands and additional fellows matriculate, its legacy, the network of support, and the contribution to congenital heart surgery research will undoubtedly hold strong.

A dynamic Norwood mortality estimation: Characterizing individual, updated, predicted mortality trajectories after the Norwood operation.

Objective: Post-Norwood mortality remains high and unpredictable. Current models for mortality do not incorporate interstage events. We sought to determine the association of time-related interstage events, along with (pre)operative characteristics, with death post-Norwood and subsequently predict individual mortality. Methods: From the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort, 360 neonates underwent Norwood operations from 2005 to 2016. Risk of death post-Norwood was modeled using a novel application of parametric hazard analysis, in which baseline and operative characteristics and time-related adverse events, procedures, and repeated weight and arterial oxygen saturation measurements were considered. Individual predicted mortality trajectories that dynamically update (increase or decrease) over time were derived and plotted. Results: After the Norwood, 282 patients (78%) progressed to stage 2 palliation, 60 patients (17%) died, 5 patients (1%) underwent heart transplantation, and 13 patients (4%) were alive without transitioning to another end point. In total, 3052 postoperative events occurred and 963 measures of weight and oxygen saturation were obtained. Risk factors for death included resuscitated cardiac arrest, moderate or greater atrioventricular valve regurgitation, intracranial hemorrhage/stroke, sepsis, lower longitudinal oxygen saturation, readmission, smaller baseline aortic diameter, smaller baseline mitral valve z-score, and lower longitudinal weight. Each patient's predicted mortality trajectory varied as risk factors occurred over time. Groups with qualitatively similar mortality trajectories were noted. Conclusions: Risk of death post-Norwood is dynamic and most frequently associated with time-related postoperative events and measures, rather than baseline characteristics. Dynamic predicted mortality trajectories for individuals and their visualization represent a paradigm shift from population-derived insights to precision medicine at the patient level.

Hybrid palliation versus nonhybrid management for a multi-institutional cohort of infants with critical left heart obstruction.

OBJECTIVE: To compare patient characteristics and overall survival for infants with critical left heart obstruction after hybrid palliation (bilateral pulmonary artery banding with or without ductal stenting) versus nonhybrid management (eg, Norwood, primary transplantation, biventricular repair, or transcatheter/surgical aortic valvotomy). METHODS: From 2005 to 2019, 1045 infants in the Congenital Heart Surgeons' Society critical left heart obstruction cohort underwent interventions across 28 institutions. Using a balancing score propensity analysis, 214 infants who underwent hybrid palliation and 831 infants who underwent nonhybrid management were proportionately matched regarding variables significantly associated with mortality and variables noted to significantly differ between groups. Overall survival between the 2 groups was adjusted by applying balancing scores to nonparametric estimates. RESULTS: Compared with the nonhybrid management group, infants who underwent hybrid palliation had lower birth weight, smaller gestational age, and higher prevalence of in-utero interventions, noncardiac comorbidities, preoperative mechanical ventilation, absent interatrial communication, and moderate or severe mitral valve stenosis (all P values < .03). Unadjusted 12-year survival after hybrid palliation and nonhybrid management, was 55% versus 69%, respectively. After matching, 12-year survival after hybrid palliation versus nonhybrid management was 58% versus 63%, respectively (P = .37). Among matched infants born weighing <2.5 kg, 2-year survival after hybrid palliation versus nonhybrid management was 37% versus 51%, respectively (P = .22). CONCLUSIONS: Infants born with critical left heart obstruction who undergo hybrid palliation have more high-risk characteristics and anatomy versus infants who undergo nonhybrid management. Nonetheless, after adjustment, there was no significant difference in 12-year survival after hybrid palliation versus nonhybrid management. Mortality remains high, and hybrid palliation confers no survival advantage, even for lower-birth-weight infants.

Norwood operation versus comprehensive stage II after bilateral pulmonary artery banding palliation for infants with critical left heart obstruction.

OBJECTIVE: To determine patient characteristics and outcomes after Norwood versus comprehensive stage II (COMPSII) for infants with critical left heart obstruction who had prior hybrid palliation (bilateral pulmonary artery banding ± ductal stent). METHODS: From 23 Congenital Heart Surgeons' Society institutions (2005-2020), 138 infants underwent hybrid palliation followed by either Norwood (n = 73, 53%) or COMPSII (n = 65). Baseline characteristics were compared between Norwood and COMPSII groups. Parametric hazard model with competing risk methodology was used to determine risk and factors associated with outcomes of Fontan, transplantation, or death. RESULTS: Infants who underwent Norwood versus COMPSII had a higher prevalence of prematurity (26% vs 14%, P = .08), lower birth weight (median 2.8 vs 3.2 kg, P < .01) and less frequent ductal stenting (37% vs 99%; P < .01). Norwood was performed at a median age of 44 days and median weight of 3.5 kg, versus COMPSII at 162 days and 6.0 kg (both P < .01). Median follow-up was 6.5 years. At 5 years after Norwood and COMPSII, respectively; 50% versus 68% had Fontan (P = .16), 3% versus 5% had transplantation (P = .70), 40% versus 15% died (P = .10), and 7% versus 11% are alive without transition, respectively. For factors associated with either mortality or Fontan, only preoperative mechanical ventilation occurred more frequently in the Norwood group. CONCLUSIONS: Higher prevalence of prematurity, lower birth weight, and other patient-related characteristics in the Norwood versus COMPSII groups may influence differences in outcomes that were not statistically significant for this limited risk-adjusted cohort. The clinical decision regarding Norwood versus COMPSII after initial hybrid palliation remains challenging.

Toward More Granular Guidelines in AAOCA: Associating Anatomical Details With Specific Surgical Strategies.

Patients with anomalous aortic origin of a coronary artery (AAOCA) require imaging to clarify the multiple potential anatomic sites of obstruction (fixed or dynamic). Once repaired, the pathway of blood to the myocardium must not encounter: (1) intrinsic ostial stenosis, (2) obstruction from compression or distortion near the commissure or the intercoronary pillar, (3) stenosis where the artery exits the aortic wall (due to an acutely angled "take-off"), (4) compression due to a pathway between the great vessels, (5) stenosis or compression along an intramural course, or (6) compression due to an intramuscular (intraseptal/intraconal) course. Detailed anatomic evaluation of each of these locations allows the surgeon to select an appropriate repair strategy, and each of these abnormal anatomic features should be "matched" with a particular surgical correction. We speculate that the most common surgical repair, unroofing with or without tacking, is often inadequate, as in isolation, it may not allow for correction with a large orifice from the appropriate sinus, without an interarterial course. While the evidence base is insufficient to call these recommendations formal guidelines, these recommendations should serve as a basis for further validity testing, and ultimate evolution to more granular guidelines on AAOCA management.

Managing uncertainty in decision-making of common congenital cardiac defects.

Decision-making in congenital cardiac care, although sometimes appearing simple, may prove challenging due to lack of data, uncertainty about outcomes, underlying heuristics, and potential biases in how we reach decisions. We report on the decision-making complexities and uncertainty in management of five commonly encountered congenital cardiac problems: indications for and timing of treatment of subaortic stenosis, closure or observation of small ventricular septal defects, management of new-onset aortic regurgitation in ventricular septal defect, management of anomalous aortic origin of a coronary artery in an asymptomatic patient, and indications for operating on a single anomalously draining pulmonary vein. The strategy underpinning each lesion and the indications for and against intervention are outlined. Areas of uncertainty are clearly delineated. Even in the presence of "simple" congenital cardiac lesions, uncertainty exists in decision-making. Awareness and acceptance of uncertainty is first required to facilitate efforts at mitigation. Strategies to circumvent uncertainty in these scenarios include greater availability of evidence-based medicine, larger datasets, standardised clinical assessment and management protocols, and potentially the incorporation of artificial intelligence into the decision-making process.

Outcomes of expanded polytetrafluoroethylene pericardial membrane implantation in left ventricular assist device explantation and heart transplantation.

OBJECTIVES: Redo sternotomy and explantation of left ventricular assist devices (LVAD) for heart transplantation (HT) involve prolonged dissection, potential injury to mediastinal structures and/or bleeding. Our study compared a complete expanded polytetrafluoroethylene (ePTFE) wrap versus minimal or no ePTFE during LVAD implantation, on outcomes of subsequent HT. METHODS: Between July 2005 and July 2018, 84 patients underwent a LVAD implant and later underwent HT. Thirty patients received a complete ePTFE wrap during LVAD implantation (Group 1), and 54 patients received either a sheet of ePTFE placed in the anterior mediastinum or no ePTFE (Group 2). RESULTS: Baseline characteristics were similar between Groups 1 and 2. Surgeons reported subjective improvements in speed, predictability, and safety of dissection with complete ePTFE compared with minimal or no ePTFE. Time from incision to initiation of cardiopulmonary bypass (CPB) were similar between groups (97 ± 38 vs. 89 ± 29 min, p = .3). Injury to mediastinal structures during the dissection was similar between groups (10% vs. 11%, p > .9). While surgeons reported less intraoperative bleeding in Group 1 (43% vs. 61%), this trend did not reach significance (p = .1). In-hospital mortality, intensive care unit length of stay and hospital length of stay were similar between both groups. CONCLUSIONS: In patients undergoing LVAD explant-HT, there was a trend toward reduced surgeon reported intraoperative bleeding with ePTFE placement. Despite qualitatively reported greater ease and speed of mediastinal dissection with ePTFE membrane placement, time to initiation of CPB did not differ, likely because surgeons remained cautious, allowing extra time for unanticipated difficulties.

An integration engineering framework for machine learning in healthcare.

Background and Objectives: Machine Learning offers opportunities to improve patient outcomes, team performance, and reduce healthcare costs. Yet only a small fraction of all Machine Learning models for health care have been successfully integrated into the clinical space. There are no current guidelines for clinical model integration, leading to waste, unnecessary costs, patient harm, and decreases in efficiency when improperly implemented. Systems engineering is widely used in industry to achieve an integrated system of systems through an interprofessional collaborative approach to system design, development, and integration. We propose a framework based on systems engineering to guide the development and integration of Machine Learning models in healthcare. Methods: Applied systems engineering, software engineering and health care Machine Learning software development practices were reviewed and critically appraised to establish an understanding of limitations and challenges within these domains. Principles of systems engineering were used to develop solutions to address the identified problems. The framework was then harmonized with the Machine Learning software development process to create a systems engineering-based Machine Learning software development approach in the healthcare domain. Results: We present an integration framework for healthcare Artificial Intelligence that considers the entirety of this system of systems. Our proposed framework utilizes a combined software and integration engineering approach and consists of four phases: (1) Inception, (2) Preparation, (3) Development, and (4) Integration. During each phase, we present specific elements for consideration in each of the three domains of integration: The Human, The Technical System, and The Environment. There are also elements that are considered in the interactions between these domains. Conclusion: Clinical models are technical systems that need to be integrated into the existing system of systems in health care. A systems engineering approach to integration ensures appropriate elements are considered at each stage of model design to facilitate model integration. Our proposed framework is based on principles of systems engineering and can serve as a guide for model development, increasing the likelihood of successful Machine Learning translation and integration.

Factors associated with mortality or transplantation versus Fontan completion after cavopulmonary shunt for patients with tricuspid atresia.

OBJECTIVE: Tricuspid atresia with normally related great vessels (TA) is considered the optimal substrate for the Fontan pathway. The factors associated with death or transplantation after cavopulmonary shunt (CPS) are underappreciated. We aimed to determine factors associated with CPS-Fontan interstage death/transplantation versus transition to Fontan in TA. METHODS: A total of 417 infants younger than 3 months of age with TA were enrolled (January 1999 to February 2020) from 40 institutions into the Congenital Heart Surgeons' Society TA cohort. Parametric competing risk methodology was used to determine factors associated with the competing end points of death/transplantation without Fontan completion, and transition to Fontan. RESULTS: CPS was performed in 382 patients with TA; of those, 5% died or underwent transplantation without transition to Fontan and 91% transitioned to Fontan by 5 years after CPS. Prenatal diagnosis (hazard ratio [HR], 0.74; P < .001) and pulmonary artery band (PAB) at CPS (HR, 0.50; P < .001) were negatively associated with Fontan completion. Preoperative moderate or greater mitral valve regurgitation (HR, 3.0; P < .001), concomitant mitral valve repair (HR, 11.0; P < .001), PAB at CPS (HR, 3.0; P < .001), postoperative superior vena cava interventions (HR, 9.0; P < .001), and CPS takedown (HR, 40.0; P < .001) were associated with death/transplantation. CONCLUSIONS: The mortality rate after CPS in patients with TA is notable. Those with preoperative mitral valve regurgitation remain a high-risk group. PAB at the time of CPS being associated with both increased risk of death and decreased Fontan completion may represent a deleterious effect of antegrade pulmonary blood flow in the CPS circulation.

Time-Related Risk of Pulmonary Conduit Re-replacement: A Congenital Heart Surgeons' Society Study.

BACKGROUND: Patients receiving a right ventricle to pulmonary artery conduit (PC) in infancy will require successive procedures or replacements, each with variable longevity. We sought to identify factors associated with time-related risk of a subsequent surgical replacement (PC3) or transcatheter pulmonary valve insertion (TPVI) after a second surgically placed PC (PC2). METHODS: From 2002 to 2016, 630 patients from 29 Congenital Heart Surgeons' Society member institutions survived to discharge after initial valved PC insertion (PC1) at age ≤ 2 years. Of those, 355 underwent surgical replacement (PC2) of that initial conduit. Competing risk methodology and multiphase parametric hazard analyses were used to identify factors associated with time-related risk of PC3 or TPVI. RESULTS: Of 355 PC2 patients (median follow-up, 5.3 years), 65 underwent PC3 and 41 TPVI. Factors at PC2 associated with increased time-related risk of PC3 were smaller PC2 Z score (hazard ratio [HR] 1.6, P < .001), concomitant aortic valve intervention (HR 7.6, P = .009), aortic allograft (HR 2.2, P = .008), younger age (HR 1.4, P < .001), and larger Z score of PC1 (HR 1.2, P = .04). Factors at PC2 associated with increased time-related risk of TPVI were aortic allograft (HR: 3.3, P = .006), porcine unstented conduit (HR 4.7, P < .001), and older age (HR 2.3, P = .01). CONCLUSIONS: Aortic allograft as PC2 was associated with increased time-related risk of both PC3 and TPVI. Surgeons may reduce risk of these subsequent procedures by not selecting an aortic homograft at PC2, and by oversizing the conduit when anatomically feasible.

Understanding the literature: Complexity of statistical methods used in high-impact cardiothoracic surgery research.

OBJECTIVE: Biostatistics are frequently used in research published in the domain of cardiothoracic surgery. The objective of this study was to describe the scope of statistical techniques reported in the literature and to highlight implications for editorial review and critical appraisal. METHODS: Original research articles published between January and April 2017 in the Journal of Thoracic and Cardiovascular Surgery, Annals of Thoracic Surgery, and the European Journal of Cardio-Thoracic Surgery were examined. For each article, the statistical method(s) reported were recorded and categorized by complexity. RESULTS: We reviewed 293 articles that reported 1068 statistical methods. The mean number of different statistical methods reported per article was 3.6 ± 1.9, with variation by subspecialty and journal. The most common statistical methods were contingency tables (in 59% of articles), t tests (49%), and survival methods (49%). Only 4% of articles used descriptive statistics alone. An introductory level of statistical knowledge was deemed sufficient for understanding 16% of articles, whereas for the remainder a higher level of knowledge would be needed. CONCLUSIONS: Contemporary cardiothoracic surgery research frequently requires the use of complex statistical methods. This was evident across articles for all cardiothoracic surgical subspecialties as reported in 3 high-impact journals. Routine review of manuscript submissions by biostatisticians is needed to ensure the appropriate use and reporting of advanced statistical methods in cardiothoracic surgery research.

Association of atrial septal fenestration with outcomes after atrioventricular septal defect repair.

OBJECTIVE: During repair of atrioventricular septal defect (AVSD), surgeons might leave an atrial level shunt when concerned about postoperative physiology, or as part of routine practice. However, the association of fenestration with outcomes is unclear. We sought to determine factors associated with mortality after biventricular repair of AVSD. METHODS: We included 581 patients enrolled from 32 Congenital Heart Surgeons' Society institutions from January 1, 2012, to June 1, 2020 in the Congenital Heart Surgeons' Society AVSD cohort. Parametric multiphase hazard analysis was used to identify factors associated with mortality. A random effect model was used to account for possible intersite variability in mortality. RESULTS: An atrial fenestration was placed during repair in 133/581 (23%) patients. Overall 5-year survival after repair was 91%. Patients who had fenestration had an 83% 5-year survival versus 93% for those not fenestrated (P < .001). Variables associated with mortality in multivariable hazard analysis included institutional diagnosis of ventricular unbalance (hazard ratio [HR], 2.7 [95% confidence interval (CI): 1.5-4.9]; P = .003), preoperative mechanical ventilation (HR, 4.1 [95% CI, 1.3-13.1]; P = .02), atrial fenestration (HR, 2.8 [95% CI, 1.5-4.9]; P < .001), and reoperation for ventricular septal defect (HR, 4.0 [95% CI, 1.3-13.1]; P = .002). There was no difference in measures of ventricular unbalance for comparisons of fenestrated with nonfenestrated patients. No significant interinstitution variability in mortality was observed on the basis of the random effect model (P = .7). CONCLUSIONS: An atrial communication at biventricular repair of AVSD is associated with significantly reduced long-term survival after adjusting for other known associated factors, including unbalance. These findings might challenge the routine practice of fenestration.