Mechanical Circulatory Support During Surgical Revascularization for Ischemic Cardiomyopathy.

BACKGROUND: This study aimed to describe the use of perioperative mechanical circulatory support (MCS) and its impact on outcomes in patients with ischemic cardiomyopathy who were undergoing surgical revascularization. METHODS: Patients with an ejection fraction <35% who underwent isolated coronary artery bypass grafting (CABG) from 2015 to 2021 were identified (N = 378). Patients were divided into no MCS, preoperative MCS, and postoperative MCS groups on the basis of timing of MCS initiation, which included intraaortic balloon pump, extracorporeal membrane oxygenation, or Impella device (Abiomed) use. The primary outcome of interest was operative mortality. RESULTS: The median Society of Thoracic Surgeons Predicted Risk of Mortality was 2.4%. Sixty-six percent (n = 246) of patients had a previous myocardial infarction, and 61.8% of these patients were within 21 days of CABG. Twenty-one patients (5.6%) presented in cardiogenic shock. The preoperative MCS cohort consisted of 31 patients (8.2%) who underwent CABG a median of 2 days after MCS initiation. Thirty (7.9%) patients required postoperative MCS. Independent risk factors for requiring postoperative MCS included the preoperative ejection fraction (odds ratio, 0.93; P = .01 and the presence of preoperative MCS (odds ratio, 3.06; P = .02). Overall, operative mortality was 3.4%, and 3-year survival was 87.0%. Operative mortality in patients who did and did not receive preoperative MCS was 7.7% and 2.9% (P = .12) with no difference in long-term survival (P = .80), whereas patients requiring postoperative MCS had significantly increased operative (16.7%) and late mortality (63%; P <.01). CONCLUSIONS: CABG can be performed safely in patients with ischemic cardiomyopathy with selective use of perioperative MCS. Despite advanced disease severity, patients requiring preoperative MCS demonstrate acceptable short- and long-term survival. Patients requiring postoperative MCS have increased postoperative morbidity and mortality.

Mitral regurgitation mechanisms related to systolic anterior motion in hypertrophic cardiomyopathy.

Background: Systolic anterior motion (SAM) of the mitral valve can result in mitral regurgitation (MR) and adverse outcomes in patients with obstructive hypertrophic cardiomyopathy (HCM). However, the mechanism and characteristics of MR severity mediated by SAM are unresolved. This study aimed to elucidate the anatomic and hemodynamic associations of MR and the impact of septal myectomy on changes in MR severity in patients with HCM. Methods: We retrospectively reviewed patients who underwent septal myectomy with SAM and interpretable imaging between 2017-2022. Significant MR was defined as moderate or more MR. The mitral valve, papillary muscle, and left ventricular geometry were quantitatively evaluated via echocardiography and cardiac computed tomography. Results: Out of 34 patients, two groups were identified: those with preoperative significant MR (n=16) and those without significant MR (n=18). Patients with significant preoperative MR exhibited worse heart failure symptoms at baseline than those without. Following myectomy, these patients showed higher residual left ventricular outflow tract (LVOT) gradients at rest and with provocative measures than those without preoperative MR. Multivariate regression analysis revealed a significant association between the tenting area and MR severity. Additionally, the chordal cutting procedure alleviated the tenting area [2.1 (1.8-2.6) vs. 1.4 (1.2-1.6) cm2] compared to those without it. Conclusions: Our preliminary data suggested that chordal cutting with septal myectomy was associated with an improvement in the tenting area, contributing to MR severity. This procedure may serve as an effective therapy for patients with SAM and significant MR.

Aortic insufficiency following balloon aortic valvuloplasty does not impact long-term autograft durability after the Ross procedure.

OBJECTIVE: Preoperative aortic insufficiency (AI) is associated with inferior autograft durability after the Ross procedure. However, many patients with aortic stenosis (AS) undergo balloon aortic valvuloplasty (BAV) early and present with longstanding AI before Ross. We studied how BAV and subsequent valvular pathology impacts autograft durability. METHODS: Patients undergoing the Ross operation from 1993 to 2020 were identified. Those who underwent BAV before Ross were compared with patients who did not undergo BAV and underwent Ross for predominant AI (AI group) or AS (AS group). Those who underwent previous open surgical aortic valve intervention were excluded. Primary outcome of interest was autograft failure, defined as a composite of autograft reintervention or severe insufficiency. RESULTS: A total of 198 patients were included. Seventy-nine (39.9%) underwent BAV and subsequently underwent the Ross for predominant AI (45.6%) or AS (54.4%). Of patients who did not undergo BAV, 66 (33.3%) presented with predominant AI and 53 (26.8%) with AS. Freedom from autograft failure at 15 years was 90%, 92%, and 62% in BAV, AS, and AI groups, respectively. The AI group was at significantly increased risk of long-term autograft failure (hazard ratio, 5.6; P = .01), whereas the AS and BAV groups had similar, low risk (hazard ratio, 1.1; P = .91). Autograft durability was similar among patients who received BAV and presented with AS or AI before the Ross (P = .84). CONCLUSIONS: BAV before the Ross procedure is common in patients with AS. These patients have excellent long-term autograft durability regardless of preoperative valvular pathology and should strongly be considered for the Ross operation.

Reintervention after valve-sparing aortic root replacement: A comprehensive analysis of 781 David V procedures.

OBJECTIVE: Studies of reintervention after valve-sparing aortic root replacement (VSRR) are limited by sample size and failure to evaluate all types of reinterventions, including distal aorta and transcatheter interventions. In this report, reintervention after VSRR using a large patient cohort was comprehensively analyzed. METHODS: In a series involving 2 academic aortic centers, 781 consecutive patients from 2005 to 2020 undergoing David V VSRR for aortic aneurysm (91%) or dissection (9%) were included. Median age was 50 years, and 23% had a bicuspid aortic valve (AV). Median follow-up was 7.0 years. Open or transcatheter reintervention on the AV, proximal, or distal thoracic aorta was identified. Cumulative incidence was calculated, and subdistribution hazard models identified factors associated with reintervention. Time-dependent incidence of reintervention was plotted using risk-hazard functions. RESULTS: Sixty-eight reinterventions (57 open, 11 transcatheter) were performed. Reinterventions were divided by indication into degenerative AV (n = 26, including 1 transcatheter aortic valve replacement), endocarditis (n = 11), proximal aorta (n = 8), and distal aorta (n = 23, including 10 thoracic endovascular aortic repairs). Risk of reintervention for endocarditis peaked 1 to 3 years after VSRR, whereas other indications had stable, low rates of occurrence throughout the follow-up period. The cumulative incidence of reintervention was 12.5% whereas the cumulative incidence of AV reintervention was 7.0% at 10 years and was associated with residual postoperative aortic insufficiency. In-hospital mortality after reintervention was 3%. CONCLUSIONS: Reintervention rates after VSRR are relatively low in long-term follow-up and can be performed with acceptable operative risk. The majority of reinterventions are performed for indications other than AV degeneration, with the timing of reintervention varying by the specific clinical indication.

Increasing waiting times for status 2 patients in new United Network for Organ Sharing allocation system: Impact on waitlist and posttransplant outcomes.

OBJECTIVE: Since the heart transplant allocation policy change in 2018, there has been an increase in temporary mechanical circulatory support for Status 2 patients. We sought to examine the temporal pattern of waitlist and posttransplant outcomes for Status 2 patients. METHODS: Adult patients in the United Network for Organ Sharing registry who were listed as Status 2 from January 2019 to June 2022 were included. Temporal trends in waitlist time, waitlist events, and posttransplant outcomes were assessed. Probability of transplant or death after being listed was compared over time. Multivariable regression was performed to identify risk factors for mortality after transplant. RESULTS: A total of 6310 patients were included. From 2019 to 2022, the number of Status 2 patients listed increased from 4.2 to 5.9 per day. Microaxial ventricular assist devices at Status 2 listing increased over time (P < .001). During the study period, median waitlist time (18 days vs 23 days, P < .001) as well as Status 2 days (8 days vs 12 days, P < .001) increased. Waitlist mortality remained stable (5.5%); however, probability of transplant within 90 days of Status 2 listing progressively declined (P < .001). Finally, longer waitlist duration was independently associated with 30-day posttransplant mortality (odds ratio, 1.01; 95% confidence interval, 1.00-1.01, P = .02). CONCLUSIONS: Since the allocation policy change there has been a steady rise in the number of patients listed for Status 2. This has led to increasing waitlist times and lower probability of transplantation for Status 2 patients, which may have negative consequences for posttransplant outcomes.

Valved Conduits for Right Ventricular Outflow Tract Reconstruction: A Review of Current Technologies and Future Directions.

The need for right ventricular outflow tract reconstruction is common and growing in congenital heart surgery given expanding indications for the repair of congenital as well as acquired heart disease. Various valved conduit options currently exist including homografts, xenograft pulmonary valved conduits (Contegra™), and porcine valved conduits. The major limitation for all conduits is implant durability, which requires reoperation. Currently, cryopreserved homografts are often used given their superiority shown in long-term data. Significant limitations remain in the cost and availability of the graft, particularly for smaller sizes. Contegra conduits are available in a variety of sizes. Nonetheless, the data regarding long-term durability are less robust and studies comparing durability with homografts have been conflicting. Additionally, there is concern for increased rates of late endocarditis in this conduit. Porcine valved conduits offer a reliable option but are limited by structural valve degeneration associated with all types of bioprosthetic heart valve replacements. New developments in the field of tissue engineering have produced promising bio-restorative valved conduits that may overcome many of the limitations of previous conduit technologies. These remain in the early stages of clinical testing. This review summarizes the clinical data surrounding the conduits used most commonly in clinical practice today and explores emerging technologies that may bring us closer to developing the ideal conduit.

Polymeric prosthetic heart valves: A review of current technologies and future directions.

Valvular heart disease is an important source of cardiovascular morbidity and mortality. Current prosthetic valve replacement options, such as bioprosthetic and mechanical heart valves are limited by structural valve degeneration requiring reoperation or the need for lifelong anticoagulation. Several new polymer technologies have been developed in recent years in the hope of creating an ideal polymeric heart valve substitute that overcomes these limitations. These compounds and valve devices are in various stages of research and development and have unique strengths and limitations inherent to their properties. This review summarizes the current literature available for the latest polymer heart valve technologies and compares important characteristics necessary for a successful valve replacement therapy, including hydrodynamic performance, thrombogenicity, hemocompatibility, long-term durability, calcification, and transcatheter application. The latter portion of this review summarizes the currently available clinical outcomes data regarding polymeric heart valves and discusses future directions of research.

Operative mortality after Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 1 to 3 procedures: Deficiencies and opportunities for quality improvement.

OBJECTIVES: We examined cases of operative mortality at a single quaternary academic center for patients undergoing relatively lower-risk (Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 1-3) procedures, as a means of identifying systemic weaknesses and opportunities for quality improvement. METHODS: A retrospective review of all operative mortality events for patients who underwent a Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 1, 2, or 3 index procedure (2009-2020) at our institution was performed. After a detailed chart review was performed by 2 independent faculty for each case, factors and system deficiencies that contributed to mortality were identified. RESULTS: A total of 42 mortalities were identified. A total of 37 patients (88%) had at least 1 Society of Thoracic Surgeons-designated risk factor, including prior cardiac operations (48%), extracardiac malformations (43%), and preoperative ventilation (33%). Eight patients (19%) had non-Society of Thoracic Surgeons-designated preoperative patient-level variables considered as at potential risk, including severe ventricular dysfunction, pulmonary hypertension, lung hypoplasia, and undiagnosed severe coronary abnormalities. Four patients (10%) had no identified preoperative risk factors. After detailed chart review, 5 broad categories were identified: patient-related factors (n = 33; 78%), postoperative infection (n = 13; 31%), postoperative residual lesions (n = 7; 17%), Fontan physiology failure (n = 4; 10%), and unexplained left ventricular failure after tetralogy of Fallot repair (n = 3; 7%). A total of 74% of patients had at least 1 preoperative, intraoperative, or postoperative system deficiency. A total of 50% of surgeries were urgent or emergency. CONCLUSIONS: Operative mortality after Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 1 to 3 procedures is related to the presence of multifactorial risk patterns (Society of Thoracic Surgeons and non-Society of Thoracic Surgeons-designated patient-level risk factors and variables, broad risk categories, system deficiencies, emergency surgery). A multidisciplinary approach to care, with early recognition and treatment of modifiable additional burdens, could reduce this risk.

Diabetes workshops for providers improve glucose control in coronary artery bypass grafting patients.

OBJECTIVES: Postoperative hyperglycemia occurs in up to 80% of cardiac surgery patients and is associated with poor outcomes. We sought to determine if case-based diabetes workshops for providers would improve postoperative glycemic control and outcomes in patients undergoing coronary artery bypass grafting  (CABG). METHODS: Healthcare providers taking care of patients in the cardiothoracic step-down unit underwent 30-min weekly case-based diabetes workshops over 6 months. Workshops focused on initiation of insulin treatment, titration of insulin dosing, and transitioning from insulin drips to subcutaneous insulin. Isolated-CABG patients were recorded during 29-month periods before (Jan 2013-June 2015) and after training (Jan 2016-June 2018). Glycemic control and outcomes were compared between groups balanced for preoperative risk factors using inverse probability treatment weights. RESULTS: A total of 938 and 1032 patients were included in pre- and posttraining groups, respectively. Compared to the pretraining period, the posttraining period had a lower median of mean patient day glucose levels (151 vs. 144 mg/dl, p < .001) and percentage of patient days with a glucose level >250 mg/dl (20% vs. 14%, p < .001). The percentage of patient days with mean glucose values in the target range (80-180 mg/dl) increased from 71% to 77% (p < .001). The incidence of hypoglycemic events did not significantly change after training (p = .15). The incidence of sepsis was significantly lower in the posttraining period (1.7% vs. 0.2%, p < .001). CONCLUSIONS: Weekly diabetes workshops for healthcare providers were associated with improved glycemic control and reduced postoperative sepsis among isolated CABG patients.

Impact of Venoarterial Extracorporeal Membrane Oxygenation Flow on Outcomes in Cardiogenic Shock.

Venoarterial extracorporeal membrane oxygenation (VA ECMO) is used to provide cardiopulmonary support in cardiogenic shock; however, high extracorporeal flow may increase left ventricular (LV) afterload leading to LV distention and intracardiac stasis. It is unclear how ECMO flow affects patient outcomes and complications related to ECMO. Retrospective review of patients at a single institution placed on VA ECMO from 2007 to 2018 was performed. Patients were divided into full flow (flow index > 2.2 L/min/m2) and partial flow (flow index < 2.2 L/min/m2) groups. In-hospital mortality and markers of end-organ perfusion were compared between groups balanced for risk factors using propensity score inverse probability of treatment weighting. ECMO-related complications such as LV distention, limb ischemia, and bleeding were recorded. There were 488 patients included, 405 (83%) in the partial flow group, and 83 (17%) in the full flow group. No major differences in age, gender, or comorbidities were found. There was no difference in in-hospital mortality between groups (51% vs. 55%, p = 0.59). At 72 hours post-ECMO initiation, there was no difference in the change in renal, hepatic function, or lactate from baseline nor in the rates of continuous venoveno hemofiltration initiation (p = 0.41). There was a trend towards the decreased incidence of LV distention requiring LV vent placement in the partial flow group (12% vs. 7%, p = 0.16). Compared with full flow VA ECMO, partial flow VA ECMO in carefully selected patients results in similar in-hospital mortality and provides similar end-organ perfusion for the treatment of refractory cardiogenic shock.

Structure of the p53/RNA polymerase II assembly.

The tumor suppressor p53 protein activates expression of a vast gene network in response to stress stimuli for cellular integrity. The molecular mechanism underlying how p53 targets RNA polymerase II (Pol II) to regulate transcription remains unclear. To elucidate the p53/Pol II interaction, we have determined a 4.6 Å resolution structure of the human p53/Pol II assembly via single particle cryo-electron microscopy. Our structure reveals that p53's DNA binding domain targets the upstream DNA binding site within Pol II. This association introduces conformational changes of the Pol II clamp into a further-closed state. A cavity was identified between p53 and Pol II that could possibly host DNA. The transactivation domain of p53 binds the surface of Pol II's jaw that contacts downstream DNA. These findings suggest that p53's functional domains directly regulate DNA binding activity of Pol II to mediate transcription, thereby providing insights into p53-regulated gene expression.

Temporary surgical ventricular assist device for treatment of acute myocardial infarction and refractory cardiogenic shock in the percutaneous device era.

BACKGROUND: Acute myocardial infarction with refractory cardiogenic shock (AMI-RCS) is associated with poor outcomes. Several percutaneous mechanical circulatory support devices exist; however, limitations exist regarding long-term use. Herein, we describe our experience with the temporary surgical CentriMag VAD. METHODS: We reviewed 74 patients with AMI-RCS who underwent CentriMag VAD insertion as bridge-to-decision device from 2007 to 2020. Patients were divided into groups based on introduction of the "shock team" model: Era 1 (2007-2014, n = 51) and Era 2 (2015-2020, n = 23). RESULTS: Era 2 had higher proportion of patients with INTERMACS Profile I. The use of percutaneous MCS as bridge to VAD and the use of minimally invasive VAD were higher in Era 2. There were fewer postoperative bleeding events in Era 2 (80% vs 61%, p = .07). Thirty-day mortality was 23% and 1-year survival was 55%, which were no differences between eras. Destinations after CentriMag VAD included myocardial recovery (39%), durable LVAD (27%), and transplantation (5%). CONCLUSION: CentriMag VAD device represents a viable bridge-to-decision device with acceptable short- and long-term outcomes for patients with AMI-RCS. Stable outcomes in a progressively sicker population may be related to changes in practice patterns as well as introduction of the "shock team" concept.

A Cross-sectional Review of Cardiothoracic Surgery Department Chairs and Program Directors.

OBJECTIVE: Departmental leadership, namely the chair and program director, are sought after positions among academic cardiothoracic surgeons. However, the path to achieving these positions remains unclear. This study sought to characterize the demographics, educational pathways, and career trajectories of current cardiothoracic academic leaders in the United States. METHODS: A comprehensive list of ACGME accredited thoracic surgery residency and fellowship programs was obtained. Department chairs and program directors were identified for each program from May to June 2019. For each surgeon, demographic data, education, and training institutions were identified. Information was obtained primarily using institutional based websites. RESULTS: A total of 72 department chairs or division chiefs and 77 program directors were identified. A minority of chairs and program directors were female (4.2%, 10.4%) or had PhD degrees (4.2%, 6.5%). A large number of surgeons trained in the North East region (35%), with Brigham and Women's hospital being the most common training institution (8%). Few chairs (31%) and program directors (39%) hold leadership positions at the institution at which they trained, however a larger proportion (52.8%, 58.4%) remain or return to the same region. Finally, 34.7% of chairs and 32.5% of program directors had some institutional exposure to where they currently practice, through medical school or training. CONCLUSION: Cardiothoracic department chairs and program directors represent an important group of surgical leaders within our evolving field. As we better understand this group of surgeon-leaders, young trainees and junior faculty that aspire for leadership positions may have a clearer idea of the path to these positions.

The Current State of Orthopaedic Educational Leadership.

INTRODUCTION: It is important to understand the current characteristics of orthopaedic surgery program leadership, especially in the current climate of modern medicine. The purpose of this report was to describe the demographic, academic, and geographic characteristics of current orthopaedic chairs and program directors (PDs). METHODS: Orthopaedic surgery residency programs were obtained from the Accreditation Council for Graduate Medical Education website and cross-referenced with the Electronic Residency Application Service, identifying 161 residency programs for the 2018 to 2019 cycle. All data were collected in January 2020 to best control for changes in leadership. Demographic and academic information were collected from public websites. For geographic analysis, the United States was divided into five regions, and training locations were categorized as appropriate. RESULTS: A total of 153 chairs and 161 PDs were identified. 98.0% of chairs were men versus 88.8% of PDs (P = 0.001). Chairs had been in practice and in their current position for longer than PDs (26.4 vs 16.8 years [P < 0.005] and 9.1 vs 7.1 years [P = 0.014], respectively). Chairs had more publications and were more likely to be professors than PDs. PDs were more likely to remain at both the same region and institution that they trained in residency. The most common subspecialty was sports among chairs and trauma among PDs, although when compared with national averages orthopaedic trauma and orthopaedic oncology were the most overrepresented subspecialties. CONCLUSION: Orthopaedic chairs are more likely to be men, have had longer careers, and have more academic accomplishments than their PD counterparts. Geography appears to have an association with where our leaders end up, especially for PDs. Subspecialization does not notably influence leadership positions, although orthopaedic trauma and orthopaedic oncology surgeons are more commonly represented than expected. This report serves to identify the current state of orthopaedic leadership and may provide guidance for those who seek these leadership positions.

Minimally invasive central venoarterial extracorporeal membrane oxygenation for long-term ambulatory support as a bridge to heart-lung transplant.

Extracorporeal membrane oxygenation (ECMO) is becoming a key tool for bridge to heart, lung, or heart-lung transplantation, and ambulatory ECMO support offers many advantages to prepare the patients. We here present a case of successful en bloc heart and lung transplantation after long-term ambulatory support with a minimally invasive central venoarterial ECMO approach as bridge to transplant.

Clinical Trials in Obstructive Sleep Apnea: Recognizing Trends and Future Opportunities.

OBJECTIVES/HYPOTHESIS: Examine US and international clinical trials in obstructive sleep apnea (OSA) to characterize researchers involved, interventions being studied, and opportunities for future investigation. STUDY DESIGN: Retrospective database review. METHODS: The information from ClinicalTrials.gov was used to assess OSA clinical trials between 1999 and 2017. Information was gathered on principle investigator (PI) demographics, interventions studied, study funding source, and regional distribution of research institutions. RESULTS: There were 813 clinical trials studied. The majority of trials examined continuous positive airway pressure interventions (43.7%), with pharmacotherapies being the second most commonly investigated treatment (19.2%). Surgical interventions made up 10.7% (n = 87) of clinical trials for OSA. Most studies were based internationally (59.9%). PIs were predominantly male (72.0%); 72.7% had an MD and 28.6% had a PhD. There were no significant differences in funding source (National Institutes of Health vs. industry, P = .14) or institutional geography (international vs. US, P = .73) between surgical and nonsurgical studies. Surgical trials were significantly more likely to have a male PI and involve pediatric patients compared to nonsurgical trials (P < .001). Otolaryngologists represented 9.2% of all PIs and had similar rates of NIH funding compared to other medical specialists (P = .22). CONCLUSIONS: This study provides a broad overview of past, current, and future treatment paradigms for OSA. Sleep surgery, specifically otolaryngology, is a small voice in the overall landscape of clinical trials for OSA. This information can help guide future research efforts and direct our specialty when setting priorities regarding research funding while encouraging a broad and interdisciplinary pursuit. LEVEL OF EVIDENCE: NA Laryngoscope, 129:1940-1944, 2019.