Survival trends in heart transplant patients supported on ECMO and IABP: A 10-year UNOS database analysis.

The United Network for Organ Sharing (UNOS) heart transplant allocation policy was changed in 2018. This study examines the impact of the change in UNOS heart transplant allocation policy on the use of temporary mechanical circulatory support (MCS) devices and post-transplant survival. The analysis included a total of 26,481 patients listed and transplanted between January 2013 and June 2022. The results showed a decrease in waiting time for transplant after the policy change, indicating a successful reduction in waitlist time for high-priority status patients. However, the length of hospital stays from transplant to discharge increased following the policy change. The study also found an increase in the frequency of ECMO and IABP use both at the time of listing and at the time of transplant following the policy change. Cumulative patient and graft survival at 1000 days decreased following the policy change (86.1 per cent versus 83.7 per cent at 1000 days, p = 0.002). However, the survival curves showed similar survival trends in the first 2 years, with late divergence in survival occurring after 2 years. In conclusion the latest UNOS heart transplant allocation policy change led to a decrease in waiting times and an increase in the use of temporary MCS devices. There was a decrease in cummulative survival at 1000 days following the policy change.

A machine learning approach to high-risk cardiac surgery risk scoring.

INTRODUCTION: In patients undergoing high-risk cardiac surgery, the uncertainty of outcome may complicate the decision process to intervene. To augment decision-making, a machine learning approach was used to determine weighted personalized factors contributing to mortality. METHODS: American College of Surgeons National Surgical Quality Improvement Program was queried for cardiac surgery patients with predicted mortality ≥10% between 2012 and 2019. Multiple machine learning models were investigated, with significant predictors ultimately used in gradient boosting machine (GBM) modeling. GBM-trained data were then used for local interpretable model-agnostic explanations (LIME) modeling to provide individual patient-specific mortality prediction. RESULTS: A total of 194 patient deaths among 1291 high-risk cardiac surgeries were included. GBM performance was superior to other model approaches. The top five factors contributing to mortality in LIME modeling were preoperative dialysis, emergent cases, Hispanic ethnicity, steroid use, and ventilator dependence. LIME results individualized patient factors with model probability and explanation of fit. CONCLUSIONS: The application of machine learning techniques provides individualized predicted mortality and identifies contributing factors in high-risk cardiac surgery. Employment of this modeling to the Society of Thoracic Surgeons database may provide individualized risk factors contributing to mortality.

Contemporary utilization of the axillary artery in cardiac surgery.

INTRODUCTION: The axillary artery is a reliable inflow vessel when addressing pathology of the aortic root and aortic arch that may preclude standard central cannulation strategies. This narrative review examines the use of the axillary artery in cardiac surgery. Anatomy, indications for use, cannulation strategies, and potential complications will be discussed. METHODS: A comprehensive review of the current literature was performed using PubMed, Cochrane Review, and authoritative committee guidelines. A narrative review incorporating current available evidence was undertaken. COMMENT: Use of the axillary artery in select cardiac surgical cases is reliable, reproducible, and may be preferable in certain cases involving ascending aortic pathology, reoperative surgery, porcelain aorta, access for transcatheter valve therapies, and peripheral mechanical circulatory support.

Aortic Prosthetic Valve Endocarditis: Analysis of The Society of Thoracic Surgeons Database.

BACKGROUND: This study sought to characterize the current US experience of aortic prosthetic valve endocarditis (PVE) compared with native valve endocarditis (NVE). METHODS: The Society of Thoracic Surgeons Database was queried for entries of active aortic infective endocarditis (IE). Two analyses were performed: (1) trends of surgical volume and operative mortality (2011-2019); and (2) descriptive and risk-adjusted comparisons between PVE and NVE (2014-2019) using multivariable logistic regression. RESULTS: From 2011 to 2019, there was a yearly increase in the proportion of PVE (20.9% to 25.9%; P < .001) with a concurrent decrease in operative mortality (PVE, 22.5% to 10.4%; P < .001; NVE, 10.9% to 8.5%; P < .001). From 2014 to 2019, active aortic IE was identified in 9768 patients (NVE, 6842; PVE, 2926). Aortic root abscess (50.1% vs 25.2%; P < .001), aortic root replacement (50.1% vs 12.8%; P < .001), homograft implantation (27.2% vs 4.1%; P < .001), and operative mortality (12.2% vs 6.4%; P < .001) were higher in PVE. After risk adjustment, PVE (odds ratio [OR], 1.5; 95% CI,1.16-1.94; P < .01), aortic root replacement (OR, 1.49; 95% CI,1.15-1.92; P < .001), Staphylococcus aureus (OR, 1.5; 95% CI,1.23-1.82; P < .001), and unplanned revascularization (OR, 5.83; 95% CI,4.12-8.23; P < .001) or mitral valve surgery (OR, 2.29; 95% CI,1.5-3.51; P < .001) correlated with a higher operative mortality, whereas prosthesis type (P = .68) was not an independent predictor. CONCLUSIONS: IE in the United States has risen over the past decade. However, operative mortality has decreased for both PVE and NVE. PVE, extension of IE requiring aortic root replacement, and additional unplanned surgical interventions carry an elevated mortality risk. Prosthesis selection did not affect operative mortality.

Long-term outcomes of etiology specific annuloplasty ring repair of ischemic mitral regurgitation.

BACKGROUND: Reductive annuloplasty repair of ischemic mitral regurgitation (IMR) is associated with high rates of recurrent MR, which may be improved with etiology-specific annuloplasty rings. METHODS: From October 2005 to May 2015, 128 consecutive patients underwent repair of IMR with the GeoForm ring. Clinical data was extracted from our local Society of Thoracic Surgeons database and electronic medical records. Mortality data was obtained from the Michigan State Social Security Death Index. RESULTS: The average age of patients was 65±11 years with mean pre-op left ventricular ejection fraction (LVEF) of 30%±10% and MR grade of 3.1±0.9 (0-4+). Thirty-day mortality was 4.7%, rate of renal failure 7.9%, rate of atrial fibrillation 27.3%, and no strokes were observed. Of the surviving patients, 89% (109/122) had a follow-up echocardiogram beyond 1 month with a mean echocardiographic follow-up of 59±39 months. LVEF improved from 30%±10% to 38%±14%, P<0.001) while end-diastolic (5.9±0.0 to 5.3±0.9 cm, P<0.001) and end-systolic (5.0±1.0 to 4.4±1.1 cm, P<0.001) left ventricular (LV) diameters decreased, as compared to pre-operative values. Seven patients were found to have recurrent moderate or greater IMR in follow-up to 10 years with three being due to ring dehiscence. One-, 5-, and 10-year freedom from recurrent moderate or severe IMR was 98%, 94%, and 80% respectively. One-, 5-, and 10-year survival was 91%, 77%, and 44%, respectively. CONCLUSIONS: Overall, etiology-specific ring repair of IMR was associated with low rates of recurrent MR on long-term follow-up, coupled with significant LV reverse remodeling and improvement in ejection fraction.

Repair of Massive Stanford Type A Aortic Dissection in a Jehovah's Witness Using Bloodless Surgery.

Refusal of blood product transfusion presents a unique challenge in patients requiring major cardiac surgery. We present a case of a 45-year-old African American female Jehovah's Witness with a history of aortic dissection who presented to the emergency department with worsening back pain. Imaging revealed aneurysmal dilatation of her known Stanford type A dissection measuring 10.9 cm. A staged carotid-subclavian bypass followed by aortic valve, ascending aorta, and aortic arch replacement with debranching was performed using a bloodless strategy.

Mechanical cardiopulmonary resuscitation for venoarterial ECMO implantation in pulmonary embolism complicated by type B aortic dissection and retroperitoneal hemorrhage.

A patient with acute pulmonary embolism suffered cardiac arrest, received manual and mechanical cardiopulmonary resuscitation and tissue plasminogen activator before extracorporeal cardiopulmonary resuscitation was initiated. She suffered a type B aortic dissection and retroperitoneal hemorrhage secondary to resuscitation measures. This case report describes high-risk anticoagulation management for contradicting treatment goals in preparation for pulmonary embolectomy on cardiopulmonary bypass.

Percutaneous venoarterial extracorporeal membrane oxygenation as a bridge to double valve implantation in acute biventricular heart failure with profound cardiogenic shock.

A 71-year-old woman was admitted with acute hypoxic and hypercapnic respiratory failure and cardiogenic shock, secondary to acute on chronic biventricular systolic and diastolic congestive heart failure and severe aortic and mitral valve stenosis. She further presented with pulmonary hypertension and moderate-to-severe tricuspid regurgitation requiring high and increasing doses of vasopressors. The patient was percutaneously cannulated for venoarterial extracorporeal membrane oxygenation (VA-ECMO) and stabilized on ECMO, with a urine output of 17.3 L within the following 8 days. Balloon valvuloplasty and/or transcatheter aortic valve replacement were discussed but ruled out by the multidisciplinary team considering the mitral valve could not be fully addressed. Though lung function was not fully optimized, a window of opportunity was identified and used for double valve replacement on day 8 of VA-ECMO support. After a 24-hour vasoplegic period, the patient was extubated to continuous positive airway pressure and further transitioned to nasal cannula, following which she recovered well.

Ascending Aortic Graft Pseudoaneurysm With Sternal Erosion: A Presentation of Candidal Infection.

Fungal aortic graft infections are unusual and have been reported primarily in the abdominal aortic position. Ascending aortic graft infections secondary to Candida species have been reported rarely and invariably localized to the confines of the aortic graft. We present an interesting case of an ascending aortic graft infection with Candida albicans, with evidence of invasion of the sternum and overlying soft tissues.

The effect of acute mechanical left ventricular unloading on ovine tricuspid annular size and geometry.

OBJECTIVES: Left ventricular assist device (LVAD) implantation may alter right ventricular shape and function and lead to tricuspid regurgitation. This in turn has been reported to be a determinant of right ventricular (RV) failure after LVAD implantation, but the effect of mechanical left ventricular (LV) unloading on the tricuspid annulus is unknown. The aim of the study was to provide insight into the effect of LVAD support on tricuspid annular geometry and dynamics that may help to optimize LV unloading with the least deleterious effect on the right-sided geometry. METHODS: In seven open-chest anaesthetized sheep, nine sonomicrometry crystals were implanted on the right ventricle. Additional nine crystals were implanted around the tricuspid annulus, with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Left ventricular unloading was achieved by connecting a cannula in the left atrium and the aorta to a continuous-flow pump. The pump was used for 15 min at a full flow of 3.8 ± 0.3 l/min. Epicardial echocardiography was used to assess the degree of tricuspid insufficiency. Haemodynamic, echocardiographic and sonomicrometry data were collected before and during full unloading. Tricuspid annular area, and the regional and total perimeter were calculated from crystal coordinates, while 3D annular geometry was expressed as the orthogonal distance of each annular crystal to the least squares plane of all annular crystals. RESULTS: There was no significant tricuspid regurgitation observed either before or during LV unloading. Right ventricular free wall to septum diameter increased significantly at end-diastole during unloading from 23.6 ± 5.8 to 26.3 ± 6.5 mm (P = 0.009), but the right ventricular volume, tricuspid annular area and total perimeter did not change from baseline. However, the septal part of the annulus significantly decreased its maximal length (38.6 ± 8.1 to 37.9 ± 8.2 mm, P = 0.03). Annular contraction was not altered. The tricuspid annulus had a complex 3D saddle-shaped geometry that was unaffected during experimental conditions. CONCLUSIONS: In healthy sheep hearts, left ventricular unloading increased septal-free wall RV diameter and reduced the length of the septal annulus, without altering the motion or geometry of the tricuspid annulus. Acute left ventricular unloading alone in healthy sheep was not sufficient to significantly perturb tricuspid annular dynamics and result in tricuspid insufficiency.

The effect of pulmonary hypertension on ovine tricuspid annular dynamics.

OBJECTIVES: Pulmonary hypertension (PHT) is associated with tricuspid annular dilatation, but the effect of acute increase of pulmonary pressure on three-dimensional (3D) tricuspid annular dynamics and shape is unknown. Better understanding of tricuspid annular dynamics may lead to improved and more durable surgical reparative techniques. METHODS: In nine open-chest anaesthetized sheep nine sonomicrometry crystals were implanted on the right ventricle while on cardiopulmonary bypass. Additional nine crystals were implanted around the tricuspid annulus (TA) with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Two additional equidistant crystals were implanted between each commissure, creating three segments for every region. Pressure transducers were placed in the left ventricular (LV), right ventricular (RV) and right atrium. PHT was induced by acute pulmonary artery constriction with a pneumatic occluder. Sonomicrometry and echocardiographic data were collected before and after induction of PHT. TA area, regional and total perimeter, and 3D annular geometry were calculated from 3D crystal coordinates. Regional annular contraction was defined as the percentage difference between maximal and minimal region length during the cardiac cycle. RESULTS: PHT increased RV pressure from 31 ± 9 mmHg to 46 ± 13 mmHg (P = 0.001) and decreased left ventricular (LV) pressure from 111 ± 24 mmHg to 78 ± 36 mmHg (P = 0.018). There was no significant tricuspid regurgitation observed with PHT. During PHT, the TA area increased by 12 ± 13% from 641 ± 139 mm(2) to 721 ± 177 mm(2) (P = 0.037). The total perimeter increased from 103 ± 11 mm to 109 ± 13 mm (P = 0.02). All annular regions dilated significantly with PHT with 8 ± 10, 5 ± 5 and 5 ± 5% increase in anterior, posterior and septal annular length, respectively (P < 0.05). PHT reduced regional annular contraction in the anterior region only (17 ± 7 vs 14 ± 8%; P = 0.02). The TA had a complex 3D saddle geometry and the shape of the annulus was altered during PHT only in the antero-posterior region. CONCLUSIONS: The changes in tricuspid annular conformation, contractility and its 3D geometry observed during acute ovine PHT may help in the design of new pathology-specific tricuspid annular rings.

The ABLATE Trial: Safety and Efficacy of Cox Maze-IV Using a Bipolar Radiofrequency Ablation System.

BACKGROUND: The Cox Maze-IV procedure (CMP-IV) has replaced the Cox Maze-III procedure as the most common approach for the surgical treatment of atrial fibrillation (AF). The Food and Drug Administration-regulated AtriCure Bipolar Radiofrequency Ablation of Permanent Atrial Fibrillation (ABLATE) trial sought to demonstrate the safety and efficacy of the CMP-IV performed with the Synergy ablation system (AtriCure, Inc, Cincinnati, OH). METHODS: Fifty-five patients (aged 70.5 ± 9.3 years), 92.7% of whom had nonparoxysmal AF, underwent CMP-IV to terminate AF during a concomitant cardiac surgical procedure. Lesions were created using the AtriCure Synergy bipolar radiofrequency ablation system. All patients were seen for follow-up visits after 30 days, 3 months, and 6 months, with 24-hour Holter monitoring at 6 months. Late evaluation was performed by 48-hour Holter monitoring at an average of 21 months. RESULTS: The primary efficacy endpoint, absence of AF (30 seconds or less) at 6-month follow-up off antiarrhythmic medications (Heart Rhythm Society definition), indicated 76% (38 of 50) were AF free (95% confidence interval: 62.6% to 85.7%). The primary safety endpoint, the rate of major adverse events within 30 days, was 9.1% (5 of 55; 95% confidence interval: 3.9% to 19.6%), with 3.6% mortality (2 of 55). Secondary efficacy endpoints included being AF free with antiarrhythmic drugs (6 months, 84%; 21 months, 75%), successful pulmonary vein isolation (100%), and AF burden at 6 and 21 months. The results, together with those for the secondary safety endpoint (6-month major adverse events), demonstrated that the Synergy system performs comparably to the cut-and-sew Cox Maze-III procedure. CONCLUSIONS: The CMP-IV using the AtriCure Synergy system was safe and effective for cardiac surgical patients who had persistent and longstanding persistent AF.

Aortic valve replacement in octogenarians with prior cardiac surgery.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has been advocated for very elderly patients with aortic stenosis, and prior cardiac surgery as a less invasive treatment option. Although surgical aortic valve replacement (AVR) is safe and effective in selected elderly patients, the perioperative and mid-term outcomes of AVR in very elderly with prior cardiac surgery are unknown. METHODS: The Society of Thoracic Surgeons (STS) Database at our center enrolled 3,735 patients after AVR since 1997. In this time interval, we identified 61 patients 80 years and older who underwent AVR for severe AS or failed aortic bioprosthesis after having prior cardiac surgery. All clinical parameters were derived from the STS database. Follow-up mortality was assessed using the Social Security Death Index. RESULTS: The average age of the patients was 83 ± 2 years, 77% were male, and 75% underwent an isolated coronary artery bypass graft (CABG) as their first cardiac procedure. The mean ejection fraction was 0.53 ± 0.13. The CABG was performed concurrently in 49% of patients at the time of redo sternotomy and AVR. Stented bioprosthesis was implanted in 61% of patients and stentless in 39%. Perioperative mortality was 1.6% (1 of 61). One, 3, 5, and 7 year survival rates were 85%, 69%, 63%, and 43%, respectively. Patients with AVR only had similar survival to patients who underwent concomitant AVR and CABG. Type of aortic prosthesis did not influence postoperative survival. CONCLUSIONS: In selected patients over the age of 80 with history of prior cardiac surgery, AVR can be performed safely with very good mid-term outcomes. Age alone should not be exclusion criteria for surgical AVR in octogenarians with prior cardiac surgery.

Five-year real world outcomes of GeoForm ring implantation in patients with ischemic mitral regurgitation.

BACKGROUND: Reductive ring annuloplasty represents the current standard surgical therapy for ischemic mitral regurgitation (IMR); however, the clinical results have been suboptimal. Etiology-specific prostheses such as the GeoForm annuloplasty ring have been designed to better address the annular and subvalvular perturbations associated with IMR. However, clinical experience is limited, and mid-term results are lacking. METHODS: We reviewed the clinical outcomes of 86 patients who had undergone implantation of a GeoForm ring at our center from 2005 to 2011. Perioperative mortality and clinical parameters were derived from The Society of Thoracic Surgeons database. Follow-up survival was assessed using the Social Security Death Index. Surviving patients were interviewed by telephone for valve-specific follow-up data and to complete the Medical Outcomes Study, short-form, 36-item, quality-of-life questionnaire. RESULTS: The mean grade of IMR preoperatively was 3.1±0.8 (range, 1-4+), 0.2±0.4 in the immediate postoperative period, and 0.7±0.7 at the last mean follow-up point of 41 months; only 2 patients developed ≥2+IMR during the follow-up period, for a 5-year freedom from recurrent 2+ IMR of 86%. The mean left ventricular end-diastolic and end-systolic diameters decreased from before to after surgery from 6.0±0.0 cm to 5.3±09 cm and 5.0±0.9 cm to 4.3±1.1 cm, respectively (P<.001). Perioperative mortality was 5.8% (5 of 86), and 1-, 3-, and 5-year survival was 87%, 81%, and 75%, respectively. At the last follow-up point, 80% of patients were in New York Heart Association class I and II, and their quality of life was equal to, or better than, age-matched controls from the general population. CONCLUSIONS: Implantation of the GeoForm ring offers very good control of IMR, with low rate of recurrent IMR at mid-term follow-up. The use of this prosthesis was associated with good perioperative mortality, mid-term survival, and quality of life.

Differences in clinical characteristics, management, and outcomes of intraoperative versus spontaneous acute type A aortic dissection.

BACKGROUND: The clinical characteristics, management, and outcomes of patients who had intraoperative aortic dissection (IAD) have not been thoroughly investigated. This study compared early and late clinical outcomes in patients with IAD vs spontaneous (non-IAD) acute type A aortic dissection. METHODS: Between January 1, 2000, and July 1, 2008, 251 patients from 4 academic medical centers underwent repair of acute type A aortic dissection; of those, 11 had IAD. The mean age was 72 ± 9 years for patients experiencing IAD and 59 ± 13 years for those with non-IAD (p = 0.001). Patients with IAD were more likely to have coronary artery disease (p = 0.003) and a history of arrhythmia (p = 0.038). Rates for major morbidity, operative mortality, and 5-year actuarial survival were compared between groups. RESULTS: Operative mortality was not adversely influenced by IAD (27% IAD vs 17% non-IAD, p = 0.42). There were no differences in the rates of reoperation for bleeding (10% IAD vs 20% non-IAD, p = 0.69), stroke (18% IAD vs 18% non-IAD, p ≥ 0.99), or acute renal failure (9% IAD vs 22% non-IAD, p = 0.47) between the two groups. Actuarial 5-year survival was 64% for IAD patients vs 73% for non-IAD patients (p = 0.33). CONCLUSIONS: IAD does not adversely influence early outcomes and actuarial 5-year survival of patients with type A dissection.

Stentless root bioprosthesis for repair of acute type A aortic dissection.

OBJECTIVE: The superior hemodynamics and excellent long-term clinical performance of stentless xenografts are well described. However, the early and midterm clinical outcomes of stentless valves in patients with acute type A dissection are widely unknown. The current study evaluated the early and midterm clinical outcomes of stentless bioprosthesis for repair of acute type A aortic dissection. METHODS: Between May 2005 and December 2009, 24 of 80 patients underwent root replacement using the Medtronic Freestyle xenograft (Medtronic Inc, Minneapolis, Minn) at the Meijer Heart Center. Prospective data collection was used for retrospective review. Univariate comparisons of preoperative, intraoperative, and postoperative variables were performed between patients who underwent stentless root bioprosthesis for the correction of acute type A aortic dissection (n = 24). RESULTS: The mean age of patients was 57 years, with 15 patients aged less than 65 years. Axillary and femoral artery cannulation were used in 16 patients (67%) and 7 patients (29%), respectively. Median crossclamp and cardiopulmonary bypass times were 198 minutes (92-480 minutes) and 288 minutes (109-588 minutes), respectively. Median circulatory arrest time was 28 minutes (24-50 minutes). Operative mortality rate was 25%. Actuarial 5-year survival was 62.5%. No patients required redo aortic root replacement. CONCLUSIONS: Stentless valve implantation can be accomplished with satisfactory early and midterm clinical outcomes and is a valuable option in patients with acute aortic dissection who require root replacement.

Repair of paravalvular prosthetic mitral valve leaks with septal occluder devices in severely high-risk patients: a word of caution.

Paravalvular leak following a mitral valve replacement is a complication seen in approximately 1 of 10 replacements. The corrective method has traditionally been reoperation. Septal occluder devices are more commonly being utilized as an alternative percutaneous correction method. We report the use of septal occluder devices in the repair of mitral paravalvular leak in two patients at severely high EuroSCORE II mortality risk. In both patients, the occluder devices became unstable, leading to a recurrence of severe paravalvular leak.