A Pilot Study Using Machine Learning Algorithms and Wearable Technology for the Early Detection of Postoperative Complications After Cardiothoracic Surgery.

OBJECTIVE: To evaluate whether a machine learning algorithm (i.e. the "NightSignal" algorithm) can be used for the detection of postoperative complications prior to symptom onset after cardiothoracic surgery. SUMMARY BACKGROUND DATA: Methods that enable the early detection of postoperative complications after cardiothoracic surgery are needed. METHODS: This was a prospective observational cohort study conducted from July 2021 to February 2023 at a single academic tertiary care hospital. Patients aged 18 years or older scheduled to undergo cardiothoracic surgery were recruited. Study participants wore a Fitbit watch continuously for at least 1 week preoperatively and up to 90-days postoperatively. The ability of the NightSignal algorithm-which was previously developed for the early detection of Covid-19-to detect postoperative complications was evaluated. The primary outcomes were algorithm sensitivity and specificity for postoperative event detection. RESULTS: A total of 56 patients undergoing cardiothoracic surgery met inclusion criteria, of which 24 (42.9%) underwent thoracic operations and 32 (57.1%) underwent cardiac operations. The median age was 62 (IQR: 51-68) years and 30 (53.6%) patients were female. The NightSignal algorithm detected 17 of the 21 postoperative events a median of 2 (IQR: 1-3) days prior to symptom onset, representing a sensitivity of 81%. The specificity, negative predictive value, and positive predictive value of the algorithm for the detection of postoperative events were 75%, 97%, and 28%, respectively. CONCLUSIONS: Machine learning analysis of biometric data collected from wearable devices has the potential to detect postoperative complications-prior to symptom onset-after cardiothoracic surgery.

Rationale and Design of the Randomized Controlled Trial of New Oral Anticoagulants Versus Warfarin for Post Cardiac Surgery Atrial Fibrillation: The NEW-AF Trial.

OBJECTIVE: This manuscript describes the rationale and design of a randomized, controlled trial comparing outcomes with Warfarin vs Novel Oral Anticoagulant (NOAC) therapy in patients with new onset atrial fibrillation after cardiac surgery. BACKGROUND: New onset atrial fibrillation commonly occurs after cardiac surgery and is associated with increased rates of stroke and mortality. in nonsurgical patients with atrial fibrillation, NOACs have been shown to confer equivalent benefits for stroke prevention with less bleeding risk and less tedious monitoring requirements compared with Warfarin. However, NOAC use has yet to be adopted widely in cardiac surgery patients. METHODS: The NEW-AF study has been designed as a pragmatic, prospective, randomized controlled trial that will compare financial, convenience and safety outcomes for patients with new onset atrial fibrillation after cardiac surgery that are treated with NOACs versus Warfarin. RESULTS: Study results may contribute to optimizing the options for stroke prophylaxis in cardiac surgery patients and catalyze more widespread application of NOAC therapy in this patient population. CONCLUSIONS: The study is ongoing and actively enrolling at the time of the publication. The trial is registered with clinicaltrials.gov under registration number NCT03702582.

Role of advanced imaging techniques in cardiac surgery: Aortic dissection.

BACKGROUND: Collaboration among cardiac surgeons and radiologists is essential to fully leverage advanced imaging technologies and improve the care of cardiac surgery patients. In this review, a cardiac surgeon and cardiovascular radiologist discuss imaging pearls and considerations in aortic dissection cases. METHODS: The surgeon and the radiologist discuss imaging considerations in two aortic dissection cases. RESULTS: It is essential to obtain and review all phases of a CTA when diagnosing acute aortic pathology. Optimizing scan parameters and careful multiplanar image review is necessary for adept interpretation. Current CT technology allows ECG gating to eliminate motion artifact and allow for dynamic assessment of the aortic pathology. Concurrent evaluation of thoracic aorta and coronary arteries is feasible. A systematic review of the scan using landmarks is critical for appropriate diagnosis and reporting. As TEVAR is increasingly used for arch repair, collaboration with radiologists is essential for preoperative planning in redo cases. CONCLUSIONS: Collaboration among cardiac surgeons and radiologists is mutually beneficial for surgeons, radiologists, and their patients.

Risk factors for ischemic gastrointestinal complications in patients undergoing open cardiac surgical procedures: A single-center retrospective experience.

BACKGROUND: Ischemic gastrointestinal complications (IGIC) following cardiac surgery are associated with high morbidity and mortality and remain difficult to predict. We evaluated perioperative risk factors for IGIC in patients undergoing open cardiac surgery. METHODS: All patients that underwent an open cardiac surgical procedure at a tertiary academic center between 2011 and 2017 were included. The primary outcome was IGIC, defined as acute mesenteric ischemia necessitating a surgical intervention or postoperative gastrointestinal bleeding that was proven to be of ischemic etiology and necessitated blood product transfusion. A backward stepwise regression model was constructed to identify perioperative predictors of IGIC. RESULTS: Of 6862 patients who underwent cardiac surgery during the study period, 52(0.8%) developed IGIC. The highest incidence of IGIC (1.9%) was noted in patients undergoing concomitant coronary artery, valvular, and aortic procedures. The multivariable regression identified hypertension (odds ratio [OR] = 5.74), preoperative renal failure requiring dialysis (OR = 3.62), immunocompromised status (OR = 2.64), chronic lung disease (OR = 2.61), and history of heart failure (OR = 2.03) as independent predictors for postoperative IGIC. Pre- or intraoperative utilization of intra-aortic balloon pump or catheter-based assist devices (OR = 4.54), intraoperative transfusion requirement of >4 RBC units(OR = 2.47), and cardiopulmonary bypass > 180 min (OR = 2.28) were also identified as independent predictors for the development of IGIC. CONCLUSIONS: We identified preoperative and intraoperative risk factors that independently increase the risk of developing postoperative IGIC after cardiac surgery. A high index of suspicion must be maintained and any deviation from the expected recovery course in patients with the above-identified risk factors should trigger an immediate evaluation with the involvement of the acute care surgical team.

Late onset atrial fibrillation in patients undergoing surgical aortic valve replacement.

OBJECTIVE: Aortic valve disease is a risk factor for atrial fibrillation (AF), and AF is associated with increased late mortality and morbidity after cardiac surgery. The evolution of alternative approaches to AF prophylaxis, including less invasive technologies and medical therapies, has altered the balance between risk and potential benefit for prophylactic intervention at the time of surgical aortic valve replacement (SAVR). Such interventions impose incremental risk, however, making an understanding of predictors of new onset AF that persists beyond the perioperative episode relevant. METHODS: We conducted a retrospective single-institution cohort analysis of patients undergoing SAVR with no history of preoperative AF (n = 1014). These patients were cross-referenced against an institutional electrocardiogram (ECG) database to identify those with ECGs 3-12 months after surgery. Logistic regression was used to identify predictors of late AF. RESULTS: Among the 401 patients (40%), who had ECGs in our institution 3-12 months after surgery, 16 (4%) had late AF. Patients with late AF were older than patients without late AF (73 vs. 65, p = .025), and underwent procedures that were more urgent/emergent (38% vs. 15%, p = .015), with higher predicted risk of mortality (2.2% vs. 1.3%, p = .012). Predictors associated with the development of late AF were advanced age, higher preoperative creatinine level and urgent/emergent surgery. CONCLUSIONS: The incidence of late AF 3-12 months after SAVR, is low. Prophylactic AF interventions at the time of SAVR may not be warranted.

Teamwork in the time of coronavirus: An MGH experience.

The global pandemic of coronavirus 2019 (COVID-19) caused by coronavirus has had a profound impact on the delivery of health care in the United States and globally. Boston was among the earliest hit cities in the United States, and within Boston, the Massachusetts General Hospital provided care for more patients with COVID-19 than any other hospital in the region. This necessitated a massive reallocation of resources and priorities, with a near doubling of intensive care bed capacity and a halt in all deferrable surgical cases. During this crisis, the Division of Cardiac Surgery responded in a unified manner, dealing honestly with the necessity to reduce Intensive Care Unit resource utilization for the benefit of both the institution and our community by deferring nonemergent cases while also continuing to efficiently care for those patients in urgent or emergent need of surgery. Many of the interventions that we instituted have continued to support teamwork as we adapt to the remarkably fluid changes in resource availability during the recovery phase. We believe that the culture of our division and the structure of our practice facilitated our ability to contribute to the mission of our hospital to support the community in this crisis, and now to its recovery. We describe here the challenge we faced in Boston and some of the details of the structure and function of our division.

Type A aortic dissection in the East and West: A comparative study between two hospitals from China and the US.

BACKGROUND: In this study, we compare the clinical characteristics, intraoperative management, and postoperative outcomes of patients with acute type A aortic dissection (ATAAD) between two academic medical hospitals in the United States and China. METHODS: From January 2011 to December 2017, 641 and 150 patients from Nanjing Drum Tower Hospital (NDTH) and Massachusetts General Hospital (MGH) were enrolled. Patient demographics, clinical features, surgical techniques, and postoperative outcomes were compared. RESULTS: The annual number of patients presenting with ATAAD at MGH remained relatively stable, while the number at NDTH increased significantly over the study period. The average age was 51 years at NDTH and 61 years at MGH (P < .001). The percentage of patients with known hypertension at the two centers was similar. The time interval from onset of symptoms to diagnosis was significantly longer at NDTH than MGH (11 vs 3.5 hours; P < .001). Associated complications at presentation were more common at NDTH than MGH. More than 90% of patients (91% NDTH and 92% MGH) underwent surgery. The postoperative stroke rate was higher at MGH (12% vs 4%; P < .001); however, the 30-day mortality rate was lower (7% vs 16%; P = .006). CONCLUSIONS: There was a significant increase in the number of ATAAD at NDTH during the study period while the number at MGH remained stable. Hypertension was a common major risk factor; however, the onset of ATAAD at NDTH was nearly one decade earlier than MGH. Chinese patients tended to have more complicated preoperative pathophysiology at presentation and underwent more extensive surgical repair.

Quantitative three-dimensional echocardiographic analysis of the bicuspid aortic valve and aortic root: A single modality approach.

BACKGROUND: Patients with bicuspid aortic valves (BAV) are heterogeneous with regard to patterns of root remodeling and valvular dysfunction. Two-dimensional echocardiography is the standard surveillance modality for patients with aortic valve dysfunction. However, ancillary computed tomography or magnetic resonance imaging is often necessary to characterize associated patterns of aortic root pathology. Conversely, the pairing of three-dimensional (3D) echocardiography with novel quantitative modeling techniques allows for a single modality description of the entire root complex. We sought to determine 3D aortic valve and root geometry with this quantitative approach. METHODS: Transesophageal real-time 3D echocardiography was performed in five patients with tricuspid aortic valves (TAV) and in five patients with BAV. No patient had evidence of valvular dysfunction or aortic root pathology. A customized image analysis protocol was used to assess 3D aortic annular, valvular, and root geometry. RESULTS: Annular, sinus and sinotubular junction diameters and areas were similar in both groups. Coaptation length and area were higher in the TAV group (7.25 ± 0.98 mm and 298 ± 118 mm2 , respectively) compared to the BAV group (5.67 ± 1.33 mm and 177 ± 43 mm2 ; P = .07 and P = .01). Cusp surface area to annular area, coaptation height, and the sub- and supravalvular tenting indices did not differ significantly between groups. CONCLUSIONS: Single modality 3D echocardiography-based modeling allows for a quantitative description of the aortic valve and root geometry. This technique together with novel indices will improve our understanding of normal and pathologic geometry in the BAV population and may help to identify geometric predictors of adverse remodeling and guide tailored surgical therapy.

Early structural valve deterioration and reoperation associated with the mitroflow aortic valve.

BACKGROUND: Structural valve deterioration (SVD) is a known limitation of bioprosthetic valves. Recent reports have suggested a concerning rate of early SVD in patients receiving a Mitroflow aortic bioprosthesis. We therefore compared the incidence of SVD and SVD requiring reoperation among patients receiving a Mitroflow versus a common contemporary bioprosthesis. METHODS: A retrospective cohort analysis was performed on 592 patients receiving a Mitroflow aortic bioprosthesis at our institution between 2010 and 2014. Patients were matched 1:1 using a coarsened exact matching algorithm with patients receiving a Carpentier-Edwards Magna Ease aortic bioprosthesis (Edwards Lifesciences, Irvine, CA) during the same period. The incidence of SVD (defined as a mean transprosthetic gradient ≥30 mmHg or moderate to severe intraprosthetic regurgitation), reoperation for SVD, and cumulative survival were compared between prosthesis types. RESULTS: The cumulative incidence of SVD at 5 years for all patients receiving a Mitroflow aortic bioprosthesis was 16% (13-21%) and 5% underwent reoperation for SVD. Implantation of a Mitroflow valve was associated with an increased risk of SVD compared to the comparator valve (hazard ratio [HR] 2.59 [1.69-3.98], P < 0.01). Older age had a protective effect against SVD (HR 0.95 [0.93-0.96], P < 0.01). Patients who received a Mitroflow valve had reduced long-term survival compared to those who received a comparator valve (P = 0.03). CONCLUSION: The Mitroflow aortic bioprosthesis is associated with increased rates of early SVD and reoperation for valvular dysfunction as well as reduced survival compared to a contemporary valve. Enhanced clinical and echocardiographic follow-up is advisable after Mitroflow implantation.

Incidental moderate mitral regurgitation in patients undergoing aortic valve replacement for aortic stenosis: review of guidelines and current evidence.

Recent evidence has shown that moderate mitral regurgitation is common and clinically relevant in patients presenting for surgical and transcatheter aortic valve replacement for aortic stenosis. Prospective multicenter clinical trials are now indicated to resolve the clinical equipoise about whether or not mitral valve intervention also is indicated at the time of aortic valve intervention. Advances in three-dimensional transesophageal echocardiography, transcatheter mitral interventions, and surgical aortic valve replacement, including the advent of sutureless valves, likely will expand the therapeutic possibilities for moderate mitral regurgitation in the setting of aortic valve interventions for severe aortic stenosis.

Three-dimensional echocardiographic analysis of mitral annular dynamics: implication for annuloplasty selection.

BACKGROUND: Proponents of flexible annuloplasty rings have hypothesized that such devices maintain annular dynamics. This hypothesis is based on the supposition that annular motion is relatively normal in patients undergoing mitral valve repair. We hypothesized that mitral annular dynamics are impaired in ischemic mitral regurgitation and myxomatous mitral regurgitation. METHODS AND RESULTS: A Philips iE33 echocardiographic module and X7-2t probe were used to acquire full-volume real-time 3-dimensional transesophageal echocardiography loops in 11 normal subjects, 11 patients with ischemic mitral regurgitation and 11 patients with myxomatous mitral regurgitation. Image analysis was performed using Tomtec Image Arena, 4D-MV Assessment, 2.1 (Munich, Germany). A midsystolic frame was selected for the initiation of annular tracking using the semiautomated program. Continuous parameters were normalized in time to provide for uniform systolic and diastolic periods. Both ischemic mitral regurgitation (9.98 ± 155 cm(2)) and myxomatous mitral regurgitation annuli (13.29 ± 3.05 cm(2)) were larger in area than normal annuli (7.95 ± 1.40 cm(2)) at midsystole. In general, ischemic mitral regurgitation annuli were less dynamic than controls. In myxomatous mitral regurgitation, annular dynamics were also markedly abnormal with the mitral annulus dilating rapidly in early systole in response to rising ventricular pressure. CONCLUSIONS: In both ischemic mitral regurgitation and myxomatous mitral regurgitation, annular dynamics and anatomy are abnormal. Flexible annuloplasty devices used in mitral valve repair are, therefore, unlikely to result in either normal annular dynamics or normal anatomy.

Infectious Aortitis of Thoracic Aortic Aneurysm From Clostridium Septicum.

A 71-year-old male presented with 1-day history of back pain. Imaging displayed an enlarging thoracic aortic aneurysm with gas in the aortic wall. Blood cultures grew Clostridium septicum. He underwent resection, debridement, and in situ aortic replacement with a rifampin-soaked graft under deep hypothermic circulatory arrest. His recovery was uncomplicated. (Level of Difficulty: Beginner.).

Multidisciplinary team approach to confront the challenge of drug use-associated infective endocarditis.

OBJECTIVES: Drug use-associated infective endocarditis is a rapidly growing clinical problem. Although operative outcomes are generally satisfactory, reinfection secondary to recurrent substance use is distressingly common, negatively affects long-term survival, generates practical and ethical challenges, and creates potential conflict among care team members. We established a Drug Use Endocarditis Treatment team including surgeons, infectious disease, and addiction medicine experts specifically focused on the unique complexities of drug use-associated infective endocarditis. METHODS: We reviewed the impact of Drug Use Endocarditis Treatment team involvement on quantitative measures of quality of care, including length of stay, time to addiction medicine consultation, time to surgery, and discharge on appropriate medications for opioid use disorder, as well as operative mortality. Standard statistical tests were used, including the Fisher exact test, t test, and Wilcoxon rank-sum test. Qualitative assessment was made of the impact on clinicians, including communication and mutual understanding. RESULTS: Comparing the pre-Drug Use Endocarditis Treatment cohort with the post-Drug Use Endocarditis Treatment cohort, patients in the post-Drug Use Endocarditis Treatment cohort who underwent surgery had a significantly lower time from admission to addiction medicine consultation (3.8 vs 1.0 days P < .001) and clinically relevant increase in discharge on medications for opioid use disorder (48% vs 67% P = .35). Additionally, involved members of the team thought communication was improved. CONCLUSIONS: The Drug Use Endocarditis Treatment team improved engagement with addiction medicine consultation and appropriate discharge care. Given the impact of relapse of injection drug use on long-term outcomes, interventions such as this offer potentially powerful tools for the treatment of this complex patient population.

Development of a semi-automated method for mitral valve modeling with medial axis representation using 3D ultrasound.

PURPOSE: Precise 3D modeling of the mitral valve has the potential to improve our understanding of valve morphology, particularly in the setting of mitral regurgitation (MR). Toward this goal, the authors have developed a user-initialized algorithm for reconstructing valve geometry from transesophageal 3D ultrasound (3D US) image data. METHODS: Semi-automated image analysis was performed on transesophageal 3D US images obtained from 14 subjects with MR ranging from trace to severe. Image analysis of the mitral valve at midsystole had two stages: user-initialized segmentation and 3D deformable modeling with continuous medial representation (cm-rep). Semi-automated segmentation began with user-identification of valve location in 2D projection images generated from 3D US data. The mitral leaflets were then automatically segmented in 3D using the level set method. Second, a bileaflet deformable medial model was fitted to the binary valve segmentation by Bayesian optimization. The resulting cm-rep provided a visual reconstruction of the mitral valve, from which localized measurements of valve morphology were automatically derived. The features extracted from the fitted cm-rep included annular area, annular circumference, annular height, intercommissural width, septolateral length, total tenting volume, and percent anterior tenting volume. These measurements were compared to those obtained by expert manual tracing. Regurgitant orifice area (ROA) measurements were compared to qualitative assessments of MR severity. The accuracy of valve shape representation with cm-rep was evaluated in terms of the Dice overlap between the fitted cm-rep and its target segmentation. RESULTS: The morphological features and anatomic ROA derived from semi-automated image analysis were consistent with manual tracing of 3D US image data and with qualitative assessments of MR severity made on clinical radiology. The fitted cm-reps accurately captured valve shape and demonstrated patient-specific differences in valve morphology among subjects with varying degrees of MR severity. Minimal variation in the Dice overlap and morphological measurements was observed when different cm-rep templates were used to initialize model fitting. CONCLUSIONS: This study demonstrates the use of deformable medial modeling for semi-automated 3D reconstruction of mitral valve geometry using transesophageal 3D US. The proposed algorithm provides a parametric geometrical representation of the mitral leaflets, which can be used to evaluate valve morphology in clinical ultrasound images.

Pericardial-Esophageal Fistula: A Rare but Increasing Complication of Cardiac Ablation.

Pericardial-esophageal fistula and/or atrial-esophageal fistula after cardiac ablation is nearly universally fatal if not detected and treated expeditiously. This condition should be assumed and ruled out in anyone with a recent history of cardiac ablation presenting with signs of sepsis, pneumomediastinum, pneumopericardium, or chest pain. Computed tomography scan of the chest is a rapid and a sensitive diagnostic modality. Tenets of treatment and repair consist of preventing an air embolism, repairing the esophageal perforation and atrial defect, and interposing autologous tissue between the esophagus and heart.

Diagnosis and Management of Infective Endocarditis in People Who Inject Drugs: JACC State-of-the-Art Review.

The incidence of injection drug use-associated infective endocarditis has been increasing rapidly over the last decade. Patients with drug use-associated infective endocarditis present an increasingly common clinical challenge with poor long-term outcomes and high reinfection and readmission rates. Their care raises issues unique to this population, including antibiotic selection and administration, indications for and ethical issues surrounding surgical intervention, and importantly management of the underlying substance use disorder to minimize the risk of reinfection. Successful treatment of these patients requires a broad understanding of these concerns. A multidisciplinary, collaborative approach providing a holistic approach to treating both the acute infection along with effectively addressing substance use disorder is needed to improve short-term and longer-term outcomes.