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.

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.

Survival after operative repair of acute type A aortic dissection varies according to the presence and type of preoperative malperfusion.

OBJECTIVE: Approximately one-quarter of patients with acute type A aortic dissection (TAAD) present with concomitant malperfusion of coronary arteries, mesenteric circulation, lower extremities, kidneys, brain, and/or coma. It is generally accepted that TAAD patients who present with malperfusion experience higher mortality rates than patients without, although how specific malperfusion syndromes, alone or in combination, affect mortality is not well described. METHODS: The International Registry of Acute Aortic Dissection database was queried for patients who underwent surgical repair of TAAD. Patients were stratified according to the presence/absence of malperfusion at presentation. Multivariable logistic regression was used to evaluate in-hospital mortality according to malperfusion type. Kaplan-Meier estimates were used to estimate 30-day postoperative survival. RESULTS: Six thousand four hundred thirty-seven patients underwent surgical repair of acute TAAD, of whom 2642 (41%) had 1 or more preoperative malperfusion syndromes. Mesenteric malperfusion (adjusted odds ratio [AOR], 4.84; P < .001) was associated with the highest odds of in-hospital mortality, followed by coma (AOR, 1.88; P = .007), limb ischemia (AOR, 1.73; P = .008), and coronary malperfusion (AOR, 1.51; P = .02). Renal malperfusion (AOR, 1.37; P = .24) and neurologic deficit (AOR, 1.35; P = .28) were not associated with increased in-hospital mortality. In patients who survived to discharge, there was no difference in 1-year postdischarge survival in the malperfusion and no malperfusion cohorts (P = .36). CONCLUSIONS: Survival during the index admission after TAAD repair varies according to the presence and type of malperfusion syndromes, with mesenteric malperfusion being associated with the highest odds of in-hospital death. Not only the presence of malperfusion but rather specific malperfusion syndromes should be considered when assessing a patient's risk of undergoing TAAD repair.

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.

Patient- and Process-Related Contributors to the Underuse of Aortic Valve Replacement and Subsequent Mortality in Ambulatory Patients With Severe Aortic Stenosis.

Background Many patients with severe aortic stenosis (AS) and an indication for aortic valve replacement (AVR) do not undergo treatment. The reasons for this have not been well studied in the transcatheter AVR era. We sought to determine how patient- and process-specific factors affected AVR use in patients with severe AS. Methods and Results We identified ambulatory patients from 2016 to 2018 demonstrating severe AS, defined by aortic valve area [Formula: see text]1.0 cm2. Propensity scoring analysis with inverse probability of treatment weighting was used to evaluate associations between predictors and the odds of undergoing AVR at 365 days and subsequent mortality at 730 days. Of 324 patients with an indication for AVR (79.3±9.7 years, 57.4% men), 140 patients (43.2%) did not undergo AVR. The odds of AVR were reduced in patients aged >90 years (odds ratio [OR], 0.24 [95% CI, 0.08-0.69]; P=0.01), greater comorbid conditions (OR, 0.88 per 1-point increase in Combined Comorbidity Index [95% CI, 0.79-0.97]; P=0.01), low-flow, low-gradient AS with preserved left ventricular ejection fraction (OR, 0.11 [95% CI, 0.06-0.21]), and low-gradient AS with reduced left ventricular ejection fraction (OR, 0.18 [95% CI, 0.08-0.40]) and were increased if the transthoracic echocardiogram ordering provider was a cardiologist (OR, 2.46 [95% CI, 1.38-4.38]). Patients who underwent AVR gained an average of 85.8 days of life (95% CI, 40.9-130.6) at 730 days. Conclusions The proportion of ambulatory patients with severe AS and an indication for AVR who do not receive AVR remains significant. Efforts are needed to maximize the recognition of severe AS, especially low-gradient subtypes, and to encourage patient referral to multidisciplinary heart valve teams.

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.

Trends in Utilization of Aortic Valve Replacement for Severe Aortic Stenosis.

BACKGROUND: Despite the rapid growth of aortic valve replacement (AVR) for aortic stenosis (AS), limited data suggest symptomatic severe AS remains undertreated. OBJECTIVES: This study sought to investigate temporal trends in AVR utilization among patients with a clinical indication for AVR. METHODS: Patients with severe AS (aortic valve area <1 cm2) on transthoracic echocardiograms from 2000 to 2017 at 2 large academic medical centers were classified based on clinical guideline indications for AVR and divided into 4 AS subgroups: high gradient with normal left ventricular ejection fraction (LVEF) (HG-NEF), high gradient with low LVEF (HG-LEF), low gradient with normal LVEF (LG-NEF), and low gradient with low LVEF (LG-LEF). Utilization of AVR was examined and predictors identified. RESULTS: Of 10,795 patients, 6,150 (57%) had an indication or potential indication for AVR, of whom 2,977 (48%) received AVR. The frequency of AVR varied by AS subtype with LG groups less likely to receive an AVR (HG-NEF: 70%, HG-LEF: 53%, LG-NEF: 32%, LG-LEF: 38%, P < 0.001). AVR volumes grew over the 18-year study period but were paralleled by comparable growth in the number of patients with an indication for AVR. In patients with a Class I indication, younger age, coronary artery disease, smoking history, higher hematocrit, outpatient index transthoracic echocardiogram, and LVEF ≥0.5 were independently associated with an increased likelihood of receiving an AVR. AVR was associated with improved survival in each AS-subgroup. CONCLUSIONS: Over an 18-year period, the proportion of patients with an indication for AVR who did not receive AVR has remained substantial despite the rapid growth of AVR volumes.

Creation of a Multidisciplinary Drug Use Endocarditis Treatment (DUET) Team: Initial Patient Characteristics, Outcomes, and Future Directions.

BACKGROUND: Consensus guidelines recommend multidisciplinary models to manage infective endocarditis, yet often do not address the unique challenges of treating people with drug use-associated infective endocarditis (DUA-IE). Our center is among the first to convene a Drug Use Endocarditis Treatment (DUET) team composed of specialists from Infectious Disease, Cardiothoracic Surgery, Cardiology, and Addiction Medicine. METHODS: The objective of this study was to describe the demographics, infectious characteristics, and clinical outcomes of the first cohort of patients cared for by the DUET team. This was a retrospective chart review of patients referred to the DUET team between August 2018 and May 2020 with DUA-IE. RESULTS: Fifty-seven patients were presented to the DUET team between August 2018 and May 2020. The cohort was young, with a median age of 35, and injected primarily opioids (82.5% heroin/fentanyl), cocaine (52.6%), and methamphetamine (15.8%). Overall, 14 individuals (24.6%) received cardiac surgery, and the remainder (75.4%) were managed with antimicrobial therapy alone. Nearly 65% of individuals were discharged on medication for opioid use disorder, though less than half (36.8%) were discharged with naloxone and only 1 patient was initiated on HIV pre-exposure prophylaxis. Overall, the cohort had a high rate of readmission (42.1%) within 90 days of discharge. CONCLUSIONS: Multidisciplinary care models such as the DUET team can help integrate nuanced decision-making from numerous subspecialties. They can also increase the uptake of addiction medicine and harm reduction tools, but further efforts are needed to integrate harm reduction strategies and improve follow-up in future iterations of the DUET team model.

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.

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.

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.

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.