Low-dose warfarin with a novel mechanical aortic valve: Interim registry results at 5-year follow-up.

OBJECTIVES: To evaluate whether warfarin targeted at an international normalized ratio of 1.8 (range, 1.5-2.0) after On-X mechanical aortic valve implant is safe for all patients. METHODS: This prospective, observational clinical registry assessed adverse event rates in adult patients receiving low-dose warfarin (target international normalized ratio, 1.8; range, 1.5-2.0) plus daily aspirin (75-100 mg) during a 5-year period after On-X aortic valve implant. The primary end point is the combined rate of major bleeding, valve thrombosis, and thromboembolism overall and in 4 subgroups. The comparator is the Prospective Randomized On-X Anticoagulation Trial control group patients on standard-dose warfarin (international normalized ratio, 2.0-3.0) plus aspirin 81 milligrams daily. RESULTS: A total of 510 patients were recruited at 23 centers in the United States, United Kingdom, and Canada between November 2015 and January 2022. This interim analysis includes 229 patients scheduled to complete 5-year follow-up by August 16, 2023. The linearized occurrence rate (in percent per patient-year) of the primary composite end point of major bleeding, valve thrombosis, and thromboembolism is 1.83% compared with 5.39% (95% confidence interval, 4.12%-6.93%) in the comparator group. Results are consistent in clinic-monitored and home-monitored patients and in those at high risk for thromboembolism. Major bleeding and total bleeding were reduced by 87% and 71%, respectively, versus the comparator group, without an increase in thromboembolic events. CONCLUSIONS: Interim results support the continued safety of the On-X aortic mechanical valve with a target international normalized ratio of 1.8 plus low-dose aspirin through 5 years after implant, with or without home monitoring.

On-X aortic valve replacement patients treated with low dose warfarin and low dose aspirin.

OBJECTIVES: To assess if warfarin targeted to INR 1.8 (range 1.5-2.0) is safe for all patients with an On-X aortic mechanical valve. METHODS: This prospective, observational registry follows patients receiving warfarin targeted at an INR of 1.8 (range 1.5-2.0) plus daily aspirin (75-100 mg) after On-X aortic valve replacement. The primary end-point is a composite of thromboembolism, valve thrombosis, and major bleeding. Secondary end-points include the individual rates of thromboembolism, valve thrombosis, and major bleeding, as well as the composite in subgroups of home or clinic-monitored INR and risk categorization for thromboembolism. The control was the patient group randomized to standard-dose warfarin (INR 2.0-3.0) plus daily aspirin 81 mg from the PROACT trial. RESULTS: A total of 510 patients were enrolled at 23 centers in the UK, United States, and Canada. Currently, the median follow-up duration is 3.4 years, and median achieved INR is 1.9. The primary composite end-point rate in the low INR patients is 2.31% vs 5.39% (95% confidence interval 4.12%-6.93%) per patient-year in the PROACT control group, constituting a 57% reduction. Results are consistent in subgroups of home or clinic-monitored, and high-risk patients, with reductions of 56%, 57%, and 57%, respectively. Major and total bleeding are decreased by 85% and 73%, respectively, with similar rates of thromboembolic events. No valve thrombosis occurred. CONCLUSIONS: Interim results suggest that warfarin targeted at an INR of 1.8 (range 1.5-2.0) plus aspirin is safe and effective in patients with an On-X aortic mechanical valve with or without home INR monitoring.

Gastrointestinal challenges in nephropathic cystinosis: clinical perspectives.

Gastrointestinal (GI) sequelae, such as vomiting, hyperacidity, dysphagia, dysmotility, and diarrhea, are nearly universal among patients with nephropathic cystinosis. These complications result from disease processes (e.g., kidney disease, cystine crystal accumulation in the GI tract) and side effects of treatments (e.g., cysteamine, immunosuppressive therapy). GI involvement can negatively impact patient well-being and jeopardize disease outcomes by compromising drug absorption and patient adherence to the strict treatment regimen required to manage cystinosis. Given improved life expectancy due to advances in kidney transplantation and the transformative impact of cystine-depleting therapy, nephrologists are increasingly focused on addressing extra-renal complications and quality of life in patients with cystinosis. However, there is a lack of clinical data and guidance to inform GI-related monitoring, interventions, and referrals by nephrologists. Various publications have examined the prevalence and pathophysiology of selected GI complications in cystinosis, but none have summarized the full picture or provided guidance based on the literature and expert experience. We aim to comprehensively review GI sequelae associated with cystinosis and its treatments and to discuss approaches for monitoring and managing these complications, including the involvement of gastroenterology and other disciplines.

Preserving Endothelial Integrity in Human Saphenous Veins during Preparation for Coronary Bypass Surgery.

INTRODUCTION: While multiple factors influence coronary artery bypass graft (CABG) success rates, preserving saphenous vein endothelium during surgery may improve patency. Standard preparations include saphenous vein preparation in heparinized saline (saline) which can result in endothelial loss and damage. Here, we investigated the impact of preparing saphenous graft vessels in heparinized patient blood (blood) versus saline. METHODS: Saphenous vein tissues from a total of 23 patients undergoing CABG were split into 2 groups (1) saline and (2) heparinized patient blood. Excess tissue was fixed for analysis immediately following surgery. Level of endothelial coverage, oxidative stress marker 4-hydroxynonenal (4HNE), and oxidative stress protective marker nuclear factor erythroid 2-related factor 2 (NRF2) were evaluated. RESULTS: In saline patient veins, histological analysis revealed a limited luminal layer, suggesting a loss of endothelial cells (ECs). Immunofluorescent staining of EC markers vascular endothelial cadherin (VE-cadherin) and endothelial nitric oxide identified a significant improvement in EC coverage in the blood versus saline groups. Although both treatment groups expressed 4HNE to similar levels, EC blood samples expressed higher levels of NRF2. CONCLUSION: Our data indicate that use of heparinized patient blood helps preserve the endothelium and promotes vein graft health. This has the potential to improve long-term outcomes in patients.

Working Around: The Use of AngioVac and Micra Transcatheter Leadless Pacemaker Implantation in a Critically Ill Patient Receiving Extracorporeal Membrane Oxygenation.

The use of extracorporeal membrane oxygenation (ECMO) in critically ill patients has been on the rise in recent years. While ECMO has provided substantial benefit to patients who need cardiopulmonary support, its required use of large-bore catheters in major blood vessels often precludes the use of other transcatheter therapies. In this article, we demonstrate that two transcatheter procedures, AngioVac right-sided cardiac thrombus removal and Micra leadless pacemaker placement, both requiring large bore access, can both be safely and effectively implemented in patients who are dependent on ECMO to maintain cardiopulmonary function.

Extracorporeal Life Support Organization Center of Excellence recognition is associated with improved failure to rescue after cardiac arrest.

OBJECTIVE: The influence of Extracorporeal Life Support Organization (ELSO) center of excellence (CoE) recognition on failure to rescue after cardiac surgery is unknown. We hypothesized that ELSO CoE would be associated with improved failure to rescue. METHODS: Patients undergoing a Society of Thoracic Surgeons index operation in a regional collaborative (2011-2021) were included. Patients were stratified by whether or not their operation was performed at an ELSO CoE. Hierarchical logistic regression analyzed the association between ELSO CoE recognition and failure to rescue. RESULTS: A total of 43,641 patients were included across 17 centers. In total, 807 developed cardiac arrest with 444 (55%) experiencing failure to rescue after cardiac arrest. Three centers received ELSO CoE recognition, and accounted for 4238 patients (9.71%). Before adjustment, operative mortality was equivalent between ELSO CoE and non-ELSO CoE centers (2.08% vs 2.36%; P = .25), as was the rate of any complication (34.5% vs 33.8%; P = .35) and cardiac arrest (1.49% vs 1.89%; P = .07). After adjustment, patients undergoing surgery at an ELSO CoE facility were observed to have 44% decreased odds of failure to rescue after cardiac arrest, relative to patients at non-ELSO CoE facility (odds ratio, 0.56; 95% CI, 0.316-0.993; P = .047). CONCLUSIONS: ELSO CoE status is associated with improved failure to rescue following cardiac arrest for patients undergoing cardiac surgery. These findings highlight the important role that comprehensive quality programs serve in improving perioperative outcomes in cardiac surgery.

Biomechanical Performance of Biodegradable Screw Fixation in Mandibular Distraction Osteogenesis.

Internal distraction devices are commonly used in congenital micrognathia. The eventual need for device and screw removal can be challenging, requiring extensive dissection and disturbance of bone regenerate. Bioabsorbable poly-L-lactide (PLLA) screws, compared to traditional titanium screws, simplify device removal. Previous in vivo studies have found that the maximal compressive force generated by mandibular distraction is 69.4N. We hypothesized that PLLA screws could support these compressive/distraction forces. Ten mandibles were obtained from 5 canine cadavers. Paired mandibles from the same cadaver were each fixated to a mandibular distractor with eight screws (either titanium or PLLA). Devices were each set to 15 and 30 mm of distraction distance. Compression force of 80 N was then generated parallel to the axis of the distraction device. Distractor displacement was measured to detect any mechanical failure during this pre-set load. Finally, if no failure was observed at 80 N, a load-to-failure compression test was done in the PLLA group to determine the mechanical failure point. All distractors in both the titanium and PLLA screw groups withstood 80 N of compression without failure. When the load-to-failure test was performed in the PLLA group, the average device failure point was 172.8 N (range 148-196 N). Review of high-frame-rate video demonstrated that all failures occurred due to the PLLA screws breaking or falling out. Bioabsorbable PLLA screws can withstand compressive forces more than double that of the maximal in vivo forces needed during mandibular distraction. These screws may be an acceptable alternative for the fixation of internal mandibular distractors.

Unplanned postoperative catheterization during admission for coronary artery bypass grafting is neither cheap nor benign, but may rescue patients.

OBJECTIVE: Literature describing outcomes of myocardial ischemia after coronary artery bypass grafting is sparse. We hypothesized these patients had more complications and incurred higher costs of care. METHODS: Using adult cardiac surgery data and cardiac catheterization (CathPCI) data from the Virginia Cardiac Services Quality Initiative, we identified patients who underwent unplanned cardiac catheterization after coronary artery bypass grafting from 2018 to 2021. Adult cardiac surgery data were matched to CathPCI data examining earliest in-hospital catheterization. Patients not requiring catheterization served as the control group. RESULTS: We identified 10,597 patients who underwent isolated coronary artery bypass grafting, of whom 41 of 10,597 underwent unplanned cardiac catheterization. A total of 21 of 41 patients (51%) received percutaneous coronary intervention, most commonly for non-ST-elevation myocardial infarction (n = 7, 33%) and ST-elevation myocardial infarction (n = 6, 29%). Postoperative cardiac arrest occurred in 14 patients (40%). In patients who underwent percutaneous coronary intervention, 14 (67%) had a single lesion, 4 (19%) had 2 lesions, and 3 (14%) had 3 lesions. The left anterior descending artery (38%) was the most frequently intervened upon vessel. Patients who underwent catheterization were more likely to require balloon pump support (26% vs 11%), to have prolonged ventilation (57% vs 20%), to have renal failure (17% vs 7.1%), and to undergo reintubation (37% vs 3.8%, all P < .04). There was no statistical difference in operative mortality (4.9% vs 2.3%, P = .2) or failure to rescue (4.9% vs 1.6%, P = .14). Total costs were higher in patients who underwent unplanned catheterization ($81,293 vs $37,011, P < .001). CONCLUSIONS: Unplanned catheterization after coronary artery bypass grafting is infrequent but associated with more complications and a higher cost of care. Therefore, determination of an association with operative mortality in patients with suspected ischemia after coronary artery bypass grafting requires additional study.

Temporal Cluster Analysis of Deep Sternal Wound Infection in a Regional Quality Collaborative.

INTRODUCTION: Deep sternal wound infection (DSWI) is a rare complication associated with high mortality. Seasonal variability in surgical site infections has been demonstrated, however, these patterns have not been applied to DSWI. The purpose of this study was to assess temporal clustering of DSWIs. METHODS: All cardiac surgery patients who underwent sternotomy were queried from a regional Society of Thoracic Surgeons database from 17 centers from 2001 to 2019. All patients with the diagnosis of DSWI were then identified. Cluster analysis was performed at varying time intervals (monthly, quarterly, and yearly) at the hospital and regional level. DSWI rates were calculated by year and month, and compared using mixed-effects negative binomial regression. RESULTS: A total of 134,959 patients underwent a sternotomy for cardiac surgery, of whom 469 (0.35%) developed a DSWI. Rates of DSWI per hospital across all years ranged from 0.12% to 0.69%. Collaborative-level rates of DSWIs were the greatest in September (0.44%) and the lowest in January (0.30%). Temporal clustering was not seen across seasonal quarters (high rate in preceeding quarter was not associated with a high rate in the next quarter) (P = 0.39). There were yearly differences across all institutions in the DSWI rates. A downward trend in DSWI rates was seen from 2001 to 2019 (P < 0.001). A difference among hospitals in the cohort was observed (P < 0.001). CONCLUSIONS: DSWI are a rare event within our region. Unlike other surgical site infection, there does not appear to be a seasonal pattern associated with DSWI.

Center case volume is associated with Society of Thoracic Surgeons-defined failure to rescue in cardiac surgery.

OBJECTIVE: Our understanding of the impact of a center's case volume on failure to rescue (FTR) after cardiac surgery is incomplete. We hypothesized that increasing center case volume would be associated with lower FTR. METHODS: Patients undergoing a Society of Thoracic Surgeons index operation in a regional collaborative (2011-2021) were included. After we excluded patients with missing Society of Thoracic Surgeons Predicted Risk of Mortality scores, patients were stratified by mean annual center case volume. The lowest quartile of case volume was compared with all other patients. Logistic regression analyzed the association between center case volume and FTR, adjusting for patient demographics, race, insurance, comorbidities, procedure type, and year. RESULTS: A total of 43,641 patients were included across 17 centers during the study period. Of these, 5315 (12.2%) developed an FTR complication, and 735 (13.8% of those who developed an FTR complication) experienced FTR. Median annual case volume was 226, with 25th and 75th percentile cutoffs of 136 and 284 cases, respectively. Increasing center-level case volume was associated with significantly greater center-level major complication rates but lower mortality and FTR rates (all P values < .01). Observed-to-expected FTR was significantly associated with case volume (P = .040). Increasing case volume was independently associated with decreasing FTR rate in the final multivariable model (odds ratio, 0.87 per quartile; confidence interval, 0.799-0.946, P = .001). CONCLUSIONS: Increasing center case volume is significantly associated with improved FTR rates. Assessment of low-volume centers' FTR performance represents an opportunity for quality improvement.

Pulmonary Hypertension and Operative Risk in Mitral Valve and Coronary Surgery.

INTRODUCTION: Pulmonary hypertension (PHT) is a known risk factor for coronary artery bypass grafting (CABG), though less well understood for valve operations. We hypothesized PHT is associated with lower risk during mitral valve operations compared to CABG. METHODS: Patients undergoing isolated mitral valve or CABG operations (2011-2019) in a regional Society of Thoracic Surgeons (STS) database were stratified by pulmonary artery systolic pressure (PASP). The association of PASP by procedure type was assessed by hierarchical regression modeling, adjusting for STS predicted risk scores. RESULTS: Of the 2542 mitral and 11,059 CABG patients, the mitral population had higher mean STS risk of mortality (3.6% versus 2.4%, P < 0.0001) and median PASP (42 mmHg versus 32 mmHg, P < 0.0001). PASP was independently associated with operative mortality and major morbidity in both mitral and CABG patients. However, for mitral patients a 10-mmHg increase in PASP was associated with lower odds of morbidity (odds ratio: 1.06 versus 1.13), mortality (odds ratio: 1.11 versus 1.18) and intensive care unit time (4.3 versus 7.6 h) compared with CABG patients (interaction terms P < 0.0001). Among mitral patients, median PASP was higher in stenotic versus regurgitant disease (57 mmHg versus 40 mmHg, P < 0.0001). However, there was no differential association of PASP on morbidity or mortality (interaction terms P > 0.05). CONCLUSIONS: Although mitral surgery patients tend to have higher preoperative pulmonary artery pressures, PHT was associated with a lower risk for mitral outcomes compared with CABG. Further research on the management and optimization of patients with PHT perioperatively is needed to improve care for these patients.

Changes in Controllable Coronary Artery Bypass Grafting Practice for White and Black Americans.

BACKGROUND: Racial disparities in outcomes after cardiac surgery are well reported. We sought to determine whether variation by race exists in controllable practices during coronary artery bypass graft surgery (CABG). We hypothesized that racial disparities exist in CABG quality metrics, but have improved over time. METHODS: All patients undergoing isolated CABG (2000 to 2019) in a multiple state database were stratified into three eras by race. Analysis included propensity matched White Americans and Black Americans. Primary outcomes included left internal mammary artery use, multiple arterial grafting, revascularization completeness, and guideline-directed medication prescription. RESULTS: Of 72 248 patients undergoing CABG, Black American patients (n = 10 270, 15%) had higher rates of diabetes mellitus, hypertension, prior stroke, and myocardial infarction. After matching, 19 806 patients (n = 9903 per group) were well balanced. Left internal mammary artery use was significantly different early (era 1, Black Americans 84.7% vs White Americans 86.6%; P = .03), but equalized over time. Importantly, multiarterial grafting differed between Black Americans and White Americans over the entire study (9.1% vs 11.5%, P < .001) and within each era. Black Americans had more incomplete revascularization during the study period (14% vs 12.8%, P = .02) driven by a large disparity in era 1 (9.5% vs 7.2%, P < .001). Despite similar rates of preoperative use, Black Americans were more often discharged on a regimen of ß-blockers (91.8% vs 89.6%, P < .001). CONCLUSIONS: Coronary artery bypass graft surgery metrics of left internal mammary artery use and optimal medical therapy have improved over time and are similar despite patient race. Black Americans undergo less frequent multiarterial grafting and greater discharge ß-blocker prescription. Identifying changes in controllable CABG quality practices across races supports a continued focus on standardizing such efforts.

Left Ventricular Diastolic Dysfunction and Pulmonary Hypertension: Outcomes in SAVR.

BACKGROUND: Severe pulmonary hypertension (PH) and left ventricular diastolic dysfunction (LVDD) are independently associated with poor outcomes in cardiac surgery. We evaluated the relationship of several measures of LVDD, PH, and hemodynamic subtypes of PH including precapillary pulmonary hypertension(pcPH) and isolated post-capillary pulmonary hypertension(ipcPH) and combined pre and post capillary pulmonary hypertension(cpcPH) capillary PH to postoperative outcomes in a cohort of patients who underwent elective isolated-AVR. METHODS: We evaluated (n = 206) patients in our local STS database who underwent elective isolated-AVR between 2014 and 2018, with transthoracic echocardiogram (n = 177) or right heart catheterization (n = 183) within 1 year of operation (or both, n = 161). The primary outcome was a composite end point of death, prolonged ventilation, ICU readmission, and hospital stay >14 days. RESULTS: Severe PH was associated with worse outcomes (moderate: OR, 1.1, p = 0.09; severe: OR, 1.28, p = 0.01), but degree of LVDD was not associated with worse outcomes. Across hemodynamic subtypes of PH, odds of composite outcome were similar (p = 0.89), however, patients with cpcPH had more postoperative complications (67 vs. 36%, p = 0.06) and patients with ipcPH had greater all-cause mortality at 1 (8 vs. 1%, p = 0.03) and 3 years (27 vs. 4%, p = 0.008). CONCLUSION: Severe PH conferred modestly greater risk of adverse events, and both LVDD grade and the combination of severe PH and LVDD were not associated with worse outcomes. However, hemodynamic stratification of PH revealed higher postoperative complications and worse long-term outcomes for those with cpcPH and ipcPH. Preoperative stratification of PH by hemodynamic subtype in valve replacement surgery may improve our risk stratification in this heterogenous condition. Further evaluation of the significance of LVDD and PH in other cardiac operations is warranted.

Operating Room Versus Intensive Care Unit Extubation Within 6 Hours After On-Pump Cardiac Surgery: Early Results and Hospital Costs.

Time-directed extubation (fast-track) protocols may decrease length of stay and cost but data on operating room (OR) extubation is limited. The objective of this study was to compare the outcomes of extubation in the OR versus fast-track extubation within 6 hours of leaving the operating room. Patients undergoing nonemergent STS index cases (2011-2021) who were extubated within 6 hours were identified from a regional STS quality collaborative. Patients were stratified by extubation in the OR versus fast track. Propensity score matching (1:n) was performed to balance baseline differences. Of the 24,962 patients, 498 were extubated in the OR. After matching, 487 OR extubation cases and 899 fast track cases were well balanced. The rate of reintubation was higher for patients extubated in the OR [21/487 (4.3%) vs 16/899 (1.8%), P = 0.008] as was the incidence of reoperation for bleeding [12/487 (2.5%) vs 8/899 (0.9%), P = 0.03]. There was no significant difference in the rate of any reoperation [16/487 (3.3%) vs 15/899 (1.6%), P = 0.06] or operative mortality [4/487 (0.8%) vs 6/899 (0.6%), P = 0.7]. OR extubation was associated with shorter hospital length of stay (5.6 vs 6.2 days, P < 0.001) and lower total cost of admission ($29,602 vs $31,565 P < 0.001). OR extubation is associated with a higher postoperative risk of reintubation and reoperation due to bleeding, but lower resource utilization.Future research exploring predictors of extubation readiness may be required prior to widespread adoption of this practice.

A retrospective comparison of albumin versus mannitol priming fluid with relation to postoperative atrial fibrillation.

BACKGROUND AND AIM OF THE STUDY: Postoperative atrial fibrillation (POAF) is a common complication following cardiac surgery which can result in increased mortality and increased healthcare costs. During Hurricane Maria (2017), a nationwide shortage of mannitol occurred, and our institution switched to the utilization of albumin as a priming fluid solution. We observed decreased rates of POAF during that time and began alternating albumin and mannitol priming fluid solutions. We hypothesized this observation may be from altered perinexal conduction from albumin utilization. METHODS: A retrospective chart review of all patients from January 2020 through December 2020 who underwent cardiac surgery was performed, to determine if albumin was associated with reduced POAF rates. Two hundred and thirteen patients were identified and 4 were excluded. Two hundred and nine patients (110 albumin priming fluid and 99 mannitol priming fluid) were included in our final analysis. RESULTS: Analysis was performed for all patients with POAF and in patients with new-onset AF (without a history of prior AF) after surgery. POAF rates showed no statistically significant difference between cohorts. For all patients, POAF occurred in 43% of the albumin subgroup and 47% of the mannitol subgroup (p = .53) and for patients with new-onset AF, POAF occurred in 35% of the albumin subgroup versus 42% of the mannitol subgroup (p = .36). Logistic regression revealed that age, ejection fraction and cardiopulmonary bypass time was associated with POAF, in our cohort. CONCLUSIONS: The use of albumin compared to mannitol as priming fluid solutions was not associated with statistically significant reductions in POAF rate, in our population.

Socioeconomic distress is associated with failure to rescue in cardiac surgery.

OBJECTIVE: The influence of socioeconomic determinants of health on failure to rescue (mortality after a postoperative complication) after cardiac surgery is unknown. We hypothesized that increasing Distressed Communities Index, a comprehensive socioeconomic ranking by ZIP code, would be associated with higher failure to rescue. METHODS: Patients undergoing Society of Thoracic Surgeons index operation in a regional collaborative (2011-2021) who developed a failure to rescue complication were included. After excluding patients with missing ZIP code or Society of Thoracic Surgeons predicted risk of mortality, patients were stratified by Distressed Communities Index scores (0-no distress, 100-severe distress) based on education level, poverty, unemployment, housing vacancies, median income, and business growth. The upper 2 quintiles of distress (Distressed Communities Index >60) were compared to all other patients. Hierarchical logistic regression analyzed the association between Distressed Communities Index and failure to rescue. RESULTS: A total of 4004 patients developed 1 or more of the defined complications across 17 centers. Of these, 582 (14.5%) experienced failure to rescue. High socioeconomic distress (Distressed Communities Index >60) was identified among 1272 patients (31.8%). Before adjustment, failure to rescue occurred more frequently among those from socioeconomically distressed communities (Distressed Communities Index >60; 16.9% vs 13.4%, P = .004). After adjustment, residing in a socioeconomically distressed community was associated with 24% increased odds of failure to rescue (odds ratio, 1.24; confidence interval, 1.003-1.54; P = .044). CONCLUSIONS: Increasing Distressed Communities Index, a measure of poor socioeconomic status, is associated with greater risk-adjusted likelihood of failure to rescue after cardiac surgery. These findings highlight that current quality metrics do not account for socioeconomic status, and as such underrepresent procedural risk for these vulnerable patients.

Predictive Capability of Metabolic Panels for Postoperative Atrial Fibrillation in Cardiac Surgery Patients.

INTRODUCTION: Postoperative atrial fibrillation (POAF) occurs in up to 65% of cardiac surgery patients and is associated with an increased risk for stroke and mortality. Electrolyte disturbances in sodium (Na+), potassium (K+), total calcium (Ca2+), chloride (Cl-), and magnesium (Mg2+) are predisposing factors for POAF, but these imbalances are yet to be used to predict POAF. The purpose of this study is to determine whether the development of POAF can be predicted by blood plasma ionic composition. METHODS: Metabolic panels of patients with no prior history of atrial fibrillation who did (n = 763) and did not develop POAF (n = 2144) after cardiac surgery were obtained from the Carilion Clinic electronic medical record system. We initially evaluated serum Na+, K+, Ca2+, Cl-, and Mg2+ in the two groups using descriptive statistics via scatter and spaghetti plots and then with predictive modeling via logistic regression and random forest models. RESULTS: Neither scatter nor spaghetti plots of electrolyte data revealed a significant difference between those who did and did not develop POAF. Two logistic regression models and two random forest models with POAF status as the outcome were generated using the first observation for each electrolyte and the coefficient of the linear regression, which was obtained from a linear fit of the scatter plot. The random forest model using the first observation had a sensitivity of only 12.2%, but all four models had specificities more than 97%. CONCLUSIONS: Neither of the two logistic regression nor two random forest models were able to effectively predict the development of POAF from plasma ionic concentrations, but the random forest models effectively classified patients who would not develop POAF.

Contemporary prevalence and outcomes of rheumatic mitral valve surgery.

OBJECTIVE: Rheumatic mitral valve disease is often viewed as a historic disease in North America with limited contemporary data. We hypothesized that rheumatic pathology remains common and has worse short-term outcomes and higher resource utilization compared to other mitral valve pathologies. METHOD: All patients undergoing mitral valve repair or replacement (2011-2019) were extracted from a regional Society of Thoracic Surgeons database. Resource utilization metrics included inflation-adjusted hospital costs. Patients were stratified by mitral valve pathology for univariate analysis. RESULT: Out of the 6625 mitral valve procedures, 835 (12.6%) were from rheumatic disease, a proportion that incrementally increased over time (+0.39% per year, p = .032). Among 19 hospitals, there was high variability in number of rheumatic mitral operations (median: 22, interquartile range [IQR]: 5-80) and rate of rheumatic repairs (median: 3%, IQR: 0%-6%). Rheumatic patients were younger (62 vs. 65, p < .0001), more often female (75% vs. 43%, p < .001) and with greater burden of heart failure, multi-valve disease, and lung disease, but less coronary disease. There were no differences in operative mortality (5.2% vs. 5.0%, p = .85) or major morbidity (22.2% vs. 21.8%, p = .83). However, resource utilization was higher for rheumatic patients, including more frequent transfusions (43% vs. 39%, p = .012), longer ICU (73 vs. 64 h, p < .0001) and postoperative length of stay (8 vs. 7 days, p < .0001). CONCLUSIONS: Rheumatic mitral disease accounts for a meaningful (12%) and rising percentage of mitral valve operations in the region, with high variability among hospitals. Rheumatic mitral surgery yielded similar short-term outcomes compared to nonrheumatic pathology, but required greater resource utilization.

Non-vitamin K oral anticoagulant use after cardiac surgery is rapidly increasing.

OBJECTIVE: The prevalence of non-vitamin K oral anticoagulant use after cardiac surgery is unknown, particularly in patients with bioprosthetic valves. We sought to define the contemporary use and short-term safety of non-vitamin K oral anticoagulants after cardiac surgery. METHODS: All patients undergoing bioprosthetic aortic valve replacement, bioprosthetic mitral valve replacement, or isolated coronary artery bypass grafting (2011-2018) were evaluated from a multicenter, regional Society of Thoracic Surgeons database. Patients were stratified by anticoagulant type (non-vitamin K oral anticoagulant vs vitamin K antagonist) and era (early [2011-2014] vs contemporary [2015-2018]). RESULTS: Of 34,188 patients, 18% (6063) were discharged on anticoagulation, of whom 23% were prescribed non-vitamin K oral anticoagulants. Among those receiving anticoagulation, non-vitamin K oral anticoagulant use has significantly increased from 10.3% to 35.4% in contemporary practice (P < .01). This trend was observed for each operation type (coronary artery bypass grafting 0.86%/year, bioprosthetic aortic valve replacement: 2.15%/year, bioprosthetic mitral valve replacement: 2.72%/year, all P < .01). In patients with postoperative atrial fibrillation receiving anticoagulation, non-vitamin K oral anticoagulant use has increased from 6.3% to 35.4% and 12.3% to 40.3% after bioprosthetic valve replacement and isolated coronary artery bypass grafting, respectively (both P < .01). In patients receiving anticoagulation at discharge, adjusted 30-day mortality (odds ratio, 1.94; P = .12) and reoperation (odds ratio, 0.79; P = .34) rates were not associated with anticoagulant choice, whereas non-vitamin K oral anticoagulant use was associated with an adjusted 0.9-day decrease (P < .01) in postoperative length of stay. CONCLUSIONS: Non-vitamin K oral anticoagulant use after cardiac surgery has dramatically increased since 2011. This trend is consistent regardless of indication for anticoagulation including bioprosthetic valves. Short-term outcomes support their safety in the cardiac surgery setting with shorter postoperative hospital stays. Long-term studies on the efficacy of non-vitamin K oral anticoagulants after cardiac surgery are still necessary.

To Anticoagulate or Not? That Is the Question. Management of High-Risk Patients with Mechanical Mitral and Double Valves: A Case Series.

The Achilles heel of mechanical valves appears to be the need for anticoagulation. Several different types of mechanical valves have come and gone. The success or lack thereof of these valves depended on their various designs. We compared the two most promising mechanical valves of different eras and the need for anticoagulation through a case review. Both the Medtronic-Hall tilting disc valve and the bileaflet On-X valve were compared and contrasted in terms of durability and management of anticoagulation in high-risk patient populations. We present two cases of challenging anticoagulation management: a patient who underwent a mitral valve replacement with a Medtronic-Hall tilting disc valve who was off anticoagulation for close to six years, and a patient who underwent On-X mitral and aortic valve replacements and suffered a subsequent intracranial bleed requiring surgical intervention. We explore the ethical dilemmas associated with these patients and the risk of restarting anticoagulation for each.