Impact of Pulmonary Complications on Outcomes and Resource Use After Elective Cardiac Surgery.

OBJECTIVE: To characterize the impact of pulmonary complications (PCs) on mortality, costs, and readmissions after elective cardiac operations in a national cohort and to test for hospital-level variation in PC. BACKGROUND: PC after cardiac surgery are targets for quality improvement efforts. Contemporary studies evaluating the impact of PC on outcomes are lacking, as is data regarding hospital-level variation in the incidence of PC. METHODS: Adults undergoing elective coronary artery bypass grafting and/or valve operations were identified in the 2016-2019 Nationwide Readmissions Database. PC was defined as a composite of reintubation, prolonged (>24 hours) ventilation, tracheostomy, or pneumonia. Generalized linear models were fit to evaluate associations between PC and outcomes. Institutional variation in PC was studied using observed-to-expected ratios. RESULTS: Of 588,480 patients meeting study criteria, 6.7% developed PC. After risk adjustment, PC was associated with increased odds of mortality (14.6, 95% CI, 12.6-14.8), as well as a 7.9-day (95% CI, 7.6-8.2) increase in length of stay and $41,300 (95% CI, 39,600-42,900) in attributable costs. PC was associated with 1.3-fold greater hazard of readmission and greater incident mortality at readmission (6.7% vs 1.9%, P <0.001). Significant hospital-level variation in PC was present, with observed-to-expected ratios ranging from 0.1 to 7.7. CONCLUSIONS: Pulmonary complications remain common after cardiac surgery and are associated with substantially increased mortality and expenditures. Significant hospital-level variation in PC exists in the United States, suggesting the need for systematic quality improvement efforts to reduce PC and their impact on outcomes.

Outcomes of heart transplant recipients bridged with percutaneous versus durable left ventricular assist devices.

BACKGROUND: The new United Network for Organ Sharing (UNOS) heart allocation policy prioritizes temporary percutaneous over durable left ventricular assist devices (LVAD) as bridge to transplant. We sought to examine 1-year outcomes of heart transplant recipients bridged with Impella versus durable LVADs. METHODS: All primary adult orthotopic heart transplant recipients registered in UNOS between January 2016 and June 2021 were analyzed. Recipients were identified as being bridged with isolated durable or percutaneous LVAD at the time of transplant. Baseline characteristics were compared and 1-year survival was examined using the Kaplan Meier method and multivariable Cox proportional hazards regression. RESULTS: During our study period, heart transplant recipients bridged with LVADs were divided between 5422(94%) durable and 324(6%) percutaneous options. Impella-bridged recipients were more likely to be status 1A under the old allocation system (98% vs. 70%, p < .01) and status 2 or higher under the new allocation system (99% vs. 24%, p < .01). Impella-bridged recipients were less likely to be obese (27% vs. 42%, p < .01), have ischemic cardiomyopathy (27% vs. 34%, p < .01), and were more likely to be on inotropic agents at the time of transplant (68% vs. 6%, p < .01). One-year post-transplant survival was not significantly different between the two groups on univariable (HR .87, 95% CI .56-1.37) or multivariable analysis (aHR .63, 95% CI .37-1.07). CONCLUSIONS: Following the UNOS allocation policy change, Impella utilization has increased with no significant difference in 1-year survival compared to bridge with durable LVADs. Impella may be a reasonable alternative to durable LVADs in select patients.

The Impact of COVID-19 on Racial and Ethnic Disparities in Cardiac Procedural Care.

OBJECTIVE: The primary objective of this study was to evaluate whether the COVID-19 pandemic altered the racial and ethnic composition of patients receiving cardiac procedural care. DESIGN: This was a retrospective observational study. SETTING: This study was conducted at a single tertiary-care university hospital. PARTICIPANTS: A total of 1,704 adult patients undergoing transcatheter aortic valve replacement (TAVR) (n = 413), coronary artery bypass grafting (CABG) (n = 506), or atrial fibrillation (AF) ablation (n = 785) from March 2019 through March 2022 were included in this study. INTERVENTIONS: No interventions were performed as this was a retrospective observational study. MEASUREMENTS AND MAIN RESULTS: Patients were grouped based on the date of their procedure: pre-COVID (March 2019 to February 2020), COVID Year 1 (March 2020 to February 2021), and COVID Year 2 (March 2021 to March 2022). Population-adjusted procedural incidence rates during each period were examined and stratified based on race and ethnicity. The procedural incidence rate was higher for White patients versus Black, and non-Hispanic patients versus Hispanic patients for every procedure and every period. For TAVR, the difference in procedural rates between White patients versus Black patients decreased between the pre-COVID and COVID Year 1 (12.05-6.34 per 1,000,000 persons). For CABG, the difference in procedural rates between White patients versus Black, and non-Hispanic patients versus Hispanic patients did not change significantly. For AF ablations, the difference in procedural rates between White patients versus Black patients increased over time (13.06 to 21.55 to 29.64 per 1,000,000 persons in the pre-COVID, COVID Year 1, and COVID Year 2, respectively). CONCLUSION: Racial and ethnic disparities in access to cardiac procedural care were present throughout all study time periods at the authors' institution. Their findings reinforce the continuing need for initiatives to reduce racial and ethnic disparities in healthcare. Further studies are needed to fully elucidate the effects of the COVID-19 pandemic on healthcare access and delivery.

Morbidity and Mortality Associated With Blood Transfusions in Elective Adult Cardiac Surgery.

OBJECTIVES: Perioperative transfusion thresholds have garnered increasing scrutiny as restrictive strategies have been shown to be noninferior. The study authors used data from a statewide academic collaborative to test the association between transfusion and 30-day mortality. DESIGN: All adult patients undergoing coronary artery bypass grafting (CABG) and/or valve surgeries between 2013 and 2019 in the authors' Academic Cardiac Surgery Consortium were examined. The relationship between the number of overall packed red blood cell (pRBC) and coagulation product (CP) (fresh frozen plasma, cryoprecipitate, platelets) transfusions on 30-day mortality was evaluated. Multivariate regression was used to evaluate predictors of transfusion and study endpoints. Machine learning (ML) models also were developed to predict 30-day mortality and rank transfusion-related features by relative importance. SETTING: At an Academic Cardiac Surgery Consortium of 5 institutions. PARTICIPANTS: Patients ≥18 years old undergoing CABG and/or valve surgeries. MEASUREMENTS AND MAIN RESULTS: Of the 7,762 patients (median hematocrit [HCT] 39%, IQR 35%-43%) who were included in the final study cohort, >40% were transfused at least 1 unit of pRBC or CP. In adjusted analyses, higher preoperative HCT was associated with reduced odds of mortality (adjusted odds ratio [aOR] 0.95, 95% CI 0.92-0.98), renal failure (aOR 0.95, 95% CI 0.92-0.98), and prolonged mechanical ventilation (aOR 0.97, 95% CI 0.95-0.99). In contrast, perioperative transfusions were associated with increased 30-day mortality after adjustment for preoperative HCT and other baseline features. The ML models were able to predict 30-day mortality with an area under the curve of 0.814-to-0.850, with perioperative transfusions displaying the highest feature importance. CONCLUSIONS: The present analysis found increasing HCT to be associated with a lower incidence of mortality. The study authors also found a direct dose-response association between transfusions and all study endpoints examined.

Validity of echocardiography for detection of left ventricular thrombus with surgical validation in patients awaiting durable left ventricular assist device.

OBJECTIVE: Unrecognized left ventricular thrombi (LVT) can have devastating clinical implications and precludes patients with end-stage heart failure from undergoing left ventricular assist device (LVAD) implantation without cardiopulmonary bypass assistance. We assessed the reliability of an echocardiogram to diagnose LVT in patients with end-stage heart disease who underwent LVAD implantation. METHODS: A single-center retrospective study evaluated 232 consecutive adult patients requiring implantation of durable LVADs between 2005 and 2019. The validity of preoperative transthoracic echocardiogram (TTE) and intraoperative transesophageal echocardiogram (TEE) for diagnosing LVT was compared to direct inspection at the time of LVAD implantation. RESULTS: There were 232 patients that underwent LVAD implantation, with 226 patients (97%) receiving a preoperative TTE. Of those 226 patients, 32 patients (14%) received ultrasound enhancing agents (UEA). Intraoperative TEE images were available in 195 patients (84%). The sensitivity of TTE without UEA was 22% and specificity was 90% for detecting LVT, compared to 50% and 86%, respectively, for TTE with UEA. For intraoperative TEE, the sensitivity and specificity were 46% and 96%, respectively. The false omission rate ranged from 4% to 8% for all modalities of echocardiography. CONCLUSION: Among patients undergoing LVAD implantation, preoperative TTE and intraoperative TEE had poor sensitivity for LVT detection. Up to 8% of echocardiograms were incorrectly concluded to be negative for LVT on surgical validation. The low sensitivity and positive predictive value for diagnosing LVT suggest that echocardiography has limited reliability in this cohort of patients who are at high risk of LVT formation and its subsequent complications.

Outcomes and Resource Utilization in Robotic Mitral Valve Repair: Beyond the Learning Curve.

BACKGROUND: After the initial learning curve associated with mastering a robotic procedure, there is a plateau where operative time and complication rates stabilize. Our objective was to evaluate one surgeon's experience with robotic mitral valve repairs (MVRep) beyond the learning curve and to compare its effectiveness against the traditional open approach. METHODS: Data from Ronald Reagan University of California, Los Angeles Medical Center was prospectively collected from January 2008 to March 2016 to identify adult patients undergoing robotic MVRep. Operative times, complication rates, and cost for robotic versus open MVRep were compared using multivariate regressions, adjusting for comorbidities and previous cardiac surgeries. RESULTS: During the study period, 175 robotic (41%) and 259 open (59%) MVRep cases were performed at our institution. As the surgeon performed more robotic operations, there was a decrease in room time (554-410 min, P < 0.001), surgery time (405-271 min, P < 0.001), and cross-clamp times (179-93 min, P < 0.001). After application of a multivariate regression model, robotic MVRep was associated with lower odds of complications (odds ratio = 0.42, P = 0.001), shorter length of stay (ß = -2.51, P < 0.001), and a reduction of 11% in direct (P = 0.003) and 24% in room costs (P < 0.001), but a 51% increase in surgery cost (P < 0.001). CONCLUSIONS: As the surgeon gained experience with robotic MVRep, operative times decreased in a steady manner. Robotic MVRep had comparable outcomes to open MVRep and lower overall cost. The observed difference in costs is likely related to shorter length of stay and lower room cost with the robotic approach.

Ferumoxytol-enhanced MR Angiography for Vascular Access Mapping before Transcatheter Aortic Valve Replacement in Patients with Renal Impairment: A Step Toward Patient-specific Care.

Purpose To assess the technical feasibility of the use of ferumoxytol-enhanced (FE) magnetic resonance (MR) angiography for vascular mapping before transcatheter aortic valve replacement in patients with renal impairment. Materials and Methods This was an institutional review board-approved and HIPAA-compliant study. FE MR angiography was performed at 3.0 T or 1.5 T. Unenhanced computed tomographic (CT) images were used to overlay vascular calcification on FE MR angiographic images as composite fused three-dimensional data. Image quality of the subclavian and aortoiliofemoral arterial tree and confidence in the assessment of calcification were evaluated by using a four-point scale (4 = excellent vascular definition or strong confidence). Signal intensity nonuniformity as reflected by the heterogeneity index (ratio between the mean standard deviation of luminal signal intensity and the mean luminal signal intensity), signal-to-noise ratio, and consistency of luminal diameter measurements were quantified. Findings at FE MR angiography were compared with pelvic angiograms. Results Twenty-six patients underwent FE MR angiography without adverse events. A total of 286 named vascular segments were scored. The image quality score was 4 for 99% (283 of 286) of the segments (κ = 0.9). There was moderate to strong confidence in the ability to assess vascular calcific morphology in all studies with complementary unenhanced CT. The steady-state luminal heterogeneity index was low, and signal-to-noise ratio was high. Interobserver luminal measurements were reliable (intraclass correlation coefficient, 0.98; 95% confidence interval: 0.98, 0.99). FE MR angiographic findings were consistent with correlative pelvic angiograms in all 16 patients for whom the latter were available. Conclusion In patients with renal impairment undergoing transcatheter aortic valve replacement, FE MR angiography is technically feasible and offers reliable vascular mapping without exposure to iodine- or gadolinium-based contrast agents. Thus, the total cumulative dose of iodine-based contrast material is minimized and the risk of acute nephropathy is reduced. © RSNA, 2017 Online supplemental material is available for this article.

National trends in volume-outcome relationships for extracorporeal membrane oxygenation.

BACKGROUND: The use of extracorporeal membrane oxygenation (ECMO) has emerged as a common therapy for severe cardiopulmonary dysfunction. We aimed to describe the relationship of institutional volume with patient outcomes and examine transfer status to tertiary ECMO centers. MATERIALS AND METHODS: Using the National Inpatient Sample, we identified adult patients who received ECMO from 2008 to 2014. Individual hospital volume was calculated as tertiles of total institutional discharges for each year independently. RESULTS: Of the total 18,684 adult patients placed on ECMO, 2548 (13.6%), 5278 (28.2%), and 10,858 (58.1%) patients were admitted to low-, medium-, and high-volume centers, respectively. Unadjusted mortality at low-volume hospitals was less than that of medium- (43.7% versus 50.3%, P = 0.03) and high-volume hospitals (43.7% versus 55.6%, P < 0.001). Length of stay and cost were reduced at low-volume hospitals compared to both medium- and large-volume institutions (all P < 0.001). In high-volume institutions, transferred patients had greater postpropensity-matched mortality (58.5% versus 53.7%, P = 0.05) and cost ($190,299 versus $168,970, P = 0.009) compared to direct admissions. On exclusion of transferred patients from propensity analysis, mortality remained greater in high-volume compared to low-volume centers (50.2% versus 42.8%, P = 0.04). Predictors of mortality included treatment at high-volume centers, respiratory failure, and cardiogenic shock (all P < 0.001). CONCLUSIONS: Our findings show increased in-hospital mortality in high-volume institutions and in patients transferred to tertiary centers. Whether this phenomenon represents selection bias or transfer from another facility deserves further investigation and will aid with the identification of surrogate markers for quality of high-risk interventions.

Myocardial functional changes in transfemoral versus transapical aortic valve replacement.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has greatly expanded the treatment options available for patients with severe aortic stenosis at high surgical risk. MATERIALS AND METHODS: We compared changes in myocardial function in TAVR with a transfemoral (TF) versus a transapical (TA) approach at a major tertiary hospital from 2012-2016. Traditional echocardiographic measures of cardiac structure and function were tracked, alongside the use of two-dimensional speckle tracking echocardiography to measure myocardial strain and strain rates. RESULTS: For the entire cohort with complete data at all time points (n = 42), between the pre-TAVR baseline (mean: 20.1 d) and the post-TAVR 1-mo follow-up (mean: 32.7 d), global longitudinal strain significantly increased (from -15.6% to -18.2%, P < 0.001). When comparing the TF (n = 31) and TA (n = 11) groups, TA patients showed persistently impaired apical longitudinal strain at the 1-mo follow-up (-15.9% versus -22.3%, P < 0.05). In terms of clinical outcomes, both groups (n = 131 for TF, n = 53 for TA) were similar in terms of 30-d mortality, readmission rate, and risk of post-TAVR acute kidney injury. However, TA patients experienced significantly longer length of hospitalization (7.58 versus 3.92 d, P = 0.02), intensive care unit hours (105.4 versus 47.1 h, P = 0.02), and were at a greater risk of long-term (>72 h) intensive care unit stay (45% versus 25%, P = 0.01). CONCLUSIONS: Patients undergoing TA-TAVR exhibit impaired apical longitudinal strain, although global myocardial function is similar to TF-TAVR otherwise. Myocardial strain measured by two-dimensional speckle tracking echocardiography appears to be a sensitive method to detect subtle cardiac remodeling after TAVR.

Are nonemergent cardiac operations performed during off-time associated with worse outcome?

BACKGROUND: With the implementation of value-based health care, it is of increasing interest to understand whether performing elective surgeries during off-time impacts surgical outcomes. The objective of this study was to evaluate the impact of start times on nonemergent cardiac operations. METHODS: The institutional Society of Thoracic Surgeons was used to identify all adult nonemergent cardiac operations performed between January 2008 and December 2015 at our institution. "Off-time" is defined as either operation "late starts," that is, an incision time after 3 PM and before 7 AM, or procedures occurring during the weekends. Univariate and multivariate logistic regression analyses were performed to examine its impact on in-hospital mortality and major adverse events. Available cost data were directly obtained from the departmental BIOME database. RESULTS: Of the 3406 cardiac operations included in the study, 2933 (86.1%) were normal-start and 473 (13.9%) were off-time-start operations. After adjusting for patient and operative characteristics, late operating room start times were not associated with increased in-hospital mortality (P = 0.28, confidence interval [CI] 95% = 0.99-1.03), readmissions (P = 0.21, CI 95% = 0.99-1.07), or major adverse events (P = 0.07, CI 95% = 1.00-1.12). In addition, there was no significant impact on total hospital cost (9.0% increase, P = 0.07). CONCLUSIONS: These findings suggest that late operating room start times are not associated with increased mortality or other complications in a tertiary-care academic medical center. Our findings should be considered during operative scheduling to optimize resource distribution and patient care strategies.

Preoperative Three-Dimensional Strain Imaging Identifies Reduction in Left Ventricular Function and Predicts Outcomes After Cardiac Surgery.

BACKGROUND: Echocardiography-based speckle-tracking strain imaging is an emerging modality to assess left ventricular function. The aim of this study was to investigate the change in left ventricular systolic function after cardiac surgery with 3-dimensional (3D) speckle-tracking strain imaging and to determine whether preoperative 3D strain is an independent predictor of acute and long-term clinical outcomes after aortic valve, mitral valve, and coronary artery bypass grafting operations. METHODS: In total, 163 adult patients undergoing aortic valve, mitral valve, and coronary artery bypass surgeries were enrolled prospectively and had complete data sets. Demographic, operative, and outcome data were collected. 3D transthoracic echocardiograms were preformed preoperatively and on second to fourth postoperative day. Blinded off-line analysis was performed for left ventricular 2-dimensional (2D) ejection fraction (EF2D) and 3D ejection fraction (EF3D) and global peak systolic area, longitudinal, circumferential, and radial strain. RESULTS: 3D global strain correlated well with EF3D. Ventricular function as measured by strain imaging decreased significantly after all types of cardiac surgery. When preoperative EF3D was used, receiver operating characteristic curves identified reference values for 3D global strain corresponding to normal, mildly reduced, and severely reduced ventricular function. Normal ventricular function (EF3D ≥ 50%) corresponded to 3D global area strain -25%, with area under curve = 0.86 (0.81-0.89). Patients with reduced preoperative 3D global area strain had worse postoperative outcomes, including length of intensive care unit stay (4 vs 3 days, P = .001), major adverse events (27% vs 11%, P = .03), and decreased 1-year event-free survival (69% vs 88%, P = .005). After we controlled for baseline preoperative risk models including European System for Cardiac Operative Risk Evaluation score and surgery type, preoperative strain was an independent predictor of both short- and long-term outcomes, including length of intensive care unit stay, postoperative inotrope score, and 1-year event-free survival. CONCLUSIONS: This study shows that cardiac surgery was associated with an acute reduction in postoperative left ventricular function, when evaluated with 3D strain imaging. In addition, preoperative 3D strain was demonstrated to be an independent predictor of acute and long-term clinical outcomes after cardiac surgery. The use of noninvasive 3D transthoracic echocardiogram strain imaging before cardiac surgery may provide added information to aid in perioperative risk stratification and management for these high-risk patients.

Financial and clinical outcomes of extracorporeal mechanical support.

BACKGROUND: Over the past decade, extracorporeal mechanical support (ECMO) has been increasingly utilized in respiratory failure and cardiogenic shock. There is a need for assessing clinical and financial outcomes of ECMO use. This study presents our institution's experience with veno-arterial ECMO (VA-ECMO) over a 9-year period. METHODS: A retrospective review of our institution's ECMO database identified patients undergoing VA-ECMO between 2005 and 2013 (N = 150). Patients were assigned to four groups by indication: post-cardiotomy syndrome, cardiogenic shock requiring cardiopulmonary resuscitation (CPR), cardiogenic shock not requiring CPR, and respiratory failure. Hospital charges from administrative records were analyzed. Trend and correlation analyses were used to evaluate clinical and financial outcomes. RESULTS: Of the 150 patients meeting inclusion criteria, 28% required VA-ECMO for post-cardiotomy syndrome, 31.3% for cardiogenic shock with CPR, 35.3% for cadiogenic shock with no CPR, and 5.4% for respiratory failure. Mean duration on ECMO was 5.0 ± 3.4 days with a survival rate of 64% and no difference between the four groups (p = 0.40). ECMO-associated charges averaged $74,500 ± 61,400 per patient, 6% of total hospital charges. Subgroup analysis of cardiogenic shock patients revealed a nearly twofold increase in ECMO-related charges among patients who did not receive CPR (p = 0.04), as well as a trend toward improved survival (69.8% vs 51.1%, p = 0.06). CONCLUSION: In view of the variations in survival and costs in ECMO patients, further studies should aim to delineate patient populations that benefit from early initiation of ECMO.

Outcomes of biventricular mechanical support patients discharged to home to await heart transplantation.

BACKGROUND: The use of left ventricular assist devices has grown rapidly in recent years for patients with end-stage heart failure. A significant proportion of patients require both left- and right-sided support with biventricular assist devices (BiVADs) as a bridge to transplantation. Traditionally, these patients have waited in the hospital until they receive a transplant. PURPOSE: The aim of this study was to characterize the clinical course of BiVAD patients discharged to home to await heart transplantation. METHODS: Between November 2009 and July 2011, 24 adult patients underwent Thoratec paracorporeal BiVAD placement at the University of California Los Angeles, all with an Interagency Registry for Mechanically Assisted Circulatory Support score 1 or 2. The disposition, complications, and rehospitalizations of these subjects were retrospectively reviewed. RESULTS: Fourteen of the 24 patients were successfully discharged to home, with a mean time of 60 ± 27 days from BiVAD implantation to discharge. Ninety-three percent (13/14) of the patients sent home went on to be transplanted. Eleven of the 14 (79%) came in from home to receive their transplant. The mean time from BiVAD implantation to transplantation was 100 ± 65 days. Of the 14 patients discharged to home, there were 18 readmissions in 8 patients. CONCLUSION: In this small single-center review, we found that complex medical patients with BiVADs can be discharged to home and can await a heart transplant from home under the close management of multidisciplinary acute care and outpatient teams.

ACCF/AHA/ASE/ASNC/HFSA/HRS/SCAI/SCCT/SCMR/STS 2013 multimodality appropriate use criteria for the detection and risk assessment of stable ischemic heart disease: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Heart Association, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Thoracic Surgeons.

The American College of Cardiology Foundation along with key specialty and subspecialty societies, conducted an appropriate use review of common clinical presentations for stable ischemic heart disease (SIHD) to consider use of stress testing and anatomic diagnostic procedures. This document reflects an updating of the prior Appropriate Use Criteria (AUC) published for radionuclide imaging (RNI), stress echocardiography (Echo), calcium scoring, coronary computed tomography angiography (CCTA), stress cardiac magnetic resonance (CMR), and invasive coronary angiography for SIHD. This is in keeping with the commitment to revise and refine the AUC on a frequent basis. A major innovation in this document is the rating of tests side by side for the same indication. The side-by-side rating removes any concerns about differences in indication or interpretation stemming from prior use of separate documents for each test. However, the ratings were explicitly not competitive rankings due to the limited availability of comparative evidence, patient variability, and range of capabilities available in any given local setting. The indications for this review are limited to the detection and risk assessment of SIHD and were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Eighty clinical scenarios were developed by a writing committee and scored by a separate rating panel on a scale of 1-9, to designate Appropriate, May Be Appropriate, or Rarely Appropriate use following a modified Delphi process following the recently updated AUC development methodology. The use of some modalities of testing in the initial evaluation of patients with symptoms representing ischemic equivalents, newly diagnosed heart failure, arrhythmias, and syncope was generally found to be Appropriate or May Be Appropriate, except in cases where low pre-test probability or low risk limited the benefit of most testing except exercise electrocardiogram (ECG). Testing for the evaluation of new or worsening symptoms following a prior test or procedure was found to be Appropriate. In addition, testing was found to be Appropriate or May Be Appropriate for patients within 90 days of an abnormal or uncertain prior result. Pre-operative testing was rated Appropriate or May Be Appropriate only for patients who had poor functional capacity and were undergoing vascular or intermediate risk surgery with 1 or more clinical risk factors or an organ transplant. The exercise ECG was suggested as an Appropriate test for cardiac rehabilitation clearance or for exercise prescription purposes. Testing in asymptomatic patients was generally found to be Rarely Appropriate, except for calcium scoring and exercise testing in intermediate and high-risk individuals and either stress or anatomic imaging in higher-risk individuals, which were all rated as May Be Appropriate. All modalities of follow-up testing after a prior test or percutaneous coronary intervention (PCI) within 2 years and within 5 years after coronary artery bypass graft (CABG) in the absence of new symptoms were rated Rarely Appropriate. Pre-operative testing for patients with good functional capacity, prior normal testing within 1 year, or prior to low-risk surgery also were found to be Rarely Appropriate. Imaging for an exercise prescription or prior to the initiation of cardiac rehabilitation was Rarely Appropriate except for cardiac rehabilitation clearance for heart failure patients.

Decreased Left Atrial Cardiomyocyte FGF13 Expression Increases Vulnerability to Postoperative Atrial Fibrillation in Humans.

Postoperative atrial fibrillation (POAF) is the most common complication after cardiac surgery and a significant cause of increased morbidity and mortality. The development of novel POAF therapeutics has been limited by an insufficient understanding of molecular mechanisms promoting atrial fibrillation. In this observational cohort study, we enrolled 28 patients without a history of atrial fibrillation that underwent mitral valve surgery for degenerative mitral regurgitation and obtained left atrial tissue samples along the standard atriotomy incision in proximity to the right pulmonary veins. We isolated cardiomyocytes and performed transcriptome analyses demonstrating 13 differentially expressed genes associated with new-onset POAF. Notably, decreased expression of fibroblast growth factor 13 (FGF13), a fibroblast growth factor homologous factor known to modulate voltage-gated sodium channel Na V 1.5 inactivation, had the most significant association with POAF. To assess the functional significance of decreased FGF13 expression in atrial myocytes, we performed patch clamp experiments on neonatal rat atrial myocytes after siRNA-mediated FGF13 knockdown, demonstrating action potential prolongation. These critical findings indicate that decreased FGF13 expression promotes vulnerability to POAF.

Transcatheter and Surgical Aortic Valve Replacement in Patients With Bicuspid Aortic Valve Stenosis.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is not widely used in patients with bicuspid aortic valve (BAV) disease and has not yet been studied in randomized clinical trials. We characterized the rate of use and outcomes of TAVR and surgical aortic valve replacement (SAVR) in patients with BAV. METHODS: Adults with BAV stenosis receiving SAVR or TAVR procedures were abstracted from the 2012 to 2019 Nationwide Readmissions Database (NRD). Risk-adjusted analyses were performed with NRD-provided weights and inverse probability of treatment weights (IPTW) to examine the association of treatment strategy on inpatient mortality, complications, and hospitalization resource utilization. Nonelective readmissions within 90 days of discharge and reintervention at the first readmission were also examined. RESULTS: Of an estimated 56 331 patients with BAV requiring aortic valve replacement, 6.8% underwent TAVR. Unadjusted analysis demonstrated higher index hospitalization mortality for TAVR compared with SAVR. Upon risk adjustment using NRD-provided weights, the odds of pacemaker implantation remained significantly higher for TAVR patients compared with SAVR, with no significant difference in mortality. When NRD-provided survey weights were applied, TAVR had higher rates of 90-day readmission. Adjustment with inverse probability of treatment weights resolved these differences between the 2 groups. Regardless of the risk-adjustment method, the odds of reintervention were consistently higher among BAV TAVR patients compared with SAVR. CONCLUSIONS: The present analysis demonstrates comparable in-hospital mortality and morbidity for TAVR and SAVR patients in the moderate-risk era. With increasing TAVR use in BAV, surgeons must further refine selection criteria with consideration of concomitant aortopathy and implications of reintervention.

Volume-outcome relationship in septal myectomy for hypertrophic obstructive cardiomyopathy.

BACKGROUND: Septal myectomy is the gold standard treatment for refractory hypertrophic obstructive cardiomyopathy. The present study characterized the association of septal myectomy volume and cardiac surgery volume with outcomes after septal myectomy. METHODS: Adults undergoing septal myectomy for hypertrophic obstructive cardiomyopathy were identified in the 2016 to 2019 Nationwide Readmissions Database. Centers were grouped into low-, medium-, and high-volume hospitals by tertiles based on institutional septal myectomy caseload. Overall cardiac surgery volume was similarly assessed. Generalized linear models were used to test the association between hospital septal myectomy or cardiac surgery volume and in-hospital mortality, mitral valve repair, and 90-day non-elective readmission. RESULTS: Of 3,337 patients, 30.8% underwent septal myectomy at high-volume hospitals, whereas 39.1% were managed at low-volume hospitals. Patients at high-volume hospitals had a similar burden of comorbidities at low-volume hospitals, although congestive heart failure was more prevalent at high-volume hospitals. Despite comparable rates of mitral regurgitation, patients more commonly avoided mitral valve intervention at high-volume hospitals compared with low-volume hospitals (72.9% vs 68.3%; P = .007). After risk adjustment, high-volume hospital status was associated with reduced odds of mortality (0.24; 95% CI, 0.08-0.77) and readmission (0.59; 95% CI, 0.3-0.97). Among cases requiring mitral intervention, high-volume hospital status was associated with greater odds of valve repair (5.33; 95% CI, 2.54-11.13) relative to low-volume hospitals. Overall cardiac surgery volume was not associated with any studied outcome. CONCLUSION: Greater septal myectomy volume, but not overall cardiac surgery volume, was associated with reduced mortality and greater mitral valve repair relative to replacement after septal myectomy. These findings suggest that septal myectomy for hypertrophic obstructive cardiomyopathy should be performed at centers with expertise in this operation.

Regional Variation in the Use and Outcomes of Transcatheter Aortic Valve Replacement in California.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has been widely adopted for management of aortic stenosis. The purpose of this study was to examine regional access to and outcomes following TAVR in California. METHODS: Patients undergoing TAVR or isolated surgical aortic valve replacement (SAVR) from 2008 to 2019 in California were identified in the Office of Statewide Health Planning and Development database. California was divided into seven regions: Northern California, San Francisco Bay Area, Central California, Los Angeles, Inland Empire, Orange, and San Diego. Regional TAVR volumes were normalized to Medicare beneficiaries or isolated SAVR volume. Outcomes included risk-adjusted 30-day mortality and major adverse cardiovascular and cerebral events (MACCE). Trends were studied using non-parametric tests, and regional outcomes using logistic regression. RESULTS: TAVR volume increased annually since 2011, with 7148 cases performed in California in 2019. After normalization, variation in utilization of TAVR was evident, with the least performed in Central California. TAVR to SAVR ratios in 2019 were greatest in Northern California, Los Angeles, and San Diego, and least in the Inland Empire. After risk adjustment, there were no significant regional differences in 30-day mortality, but lower 30-day MACCE in the San Francisco Bay Area. CONCLUSIONS: Regional differences in TAVR utilization exist, with limited access in Central California and the Inland Empire, but risk-adjusted outcomes are similar. Efforts to reach underserved areas through existing program expansion or regional referrals may distribute transcatheter technology more equitably across California.

Left atrial appendage closure during cardiac surgery: Safe but underutilized in California.

Objective: Left atrial appendage (LAA) closure is associated with reduced rates of stroke in patients with atrial fibrillation (AF). We evaluated trends in LAA closure, the association of LAA closure with stroke/systemic embolism, and its safety profile in patients with AF who underwent cardiac surgery in California. We further tested for hospital-level variation in concomitant LAA closure. Methods: Adults who underwent coronary artery bypass grafting and/or valve surgery with preoperative AF were identified in the 2016 to 2019 Office of Statewide Health Planning and Development databases. Propensity score matching was performed to study risk-adjusted associations of LAA closure with ischemic stroke/systemic embolism. Hospital-level variation was studied using intraclass correlation coefficients. Results: Among 18,434 patients with AF who underwent coronary artery bypass grafting/valve surgery, 47.7% received LAA closure. Rates of LAA closure increased from 44.4% to 51.4% from 2016 to 2019 (P < .001). In 4652 propensity score-matched patients, LAA closure was associated with reduced incidence of stroke/systemic embolism at discharge (1.6% vs 3.1%; P < .001) and readmission with stroke/systemic embolism at 1 year (2.9% vs 4.5%; P = .004). LAA closure was not associated with acute kidney injury, pulmonary complications, blood transfusion, reoperation, or in-hospital mortality. Approximately 18% of the risk-adjusted variation in LAA use was attributed to the hospital, with median center-level rate of 44.9% (interquartile range, 29.6%-57.4%). Conclusions: LAA closure was associated with minimal surgical morbidity, and reduced short- and midterm incidence of stroke/systemic embolism. Although the use of LAA closure has increased, substantial variation exists among programs in California, suggesting the need for further standardization of care.