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.

Single versus double Perclose techniques for vascular closure during transfemoral transcatheter aortic valve replacement.

INTRODUCTION: The preferred approach for transcatheter aortic valve replacement (TAVR) is transfemoral. There has been widespread adoption of the Perclose ProglideTM device for vascular closure. Typically, two devices are deployed before upsizing the access sheath in the "preclose technique." Prior investigations have compared the use of a single device versus double device technique, but none have shown significant clinical benefit to either approach. METHODS: Five hundred and six patients underwent transfemoral TAVR (TF-TAVR) with single or double Perclose devices for vascular closure from July 2015 to February 2020. A retrospective review was conducted, and propensity-matched analyses were used to account for differences in baseline characteristics. RESULTS: In the matched analysis, there were 251 patients in the single Perclose group and 238 in the double. There was a statistically significant improvement in overall procedural success using the single closure device (94.6% vs. 88.5%, p = 0.009) This was defined as intraprocedural hemostatic control, lack of contrast extravasation, arterial dissection, occlusion, or stenosis >50% in the final crossover angiogram, as well as unimpaired limb perfusion without claudication throughout the index hospitalization. There was also a significant improvement in arterial dissection rates (0.6% vs. 4.6%, p = 0.004), stenosis >50% (1.3% vs. 4.4%, p = 0.028), and Valve Academic Research Consortium major vascular complications (1.8% vs. 4.9%, p = 0.038). CONCLUSION: A single Perclose device is a safe means of vascular closure during TF-TAVR and may have important clinical benefits compared to the commonly used two-device technique.

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.

Temporary Venoarterial Extracorporeal Membrane Oxygenation: Ten-Year Experience at a Cardiac Transplant Center.

OBJECTIVE: Advances in extracorporeal membrane oxygenation (ECMO) have enabled rapid deployment in a wide range of clinical settings. We report our experience with venoarterial (VA) ECMO in adult patients over 10 years and aim to identify predictors of mortality. DESIGN: This is a retrospective analysis of all adult patients undergoing VA ECMO at a tertiary care center from January 1, 2004, to December 31, 2013. RESULTS: A total of 224 consecutive cases were reviewed. Eighty (35.7%) patients survived to discharge and 144 (64.3%) patients died. Patients requiring ECMO for heart transplant graft failure had lower mortality (51.6%) compared to all other etiologies (69.1%; P = .02). Forty-two percent (94 of the 224) of the patients required cardiopulmonary resuscitation (CPR) preceding ECMO and had higher rate of in-hospital mortality (74.5%) compared with patients without cardiac arrest (56.9%; P = .01). Patients with less than 30 minutes of CPR had a mortality rate of 40.0% compared to 91.4% for CPR > 30 minutes ( P = .001). In all, 24.1% of patients (54 of the 224) experienced ECMO-associated complications without significant increase in mortality, and 22.3% (50 of the 224) of the patients were transitioned to ventricular assist devices (VADs) or transplant. Patients bridged to a VAD including left ventricular assist devices and biventricular assist devices had a mortality rate of 56.1% versus 22.2% when bridged directly to transplant ( P = .01). Paradoxically, patients with an ejection fraction (EF) > 35% had a higher mortality compared to patients with an EF < 35% (75.3% vs 49.4%, respectively, P = .001). CONCLUSION: Extracorporeal membrane oxygenation in patients with heart transplant graft failure had the best outcome. In patients who had cardiac arrest, prolonged CPR > 30 minutes was associated with very high mortality. Paradoxically, patients with EF > 35% had a higher mortality than patients with EF < 35%, likely reflecting patients with diastolic heart failure or noncardiac causes necessitating ECMO. For transplant candidates, direct bridge from ECMO to transplant could achieve a very good outcome.

Incidence of Cerebral Microemboli in Single-Dose vs. Multidose Cardioplegia in Adult Cardiac Surgery.

Cerebral microemboli have been associated with neurocognitive deficits after cardiac operations using cardiopulmonary bypass (CPB). Interventions by the perfusionist and alterations in blood flow account for a large proportion of previously unexplained microemboli. This study compared the incidence of microemboli during cardiac operations using conventional (multidose) and del Nido (single-dose) cardioplegia delivery. Transcranial Doppler ultrasonography was used to detect microemboli in bilateral middle cerebral arteries of 30 adult patients undergoing cardiac operations using CPB and aortic clamping. Multidose conventional blood cardioplegia (CBC) was used in 15 patients and single-dose del Nido cardioplegia (DNC) in 15. Manual count of microemboli during cross-clamp and during administration of cardioplegia was performed. Baseline preoperative characteristics were similar between groups. There were no differences in the ascending aortic atheroma grade (1.4 ± .4 CBC vs. 1.6 ± .7 DNC, p = .44), bypass times (141 ± 36 minutes CBC vs. 151 ± 33 minutes DNC, p = .64), and cross-clamp times (118 ± 32 minutes CBC vs. 119 ± 45 minutes DNC, p = .95). The use of multidose CBC was associated with a seven-fold increase in the number of microemboli per minute of bypass (1.65 ± 1 vs. .24 ± .18 emboli/min DNC, p = .0004). In this prospective pilot study, we found that the use of single-dose cardioplegia strategy led to fewer cerebral microemboli when compared with the traditional multidose approach. Our findings warrant further investigation of various cardioplegia strategies and neurologic outcomes in larger cohorts.

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.

Creation and Validation of an Automated Algorithm to Determine Postoperative Ventilator Requirements After Cardiac Surgery.

BACKGROUND: In medical practice today, clinical data registries have become a powerful tool for measuring and driving quality improvement, especially among multicenter projects. Registries face the known problem of trying to create dependable and clear metrics from electronic medical records data, which are typically scattered and often based on unreliable data sources. The Society for Thoracic Surgery (STS) is one such example, and it supports manually collected data by trained clinical staff in an effort to obtain the highest-fidelity data possible. As a possible alternative, our team designed an algorithm to test the feasibility of producing computer-derived data for the case of postoperative mechanical ventilation hours. In this article, we study and compare the accuracy of algorithm-derived mechanical ventilation data with manual data extraction. METHODS: We created a novel algorithm that is able to calculate mechanical ventilation duration for any postoperative patient using raw data from our EPIC electronic medical record. Utilizing nursing documentation of airway devices, documentation of lines, drains, and airways, and respiratory therapist ventilator settings, the algorithm produced results that were then validated against the STS registry. This enabled us to compare our algorithm results with data collected by human chart review. Any discrepancies were then resolved with manual calculation by a research team member. RESULTS: The STS registry contained a total of 439 University of California Los Angeles cardiac cases from April 1, 2013, to March 31, 2014. After excluding 201 patients for not remaining intubated, tracheostomy use, or for having 2 surgeries on the same day, 238 cases met inclusion criteria. Comparing the postoperative ventilation durations between the 2 data sources resulted in 158 (66%) ventilation durations agreeing within 1 hour, indicating a probable correct value for both sources. Among the discrepant cases, the algorithm yielded results that were exclusively correct in 75 (93.8%) cases, whereas the STS results were exclusively correct once (1.3%). The remaining 4 cases had inconclusive results after manual review because of a prolonged documentation gap between mechanical and spontaneous ventilation. In these cases, STS and algorithm results were different from one another but were both within the transition timespan. This yields an overall accuracy of 99.6% (95% confidence interval, 98.7%-100%) for the algorithm when compared with 68.5% (95% confidence interval, 62.6%-74.4%) for the STS data (P < .001). CONCLUSIONS: There is a significant appeal to having a computer algorithm capable of calculating metrics such as total ventilator times, especially because it is labor intensive and prone to human error. By incorporating 3 different sources into our algorithm and by using preprogrammed clinical judgment to overcome common errors with data entry, our results proved to be more comprehensive and more accurate, and they required a fraction of the computation time compared with manual review.

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.

Use of digital health kits to reduce readmission after cardiac surgery.

BACKGROUND: Unintended rehospitalizations after surgical procedures represent a large percentage of readmissions and have been associated with increased morbidity and cost of care. Beginning in 2017, Medicare will expand diagnostic categories subject to financial penalties for excess postoperative readmissions to include coronary revascularization procedures. Arrhythmias and pulmonary complications comprise the largest categories for readmission after cardiac surgery. Technologic advances in remote monitoring have led to the use of web-based digital health kits (DHK) aimed at reducing readmissions and improving postoperative outcomes. The present study was performed to determine the added benefit of incorporating DHK's into a formal readmissions reduction program (RRP) in preventing 30-d readmissions and to evaluate patient and provider satisfaction with the use of these devices. MATERIALS AND METHODS: This was a prospective study of all adult patients who underwent cardiac surgery at our institution from March 2014 to June 2015. During the study period, 443 adult patients (mean age, 65 ± 14, 33% female) were identified and participated in the formal RRP, 27 of whom also received a DHK after discharge (416 control group). In addition to providing a live video link to a provider specializing in cardiac surgery, the DHK also allowed for automatic daily transmission of weight, oxygen saturation, heart rate, and blood pressure. Patients also completed a daily health survey targeting symptoms concerning for heart failure, poor wound healing, poor ambulation, and nonadherence to medications. Abnormal vitals or survey responses triggered automatic notifications to the healthcare team. Satisfaction surveys were administered to participants and members of the healthcare team. Pearson χ(2) test and the Welch's t-test were used to assess statistical differences in baseline characteristics and outcome variables. RESULTS: During the study period, the readmission rate for the DHK and control groups were similar (7.4% versus 9.9%, P = 0.65). The use of DHKs led to 1649 alerts and 144 interventions, with the highest number of alerts occurring during d 5-9. The majority of alerts (64%) were prompted by abnormal biometric measurements, and a significant correlation was noted between abnormal biometrics and required intervention (r = 0.62, P < 0.001). No correlation was seen between alerts because of health survey responses (r = 0.07, P = 0.71) or missed check-ins (r = 0.06, P = 0.76) and required interventions. Poststudy satisfaction surveys showed an overall satisfaction rating of 4.9 ± 0.5 for DHK patients and 4.9 ± 0.2 for members of the care team (scale 1-5, 5 = agree). CONCLUSIONS: In our study, adding DHKs to a formal RRP was not associated with a significant decrease in 30-d readmission rates. We also found that notifications because of abnormal biometric measures were significantly correlated with required interventions. In contrast, notifications due to abnormal health survey responses were not associated with increased interventions. Both patients and members of the healthcare team were highly satisfied with this technology. DHKs appear to extend care beyond the inpatient period and provide a portal for telemonitoring of surgical patients. However, this modality is highly resource intensive and may not significantly reduce readmissions. Further studies are warranted to evaluate the efficacy of such kits in reducing readmissions and costs of care.

Impact of an Institutional Antimicrobial Stewardship Program on Bacteriology of Surgical Site Infections in Cardiac Surgery.

BACKGROUND: Surgical site infections (SSIs) occur in 1% to 4% of cardiac surgery patients and are associated with significantly reduced survival. The present study evaluated trends in the incidence and bacteriology of SSIs before and after the implementation of an antimicrobial stewardship program. METHODS: Starting in 2010, our institution utilized a protocol that included daily chlorhexidine baths, and strict cessation of prophylactic antibiotics after 48 hours. We used our institutional Society of Thoracic Surgery Database to identify all adult patients who underwent cardiac operations. Data from the microbiology laboratory were used to identify SSIs. Patients undergoing cardiac surgery between January 2008 and December 2010 (pre-stewardship group: PRE) and January 2011 and December 2012 (post-stewardship group: POST) were compared. RESULTS: Of the 3233 patients who underwent cardiac surgery during the study period, 23 (0.71%) developed SSIs (PRE: 0.69%, POST: 0.75%, p = 0.843). The proportion of gram positive, gram negative, fungal, and anaerobic organisms was not significantly different between time periods. The most commonly identified organisms were Staphylococcus aureus, Enterococcus spp., and Pseudomonas aeruginosa. CONCLUSION: Despite changes in antibiotic prophylaxis duration and postoperative skin treatment, our data demonstrate a stable incidence and composition of surgical wound infections during the study period. doi: 10.1111/jocs.12756 (J Card Surg 2016;31:367-372).

Predicting postoperative atrial fibrillation using CHA2DS2-VASc scores.

BACKGROUND: Postoperative atrial fibrillation (POAF) is the most frequent complication of cardiac surgery and is associated with increased morbidity and mortality. Pharmacologic prophylaxis is the main method of preventing POAF but needs to be targeted to patients at high risk of developing POAF. The CHA2DS2-VASc scoring system is a clinical guideline for assessing ischemic stroke risk in patients with atrial fibrillation. The present study evaluated the utility of this scoring system in predicting the risk of developing de novo POAF in cardiac surgery patients. MATERIALS AND METHODS: A total of 2385 patients undergoing cardiac surgery at our institution from 2008-2014 were identified for analysis. Each patient was assigned a CHA2DS2-VASc score and placed into a low- (score of 0), intermediate- (1), or high-risk (≥2) group. A multivariate regression model was created to control for known risk factors of atrial fibrillation. RESULTS: POAF occurred in 380 of 2385 patients (15.9%). Mean CHA2DS2-VASc scores among patients with POAF and without POAF were 3.6 ± 1.7 and 2.8 ± 1.7, respectively (P < 0.0001). Using multivariate analysis, as a patient's CHA2DS2-VASc score rose from 0-9, the risk of developing POAF increased from 8.2%-42.3%. Each point increase was associated with higher odds of developing POAF (adjusted odds ratio, 1.27; 95% confidence interval, 1.18-1.36, P < 0.0001). Compared with low-risk patients, patients in the high-risk group were 5.21 times more likely to develop POAF (P < 0.0001). CONCLUSIONS: The CHA2DS2-VASc algorithm is a simple risk-stratification tool that could be used to direct pharmacologic prophylaxis toward patients most likely to experience POAF.

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.