The Society of Thoracic Surgeons National Cardiac Surgery Database: current risk assessment

Validation of the GERAADA score to predict 30-day mortality in acute type A aortic dissection in a single high-volume aortic centre

OBJECTIVES

This study aimed to evaluate employing the German Registry of Acute Aortic Dissection Type A (GERAADA) score to predict 30-day mortality in an aortic centre in the USA.

METHODS

Between January 2010 and June 2021, 689 consecutive patients underwent surgery for acute type A dissection at a single institution. Excluded were patients with missing clinical data (N = 4). The GERAADA risk score was retrospectively calculated via a web-based application. Model discrimination power was calculated with c-statistics from logistic regression and reported as the area under the receiver operating characteristic curve with 95% confidence intervals. The calibration was measured by calculating the observed versus estimated mortality ratio. The Brier score was used for the overall model evaluation.

RESULTS

Included were 685 patients [mean age 60.6 years (SD: 13.5), 64.8% male] who underwent surgery for acute type A aortic dissection. The 30-day mortality rate was 12.0%. The GERAADA score demonstrated very good discrimination power with an area under the receiver operating characteristic curve of 0.762 (95% confidence interval 0.703-0.821). The entire cohort's observed versus estimated mortality ratio was 0.543 (0.439-0.648), indicating an overestimation of the model-calculated risk. The Brier score was 0.010, thus revealing the model's acceptable overall performance.

CONCLUSIONS

The GERAADA score is a practical and easily accessible tool for reliably estimating the 30-day mortality risk of patients undergoing surgery for acute type A aortic dissection. This model may naturally overestimate risk in patients undergoing surgery in experienced aortic centres.

A Novel Score to Predict One-Year Mortality after Transcatheter Aortic Valve Replacement, Naples Prognostic Score

Background and Objectives: Aortic stenosis (AS) is a widespread valvular disease in developed countries, primarily among the elderly. Transcatheter aortic valve replacement (TAVR) has become a viable alternative to aortic valve surgery for patients with severe AS who are deemed a high surgical risk or for whom the AS is found to be inoperable. Predicting outcomes after TAVR is essential. The Naples Prognostic Score (NPS) is a new scoring method that evaluates nutritional status and inflammation. Our study is aims to examine the relationship between the NPS and outcomes for patients receiving TAVR. Material and Methods: We conducted a retrospective study of 370 patients who underwent TAVR across three tertiary medical centres from March 2019 to March 2023. The patients were divided into two groups based on their NPS, namely, low (0, 1, and 2) and high (3 and 4). Our study is primarily aimed to determine the one-year mortality rate. Results: Within one year, the mortality rate for the entire group was 8.6%. Nonetheless, the low-NPS group had a rate of 5.0%, whereas the high-NPS group had a rate of 13%. The difference between the two groups was statistically significant, with a p-value of 0.06. Conclusions: Our results show that NPS is an independent predictor of one-year mortality in patients undergoing TAVR.

Prediction Nomogram for Postoperative 30-Day Mortality in Acute Type A Aortic Dissection Patients Receiving Total Aortic Arch Replacement With Frozen Elephant Trunk Technique

Objective

To develop and validate a nomogram model to predict postoperative 30-day mortality in acute type A aortic dissection patients receiving total aortic arch replacement with frozen elephant trunk technique.

Method

Clinical data on 1,156 consecutive acute type A aortic dissection patients who got total aortic arch replacement using the frozen elephant trunk technique was collected from January 2010 to December 2020. These patients were divided into training and testing cohorts at random with a ratio of 7:3. To predict postoperative 30-day mortality, a nomogram was established in the training set using the logistic regression model. The novel nomogram was then validated in the testing set. The nomogram's calibration and discrimination were evaluated. In addition, we created four machine learning prediction models in the training set. In terms of calibration and discrimination, the nomogram was compared to these machine learning models in testing set.

Results

Left ventricular end-diastolic diameter <45 mm, estimated glomerular filtration rate <50 ml/min/1.73 m², persistent abdominal pain, radiological celiac trunk malperfusion, concomitant coronary artery bypass grafting and cardiopulmonary bypass time >4 h were independent predictors of the 30-day mortality. The nomogram based on these 6 predictors manifested satisfying calibration and discrimination. In testing set, the nomogram outperformed the other 4 machine learning models.

Conclusion

The novel nomogram is a simple and effective tool to predict 30-day mortality rate for acute type A aortic dissection patients undergoing total aortic arch replacement with frozen elephant trunk technique.

A Novel Risk Scoring Tool to Predict Saphenous Vein Graft Occlusion After Cardiac Artery Bypass Graft Surgery

Objectives: Coronary artery bypass grafting (CABG) success is reduced by graft occlusion. Understanding factors associated with graft occlusion may improve patient outcomes. The aim of this study was to develop a predictive risk score for saphenous vein graft (SVG) occlusion after CABG.

Methods: This retrospective cohort study enrolled 3,716 CABG patients from January 2012 to March 2013. The development cohort included 2,477 patients and the validation cohort included 1,239 patients. The baseline clinical data at index CABG was analyzed for their independent impact on graft occlusion in our study using Cox proportional hazards regression. The predictive risk scoring tool was weighted by beta coefficients from the final model. Concordance (c)-statistics and comparison of the predicted and observed probabilities of predicted risk were used for discrimination and calibration.

Results: A total of 959 (25.8%) out of 3,716 patients developed at least one late SVG occlusion. Significant risk factors for occlusion were female sex [beta coefficients (β) = 0.52], diabetes (β = 0.21), smoking (currently) (β = 0.32), hyperuricemia (β = 0.22), dyslipidemia (β = 0.52), prior percutaneous coronary intervention (PCI) (β = 0.21), a rising number of SVG (β = 0.12) and lesion vessels (β = 0.45). On-pump surgery (β = −0.46) and the use of angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) (β = −0.59) and calcium channel blockers (CCB) (β = −0.23) were protective factors. The risk scoring tool with 11 variables was developed from the derivation cohort, which delineated each patient into risk quartiles. The c-statistic for this model was 0.71 in the validation cohort.

Conclusions: An easy-to-use risk scoring tool which included female sex, diabetes, smoking, hyperuricemia, dyslipidemia, prior PCI, a rising number of SVG and lesion vessels, on-pump surgery, the use of ACEI/ ARB and CCB was developed and validated. The scoring tool accurately estimated the risk of late SVG occlusion after CABG (c-statistic = 0.71).

Perioperative ADministration of Dexamethasone And blood Glucose concentrations in patients undergoing elective non-cardiac surgery - the randomised controlled PADDAG trial

BACKGROUND

The hyperglycaemic effect of dexamethasone in diabetic and nondiabetic patients in the peri-operative period is unknown.

OBJECTIVE

To assess the effect of a single dose of intra-operative dexamethasone on peri-operative blood glucose.

DESIGN

Multicentre, stratified, randomised trial.

SETTING

University hospitals in Australia and Hong Kong.

PATIENTS

A total of 302 adults scheduled for elective, noncardiac and nonobstetric surgical procedures under general anaesthesia, stratified by diabetes mellitus status, were randomised to receive placebo, 4 or 8 mg dexamethasone administered intravenously after induction of anaesthesia.

MAIN OUTCOME MEASURES

Maximum blood glucose within 24 h of surgery, and the interaction between glycated haemoglobin (HbA1c) and dexamethasone were the primary and secondary outcomes.

RESULTS

The median [IQR] baseline blood glucose in the nondiabetes stratum in the placebo (n=81), 4 mg (n=81) and 8 mg dexamethasone (n=77) trial arms were respectively 5.3 [4.6 to 5.8], 5.0 [4.7 to 5.4] and 5.0 [4.2 to 5.9] mmol l-1. In the diabetes stratum these values were 6.6 [6.0 to 8.3]; (n=22), 6.1 [5.5 to 10.4]; (n=22) and 6.7 [5.6 to 8.3]; (n=19) mmol l-1. The median [IQR] maximum peri-operative blood glucose values in the nondiabetes stratum were 6.0 [5.3 to 6.8], 6.3 [5.5 to 7.3] and 6.3 [5.8 to 7.4] mmol l-1 in the control, dexamethasone 4 mg and dexamethasone 8 mg arms, respectively. In the diabetes stratum these values were 10.3 [8.1 to 12.4], 12.6 [10.3 to 18.3] and 13.6 [11.2 to 20.1] mmol l-1. There was a significant interaction between pre-operative HbA1c value and 8 mg dexamethasone: every 1% increment in HbA1c produced a 4.0 mmol l-1 elevation in maximal peri-operative glucose concentration.

CONCLUSION

Dexamethasone 4 mg or 8 mg did not induce greater hyperglycaemia compared with placebo for nondiabetic and well controlled diabetic patients. Maximal peri-operative blood glucose concentrations in patients with diabetes were related to baseline HbA1c values in a concentration-dependent fashion after 8 mg of dexamethasone.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Registry (ACTRN12614001145695): URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=367272.

Trends in sex-based differences in outcomes following coronary artery bypass grafting in the United States between 2004 and 2015

BACKGROUND

The present study sought to examine the trends of sex-based differences in clinical outcomes after coronary artery bypass grafting (CABG), an area in which the current evidence remains limited.

METHODS

All US adults hospitalized for first-time isolated CABG in the National Inpatient Sample database between 2004 and 2015 were included, stratified by sex. Multivariable regression analysis examined the adjusted odds ratios (OR) of postoperative in-hospital complications in females versus males. Trend analyses of sex-based differences in in-hospital post-operative complications over the study period were performed.

RESULTS

Overall, 2,537,767 CABG procedures were analyzed, including 27.9% (n = 708,459) females. Female sex was associated with an increase in adjusted odds of all-cause mortality (OR 1.43 95% CI 1.40, 1.45), stroke (OR 1.34 95% CI 1.32, 1.37) and thoracic complications (OR 1.28 95% CI 1.27, 1.29) and lower odds of all-cause bleeding (OR 0.87 95% CI 0.86, 0.89) compared to males. Trend analysis revealed these sex differences to be persistent for mortality, stroke and thoracic complications (p_trend = non-significant) but eliminated for bleeding over the study period (p_trend < 0.001).

CONCLUSION

Despite technical advances over the 12-year period, worse post-operative outcomes including death, stroke, and thoracic complications have persisted in female patients after CABG. These findings are concerning and underscore the need for risk reduction strategies to address this disparity gap.

United States national trends in comorbidity and outcomes of adult cardiac surgery patients

BACKGROUND

Comorbidity profiles of cardiac surgery patients are known to have changed over time, but modern national trends in these comorbidities and outcomes are not described. This study describes comorbidity trends over time for common adult cardiac surgery procedures.

METHODS

A retrospective, cross-sectional analysis of the National Inpatient Sample was conducted for years 2005-2014. Hospitalizations with coronary artery bypass grafting (CABG), aortic valve replacement (AVR), and mitral valve repair/replacement (MVRR), as well as combined CABG/valve operations, were identified by ICD-9 procedure codes. Comorbidities were defined based on ICD-9 codes to discriminate between comorbidities and complications. Surgical volume, patient age, in-hospital mortality, and length of stay trends over time were evaluated by linear regression.

RESULTS

Incidence increased for AVR, MVRR, and CABG + AVR and declined for CABG and CABG + MVRR (P < .001). The mean number of comorbidities across all surgeries increased from 1.4 to 1.9 (P < .001). Length of stay declined for AVR, CABG + AVR, and CABG + MVRR (P < .001) with an overall decline from 10.1 to 9.7 days (P = .003). In-hospital mortality decreased in all categories over time (P < .001). Overall, in-hospital mortality decreased from 2.9% to 2.3% (P < .001).

CONCLUSIONS

Despite increasing comorbidity in cardiac surgery, operations are being conducted with fewer in-hospital mortalities across all types of surgery and decreasing length of stay for most types of surgery, which should inform the frequency of risk model updates and raise questions of the applicability of earlier studies in cardiac surgery to the modern population.

Risk Stratification for Transcatheter Aortic Valve Replacement

Risk assessment models developed from administrative and clinical databases are used for clinical decision making. Since these models are derived from a database, they have an inherent limitation of being as good as the data they are derived from. Many of these models under or overestimate certain clinical outcomes particularly mortality in certain group of patients. Undeniably, there is significant variability in all these models on account of patient population studied, the statistical analysis used to develop the model and the period during which these models were developed. This review aims to shed light on development and application of risk assessment models for cardiac surgery with special emphasis on risk stratification in severe aortic stenosis to select patients for transcatheter aortic valve replacement.

Lupus and Left Ventricular Assist Devices: High-Risk for Bleeding?

Continuous-flow left ventricular assist devices (LVAD) have become an increasingly utilized treatment strategy for patients with end-stage heart failure. Despite the improved outcomes evident with current generation pumps, proper patient selection remains crucial to minimize the risk of potential adverse events. The evolving use of these devices as destination therapy (DT) has led to growing numbers of patients with higher risk comorbid conditions being evaluated as potential LVAD candidates. Understanding which patient and disease-specific characteristics increase postoperative morbidity and mortality is paramount as this technology continues to expand and the experience with select populations remains limited. Presented here is a case of a patient with systemic lupus erythematosus receiving a HeartWare LVAD as DT complicated by recurrent, diffuse spontaneous bleeding. The case presented here highlights a potential unique bleeding complication in a high-risk patient cohort and underscores the need to enhance our understanding of factors influencing outcomes in high-risk populations after LVAD therapy.

Practical laboratory-based clinical decision tools and associations with short-term bleeding and mortality outcomes

BACKGROUND

The red cell distribution width (RDW) predicts mortality in numerous populations. The Intermountain Risk Scores (IMRS) predict patient outcomes using laboratory measurements including RDW. Whether the RDW or IMRS predicts in-hospital outcomes is unknown.

METHODS

The predictive abilities of RDW and two IMRS formulations (the complete blood count [CBC] risk score [CBC-RS] or full IMRS using CBC plus the basic metabolic profile) were studied among percutaneous coronary intervention patients at Intermountain (males: N = 6007, females: N = 2165). Primary endpoints were a composite bleeding outcome and in-hospital mortality.

RESULTS

IMRS predicted the composite bleeding endpoint (females: χ² = 47.1, odds ratio [OR] = 1.13 per +1 score, p < 0.001; males: χ² = 108.7, OR = 1.13 per +1 score, p < 0.001) more strongly than RDW (females: χ² = 1.6, OR = 1.04 per +1%, p = 0.20; males: χ² = 11.2, OR = 1.09 per +1%, p < 0.001). For in-hospital mortality, RDW was predictive in females (χ² = 4.3, OR = 1.13 per +1%, p = 0.037) and males (χ² = 4.4, OR = 1.11 per +1%, p = 0.037), but IMRS was profoundly more predictive (females: χ² = 35.5, OR = 1.36 per +1 score, p < 0.001; males: χ² = 72.9, OR = 1.40 per+1 score, p < 0.001). CBC-RS was more predictive than RDW but not as powerful as IMRS.

CONCLUSIONS

The IMRS, the CBC-RS, and RDW predict in-hospital outcomes. Risk score-directed personalization of in-hospital clinical care should be studied.

Validation of SinoSCORE for isolated CABG operation in East China

From January 2010 to December 2016, 1616 consecutive patients who underwent isolated coronary artery bypass grafting (CABG) were evaluated for their predicted mortality according to the online Sino System for Coronary Operative Risk Evaluation (SinoSCORE), European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) and Society of Thoracic Surgeons (STS) risk evaluation system. The calibration and discrimination in the total and in the subsets were assessed by the Hosmer-Lemeshow (H-L) statistics and by the C statistics respectively, to evaluate the efficiency of the three risk evaluation systems. The realized mortality was 1.92% (31/1616). The predictive mortality of SinoSCORE, EuroSCORE II and STS risk evaluation system were 1.35%, 1.74% and 1.05%, respectively. SinoSCORE achieved best discrimination. When grouping by risk, SinoSCORE also achieved the best discrimination in high-risk group, followed by STS risk evaluation system and EuroSCORE II while SinoSCORE and EuroSCORE II had excellent performance in low-risk group. In terms of calibration, SinoSCORE, EuroSCORE II and STS risk evaluation system all achieved positive calibrations (H-L: P > 0.05) in the overall population and grouped subsets. SinoSCORE achieved good predictive efficiency in East China patients undergoing isolated CABG and showed no compromise when compared with EuroSCORE II and STS risk evaluation system.

Impact of Accurate 30-Day Status on Operative Mortality: Wanted Dead or Alive, Not Unknown

BACKGROUND

Risk-adjusted operative mortality is the most important quality metric in cardiac surgery for determining The Society of Thoracic Surgeons (STS) Composite Score for star ratings. Accurate 30-day status is required to determine STS operative mortality. The goal of this study was to determine the effect of unknown or missing 30-day status on risk-adjusted operative mortality in a regional STS Adult Cardiac Surgery Database cooperative and demonstrate the ability to correct these deficiencies by matching with an administrative database.

METHODS

STS Adult Cardiac Surgery Database data were submitted by 27 hospitals from five hospital systems to the Texas Quality Initiative (TQI), a regional quality collaborative. TQI data were matched with a regional hospital claims database to resolve unknown 30-day status. The risk-adjusted operative mortality observed-to-expected (O/E) ratio was determined before and after matching to determine the effect of unknown status on the operative mortality O/E.

RESULTS

TQI found an excessive (22%) unknown 30-day status for STS isolated coronary artery bypass grafting cases. Matching the TQI data to the administrative claims database reduced the unknowns to 7%. The STS process of imputing unknown 30-day status as alive underestimates the true operative mortality O/E (1.27 before vs 1.30 after match), while excluding unknowns overestimates the operative mortality O/E (1.57 before vs 1.37 after match) for isolated coronary artery bypass grafting.

CONCLUSIONS

The current STS algorithm of imputing unknown 30-day status as alive and a strategy of excluding cases with unknown 30-day status both result in erroneous calculation of operative mortality and operative mortality O/E. However, external validation by matching with an administrative database can improve the accuracy of clinical databases such as the STS Adult Cardiac Surgery Database.

Analyzing a Lung Cancer Patient Dataset with the Focus on Predicting Survival Rate One Year after Thoracic Surgery

Background: Data mining, a new concept introduced in the mid-1990s, can help researchers to gain new, profound insights and facilitate access to unanticipated knowledge sources in biomedical datasets. Many issues in the medical field are concerned with the diagnosis of diseases based on tests conducted on individuals at risk. Early diagnosis and treatment can provide a better outcome regarding the survival of lung cancer patients. Researchers can use data mining techniques to create effective diagnostic models. The aim of this study was to evaluate patterns existing in risk factor data of for mortality one year after thoracic surgery for lung cancer. Methods: The dataset used in this study contained 470 records and 17 features. First, the most important variables involved in the incidence of lung cancer were extracted using knowledge discovery and datamining algorithms such as naive Bayes, maximum expectation and then, using a regression analysis algorithm, a questionnaire was developed to predict the risk of death one year after lung surgery. Outliers in the data were excluded and reported using the clustering algorithm. Finally, a calculator was designed to estimate the risk for one-year post-operative mortality based on a scorecard algorithm. Results: The results revealed the most important factor involved in increased mortality to be large tumor size. Roles for type II diabetes and preoperative dyspnea in lower survival were also identified. The greatest commonality in classification of patients was Forced expiratory volume in first second (FEV1), based on levels of which patients could be classified into different categories. Conclusion: Development of a questionnaire based on calculations to diagnose disease can be used to identify and fill knowledge gaps in clinical practice guidelines.

The Impact of Robotic Versus Conventional Coronary Artery Bypass Grafting on In-Hospital Narcotic Use: A Propensity-Matched Analysis

OBJECTIVE

The aim of this study was to compare narcotic use in the perioperative hospital stay as a measure of pain in patients undergoing robotic versus conventional coronary artery bypass grafting (CABG).

METHODS

Propensity score matching of patients undergoing robotically assisted CABG and conventional CABG over a period of 5 years was performed. A retrospective chart review was performed to identify the total amount of narcotics used by both groups calculated as morphine equivalent dosing (MED).

RESULTS

From 2007 to 2012, 154 patients underwent robotic CABG, and 1660 underwent conventional CABG. Propensity matching resulted in 142 patients in each group. Patients undergoing robotic CABG received less blood transfusion, were more frequently extubated in the operating room, and had a shorter length of stay. The robotic group had a lower MED than the conventional group as defined by the primary end point [181 (11) vs 251 (8)]. If intraoperative narcotic use was eliminated, there was no difference in MED from postoperative days 0 to 3.

CONCLUSIONS

Patients undergoing robotic CABG use fewer narcotics over the first three hospital days than patients undergoing conventional CABG. The surrogate of narcotics use for postoperative pain shows that the minithoracotomy of robotic CABG may result in either less or equivalent pain than the sternotomy of conventional CABG.

Safety of Perioperative Glucocorticoids in Elective Noncardiac Surgery

Background

Glucocorticoids are increasingly used perioperatively, principally to prevent nausea and vomiting. Safety concerns focus on the potential for hyperglycemia and increased infection. The authors hypothesized that glucocorticoids predispose to such adverse outcomes in a dose-dependent fashion after elective noncardiac surgery.

Methods

The authors conducted a systematic literature search of the major medical databases from their inception to April 2016. Randomized glucocorticoid trials in adults specifically reporting on a safety outcome were included and meta-analyzed with Peto odds ratio method or the quality effects model. Subanalyses were performed according to a dexamethasone dose equivalent of low (less than 8 mg), medium (8 to 16 mg), and high (more than 16 mg). The primary endpoints of any wound infection and peak perioperative glucose concentrations were subject to meta-regression.

Results

Fifty-six trials from 18 countries were identified, predominantly assessing dexamethasone. Glucocorticoids did not impact on any wound infection (odds ratio, 0.8; 95% CI, 0.6 to 1.2) but did result in a clinically unimportant increase in peak perioperative glucose concentration (weighted mean difference, 20.0 mg/dl; CI, 11.4 to 28.6; P &lt; 0.001 or 1.1 mM; CI, 0.6 to 1.6). Glucocorticoids reduced peak postoperative C-reactive protein concentrations (weighted mean difference, −22.1 mg/l; CI, −31.7 to −12.5; P &lt; 0.001), but other adverse outcomes and length of stay were unchanged. No dose–effect relationships were apparent.

Conclusions

The evidence at present does not highlight any safety concerns with respect to the use of perioperative glucocorticoids and subsequent infection, hyperglycemia, or other adverse outcomes. Nevertheless, collated trials lacked sufficient surveillance and power to detect clinically important differences in complications such as wound infection.

Improvement in the predictive ability of the Intermountain Mortality Risk Score by adding routinely collected laboratory tests such as albumin, bilirubin, and white cell differential count

Background:

The Intermountain Mortality Risk Score (IMRS), a sex-specific mortality-prediction metric, has proven to be effective in various populations. IMRS is comprised of the complete blood count (CBC), basic metabolic panel (BMP), and age. Whether the addition of factors from the comprehensive metabolic panel (CMP) and white blood cell (WBC) differential count improves risk stratification is unknown.

Methods:

Patients with baseline complete metabolic panel (CMP) and IMRS measurements were randomly assigned (60%/40%) to independent derivation (n=84,913) and validation (n=56,584) populations. A sex-specific risk score based on IMRS methods was computed in the derivation population using adjusted multivariable regression weights from all significant and noncollinear CMP [expanded IMRS (eIMRS)] and, when available, WBC differential components (eIMRS+diff).

Results:

Age averaged 67±16 years for females and 67±15 years for males. Receiver operator characteristic (ROC) c-statistics for 30-day death showed marked improvement for the eIMRS compared to the IMRS in both females [0.895 (0.882, 0.908) vs. 0.865 (0.850, 0.880)] and males [0.861 (0.847, 0.876) vs. 0.824 (0.807, 0.841)]. These results persisted for 1-year death: females [0.854 (0.847, 0.862) vs. 0.828 (0.819, 0.836)] and males [0.835 (0.826, 0.844) vs. 0.796 (0.789, 0.808)]. In addition, the eIMRS significantly improved risk reclassification. Further precision was seen when WBC differential components were included.

Conclusions:

The addition of the CMP components to the IMRS improved risk prediction. WBC differential also improved risk score predictive ability. These results suggest that the eIMRS may function even better than IMRS as a tool in patient care, risk-adjustment, and clinical research settings for predicting outcomes.

Hyperglycemia and Acute Kidney Injury During the Perioperative Period

Hyperglycemia and acute kidney injury (AKI) are frequently observed during the perioperative period. Substantial evidence indicates that hyperglycemia increases the prevalence of AKI as a surgical complication. Patients who develop hyperglycemia and AKI during the perioperative period are at significantly elevated risk for poor outcomes such as major adverse cardiac events and all-cause mortality. Early observational and interventional trials demonstrated that the use of intensive insulin therapy to achieve strict glycemic control resulted in remarkable reductions of AKI in surgical populations. However, more recent interventional trials and meta-analyses have produced contradictory evidence questioning the renal benefits of strict glycemic control. Although the exact mechanisms through which hyperglycemia increases the risk of AKI have not been elucidated, multiple pathophysiologic pathways have been proposed. Hypoglycemia and glycemic variability may also play a significant role in the development of AKI. In this literature review, the complex relationship between hyperglycemia and AKI as well as its impact on clinical outcomes during the perioperative period is explored.

Comparison of Index Hospitalization Costs Between Robotic CABG and Conventional CABG: Implications for Hybrid Coronary Revascularization

OBJECTIVES

To compare the direct costs of the index hospitalization and 30-day morbidity and mortality incurred during robotic and conventional coronary artery bypass grafting at a single institution based on hospital clinical and financial records.

DESIGN

Retrospective study, propensity-matched groups with one-to-one nearest neighbor matching.

SETTING

University hospital, a tertiary care center.

PARTICIPANTS

Two thousand eighty-eight consecutive patients who underwent primary coronary artery bypass grafting (CABG) from January 2007 to March 2012.

INTERVENTIONS

One hundred forty-one matched pairs were created and analyzed.

MEASUREMENTS AND MAIN RESULTS

Robotic CABG was associated with a decrease in operative time (5.61±1.1 v 6.6±1.15 hours, p<0.001), a lower need for blood transfusion (12.8% v 22.6%, p = 0.04), a shorter length of stay (6 [4-9]) v 7 [5-11] days, p = 0.001), a shorter ICU stay (31 [24-49] hours v 52 [32-96.5] hours, p<0.001) and lower NY state complications composite rate (4.26% v 13.48%, p = 0.01). In spite of that, the cost of robotic procedures was not significantly different from matched conventional cases ($18,717.35 [11,316.1-34,550.6] versus $18,601 [13,137-50,194.75], p = 0.13), except 26 hybrid coronary revascularizations in which angioplasty was performed on the same admission (hybrid 25,311.1 [18,537.1-41,167.85] versus conventional 18,966.13 [13,337.75-56,021.75], p = 0.02).

CONCLUSION

Robotically assisted CABG does not increase the cost of the index hospitalization when compared to conventional CABG unless hybrid revascularization is performed on the same admission.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: The Driving Force for Improvement in Cardiac Surgery

Initiated in 1989, the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) includes more than 1085 participating centers, representing 90%-95% of current US-based adult cardiac surgery hospitals. Since its inception, the primary goal of the STS ACSD has been to use clinical data to track and improve cardiac surgical outcomes. Patients' preoperative risk characteristics, procedure-related processes of care, and clinical outcomes data have been captured and analyzed, with timely risk-adjusted feedback reports to participating providers. In 2006, STS initiated an external audit process to evaluate STS ACSD completeness and accuracy. Given the extremely high inter-rater reliability and completeness rates of STS ACSD, it is widely regarded as the "gold standard" for benchmarking cardiac surgery risk-adjusted outcomes. Over time, STS ACSD has expanded its quality horizons beyond the traditional focus on isolated, risk-adjusted short-term outcomes such as perioperative morbidity and mortality. New quality indicators have evolved including composite measures of key processes of care and outcomes (risk-adjusted morbidity and risk-adjusted mortality), longer-term outcomes, and readmissions. Resource use and patient-reported outcomes would be added in the future. These additional metrics provide a more comprehensive perspective on quality as well as additional end points. Widespread acceptance and use of STS ACSD has led to a cultural transformation within cardiac surgery by providing nationally benchmarked data for internal quality assessment, aiding data-driven quality improvement activities, serving as the basis for a voluntary public reporting program, advancing cardiac surgery care through STS ACSD-based research, and facilitating data-driven informed consent dialogues and alternative treatment-related discussions.

Robotic coronary artery bypass grafting decreases 30-day complication rate, length of stay, and acute care facility discharge rate compared with conventional surgery

OBJECTIVE

The objective of this study was to compare the short-term outcomes of robotic with conventional on-pump coronary artery bypass grafting (CABG).

METHODS

The study population included 2091 consecutive patients who underwent either conventional or robotic CABG from January 2007 to March 2012. Preoperative, intraoperative, and 30-day postoperative variables were collected for each group. To compare the incidence of rapid recovery between conventional and robotic CABG, the surrogate variables of early discharge and discharge to home (vs rehabilitation or acute care facility) were evaluated. A multivariate logistic regression analysis was used.

RESULTS

One hundred fifty robotic and 1619 conventional CABG cases were analyzed. Multivariate logistic regression analysis demonstrated that robotic surgery was a strong predictor of lower 30-day complications [odds ratio (OR), 0.24; P = 0.005], short length of stay (OR, 3.31; P < 0.001), and decreased need for an acute care facility (OR, 0.55; P = 0.032). In the presence of complications (New York State Complication Composite), the robotic technique was not associated with a change in discharge status.

CONCLUSIONS

In this retrospective review, robotic CABG was associated with a lower 30-day complication rate, a shorter length of stay, and a lower incidence of acute care facility discharge than conventional on-pump CABG. It may suggest a more rapid recovery to preoperative status after robotic surgery; however, only a randomized prospective study could confirm the advantages of a robotic approach.

The impact of high-risk cases on hospitals' risk-adjusted coronary artery bypass grafting mortality rankings

BACKGROUND

Risk-adjusted mortality (RAM) models are increasingly used to evaluate hospital performance, but the validity of the RAM method has been questioned. Providers are concerned that these methods might not adequately account for the highest levels of risk and that treating high-risk cases will have a negative impact on RAM rankings.

METHODS

Using cases of isolated coronary artery bypass grafting (CABG) performed at 1002 sites in the United States participating in The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database from 2008 to 2010 (N = 494,955), the STS CABG RAM model performance in high-risk patients was assessed. The ratios of observed to expected (O/E) perioperative mortality were compared among groups of hospitals with varying expected risks. Finally, RAM rates during the overall study period for each site were compared with its performance in a simulated "nightmare year" in which the site's highest risk cases over a 3-year period were concentrated into a 1-year period of exceptional risk.

RESULTS

The average predicted mortality for center risk groups ranged from 1.46% for the lowest risk quintile to 2.87% for the highest. The O/E ratios for center risk quintiles 1 to 5 during the overall period were 1.01 (95% confidence interval, 0.96% to 1.06%), 1.00 (0.95% to 1.04%), 0.98 (0.94% to 1.03%), 0.97 (0.93% to 1.01%), and 0.80 (0.77% to 0.84%), respectively. The sites' risk-adjusted mortality rates were not increased when the centers' highest risk cases were concentrated into a single "nightmare year."

CONCLUSIONS

Our results show that the current risk-adjusted models accurately estimate CABG mortality and that hospitals accepting more high-risk CABG patients have equal or better outcomes than do those with predominately lower-risk patients.

Pharmacotherapy for Hyperglycemia in Noncritically Ill Hospitalized Patients

In Brief Hyperglycemia in the hospital setting affects 38-46% of noncritically ill hospitalized patients. Evidence from observational studies indicates that inpatient hyperglycemia, in patients with and without diabetes, is associated with increased risks of complications and mortality. Substantial evidence indicates that correction of hyperglycemia through insulin administration reduces hospital complications and mortality in critically ill patients, as well as in general medicine and surgery patients. This article provides a review of the evidence on the different therapies available for hyperglycemia management in noncritically ill hospitalized patients.

Bilateral internal thoracic artery use in patients with low ejection fraction: is there any additional long-term benefit?

OBJECTIVES

The use of bilateral internal thoracic arteries (BITA) has been associated with improved long-term outcomes following coronary artery bypass graft (CABG) surgery. The objective of this study was to evaluate the impact of BITA use on long-term survival among patients with low ejection fraction (EF) undergoing CABG.

METHODS

Between April 1991 and October 2011, 2035 consecutive patients underwent primary BITA grafting. Among them, there were 129 patients with left ventricular EF ≤40%. During the same time period, 1666 primary CABGs were performed using a single internal thoracic artery (SITA) in patients with EF ≤40%. A propensity score optimal matching algorithm was used to create the matched SITA and BITA groups (n = 111 in each group). Also, Cox regression multivariable analyses were performed to determine the independent risk factors for long-term mortality. The date of death was obtained from provincial vital statistics.

RESULTS

There was no difference in operative mortality between matched BITA and SITA (n = 2, 1.8% vs n = 1, 0.9%, respectively, P = 0.6) groups. The mean follow-up was 8.6 ± 5.1 and 7.7 ± 5.5 years for BITA and SITA groups, respectively (P = 0.2). Five-, 10- and 15-year survival rates were 93.7, 77.5 and 59.0% in the matched BITA patients vs 82.8, 68.1 and 65.2% in the matched SITA patients (P = 0.3). In multivariate analysis, the independent risk factors for late mortality among hospital survivors were: insulin-dependent diabetes [adjusted hazard ratio (HR): 3.4, 95% confidence interval (CI): 1.4-8.4, P = 0.008], perioperative intra-aortic balloon pump insertion (HR: 3.2, 95% CI: 1.5-6.9, P = 0.004), postoperative deep sternal wound infection (HR: 7.4, 95% CI: 2.2-24.1, P = 0.001) and neurological complications (HR: 3.5, 95% CI: 1.4-8.4, P = 0.006). Choice of BITA versus SITA was not an independent predictor of long-term mortality (P = 0.3).

CONCLUSIONS

The use of a second internal thoracic artery (ITA) does not prolong late survival in patients with low EF undergoing CABG compared with a propensity-matched group of SITA graft patients.

Simple bedside clinical evaluation versus established scores in the estimation of operative risk in valve replacement for severe aortic stenosis

BACKGROUND

The operative risk of cardiac surgery is ascertained preoperatively on the basis of scores validated in multinational studies. However, the value they add to a simple bedside clinical evaluation (CE) remains controversial.

AIMS

To compare operative mortality (defined as death from all causes before the 31st postoperative day) predicted by CE with that predicted by additive and logistic EuroSCOREs, EuroSCORE II and Society of Thoracic Surgeons (STS), Ambler and age-creatinine-ejection fraction (ACEF) scores in patients undergoing aortic valve replacement (AVR) for severe aortic stenosis.

METHODS

Overall, 314 consecutive patients were included who underwent AVR between October 2009 and November 2011 (22% with coronary artery bypass graft); mean age 73.4 ± 9.7 years (29% aged>80 years). Based on CE, patients were divided into four predefined groups of increasing estimated mortality risk: I ≤ 3.9%; II 4-6.9%; III 7-9.9%; IV ≥ 10%. The positive and negative predictive values of the six scores and CE were compared.

RESULTS

The observed overall operative mortality was 5.7%. The distribution of the four predicted mortality groups by each score was highly variable. The positive predictive value, calculated for the 64 patients classified at highest risk by CE (groups III or IV) or each score, was 17.2% for EuroSCORE II, 14.1% for CE and STS scores, 10.9% for additive and logistic EuroSCOREs, 10.6% for ACEF and 10.2% for Ambler. The positive predictive value of each score in the low-risk groups (I and II) ranged from 2.8% to 4.4%.

CONCLUSION

A simple bedside CE appears as reliable as the various established scores for predicting operative risk in patients undergoing surgical aortic valve replacement. The development and validation of more comprehensive risk stratification tools, including risk factors thus far neglected, seems warranted.

Incidence, management, and outcomes of cardiac tamponade during transcatheter aortic valve implantation: a single-center study

OBJECTIVES

The aim of this study was to explore the incidence, causes, and outcomes of cardiac tamponade in patients undergoing transcatheter aortic valve implantation (TAVI).

BACKGROUND

Use of TAVI is increasing, but the procedure is vulnerable to complications, given the cohort of patients. Cardiac tamponade is a possible complication, and there is a scarcity of data on the incidence and outcomes of cardiac tamponade during TAVI.

METHODS

All patients who sustained cardiac tamponade during or post-TAVI between 2007 and 2012 were included in the study.

RESULTS

Of 389 patients who underwent TAVI, 17 (4.3%) had cardiac tamponade. The mean age was 82.3 ± 3.7 years, and most were women (n = 12, 70.6%). Causes of cardiac tamponade were right ventricular perforation by temporary pacemaker (9 patients, 52.9%), annular rupture or aortic dissection (4 patients, 23.5%), and tear in the left ventricular free wall caused by Amplatz stiff wire or catheters (4 patients, 23.5%). Mortality occurred in 4 patients (23.5%), and all had tamponade caused by injury to the high-pressured left-sided circulation (left ventricle and aorta). Most patients (n = 14, 82.4%) sustained cardiac tamponade during the procedure-2 patients (11.7%) within 24 h, and 1 patient after 24 h.

CONCLUSIONS

Cardiac tamponade during TAVI is not frequent but is associated with high mortality rates especially when left-sided structures are involved. Meticulous handling of the equipment and improvements in the safety of currently used devices could further reduce the occurrence of this complication.

Intensive glycemic control after heart transplantation is safe and effective for diabetic and non-diabetic patients

Some studies have shown increased mortality, infection, and rejection rates among diabetic (DM) compared to non-diabetic (non-DM) patients undergoing heart transplant (HT). This is a retrospective chart review of adult patients (DM, n = 26; non-DM, n = 66) undergoing HT between June 1, 2005, and July 31, 2009. Glycemic control used intravenous (IV) and subcutaneous (SQ) insulin protocols with a glucose target of 80-110 mg/dL. There were no significant differences between DM and non-DM patients in mean glucose levels on the IV and SQ insulin protocols. Severe hypoglycemia (glucose <40 mg/dL) did not occur on the IV protocol and was experienced by only 3 non-DM patients on the SQ protocol. Moderate hypoglycemia (glucose >40 and <60 mg/dL) occurred in 17 (19%) patients on the IV protocol and 24 (27%) on the SQ protocol. There were no significant differences between DM and non-DM patients within 30 d of surgery in all-cause mortality, treated HT rejection episodes, reoperation, prolonged ventilation, 30-d readmissions, ICU readmission, number of ICU hours, hospitalization days after HT, or infections. This study demonstrates that DM and non-DM patients can achieve excellent glycemic control post-HT with IV and SQ insulin protocols with similar surgical outcomes and low hypoglycemia rates.

The dangers of gathering data: surgeon-specific outcomes revisited

The accuracy of risk adjustment is important in developing surgeon profiles. As surgeon profiles are obtained from observational, nonrandomized data, we hypothesized that selection bias exists in how patients are matched with surgeons and that this bias might influence surgeon profiles. We used the Society of Thoracic Surgeons risk model to calculate observed to expected (O/E) mortality ratios for each of six cardiac surgeons at a single institution. Propensity scores evaluated selection bias that might influence development of risk-adjusted mortality profiles. Six surgeons (four high and two low O/E ratios) performed 2298 coronary artery bypass grafting (CABG) operations over 4 years. Multivariate predictors of operative mortality included preoperative shock, advanced age, and renal dysfunction, but not the surgeon performing CABG. When patients were stratified into quartiles based on the propensity score for operative death, 83% of operative deaths (50 of 60) were in the highest risk quartile. There were significant differences in the number of high-risk patients operated upon by each surgeon. One surgeon had significantly more patients in the highest risk quartile and two surgeons had significantly less patients in the highest risk quartile (p < 0.05 by chi-square). Our results show that high-risk patients are preferentially shunted to certain surgeons, and away from others, for unexplained (and unmeasured) reasons. Subtle unmeasured factors undoubtedly influence how cardiac surgery patients are matched with surgeons. Problems may arise when applying national database benchmarks to local situations because of this unmeasured selection bias.

Hematologic and clinical parameters after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis

BACKGROUND

Previous studies have demonstrated that platelet activation occurs in patients with aortic stenosis (AS). This study sought to evaluate the changes in hematologic and clinical parameters noted with the improvement in AS following transcatheter aortic valve implantation (TAVI) in patients with severe AS at high risk of surgery.

PATIENTS AND METHODS

The study included 33 patients who underwent TAVI. In addition to biochemical, clinical, and echocardiographic examinations, hematologic blood parameters were recorded before TAVI, at discharge, and at 1 and 4 months.

RESULTS

Mean platelet volume (MPV) showed a progressive decrease after TAVI. On echocardiography at 1 month, aortic valve area significantly increased, with significant decreases in peak and mean gradients. Progressive decreases were also noted in N-terminal proB-type natriuretic peptide levels.

CONCLUSION

Our findings show that TAVI improves hemodynamic parameters of the valve with marked clinical and echocardiographic improvement, resulting in decreased platelet activation and MPV in patients with severe AS.

Comparative study of same sitting hybrid coronary artery revascularization versus off-pump coronary artery bypass in multivessel coronary artery disease

OBJECTIVE

We compared the outcomes of same sitting robotic-assisted hybrid coronary artery revascularization (HCR) with off-pump coronary artery bypass grafting (OPCABG) in similar patients with multivessel coronary artery disease.

BACKGROUND

HCR is a novel procedure in selected patients with multivessel coronary artery disease (CAD). Although there are some data on staged HCR, the data on same sitting HCR are limited.

METHODS

We conducted a prospective study comparing same sitting robotic-assisted HCR patients (n = 25) to a group of consecutive low to moderate risk OPCABG patients (n = 27) during the study period. HCR patients underwent robotic internal mammary artery takedown followed by OPCABG via minithoracotomy. After confirming graft patency, immediate percutaneous coronary intervention on the nonbypass arteries was performed. Comparative analyses were performed on in-hospital and 30 day outcomes.

RESULTS

The baseline characteristics were similar for both groups including the severity of CAD (Syntax score 33.5+/-8.2 vs. 34.9+/-8.2, P = 0.556). Overall MACE was similar between both groups; however, the HCR group showed improved hospital outcomes with lower need for postoperative transfusions (12% vs. 67%, P < 0.001), and shorter length of hospital stay (5.1+/-2.8 vs. 8.2+/-5.4 days, P < 0.01). Despite lower postoperative costs, the HCR group had higher overall hospital costs due to higher procedural costs ($33,984 +/-$4,806 vs. $27,816+/-$11,172, P < 0.0001). Propensity model analysis showed similar findings. The HCR group showed improved quality of life measures with shorter time to return to work (5.3+/-3.0 vs. 8.2+/- 4.6 weeks, P = 0.01).

CONCLUSIONS

Same sitting HCR appears to be feasible and may offer superior outcomes to standard OPCABG, further studies are warranted.

Percutaneous treatment of patients with heart diseases: selection, guidance and follow-up. A review

Aortic stenosis and mitral regurgitation, patent foramen ovale, interatrial septal defect, atrial fibrillation and perivalvular leak, are now amenable to percutaneous treatment. These percutaneous procedures require the use of Transthoracic (TTE), Transesophageal (TEE) and/or Intracardiac echocardiography (ICE). This paper provides an overview of the different percutaneous interventions, trying to provide a systematic and comprehensive approach for selection, guidance and follow-up of patients undergoing these procedures, illustrating the key role of 2D echocardiography.

Insulin therapy for the management of hyperglycemia in hospitalized patients

It has long been established that hyperglycemia with or without a prior diagnosis of diabetes increases both mortality and disease-specific morbidity in hospitalized patients and that goal-directed insulin therapy can improve outcomes. This article reviews the pathophysiology of hyperglycemia during illness, the mechanisms for increased complications and mortality due to hyperglycemia and hypoglycemia, and beneficial mechanistic effects of insulin therapy and provides updated recommendations for the inpatient management of diabetes in the critical care setting and in the general medicine and surgical settings.