A retrospection on the content, association, and significance of mercury in coals and coal ashes from Bulgarian thermoelectric power stations.

A short overview on the content, association, and significance of toxic Hg in 9 coal types and their fly ashes (FAs) from 12 Bulgarian thermoelectric power stations (TPSs) was conducted by a compilation of reference and our own data obtained by a combination of different chemical and mineralogical analyses, and separation procedures. The Bulgarian and Ukrainian coals studied are enriched in Hg (0.14-0.57 mg/kg) occurring in both organic and inorganic associations. The most abundant coals in Hg have higher S contents and ash yields, and are enriched in Fe sulphides, calcite, and Ca and Fe sulphates, as well as some clay minerals and feldspars. The dominant quantity (about 50-98%) from the fuel Hg was not captured by the coal ashes in TPSs. The significant Hg capture potential (38-50%) show FAs enriched in char, Ca and Fe sulphates and oxides, and Ca carbonates. It was found that the Hg concentrations in some FA water leachates are significantly higher in comparison with the Clarke values for fresh water and could provoke environmental risks. Alternative and sustainable biomass poor in Hg is suggested to substitute totally or partially the industrial coals used in Bulgarian TPSs to avoid the Hg problems.

The STS Participant-Level, Multiprocedural Composite Measure for Adult Cardiac Surgery.

BACKGROUND: Composite performance measures for the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database participants (typically hospital departments or practice groups) are currently available only for individual procedures. To assess overall participant performance, STS has developed a composite metric encompassing the most common adult cardiac procedures. METHODS: Analyses included 1-year (July 1, 2018 to June 30, 2019) and 3-year (July 1, 2016 to June 30, 2019) time windows. Operations included isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR), isolated mitral valve repair (MVr) or replacement (MVR), AVR + CABG, MVr or MVR + CABG, AVR + MVr or MVR, and AVR + (MVr or MVR) + CABG. The composite was estimated using Bayesian hierarchical models with risk-adjusted mortality and morbidity end points. Star ratings were based upon whether the 95% credible interval of a participant's score was entirely lower than (1 star), overlapping (2 star), or higher than (3 star) the STS average composite score. RESULTS: The North American procedural mix in the 3-year study cohort was as follows: 448 569 CABG, 72 067 AVR, 35 708 MVr, 29 953 MVR, 45 254 AVR + CABG, 12 247 MVr + CABG, 10 118 MVR + CABG, 3743 AVR + MVr, 6846 AVR + MVR, and 3765 AVR + (MVr or MVR) + CABG. Mortality and morbidity weightings were similar for 1- and 3-year analyses (76% and 24% [3-year]), as were composite score distributions (median, 94.7%; interquartile range, 93.6% to 95.6% [3-year]). The 3-year time frame was selected for operational use because of higher model reliability (0.81 [0.78-0.83]) and better outlier discrimination (26%, 3 star; 16%, 1 star). Risk-adjusted outcomes for 1-, 2-, and 3-star programs were 4.3%, 3.0%, and 1.8% mortality and 18.4%, 13.4%, and 9.7% morbidity, respectively. CONCLUSIONS: The STS participant-level, multiprocedural composite measure provides comprehensive, highly reliable, overall quality assessment of adult cardiac surgery practices.

The Society of Thoracic Surgeons 2021 Adult Cardiac Surgery Risk Models for Multiple Valve Operations.

BACKGROUND: The Society of Thoracic Surgeons (STS) Quality Measurement Task Force has developed risk models and composite performance measures for isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR), isolated mitral valve replacement or repair (MVRR), AVR+CABG, and MVRR+CABG. To further enhance its portfolio of risk-adjusted performance metrics, STS has developed new risk models for multiple valve operations ± CABG procedures. METHODS: Using July 2011 to June 2019 STS Adult Cardiac Surgery Database data, risk models for AVR+MVRR (n = 31,968) and AVR+MVRR+CABG (n = 12,650) were developed with the following endpoints: Operative Mortality, major morbidity (any 1 or more of the following: cardiac reoperation, deep sternal wound infection/mediastinitis, stroke, prolonged ventilation, and renal failure), and combined mortality and/or major morbidity. Data were divided into development (July 2011 to June 2017; n = 35,109) and validation (July 2017 to June 2019; n = 9509) samples. Predictors were selected by assessing model performance and clinical face validity of full and progressively more parsimonious models. Performance of the resulting models was evaluated by assessing discrimination and calibration. RESULTS: C-statistics for the overall population of multiple valve ± CABG procedures were 0.7086, 0.6734, and 0.6840 for mortality, morbidity, and combined mortality and/or morbidity in the development sample, and 0.6953, 0.6561, and 0.6634 for the same outcomes, respectively, in the validation sample. CONCLUSIONS: New STS Adult Cardiac Surgery Database risk models have been developed for multiple valve ± CABG operations, and these models will be used in subsequent STS performance metrics.

The Society of Thoracic Surgeons Coronary Artery Bypass Graft Composite Measure: 2021 Methodology Update.

BACKGROUND: The Society of Thoracic Surgeons (STS) original coronary artery bypass graft surgery (CABG) composite measure uses a 1-year analytic cohort and 98% credible intervals (CrI) to classify better than expected (3-star) performance or worse than expected (1-star) performance. As CABG volumes per STS participant (eg, hospital or practice group) have decreased, it has become more challenging to classify performance categories using this approach, especially for lower volume programs, and alternative approaches have been explored. METHODS: Among 990 STS Adult Cardiac Surgery Database participants, performance classifications for the CABG composite were studied using various analytic cohorts: 1 year (current approach, 2017); 3 years (2015 to 2017); last 450 cases within 3 years; and most recent year (2017) plus additional cases to 450 total. We also compared 98% CrI with 95% CrI (used in other STS composite measures). RESULTS: Using 3 years of data and 95% CrIs, 113 of 990 participants (11.4%) were classified 1-star and 198 (20%) 3-star. Compared with 1-year analytic cohorts and 98% CrI, the absolute and relative increases in the proportion of 3-star participants were 14 percentage points and 233% (n = 198 [20%] vs n = 59 [6%]). Corresponding changes for 1-star participants were 6.5 percentage points and 133% (n = 113 [11.4%] vs n = 48 [4.9%]). These changes were particularly notable among lower volume (fewer than 199 CABG per year) participants. Measure reliability with the 3-year, 95% CrI modification is 0.78. CONCLUSIONS: Compared with current STS CABG composite methodology, a 3-year analytic cohort and 95% CrI increases the number and proportion of better or worse than expected outliers, especially among lower-volume Adult Cardiac Surgery Database participants. This revised methodology is also now consistent with other STS procedure composites.

Failure to Rescue: A New Society of Thoracic Surgeons Quality Metric for Cardiac Surgery.

BACKGROUND: Failure to rescue (FTR) focuses on the ability to prevent death among patients who have postoperative complications. The Society of Thoracic Surgeons (STS) Quality Measurement Task Force has developed a new, risk-adjusted FTR quality metric for adult cardiac surgery. METHODS: The study population was taken from 1118 STS Adult Cardiac Surgery Database participants including patients who underwent isolated CABG, aortic valve replacement with or without CABG, or mitral valve repair or replacement with or without CABG between January 2015 and June 2019. The FTR analysis was derived from patients who had one or more of the following complications: prolonged ventilation, stroke, reoperation, and renal failure. Data were randomly split into 70% training samples (n = 89,059) and 30% validation samples (n = 38,242). Risk variables included STS predicted risk of mortality, operative procedures, and intraoperative variables (cardiopulmonary bypass and cross-clamp times, unplanned procedures, need for circulatory support, and massive transfusion). RESULTS: Overall mortality for patients undergoing any of the index operations during the study period was 2.6% (27,045 of 1,058,138), with mortality of 0.9% (8316 of 930,837), 8% (7618 of 94,918), 30.6% (8247 of 26,934), 51.9% (2661 of 5123), and 62.3% (203 of 326), respectively, among patients having none, one, two, three, or four complications. The FTR risk model calibration was excellent, as were model discrimination (c-statistic 0.806) and the Brier score (0.102). Using 95% Bayesian credible intervals, 62 participants (5.6%) performed worse and 53 (4.7%) performed better than expected. CONCLUSIONS: A new risk-adjusted FTR metric has been developed that complements existing STS performance measures. The metric specifically assesses institutional effectiveness of postoperative care, allowing hospitals to target quality improvement efforts.

Mineral Carbonation of Biomass Ashes in Relation to Their CO2 Capture and Storage Potential.

Short-term stored, long-term stored, and weathered biomass ashes (BAs) produced from eight biomass varieties were studied to define their composition, mineral carbonation, and CO2 capture and storage (CCS) potential by a combination of methods. Most of these BAs are highly enriched in alkaline-earth and alkaline oxides, and the minerals responsible for CCS in them include carbonates such as calcite, kalicinite, and fairchildite, and to a lesser extent, butschliite and baylissite. These minerals are a result of reactions between alkaline-earth and alkaline oxyhydroxides in BA and flue CO2 gas during biomass combustion and atmospheric CO2 during BA storage and weathering. The mineral composition of the short-term stored, long-term stored, and weathered BAs is similar; however, there are increased proportions of carbonates and especially bicarbonates in the long-term stored BAs and particularly weathered BAs. The carbonation of BAs based on the measurement of CO2 volatilization determined in fixed temperature ranges is approximately 1-27% (mean 11%) for short-term stored BAs, 2-33% (mean 18%) for long-term stored BAs, and 2-34% (mean 22%) for weathered BAs. Hence, biomass has some extra CCS potential because of sequestration of atmospheric CO2 in BA, and the forthcoming industrial bioenergy production in a sustainable way can contribute for decreasing CO2 emissions and can reduce the use of costly CCS technologies.

Volume-Outcome Association of Mitral Valve Surgery in the United States.

Importance: Early surgery for severe primary degenerative mitral regurgitation is recommended, provided optimal outcomes are achievable. Contemporary national data defining mitral valve surgery volume and outcomes are lacking. Objective: To assess national 30-day and 1-year outcomes of mitral valve surgery and define the hospital- and surgeon-level volume-outcome association with mitral valve repair or replacement (MVRR) in patients with primary mitral regurgitation. Design, Setting, and Participants: This multicenter cross-sectional observational study used the Society of Thoracic Surgeons Adult Cardiac Surgery Database to identify patients undergoing isolated MVRR for primary mitral regurgitation in the United States. Operative data were collected from July 1, 2011, to December 31, 2016, and analyzed from March 1 to July 1, 2019, with data linked to the Centers for Medicare and Medicaid Services. Main Outcomes and Measures: The primary outcome was 30-day in-hospital operative mortality after isolated MVRR for primary mitral regurgitation. Secondary outcomes were 30-day composite mortality plus morbidity (any occurrence of bleeding, stroke, prolonged ventilation, renal failure, or deep wound infection), rate of successful mitral valve repair of primary mitral regurgitation (residual mitral regurgitation of mild [1+] or better), and 1-year mortality, reoperation, and rehospitalization for heart failure. Results: A total of 55 311 patients, 1094 hospitals, and 2410 surgeons were identified. Increasing hospital and surgeon volumes were associated with lower risk-adjusted 30-day mortality, lower 30-day composite mortality plus morbidity, and higher rate of successful repair. The lowest vs highest hospital volume quartile had higher 1-year risk-adjusted mortality (hazard ratio [HR], 1.61, 95% CI, 1.31-1.98), but not mitral reoperation (odds ratio [OR], 1.51; 95% CI, 0.81-2.78) or hospitalization for heart failure (HR, 1.25; 95% CI, 0.96-1.64). The surgeon-level 1-year volume-outcome associations were similar for mortality (HR, 1.60; 95% CI, 1.32-1.94) but not significant for mitral reoperation (HR, 1.14; 95% CI, 0.60-2.18) or hospitalization for heart failure (HR, 1.17; 95% CI, 0.91-1.50). Conclusions and Relevance: National hospital- and surgeon-level inverse volume-outcome associations were observed for 30-day and 1-year mortality after mitral valve surgery for primary mitral regurgitation. These findings may help to define access to experienced centers and surgeons for the management of primary mitral regurgitation.

Mitral Valve Repair Versus Replacement in Elderly With Degenerative Disease: Analysis of the STS Adult Cardiac Surgery Database.

BACKGROUND: It has been postulated that mitral valve repair in the elderly does not confer short-term benefits over mitral valve replacement with complete preservation of the chordal apparatus. Our purpose was to test this hypothesis using data from The Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS ACSD). METHODS: Patients aged 70 years or more undergoing primary isolated elective mitral valve repair or mitral valve replacement for degenerative disease were obtained from the STS ACSD versions 2.73 and 2.81. Patients with a concomitant tricuspid procedure, atrial fibrillation surgery, or atrial septal defect/patent foramen ovale repair were included. The two treatment groups were further stratified by age in years (70 to 74, 75 to 79, and 80 or more). Adjusted 30-day mortality rates were analyzed by mitral procedure and chordal preservation strategy. RESULTS: The study included 12,043 patients, of whom 71% underwent mitral valve repair. Observed 30-day mortality after repair was lower than after replacement (2.2% versus 4.8%, respectively; p < 0.0001). Using repair as reference, adjusted operative mortality was higher for replacement in the overall cohort (odds ratio 1.83, 95% confidence interval: 1.45 to 2.31). There was no significant difference in mortality between complete versus partial chordal preservation in repair (odds ratio 1.24, 95% confidence interval: 0.80 to 1.93). Mitral valve replacement with chordal preservation remained inferior to repair (odds ratio 1.66, 95% confidence interval: 1.28 to 2.14). The failed repair rate was 7.9%, with a 30-day mortality of 6%. CONCLUSIONS: In patients aged 70 years or more, degenerative mitral repair was associated with lower operative mortality compared with replacement, irrespective of chordal preservation strategy. Failed repairs reduced this short-term benefit compared with chordal-sparing replacement as evidenced by the similar operative mortality on an intention to treat analysis.

Racial Comparisons of the Outcomes of Transcatheter and Surgical Aortic Valve Implantation Using the Medicare Database.

Racial disparities in the outcomes after intervention for aortic valve disease remain understudied. We stratified patients by race who underwent surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) in the Medicare database. The TAVI cohort consisted of 17,973 patients (3.9% were black and 1.0% were Hispanic). The SAVR cohort consisted of 95,078 patients, (4.8% were black and 1.3% were Hispanic). Most comorbidities were more common in blacks. After TAVI, 30-day mortality was not significantly different in races with both unadjusted and adjusted data. There were no significant racial differences in readmission rates or discharge to home after TAVI. After SAVR, black patients had worse unadjusted 30-day and 1-year mortality than whites or Hispanics (30-day mortality, 4.7% vs 6.2% vs 4.7% for whites, blacks, and Hispanics, respectively, p = 0.0001; 1-year mortality 11.7% vs 16.1% vs 12.5%, respectively, p = 0.0001); however, after adjustment, there were no differences in mortality. Black patients had higher 30-day readmission rates after SAVR (20.1% vs 25.2% vs 21.7% for whites, blacks, and Hispanics, respectively, p = 0.0001), which persisted after adjustment for comorbidities. Minorities were underrepresented in both SAVR and TAVI relative to what would be predicted by population prevalence. In conclusion, while blacks have worse outcomes in SAVR compared with whites or Hispanics, race did not impact mortality, readmission, or discharge to home in TAVI. Both blacks and Hispanics were underrepresented compared with what would be predicted by population prevalence.

The Society of Thoracic Surgeons 2018 Adult Cardiac Surgery Risk Models: Part 2-Statistical Methods and Results.

BACKGROUND: The Society of Thoracic Surgeons (STS) uses statistical models to create risk-adjusted performance metrics for Adult Cardiac Surgery Database (ACSD) participants. Because of temporal changes in patient characteristics and outcomes, evolution of surgical practice, and additional risk factors available in recent ACSD versions, completely new risk models have been developed. METHODS: Using July 2011 to June 2014 ACSD data, risk models were developed for operative mortality, stroke, renal failure, prolonged ventilation, mediastinitis/deep sternal wound infection, reoperation, major morbidity or mortality composite, prolonged postoperative length of stay, and short postoperative length of stay among patients who underwent isolated coronary artery bypass grafting surgery (n = 439,092), aortic or mitral valve surgery (n = 150,150), or combined valve plus coronary artery bypass grafting surgery (n = 81,588). Separate models were developed for each procedure and endpoint except mediastinitis/deep sternal wound infection, which was analyzed in a combined model because of its infrequency. A surgeon panel selected predictors by assessing model performance and clinical face validity of full and progressively more parsimonious models. The ACSD data (July 2014 to December 2016) were used to assess model calibration and to compare discrimination with previous STS risk models. RESULTS: Calibration in the validation sample was excellent for all models except mediastinitis/deep sternal wound infection, which slightly underestimated risk and will be recalibrated in feedback reports. The c-indices of new models exceeded those of the last published STS models for all populations and endpoints except stroke in valve patients. CONCLUSIONS: New STS ACSD risk models have generally excellent calibration and discrimination and are well suited for risk adjustment of STS performance metrics.

The Society of Thoracic Surgeons 2018 Adult Cardiac Surgery Risk Models: Part 1-Background, Design Considerations, and Model Development.

BACKGROUND: The last published version of The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) risk models were developed in 2008 based on patient data from 2002 to 2006 and have been periodically recalibrated. In response to evolving changes in patient characteristics, risk profiles, surgical practice, and outcomes, the STS has now developed a set of entirely new risk models for adult cardiac surgery. METHODS: New models were estimated for isolated coronary artery bypass grafting surgery (CABG [n = 439,092]), isolated aortic or mitral valve surgery (n = 150,150), and combined valve plus CABG procedures (n = 81,588). The development set was based on July 2011 to June 2014 STS ACSD data; validation was performed using July 2014 to December 2016 data. Separate models were developed for operative mortality, stroke, renal failure, prolonged ventilation, reoperation, composite major morbidity or mortality, and prolonged or short postoperative length of stay. Because of its low occurrence rate, a combined model incorporating all operative types was developed for deep sternal wound infection/mediastinitis. RESULTS: Calibration was excellent except for the deep sternal wound infection/mediastinitis model, which slightly underestimated risk because of higher rates of this endpoint in the more recent validation data; this will be recalibrated in each feedback report. Discrimination (c-index) of all models was superior to that of 2008 models except for the stroke model for valve patients. CONCLUSIONS: Completely new STS ACSD risk models have been developed based on contemporary patient data; their performance is superior to that of previous STS ACSD models.

Outcomes of Early Mitral Valve Reoperation in the Medicare Population.

BACKGROUND: Surgical series on mitral valve reoperation are limited by small numbers and lack of national representation. Large-scale outcomes of reoperation for mitral valve surgery remain uncertain. METHODS: This is a descriptive analysis of 1,627 Medicare beneficiaries who underwent mitral valve reoperation within a 3-year follow-up period after an initial mitral operation (repair or replacement) that took place between 2000 and 2006. The primary outcomes were hospital mortality and long-term survival. RESULTS: The 1,627 patients included in the study comprise 1.6% of patients who underwent operation between 2000 and 2006. The initial surgery was repair in 49.9%, bioprosthetic replacement in 22.0%, and mechanical replacement in 28.1%. Re-repair was performed in 15.4%. Hospital mortality was 12.0% and was similar for repair and bioprosthetic or mechanical replacement. Reoperative mortality was similar for men and women and for patients aged 75 years or less versus more than 75 years; and was significantly higher for nonelective than for elective operations (15.6% versus 5.5%, p = 0.0001), for patients with endocarditis than without endocarditis (21.4% versus 11.0%, p = 0.0001), and for patients with heart failure than without heart failure (14.2% versus 9.9%, p = 0.0080). Cumulative long-term survival rates were 58.6% at 5 years. CONCLUSIONS: The incidence of mitral valve reoperation within 3 years after initial repair or replacement is low but carries high surgical risk, which is significantly increased by certain preoperative characteristics, such as urgent status, endocarditis, and heart failure.

Improving coronary artery bypass grafting readmission outcomes from 2000 to 2012 in the Medicare population.

OBJECTIVE: The study objective was to examine trends in 30-day readmission after coronary artery bypass grafting in the Medicare population over 13 years. METHODS: The study included isolated coronary artery bypass grafting procedures in the Medicare population from January 2000 to November 2012. Comorbidities and causes of readmission were determined using Internal Classification of Diseases, 9th Revision, Clinical Modification diagnostic codes. RESULTS: The cohort included 1,116,991 patients. Readmission rates decreased from 19.5% in 2000 to 16.6% in 2012 (P = .0001). There was significant improvement across all categories of admission status, age, race, gender, and hospital annual coronary artery bypass grafting volume that were analyzed. Adjusted odds of readmission in 2000 compared with 2012 was 1.28 (95% confidence interval, 1.24-1.32). Median length of stay for the readmission episode was 5 days, which improved to 4 days by 2012. Hospital mortality during the readmission episode was 2.8% overall and declined to 2.4% in 2012 (P = .0001). The most common primary readmission diagnoses were heart failure (12.6%), postoperative wound infection/nonhealing wound (8.9%), arrhythmias (6.4%), and pleural effusions (3.7%). Readmission for wound infections/nonhealing wounds decreased significantly over time, from 9.8% to 6.5% (P = .0001). CONCLUSIONS: In a large cohort of Medicare patients undergoing coronary artery bypass grafting over 13 years, there was a significant decrease in 30-day readmission rates, a reduction in readmission for wound infections, and reduced mortality during the readmission episode, despite an increase in patient comorbidities. The improvement in readmission rates was seen regardless of patient variables examined.

Transcatheter Aortic Valve Replacement Outcomes in Nonagenarians Stratified by Transfemoral and Transapical Approach.

BACKGROUND: Survival and other outcomes of nonagenarians undergoing transcatheter aortic valve replacement (TAVR) in the Medicare population are unclear. METHODS: Patients aged 65 years and older who underwent TAVR from November 2011 through 2013 were considered for inclusion. RESULTS: The study consisted of 18,283 patients and 19.3% were aged 90 years or older. Compared with patients younger than 90 years, patients 90 years or older were less likely to have a number of comorbidities, including previous myocardial infarction (17.5% versus 21.8%), previous coronary artery bypass grafting (20.0% versus 35.0%), and chronic obstructive pulmonary disease (25.4% versus 39.0%) among others. The 30-day and 1-year mortality rates were 8.4% versus 5.9% (p = 0.0001) and 25.4% versus 21.5% (p = 0.0001) in the older and younger groups, respectively (odds ratio [OR] 1.47, 95% confidence interval [CI]: 1.28 to 1.70, p = 0.0001). Patients 90 years and older were more likely to undergo pacemaker insertion (11.1% versus 8.3%, p = 0.0001). Among nonagenarians, compared with the transapical group, patients undergoing transfemoral TAVR had lower 30-day (7.2% versus 13.6%, p = 0.0001) and 1-year (23.8% versus 31.6%, p = 0.0001) mortality rates, were more likely to be discharged home (54.4% versus 34.1%, p = 0.0001), and had lower 30-day readmission rates (23.8% versus 31.8%, p = 0.0001). After adjustment for patient characteristics, transapical TAVR was an independent predictor of 30-day mortality rate (OR 1.94, 95% CI: 1.48 to 2.56, p = 0.0001) and readmission (OR 1.46, 95% CI: 1.19 to 1.80, p = 0.0003). CONCLUSIONS: In patients undergoing TAVR, although 30-day and 1-year mortality rates were slightly worse for nonagenarians than their younger counterparts, long-term survival was still encouraging, with 75% of nonagenarians living to 1 year. Transapical TAVR was associated with worse outcomes in nonagenarians.

Hospital Readmission after Aortic Valve Replacement: Impact of Preoperative Heart Failure.

BACKGROUND AND AIM OF THE STUDY: Large-scale data of heart failure (HF) readmission after aortic valve replacement (AVR) are limited. METHODS: A total of 40,751 Medicare beneficiaries >65 years who underwent primary isolated AVR between 2000 and 2004 were included in the study. Preoperative HF was defined using ICD-9-CM diagnostic codes from the index admission and any hospitalization during the preceding year. Cumulative readmission incidences over five years were computed for those patients with and without preoperative HF, while adjusting for propensity scores. RESULTS: The median patient age was 76 years. At 30 days, all-cause readmission was 21.5% and HF readmission was 3.9%. Patients with preoperative HF had higher postoperative HF readmission rates compared to those without (30 days, 6.3% versus 2.2%; one year, 13.9% versus 4.4%; five years, 6.6% versus 10.3%, p = 0.0001). The incremental risk of HF on readmission was >2 following adjustment. In patients with preoperative HF, the number of admissions was associated with increased postoperative HF readmissions. At 30 days, patients with no preoperative HF admissions had a HF readmission rate of 5.3%, while those with one, two, three and four or more preoperative HF admissions had rates of 8.2%, 11.9%, 13.8% and 17.4%, respectively. This trend persisted over the five-year follow up period. CONCLUSIONS: Postoperative HF readmission accounted for about one-fifth of all-cause readmissions after AVR in Medicare beneficiaries. Preoperative HF significantly contributed to postoperative readmission, both all-cause and HF-specific, which likely limits the symptomatic benefit of surgery. These data support early aortic valve intervention prior to the development of clinically apparent HF.

Readmission after inpatient percutaneous coronary intervention in the Medicare population from 2000 to 2012.

BACKGROUND: Since year 2000, reducing hospital readmissions has become a public health priority. In addition, there have been major changes in percutaneous coronary intervention (PCI) during this period. METHODS: The cohort consisted of 3,250,194 patients admitted for PCI from January 2000 through November 2012. RESULTS: Overall, 30-day readmission was 15.8%. Readmission rates declined from 16.1% in 2000 to 15.4% in 2012 (adjusted odds ratio for readmission 1.33 in 2000 compared with 2012). Of all readmissions after PCI, the majority were for cardiovascular-related conditions (>60%); however, only a small percentage (<8%) of total readmissions were for acute myocardial infarction, unstable angina, or cardiac arrest/cardiogenic shock. A much larger percentage of patients were readmitted with chest pain/angina (7.9%), chronic ischemic heart disease (26.6%), and heart failure (12%). A small proportion was due to procedural complications and gastrointestinal (GI) bleeding. The use of PCI with stenting during readmissions was variable, increasing from 14.2% in 2000 to 23.7% in 2006 and then declining to 12.1% in 2012. Hospital mortality during readmission was 2.5% overall and varied over time (2.8% in 2000, decreasing to 2.2% in 2006 and then rising again to 3.1% in 2012). Patients who were readmitted had >4× higher 30-day mortality than those who were not. CONCLUSIONS: Among Medicare beneficiaries, readmission after PCI declined over time despite patients having more comorbidities. This translated into a 33% lower likelihood of readmission in 2012 compared with 2000. A small proportion of readmissions were for acute coronary syndromes.

Failure to Rescue Rates After Coronary Artery Bypass Grafting: An Analysis From The Society of Thoracic Surgeons Adult Cardiac Surgery Database.

BACKGROUND: Failure to rescue (FTR) is increasingly recognized as an important quality indicator in surgery. The Society of Thoracic Surgeons National Database was used to develop FTR metrics and a predictive FTR model for coronary artery bypass grafting (CABG). METHODS: The study included 604,154 patients undergoing isolated CABG at 1,105 centers from January 2010 to January 2014. FTR was defined as death after four complications: stroke, renal failure, reoperation, and prolonged ventilation. FTR was determined for each complication and a composite of the four complications. A statistical model to predict FTR was developed. RESULTS: FTR rates were 22.3% for renal failure, 16.4% for stroke, 12.4% for reoperation, 12.1% for prolonged ventilation, and 10.5% for the composite. Mortality increased with multiple complications and with specific combinations of complications. The multivariate risk model for prediction of FTR demonstrated a C index of 0.792 and was well calibrated, with a 1.0% average difference between observed/expected (O/E) FTR rates. With centers grouped into mortality terciles, complication rates increased modestly (11.4% to 15.7%), but FTR rates more than doubled (6.8% to 13.9%) from the lowest to highest terciles. Centers in the lowest complication rate tercile had an FTR O/E of 1.14, whereas centers in the highest complication rate tercile had an FTR O/E of 0.91. CONCLUSIONS: CABG mortality rates vary directly with FTR, but complication rates have little relation to death. FTR rates derived from The Society of Thoracic Surgeons data can serve as national benchmarks. Predicted FTR rates may facilitate patient counseling, and FTR O/E ratios have promise as valuable quality metrics.

Trends in Patient Characteristics and Outcomes of Coronary Artery Bypass Grafting in the 2000 to 2012 Medicare Population.

BACKGROUND: The purpose of this analysis was to examine the trends in patient characteristics and outcomes in patients who underwent coronary artery bypass grafting (CABG) over a 12-year period in the Medicare database. METHODS: The study included 1,264,265 isolated CABG procedures in the Medicare population from January 2000 through November 2012. Comorbidities were determined using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes. Trends in patient characteristics and hospital outcomes were assessed with Cochran-Armitage trend tests. Long-term survival was examined with Kaplan-Meier survival curves. RESULTS: The median age was 74 years. Comorbidity profiles increased significantly over time. The number of patients undergoing CABG decreased from 131,385 in 2000 to 71,086 in 2012. The majority of patients underwent multivessel revascularization (13.5% single-vessel CABG, 35.2% 2-vessel CABG, 32.1% 3-vessel CABG, and 15.7% ≥4-vessel CABG). The percentage of patients undergoing 1- and 2-vessel revascularization increased over time, whereas that of ≥3-vessel CABG decreased. Single internal mammary artery (IMA) use increased from 75.6% to 88.6%. Median length of stay (LOS) was 8 days. Thirty-day mortality decreased from 4.2% to 3.0%. Hospital mortality fell from 4.0% in 2000 to 2.7% in 2012 (odds ratio [OR], 0.73; 95% confidence interval [CI], 0.69-0.77). Survival was 93% at 6 months, 91% at 1 year, 84% at 3 years, and 76% at 5 years. Five-year survival changed little over time (range, 75%-77%). CONCLUSIONS: Despite rising comorbidities in Medicare patients undergoing CABG, hospital mortality fell significantly from 2000 to 2012. When adjusted for comorbidities, this signified a 27% reduction in hospital mortality. IMA use increased during the study period, and there was a trend of decreased use of 3 or more grafts.