STS Adult Cardiac Surgery Database: 2021 Update on Outcomes, Quality, and Research

Heart surgery over two decades: what we have learned about results and changing risks

OBJECTIVES

Using the cardiac surgery database is of high importance in referral centers and can lead to a better quality of care for patients. Tehran Heart Center (THC) is a cardiovascular referral center that was inaugurated in 2001. In this report, we aimed to present the third report of trends in patients' cardiovascular risk factors and surgical procedures from 2002 to 2021 that have been gathered for all THC patients.

METHODS

This serial cross-sectional study was conducted at Tehran Heart Center from 2002 to 2021. All patients undergoing cardiac surgeries were eligible to enter the study (N = 63,974). Those with miscellaneous types of surgeries were excluded (N = 9556). The distribution of cardiac surgeries (including isolated coronary artery bypass graft (CABG), isolated valve, and CABG + valve surgeries) and their respective in-hospital mortality were recorded. Furthermore, 20-year trends in the prevalence of various cardiovascular risk factors (CVRFs) among the following groups were evaluated: a) isolated CABG, b) aortic valve replacement/repair for aortic stenosis (AS/AVR/r), and c) isolated other valve surgeries (IVS).

RESULTS

A total of 54,418 patients (male: 70.7%, age: 62.7 ± 10.8 years) comprised the final study population, with 84.5% prevalence of isolated CABG. Overall, the AS/AVR/r group was in between the CABG and IVS groups concerning CVRFs distribution. Excluding some exceptions for the AS/AVR/r group (in which the small sample size (N = 909) precluded observing a clear trend), all studied CVRFs demonstrated an overall rising trend from 2002 to 2021 in all three groups. Regarding in-hospital mortality, the highest rate was recorded as 4.0% in 2020, while the lowest rate was 2.0% in 2001.

CONCLUSIONS

Isolated CABG remained the most frequent procedure in THC. Notable, increasing trends in CVRFs were observed during this 20-year period and across various types of cardiac surgeries, which highlights the clinical and policy-making implications of our findings.

Long-term outcomes for hybrid aortic arch repair

OBJECTIVE

Since its inception in the early 2000s, hybrid arch repair (HAR) has evolved from novel approach to well-established treatment modality for aortic arch pathology in appropriately selected patients. Despite this nearly 20-year history of use, long-term results of HAR remain to be determined. As such, objectives of this study are to detail the long-term outcomes for HAR within an expanded classification scheme.

METHODS

From August 2005 to August 2022, 163 consecutive patients underwent HAR at a single referral institution. Operative approach was selected according to an institutional algorithm and included zone 0/1 HAR in 25% (n = 40), type I HAR in 34% (n = 56), and type II/III HAR in 41% (n = 67). Specific zone 0/1 technique was zone 1 HAR in 31 (78%), zone 0 with innominate snorkel (zone 0S HAR) in 7 (18%), and zone 0 with single side-branch endograft (zone 0B HAR) in 2 (5%). The 30-day and long-term outcomes, including overall and aortic-specific survival, as well as freedom from reintervention, were assessed.

RESULTS

The mean age was 63 ± 13 years and almost one-half of patients (47% [n = 77]) had prior sternotomy. Presenting pathology included degenerative aneurysm in 44% (n = 71), residual dissection after prior type A repair in 38% (n = 62), chronic type B dissection in 12% (n = 20), and other indications in 6% (n = 10). Operative outcomes included 9% mortality (n = 14) at 30 days, 5% mortality (n = 8) in hospital, 4% stroke (n = 7), 2% new dialysis (n = 3), and 2% permanent paraparesis/plegia (n = 3). The median follow-up was 44 month (interquartile range, 12-84 months). Overall survival was 59% and 47% at 5 and 10 years, respectively, whereas aorta-specific survival was 86% and 84% at the same time points. At 5 and 10 years, freedom from major reintervention was 92% and 91%, respectively. Institutional experience had a significant impact on both early and late outcomes: comparing the first (2005-2012) and second (2013-2022) halves of the series, 30-day mortality decreased from 14% to 1% (P = .01) and stroke from 6% to 3% (P = .62). Improved operative outcomes were accompanied by improved late survival, with 78% of patients in the later era vs 45% in the earlier era surviving to 5 years.

CONCLUSIONS

HAR is associated with excellent operative outcomes, as well as sustained protection from adverse aortic events as evidenced by high long-term aorta-specific survival and freedom from reintervention. However, surgeon and institutional experience appear to play a major role in achieving these superior outcomes, with a five-fold decrease in operative mortality and a two-fold decrease in stroke rate in the latter half of the series. These long-term results expand on prior midterm data and continue to support use of HAR for properly selected patients with arch disease.

Risk factors for surgical site infection following cardiac surgery in a region endemic for multidrug resistant organisms

OBJECTIVES

To identify risk factors for surgical site infections following cardiosurgery in an area endemic for multidrug resistant organisms.

DESIGN

Single-center, historical cohort study including patients who underwent cardiosurgery during a 6-year period (2014-2020).

SETTING

Joint Commission International accredited, multiorgan transplant center in Palermo, Italy.

MAIN OUTCOME MEASURES

Surgical site infection was the main outcome.

RESULTS

On a total of 3609 cardiosurgery patients, 184 developed surgical site infection (5.1 %). Intestinal colonization with multidrug resistant organisms was more frequent in patients with surgical site infections (69.6 % vs. 33.3 %; p < 0.001). About half of surgical site infections were caused by Gram-negative bacteria (n = 97; 52.7 %). Fifty surgical site infections were caused by multidrug resistant organisms (27.1 %), with extended-spectrum Beta-lactamase-producing Enterobacterales (n = 16; 8.7 %) and carbapenem-resistant Enterobacterales (n = 26; 14.1 %) being the predominant resistance problem. However, in only 24 of surgical site infections caused by multidrug resistant organisms (48 %), mostly carbapenem-resistant Enterobacterales (n = 22), a pathogen match between the rectal surveillance culture and surgical site infections clinical culture was demonstrated. Nevertheless, multivariate logistic regression analysis identified a rectal swab culture positive for multidrug resistant organisms as an independent risk factor for SSI (odds ratio 3.95, 95 % confidence interval 2.79-5.60). Other independent risk factors were female sex, chronic dialysis, diabetes mellitus, previous cardiosurgery, previous myocardial infarction, being overweight/obese, and longer intubation time.

CONCLUSION

In an area endemic for carbapenem-resistant Enterobacterales, intestinal colonization with multidrug resistant organisms was recognized as independent risk factor for surgical site infections.

IMPLICATIONS FOR CLINICAL PRACTICE

No causal relationship between colonization with resistant pathogens and subsequent infection could be demonstrated. However, from a broader epidemiological perspective, having a positive multidrug resistant organisms colonization status appeared a risk factor for surgical site infections. Therefore, strict infection control measures to prevent cross-transmission remain pivotal (e.g., nasal decolonization, hand hygiene, and skin antisepsis).

Artificial Intelligence in Surgical Research: Accomplishments and Future Directions

MINI-ABSTRACT

The study introduces various methods of performing conventional ML and their implementation in surgical areas, and the need to move beyond these traditional approaches given the advent of big data.

OBJECTIVE

Investigate current understanding and future directions of machine learning applications, such as risk stratification, clinical data analytics, and decision support, in surgical practice.

SUMMARY BACKGROUND DATA

The advent of the electronic health record, near unlimited computing, and open-source computational packages have created an environment for applying artificial intelligence, machine learning, and predictive analytic techniques to healthcare. The "hype" phase has passed, and algorithmic approaches are being developed for surgery patients through all stages of care, involving preoperative, intraoperative, and postoperative components. Surgeons must understand and critically evaluate the strengths and weaknesses of these methodologies.

METHODS

The current body of AI literature was reviewed, emphasizing on contemporary approaches important in the surgical realm.

RESULTS AND CONCLUSIONS

The unrealized impacts of AI on clinical surgery and its subspecialties are immense. As this technology continues to pervade surgical literature and clinical applications, knowledge of its inner workings and shortcomings is paramount in determining its appropriate implementation.

Expert proposal to analyze the combination of aortic and mitral regurgitation in multiple valvular heart disease by comprehensive echocardiography

The assessment of valvular pathologies in multiple valvular heart disease by echocardiography remains challenging. Data on echocardiographic assessment-especially in patients with combined aortic and mitral regurgitation-are rare in the literature. The proposed integrative approach using semi-quantitative parameters to grade the severity of regurgitation often yields inconsistent findings and results in misinterpretation. Therefore, this proposal aims to focus on a practical systematic echocardiographic analysis to understand the pathophysiology and hemodynamics in patients with combined aortic and mitral regurgitation. The quantitative approach of grading the regurgitant severity of each compound might be helpful in elucidating the scenario in combined aortic and mitral regurgitation. To this end, both the individual regurgitant fraction of each valve and the total regurgitant fraction of both valves must be determined. This work also outlines the methodological issues and limitations of the quantitative approach by echocardiography. Finally, we present a proposal that enables verifiable assessment of regurgitant fractions. The overall interpretation of echocardiographic results includes the symptomatology of patients with combined aortic and mitral regurgitation and the individual treatment options with respect to their individual risk. In summary, a reproducible, verifiable, and transparent in-depth echocardiographic investigation might ensure consistent hemodynamic plausibility of the quantitative results in patients with combined aortic and mitral regurgitation.

Sternal sparing aortic valve replacement via right anterior minithoracotomy: An early experience

Purpose

This study aims to evaluate the perioperative outcomes of aortic valve replacement (AVR) via right anterior minithoracotomy (RAT) during the learning curve.

Methods

It was a retrospective, observational, cohort study of patients who underwent RAT AVR from June 2015 to April 2022. Primary outcomes measured were 30-day morbidity and mortality.

Results

A total of 107 consecutive patients underwent elective RAT AVR. Our patients were mostly male (78.5%), elderly (mean 68.7 years), and obese (34.6%). A majority of the patients (93.5%) were of low operative risk. Median cross-clamp and bypass times were 95 and 123 minutes respectively. There was a statistically significant correlation between increase in number of cases and decrease in operative time. All patients had no paravalvular leak at discharge. There were no operative cardiovascular mortality or major morbidity including stroke, myocardial infarction, renal failure requiring dialysis, or vascular complication. No patient required intraoperative conversion to full sternotomy for completion of AVR.

Conclusion

Our study demonstrated that RAT AVR can be safely introduced. The learning curve required in performing RAT AVR can be safely negotiated through training, previous experience in minimally invasive surgery, careful patient selection including use of preoperative computed tomography of the aorta, and introduction of sutureless/rapid deployment valves.

Hypotension prediction index for the prevention of hypotension during surgery and critical care: A narrative review

Surgeons and anesthesia clinicians commonly face a hemodynamic disturbance known as intraoperative hypotension (IOH), which has been linked to more severe postoperative outcomes and increases mortality rates. Increased occurrence of IOH has been positively associated with mortality and incidence of myocardial infarction, stroke, and organ dysfunction hypertension. Hence, early detection and recognition of IOH is meaningful for perioperative management. Currently, when hypotension occurs, clinicians use vasopressor or fluid therapy to intervene as IOH develops but interventions should be taken before hypotension occurs; therefore, the Hypotension Prediction Index (HPI) method can be used to help clinicians further react to the IOH process. This literature review evaluates the HPI method, which can reliably predict hypotension several minutes before a hypotensive event and is beneficial for patients' outcomes.

Assessment of Price Variation in Coronary Artery Bypass Surgery at US Hospitals

BACKGROUND

Little is known about hospital pricing for coronary artery bypass grafting (CABG). Using new price transparency data, we assessed variation in CABG prices across US hospitals and the association between higher prices and hospital characteristics, including quality of care.

METHODS AND RESULTS

Prices for diagnosis related group code 236 were obtained from the Turquoise database and linked by Medicare Facility ID to publicly available hospital characteristics. Univariate and multivariable analyses were performed to assess factors predictive of higher prices. Across 544 hospitals, median commercial and self-pay rates were 2.01 and 2.64 times the Medicare rate ($57 240 and $75 047, respectively, versus $28 398). Within hospitals, the 90th percentile insurer-negotiated price was 1.83 times the 10th percentile price. Across hospitals, the 90th percentile commercial rate was 2.91 times the 10th percentile hospital rate. Regional median hospital prices ranged from $35 624 in the East South Central to $84 080 in the Pacific. In univariate analysis, higher inpatient revenue, greater annual discharges, and major teaching status were significantly associated with higher prices. In multivariable analysis, major teaching and investor-owned status were associated with significantly higher prices (+$8653 and +$12 200, respectively). CABG prices were not related to death, readmissions, patient ratings, or overall Centers for Medicare and Medicaid Services hospital rating.

CONCLUSIONS

There is significant variation in CABG pricing, with certain characteristics associated with higher rates, including major teaching status and investor ownership. Notably, higher CABG prices were not associated with better-quality care, suggesting a need for further investigation into drivers of pricing variation and the implications for health care spending and access.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Low-Volume Acute Normovolemic Hemodilution Does Not Reduce Allogeneic Red Blood Cell Transfusion in Cardiac Surgery in the Modern Era of Patient Blood Management: A Propensity Score-Matched Cohort Study

OBJECTIVES

Patients undergoing cardiac surgery often require blood transfusions, which are associated with increased morbidity and mortality. Patient blood management (PBM) strategies, including acute normovolemic hemodilution (ANH), have been implemented to minimize allogeneic transfusion requirements. Older studies suggested that ANH is associated with reduced transfusions; however, its effectiveness in the modern era of PBM remains unclear.

DESIGN

This was a retrospective cohort study.

SETTING

The study was held at a single university hospital.

PARTICIPANTS

542 patients who underwent elective cardiac surgery with cardiopulmonary bypass (CPB) using low-priming-volume circuits between January 2017 and March 2022.

INTERVENTIONS

Patients who received ANH were matched with those who did not receive ANH, using propensity scores.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the proportion of patients who received perioperative red blood cell (RBC) transfusion. Of the 542 eligible patients, 49 ANH cases were propensity-score matched to 97 controls. The median ANH volume was 450 mL (IQR, 400-800 mL). There was no significant difference in perioperative RBC transfusion rates between the 2 groups (24.5% in the ANH group vs 30.9% in the control group, p = 0.42). The odds ratio for perioperative RBC transfusion in the ANH group versus the control group was 0.72 (95% CI, 0.32-1.55, p = 0.42).

CONCLUSIONS

Low-volume ANH was not associated with a significant reduction in perioperative allogeneic RBC transfusion during cardiac surgery with CPB using low-priming-volume circuits. The benefits of low-volume ANH in reducing the requirement for RBC transfusion in the modern era of PBM may be smaller than reported previously.

Safety-Net Hospital Status Is Associated With Coronary Artery Bypass Grafting Outcomes at an Urban Academic Medical Center

INTRODUCTION

Socioeconomic disparities impact outcomes after cardiac surgery. At our institution, cardiac surgery cases from the safety-net, county funded hospital (CH), which primarily provides care for underserved patients, are performed at the affiliated university hospital. We aimed to investigate the association of socioeconomic factors and CH referral status with outcomes after coronary artery bypass grafting (CABG).

METHODS

The institutional Adult Cardiac Surgery database was queried for perioperative and demographic data from patients who underwent isolated CABG between January 2014 and June 2020. The primary outcome was major adverse cardiovascular event (MACE), a composite of postoperative myocardial infarction, stroke, or death. Secondary outcomes included individual complications. Chi-square, Wilcoxon rank-sum, and logistic regression analyses were used to compare differences between CH and non-CH cohorts.

RESULTS

We included 836 patients with 472 (56.5%) from CH. Compared to the non-CH cohort, CH patients were younger, more likely to be Hispanic, non-English speaking, and be completely uninsured or require state-specific financial assistance. CH patients were more likely to have a history of tobacco and drug use, liver disease, diabetes, prior myocardial infarction, and greater degrees of left main coronary and left anterior descending artery stenosis. CH cases were less likely to be elective. The incidence of MACE was significantly higher in the CH cohort (16.3% versus 8.2%, P = 0.001). There were no significant differences in 30-d mortality, home discharge, prolonged mechanical ventilation, bleeding, sepsis, pneumonia, new dialysis requirement, cardiac arrest, or multiorgan system failure between cohorts. CH patients were more likely to develop renal failure and less likely to develop atrial fibrillation. On multivariable analysis, CH status (odds ratio 2.39, 95% confidence interval 1.25-4.55, P = 0.008) was independently associated with MACE.

CONCLUSIONS

CH patients undergoing CABG presented with greater comorbidity burden, more frequently required nonelective surgery, and are at significantly higher risk of postoperative MACE.

Prospective Study of Risk Factors for Postoperative Atrial Fibrillation After Cardiac Surgery

INTRODUCTION

To examine risk factors for new-onset postoperative atrial fibrillation (POAF) after cardiac surgery.

METHODS

Patients enrolled in the Cardiothoracic Surgical Trials Network multicenter, randomized trial of rate control versus rhythm control for POAF were included. Predictors of POAF were determined using multivariable logistic regression.

RESULTS

Among the 2104 patients who were enrolled preoperatively, 695 developed POAF (33.0%). Rates of POAF were 28.1% after isolated coronary artery bypass grafting (CABG), 33.7% after isolated valve repair or replacement, and 47.3% after CABG plus valve repair or replacement. Baseline characteristics associated with an increased risk of POAF identified on multivariable analysis included older age (odds ratio [OR] 1.57; 95% confidence interval [CI] 1.42-1.73, per 10 y), White race or non-Hispanic ethnicity (OR 1.52; CI: 1.11-2.07), history of heart failure (OR 1.55; CI: 1.16-2.08), and history of hypothyroidism (OR 1.42; CI 1.04-1.94). The type of cardiac procedure was associated with an increased risk of POAF with both isolated valve repair or replacement (OR 1.33, CI 1.08-1.64) and combined CABG plus valve repair or replacement (OR 1.64, CI 1.24-2.17) having increased risk of POAF compared to isolated CABG. No preoperative cardiac medication was associated with POAF.

CONCLUSIONS

In this prospective cohort of patients, older age, a history of hypothyroidism, a history of heart failure, and valve repair or replacement, with or without CABG, and White non-Hispanic race were associated with an increased risk of POAF.

Nationwide Trends and Outcomes for Coronary Artery Bypass Grafting in End-Stage Kidney Disease and Stable Coronary Artery Disease

Patients with end-stage kidney disease (ESKD) on dialysis have an increased burden of coronary artery disease (CAD). This study assessed the trend and outcomes for coronary artery bypass surgery (CABG) in patients with ESKD and stable CAD. We conducted a longitudinal study using the United States Renal Data System of patients with ESKD and stable CAD who underwent CABG from the years 2009 to 2017. The outcomes included in-hospital, long-term mortality, and repeat revascularization. The follow-up was until death, end of Medicare AB coverage, or December 31, 2018. A total of 11,952 patients were identified. The mean age was 62.8 years, 68% were male, and 67% were white. The common co-morbidities included hypertension (97%), diabetes mellitus (75%), and congestive heart failure (53%). A significant decrease in CABG procedures from 2.9 to 1.3 procedures per 1,000 patients with ESKD (p <0.001) was noted during the years studied. The overall in-hospital mortality rate was 5.9%, and there was a significant decrease over the study period (p = 0.01). Although the 30-day mortality rate was 6.9% and remained steady (p = 0.14), the 1-year mortality rate was 22.8% and decreased significantly (p <0.001). At 5 years, the overall survival rate was 35%, and patients with internal mammary artery grafts showed better survival than those without (36% vs 25%). In conclusion, there has been a decrease in CABG procedures performed in patients with ESKD with stable CAD with decreasing in-hospital and 1-year mortality. Those with an internal mammary artery graft do better, but the overall long-term survival remains dismal in this population. There remains need for caution and individualization of revascularization decisions in this high-risk population.

Quality and Impact of Manuscripts Using The Society of Thoracic Surgeons National Databases

BACKGROUND

The Society of Thoracic Surgeons (STS) National Databases contain the largest and most comprehensive cardiac, thoracic, and congenital surgery data available. In this analysis characteristics of manuscripts that used the STS National Databases were examined to evaluate the quality and impact of these publications.

METHODS

Manuscripts published from 2010 to 2020 that used the STS National Databases (Adult Cardiac, General Thoracic, and Congenital Heart Surgery) were examined. The number of times cited per published manuscript, journal of publication, and journal CiteScore were assessed. Author characteristics, including institutional association and h-index, were evaluated for first and last authors.

RESULTS

Of 539 published manuscripts, 179 (33.2%) used the Adult Cardiac Surgery, 128 (23.7%) the Congenital Heart Surgery, 85 (15.8%) the General Thoracic Surgery, and 136 (25.2%) used unspecified STS National Databases. Collectively the analyzed manuscripts were cited 18,943 times, with a mean of 35.1 (range, 0-528) citations per manuscript. Manuscripts were published in 97 journals with a mean year-adjusted CiteScore of 5.6 (range, 0.1-60.2). Authors associated with 361 institutions contributed to published manuscripts. The mean h-index of first authors was 24.6 (range, 0-100) and of last authors was 44.1 (range, 0-164). From 2010 to 2020 first authors wrote a mean of 1.6 (range, 1-31) and last authors wrote a mean of 1.9 (range, 1-29) STS National Databases publications.

CONCLUSIONS

The STS National Databases are some of the most robust data collection sources available to cardiothoracic surgeons. These data have enabled valuable research in respected journals from authors of varying experience levels.

Survival After Surgical Aortic Valve Replacement in Low-Risk Patients: A Contemporary Trial Benchmark

BACKGROUND

The use of transcatheter aortic valve replacement for severe aortic stenosis in low-risk patients necessitates an evaluation of contemporary long-term, real-world outcomes of similar patients undergoing surgical aortic valve replacement (SAVR) in a national cohort.

METHODS

All patients undergoing primary, isolated SAVR in The Society of Thoracic Surgeons (STS) database between 2011 and 2019 were examined. The study population of 42,586 adhered to the inclusion/exclusion criteria of the Placement of Aortic Transcatheter Valves (PARTNER) 3 and Evolut Low Risk randomized trials. Patients were further stratified by STS predicted risk of mortality (PROM), age, and left ventricular ejection fraction. The primary end-point was all-cause National Death Index mortality. Unadjusted survival to 8 years was estimated using the Kaplan-Meier method.

RESULTS

Mean age was 74.3 ± 5.7 years and mean STS PROM was 1.9% ± 0.8%. The overall Kaplan-Meier time to event analysis for all-cause mortality at 1, 3, 5, and 8 years was 2.6%, 4.5%, 7.1%, and 12.4%, respectively. In subset analyses, survival was significantly better for (1) lower STS PROM (P < .001), (2) younger vs older age (P < .001), and (3) higher vs lower left ventricular ejection fraction (P < .001). When STS PROM was below 1% or the patient age was below age 75 years, the 8-year survival after SAVR was 95%.

CONCLUSIONS

The results of this national study confirm that long-term survival after SAVR remains excellent, at 92.9% at 5 years. These contemporary longitudinal data serve to aid in the balanced interpretation of current and future trials comparing SAVR and transcatheter aortic valve replacement and may assist in the clinical decision-making process for patients of lower surgical risk.

Influence of concomitant ablation of nonparoxysmal atrial fibrillation during coronary artery bypass grafting on mortality and readmissions

Objective

We determined the utilization rate of surgical ablation (SA) during coronary artery bypass grafting (CABG) and compared outcomes between CABG with or without SA in a national cohort.

Methods

The January 2016 to December 2018 Nationwide Readmissions Database was searched for all patients undergoing isolated CABG with preoperative persistent or chronic atrial fibrillation by using the International Classification of Diseases, 10th Revision classification. Propensity score matching and multivariate logistic regressions were performed to compare outcomes, and Cox proportional hazards model was used to assess risk factors for 1-year readmission.

Results

Of 18,899 patients undergoing CABG with nonparoxysmal atrial fibrillation, 78% (n = 14,776) underwent CABG alone and 22% (n = 4123) underwent CABG with SA. In the propensity score-matched cohort (n = 8116), CABG with SA (n = 4054) (vs CABG alone [n = 4112]) was not associated with increased in-hospital mortality (3.4% [139 out of 4112] vs 3.9% [159 ut of 4054]; P = .4), index-hospitalization length of stay (10 days vs 10 days; P = .3), 30-day readmission (19.1% [693 out of 3362] vs 17.2% [609 out of 3537]; P = .2), or 90-day readmission (28.9% [840 out of 2911] vs 26.2% [752 out of 2875]; P = .1). Index hospitalization costs were significantly higher for those undergoing SA ($52,556 vs $47,433; P < .001). Rates of readmission at 300 days were similar between patients receiving SA (43.8%) and no SA (42.8%; log-rank P = .3). The 3 most common causes of readmission were not different between groups and included heart failure (24.3% [594 out of 2444]; P = .6), infection (16.8% [411 out of 2444]; P = .5), and arrhythmia (11.7% [286 out of 2444]; P = .2).

Conclusions

In patients with nonparoxysmal atrial fibrillation, utilization of SA during CABG remains low. SA during CABG did not adversely influence mortality or short-term readmissions. These findings support increased use of SA during CABG.

Sex-specific disparities in patients undergoing isolated CABG

Study objective

Examine sex-specific characteristics in patients undergoing coronary artery bypass grafting (CABG) at our institution.

Design

Retrospective chart review was performed utilizing our institutional Society of Thoracic Surgeons (STS) database.

Setting

An academic, quaternary care center from 2010 to 2021.

Participants

3163 females and 9573 males underwent isolated CABG.

Interventions

The institutional STS database was queried for preoperative, intraoperative, and postoperative variables.

Main outcome measures

Univariate comparisons between female and male groups were performed using chi-squared tests or fisher exact tests. Multivariate logistic regression was used to assess risk factors for 30-day mortality.

Results

Females had more preoperative comorbidities than males, including hypertension, diabetes, peripheral arterial disease, cerebrovascular disease, renal failure, and prior myocardial infarction. Females more frequently underwent urgent (61 % vs. 58 %) or emergent CABG (5.8 % vs. 4.3 %) compared to males (p < 0.0001). Females experienced longer total intensive care unit (ICU) hours (48.3 h vs. 43.5 h) (p < 0.0001), were more frequently discharged to an extended care facility (13 % vs. 6.4 %) (p < 0.0001) and prescribed less aspirin and beta blocker therapy at discharge than males. In-hospital mortality was higher in females (1.9 % vs. 1.2 %, p = 0.002), as was 30-day mortality (2.7 % vs. 1.6 %, p = 0.0001). Female sex was an independent risk factor for 30-day mortality (odds ratio = 1.46, 95 % CI: 1.06, 2.03, p = 0.02).

Conclusion

Over the past decade, females undergoing CABG had more preoperative comorbidities, urgent and emergent operations, longer postoperative ICU stay and a higher risk of mortality than their male counterparts. Further studies must investigate these disparities to improve outcomes for females undergoing CABG.

Practice makes perfect? Institutional coronary artery bypass case volumes and outcomes

OBJECTIVES

Older studies of coronary artery bypass grafting (CABG) institutional case volumes and outcomes reported conflicting results. We explored this association in the rapidly changing contemporary practice of American surgeons using the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database.

METHODS

The 2018-2019 isolated primary CABG experience in the STS Adult Cardiac Surgery Database was analysed (241 902 patients; 1014 hospitals; 2718 surgeons). Generalized Estimating Equations were used to estimate coefficients between CABG institutional case volumes and outcomes. The observed-to-expected ratios based on STS risk models were used to assess risk-adjusted operative mortality (OM), mortality/major morbidity (MM) and deep sternal wound infections (DSWI) as a function of institutional case volumes.

RESULTS

The mean (standard deviation) OM, MM and DSWI rates were 2.1% (2.7), 11.1% (9.2) and 0.6% (0.5), respectively. The mean (standard deviation) institutional case volumes per study period was 239 (192); 23% and 9% of institutions performed <100 and >500 cases/study period, respectively. There was a weak negative correlation between expected mortality (R2 -0.0014), OM (R2 -0.0272), MM (R2 -0.1213) and DSWI (R2 -0.003) and institutional case volumes.

CONCLUSIONS

CABG outcomes generally improve with increasing institutional case volumes. Given the large number of CABG cases performed nationally, even the documented weak correlation has the potential to appreciably decrease OM, MM and DSWI if cases are performed at higher volume institutions. Studies focusing on additional hospital and surgeon factors are warranted to further define quality improvement opportunities.

Coronary Artery Bypass Graft Surgery After Primary Percutaneous Coronary Intervention in Patients With ST-Elevation Myocardial Infarction

OBJECTIVE

To determine whether primary percutaneous coronary intervention (PPCI) is associated with adverse outcomes following coronary artery bypass graft (CABG) among patients with ST-elevation myocardial infarction (STEMI).

METHODS

Patients presenting with acute STEMI who underwent CABG between September 2015 and November 2020 were included. Among 354 patients, 222 (62.7%) underwent PPCI prior to CABG (PPCI+CABG group) and were compared with the rest of the patients (CABG only group). The effects of PPCI on primary endpoints---including in-hospital mortality, length of stay (LOS), and bleeding events---were investigated using the stabilised inverse probability weighting method (S-IPW). Further, in-hospital mortality in various PPCI subgroups was analysed using univariable regression.

RESULTS

Patients with and without PPCI were comparable regarding their baseline and surgical characteristics, except that those without PPCI were more likely to have left-main disease (29.5% vs 16.2%, p-value=0.003). Among the PPCI+CABG group, 3.6% mortality and 55.9% bleeding events occurred, and the LOS was 7 [5-10] days. The respective figures for the CABG only group were 4.5%, 50.8%, and 7 [6-10.5] days. Primary percutaneous coronary intervention, as a whole, was not significantly associated with either morality (S-IPW odds ratio (S-IPW OR) 0.61; p=0.393), LOS logarithm (S-IPW β -0.050; p=0.403), or bleeding events (S-IPW OR 1.06; p=0.821). Nevertheless, the unadjusted mortality risk was significantly higher in complicated PPCIs compared with the CABG only group (OR 7.50, 95% CI 2.03-27.77); it was also higher among some other PPCI subgroups, albeit non-significantly.

CONCLUSION

This study found that PPCI did not confer additional risk regarding in-hospital mortality, LOS, or bleeding among patients with acute STEMI who underwent CABG. However, some PPCI subgroups, especially those with complicated PPCI, were at increased risk.

Two Decades of Declining Medicare Reimbursement in Cardiac Surgery

BACKGROUND

Given the uncertainty of US health care finances, an understanding of reimbursement trends has become increasingly important in the field of cardiac surgery. We aimed to assess Medicare reimbursement trends for common cardiac surgical procedures from 2000 to 2022.

METHODS

Reimbursement data were extracted from the Centers for Medicare and Medicaid Services Physician Fee Schedule Look-Up Tool during the study period for 6 common cardiac operations: aortic valve replacement, mitral valve repair and replacement, tricuspid valve replacement, Bentall procedure, and coronary artery bypass grafting. Reimbursement rates were adjusted for inflation to 2022 US dollars using the Consumer Price Index. Total percentage change and compound annual growth rate were calculated. A split-time analysis was performed to assess trends before and after 2015. Least squares and linear regressions were performed. The R2 value was calculated for each procedure, and slope was used to determine change in reimbursements over time.

RESULTS

Inflation-adjusted reimbursement decreased by 34.1% during the study period. The overall compound annual growth rate was -1.8%. Reimbursement trends differed by procedure (P < .001), with all reimbursements trending down (R2 > 0.62), except for mitral valve replacement (P = .21) and tricuspid valve replacement (P = .43). Coronary artery bypass grafting decreased the most (-44.4%), followed by aortic valve replacement (-40.1%), mitral valve repair (-38.5%), mitral valve replacement (-29.8%), Bentall procedure (-28.5%), and tricuspid valve replacement (-25.3%). In split-time analysis, reimbursement rates did not significantly change from 2000 to 2015 (P = .24) but decreased significantly from 2016 to 2022 (P = .001).

CONCLUSIONS

Medicare reimbursement significantly decreased for most cardiac surgical procedures. These trends justify further advocacy by The Society of Thoracic Surgeons to maintain access to quality cardiac surgical care.

Mitral Repair vs Replacement for Degenerative Mitral Regurgitation in Patients Aged ≥65 Years

BACKGROUND

The benefits of mitral valve repair vs replacement are well documented. However, survival benefits in the elderly population are more controversial. In this novel lifetime analysis, we hypothesize that survival benefits for valve repair vs replacement in the elderly are sustained throughout the patient's lifetime.

METHODS

From January 1985 through December 2005, 663 patients, aged ≥65 years with myxomatous degenerative mitral valve disease underwent primary isolated mitral valve repair (n = 434) or replacement (n = 229). Propensity score matching was used to balance variables potentially related to outcome.

RESULTS

Follow-up was complete in 99.1% of mitral repair and 99.6% of mitral replacement patients. In matched patients, perioperative mortality was 3.9% (9 of 229) for repair and 10.9% (25 of 229) for replacement (P = .004). Survival estimates (95% confidence limits) from 29-year follow-up for matched patients were 54.6% (48.0%, 61.1%) and 11.0% (6.8%, 15.2%) at 10 years and 20 years for repair patients, and 34.2% (27.7%, 40.7%) and 3.7% (1%, 6.4%) for replacement patients, respectively. Median survival (95% confidence limits) was 11.3 years (9.6, 12.2 years) for repair patients compared with 6.9 years (6.3, 8.0 years) for replacement patients (P < .001).

CONCLUSIONS

This study demonstrates that although the elderly population is prone to multiple comorbidities, survival benefits of isolated mitral valve repair vs replacement are sustained throughout the patient's lifetime.

Considerations for Left Atrial Appendage Occlusion During Cardiac Surgery

Atrial fibrillation is associated with an increased risk of stroke secondary to thrombus formation in the left atrial appendage. Left atrial appendage occlusion (LAAO) is an effective method of reducing the risk of stroke in patients with atrial fibrillation. Although LAAO does not remove the requirement for anticoagulation, it reduces the risk of stroke when compared to anticoagulation alone. We critically analyze the data on LAAO in cardiac surgery. We also discuss the methods of LAAO, the risks of LAAO, and patient populations that could benefit from LAAO. We discuss high-level evidence that LAAO at the time of cardiac surgery reduces the risk of stroke in patients with a history of atrial fibrillation. In patients without a history of atrial fibrillation undergoing cardiac surgery, we suggest that LAAO should be considered in select patients at high risk of atrial fibrillation and stroke, when technically feasible.

Dynamic prediction modeling of postoperative mortality among patients undergoing surgical aortic valve replacement in a statewide cohort over a 12-year period

Objective

Clinical prediction models for surgical aortic valve replacement mortality, are valuable decision tools but are often limited in their ability to account for changes in medical practice, patient selection, and the risk of outcomes over time. Recent research has identified methods to update models as new data accrue, but their effect on model performance has not been rigorously tested.

Methods

The study population included 44,546 adults who underwent an isolated surgical aortic valve replacement from January 1, 1999, to December 31, 2018, statewide in Pennsylvania. After chronologically splitting the data into training and validation sets, we compared calibration, discrimination, and accuracy measures amongst a nonupdating model to 2 methods of model updating: calibration regression and the novel dynamic logistic state space model.

Results

The risk of mortality decreased significantly during the validation period (P < .01) and the nonupdating model demonstrated poor calibration and reduced accuracy over time. Both updating models maintained better calibration (Hosmer-Lemeshow χ2 statistic) than the nonupdating model: nonupdating (156.5), calibration regression (4.9), and dynamic logistic state space model (8.0). Overall accuracy (Brier score) was consistently better across both updating models: dynamic logistic state space model (0.0252), calibration regression (0.0253), and nonupdating (0.0256). Discrimination improved with the dynamic logistic state space model (area under the curve, 0.696) compared with the nonupdating model (area under the curve, 0.685) and calibration regression method (area under the curve, 0.687).

Conclusions

Dynamic model updating can improve model accuracy, discrimination, and calibration. The decision as to which method to use may depend on which measure is most important in each clinical context. Because competing therapies have emerged for valve replacement models, updating may guide clinical decision making.

Generalizability of an EHR-network dataset to the United States for cardiovascular disease conditions: Comparison of Cerner real world data with the national inpatient sample

BACKGROUND

Electronic Health Record (EHR) data from health systems are increasingly being combined for clinical research purposes. Yet, it remains unclear whether these large EHR data sources provide a representative assessment of national disease prevalence and treatment. To evaluate this, we compared Cerner RealWorldData (CRWD), a large EHR data source, to those seen in the National Inpatient Sample (NIS) for 3 cardiovascular conditions (myocardial infarction (MI), congestive heart failure (CHF), and stroke.

METHODS

Adult patients (age ≥18 years) hospitalized with MI, CHF, and stroke were identified in both CRWD (86 health systems) and the NIS (4,782 hospitals). Patient demographics, comorbidities, procedures, outcomes (length of stay and in-hospital mortality) and hospital type (teaching or nonteaching) were compared between NIS and CRWD patients.

RESULTS

Of 86 health systems participating in CRWD, 33 were excluded for potential data quality issues which accounted for about 11% of hospitalizations in the dataset, leaving 53 for inclusion in analysis which accounted for about 89% of hospitalizations in the dataset. Between January 1, 2017 and December 31, 2018, 116,956 MI, 188,107 CHF, and 93,968 stroke hospitalizations were identified in CRWD vs 2,245,300 MI, 4,310,745 CHF, and 1,333,480 stroke hospitalizations in the NIS. Patient demographics were similar among patients in CWRD and the NIS for all 3 cardiovascular groups except for ethnicity, with underrepresentation of Hispanic individuals in CRWD vs the NIS. Patients hospitalized in CRWD had a slightly higher proportion of coded co-morbidities compared with NIS hospitalizations due to a longer potential look-back period. For patients with MI, hospital mortality, length of stay, coronary artery bypass graft (CABG) rates, and percutaneous coronary intervention (PCI) rates were similar between CRWD and NIS. Additionally, there was similar in hospital mortality and length of stay for those with CHF and stroke hospitalizations between CRWD and NIS.

CONCLUSIONS

On aggregate, characteristics of hospitalizations for MI, CHF, and stroke using EHR data from one nationwide EHR-derived database, CRWD, appears similar to characteristics of hospitalizations in the nationally representative NIS. Important limitations of CRWD include lack of geographic representativeness, under-representation of Hispanic adults, and the need to exclude health systems for missing data.

Chordal force profile after neochordal repair of anterior mitral valve prolapse: An ex vivo study

Objective

This study aimed to biomechanically evaluate the force profiles on the anterior primary and secondary chordae after neochord repair for anterior valve prolapse with varied degrees of residual mitral regurgitation using an ex vivo heart simulator.

Methods

The experiment used 8 healthy porcine mitral valves. Chordal forces were measured using fiber Bragg grating sensors on primary and secondary chordae from A2 segments. The anterior valve prolapse model was generated by excising 2 primary chordae at the A2 segment. Neochord repair was performed with 2 pairs of neochords. Varying neochord lengths simulated postrepair residual mitral regurgitation with regurgitant fraction at >30% (moderate), 10% to 30% (mild), and <10% (perfect repair).

Results

Regurgitant fractions of baseline, moderate, mild, and perfect repair were 4.7% ± 0.8%, 35.8% ± 2.1%, 19.8% ± 2.0%, and 6.0% ± 0.7%, respectively (P < .001). Moderate had a greater peak force of the anterior primary chordae (0.43 ± 0.06 N) than those of baseline (0.19 ± 0.04 N; P = .011), mild (0.23 ± 0.05 N; P = .041), and perfect repair (0.21 ± 0.03 N; P = .006). In addition, moderate had a greater peak force of the anterior secondary chordae (1.67 ± 0.17 N) than those of baseline (0.64 ± 0.13 N; P = .003), mild (0.84 ± 0.24 N; P = .019), and perfect repair (0.68 ± 0.14 N; P = .001). No significant differences in peak and average forces on both primary and secondary anterior chordae were observed between the baseline and perfect repair as well as the mild and perfect repair.

Conclusions

Moderate residual mitral regurgitation after neochord repair was associated with increased anterior primary and secondary chordae forces in our ex vivo anterior valve prolapse model. This difference in chordal force profile may influence long-term repair durability, providing biomechanical evidence in support of obtaining minimal regurgitation when repairing mitral anterior valve prolapse.

Mid-term results of endoscopic mitral valve repair and insights in surgical techniques for isolated posterior prolapse

BACKGROUND

The adoption of minimally invasive techniques to perform mitral valve repair surgery is increasing. This is enhanced by the compelling evidence of satisfactory short-term results and lower major morbidity. We analyzed mid-term follow-up results of our experience, and further compared two techniques: isolated leaflet resection and neochord implantation for posterior leaflet prolapse.

METHODS

Data for all consecutive endoscopic mitral valve repairs via video-assisted right anterior mini-thoracotomy were analyzed between December 2012 and September 2021. The early and mid-term follow-up results were ascertained. The main outcome was the incidence of mortality and the recurrence of significant mitral regurgitation during follow-up which were summarized by the Kaplan-Meier estimator and compared between treatment arms using the stratified log-rank test. Secondary outcomes were the early-postoperative results including 30-days mortality and the occurrence of major complications.

RESULTS

A total of 309 patients were included. Along with ring annuloplasty, 136 (44.4%) patients received posterior leaflet resection (122 isolated) whereas 97 (31.1%) underwent posterior leaflet chords implantation (88 isolated). Forty-nine patients had annuloplasty alone. In-hospital mortality was 1.0%. Mean follow-up was 28.8 ± 22.0 months (maximum 8.3 years). Kaplan-Meier survival rate at 5 years was 97.3 ± 1.0%, mitral regurgitation ([Formula: see text]3+) or valve reoperation free-survival at 5 years was estimated as 94.5 ± 2.3%. Subgroup time-to-event analysis for the indexed outcomes showed no statistical significance between the techniques.

CONCLUSIONS

Endoscopic mitral valve repair is safe and associated with excellent short- and mid-term outcomes. No differences were found between leaflet resection and gore-tex chords implantation for posterior leaflet prolapse.

Safety and performance of the Vienna self-expandable transcatheter aortic valve system: 6-month results of the VIVA first-in-human feasibility study

Background

The novel Vienna TAVI system is repositionable and retrievable, already pre-mounted on the delivery system, eliminating the need for assembly and crimping of the device prior to valve implantation.

Aims

The purpose of this first-in-human feasibility study was to determine the safety, feasibility, clinical and hemodynamic performance of the Vienna TAVI system at 6-month follow-up. (ClinicalTrials.gov identifier NCT04861805).

Methods

This is a prospective, non-randomized, single-arm, single-center, first-stage FIH feasibility study, which is followed by a second-stage pivotal, multicenter, multinational study in symptomatic patients with severe aortic stenosis (SAS). The first-stage FIH study evaluated the safety and feasibility, clinical and hemodynamic performance of the device in 10 patients with SAS based on recommendations by the VARC-2.

Results

All patients were alive at 3-month follow-up. 1 non-cardiovascular mortality was reported 5 months after implantation. There were no new cerebrovascular events, life-threatening bleeding or conduction disturbances observed at 6-month follow-up. The mean AV gradient significantly decreased from 48.7 ± 10.8 to 7.32 ± 2.0 mmHg and mean AVA increased from 0.75 ± 0.18 to 2.16 ± 0.42 cm² (p < 0.00001). There was no incidence of moderate or severe total AR observed. In the QoL questionnaires, the patients reported a significant improvement from the baseline 12-KCCQ mean score 58 ± 15 to 76 ± 20. NYHA functional class improved in two patients, remained unchanged in one patient. There was an increase in mean 6-min-walk distance from baseline 285 ± 97 to 347 ± 57 m.

Conclusions

This study demonstrates that using Vienna TAVI system has favourable and sustained 6-month safety and performance outcomes in patients with symptomatic severe aortic stenosis.

Primary Mitral Regurgitation and Heart Failure: Current Advances in Diagnosis and Management

Primary mitral regurgitation is a frequent etiology of congestive heart failure and is best treated with intervention when patients are symptomatic or when additional risk factors exist. Surgical intervention improves outcomes in appropriately selected patients. However, for those at high surgical risk, transcatheter intervention provides less invasive repair and replacement options while providing comparable outcomes to surgery. The excess mortality and high prevalence of heart failure in untreated mitral regurgitation illuminate the need for further developments in mitral valve intervention ideally fulfilled by expanding these types of procedures and eligibility to these procedures beyond only those at high surgical risk.

Temporal Changes in Quality Indicators in a Regional System of Care After Surgical and Transcatheter Aortic Valve Replacement

Background

Historically, quality-of-care monitoring was performed separately for transcatheter and surgical aortic valve replacement (TAVR, SAVR). Using consensus indicators, we provide a global report on the quality of care for treatment of aortic stenosis across the highest-volume treatments: transfemoral (TF) TAVR, isolated SAVR, and SAVR combined with coronary artery bypass graft.

Methods

Retrospective observational cohort study of consecutive patients in a regional system of care. Primary endpoint was 30-day and 1-year mortality (2015-2019). Secondary endpoints included rate of new pacemaker, rate of readmission, and length of stay (2012-2019). Following multivariable logistic regressions, we developed mortality case-mix adjustment models to report risk estimates.

Results

The proportion of patients receiving TAVR grew from 32% to 53% (2015-2019). Those receiving TF TAVR were significantly older, with higher rates of comorbidities. Observed 30-day and 1-year all-cause mortality after TF TAVR decreased from 3.1% to 0.6% (P = 0.03), and 13.6% to 6.6% (P = 0.09), respectively; surgical mortality rates for isolated SAVR and SAVR combined with coronary artery bypass graft were low and did not change significantly over time, ranging from 0.3% to 1.4% and from 0.9% to 3.4%, respectively at 30 days, and from 0.9% to 3.4% and from 4.7% to 6.7 at 1 year. In the TF TAVR cohort, the observed vs expected ratio for 30-day and 1-year mortality decreased significantly from 1.9 (95% confidence interval [CI] 0.9, 3.5) to 0.3 (95% CI 0.1, 0.8), and from 1.3 (95% CI 0.9, 1.7) to 0.7 (95% CI 0.5, 0.99), respectively; no change occurred in risk-adjusted surgical mortality.

Conclusions

Consensus quality indicators provide unique insights on the quality of care for patients receiving treatment for aortic stenosis.

Early and midterm outcomes after off pump coronary artery bypass surgery

Purpose

There has been debate whether off pump coronary artery bypass surgery (OPCAB) has results comparable to conventional on pump bypass surgery. This has led to the low uptake of OPCAB in the West. In India, OPCAB is the default mode of coronary revascularization. However, there is scarce data on mid-term outcomes of OPCAB in our patients. This study aims to evaluate both short and mid-term mortality and analyze factors associated with mortality.

Methods

This is a single center study of all consecutive patients undergoing isolated OPCAB from October 2014 to December 2019. Patient data was collected from hospital records and follow-up was from the hospital electronic medical records and telephone interviews. Mortality and factors contributing to survival were analyzed.

Results

Operative mortality was 2.3%. Mid-term mortality was 5.5%. Preoperative renal dysfunction, post-operative renal failure, use of the intra-aortic balloon pump (IABP), re-exploration for bleeding, postoperative stroke, ventilation > 24 h, and postoperative atrial fibrillation were associated with operative mortality. Factors associated with mid-term mortality were age > 62 years, postoperative renal failure, IABP usage, ventilation time > 24 h, and postoperative atrial fibrillation. The mean survival time was 2343.55 + / - 15.27 days and 6-year survival was 88.7%.

Conclusion

OPCAB can safely be performed with satisfactory short and mid-term outcomes. Further corroborative studies from different regions of the country or a multi-center study will help to establish the suitability of the technique in Indian patients.

Sutureless and Rapid Deployment vs. Transcatheter Valves for Aortic Stenosis in Low-Risk Patients: Mid-Term Results

BACKGROUND

Recent trials showed that TAVI is neither inferior nor superior to surgical aortic valve replacement. The aim of this study was to evaluate the outcomes of Sutureless and Rapid Deployment Valves (SuRD-AVR) when compared to TAVI in low surgical risk patients with isolated aortic stenosis.

METHODS

Data from five European Centers were retrospectively collected. We included 1306 consecutive patients at low surgical risk (EUROSCORE II < 4) who underwent aortic valve replacement by means of SuRD-AVR (n = 636) or TAVI (n = 670) from 2014 to 2019. A 1:1 nearest-neighbor propensity-score was performed, and two balanced groups of 346 patients each were obtained. The primary endpoints of the study were: 30-day mortality and 5-year overall survival. The secondary endpoint was 5-year survival freedom from major adverse cardiovascular and cerebrovascular events (MACCEs).

RESULTS

Thirty-day mortality was similar between the two groups (SuRD-AVR:1.7%, TAVI:2.0%, p = 0.779), while the TAVI group showed a significantly lower 5-year overall survival and survival freedom from MACCEs (5-year matched overall survival: SuRD-AVR: 78.5%, TAVI: 62.9%, p = 0.039; 5-year matched freedom from MACCEs: SuRD-AVR: 64.6%, TAVI: 48.7%, p = 0.004). The incidence of postoperative permanent pacemaker implantation (PPI) and paravalvular leak grade ≥ 2 (PVL) were higher in the TAVI group. Multivariate Cox Regression analysis identified PPI as an independent predictor for mortality.

CONCLUSIONS

TAVI patients had a significantly lower five-year survival and survival freedom from MACCEs with a higher rate of PPI and PVL ≥ 2 when compared to SuRD-AVR.

The modified frozen elephant trunk may outperform limited and extended-classic repair in acute type I dissection

OBJECTIVES

A better surgical approach for acute DeBakey type I dissection has been sought for decades. We compare operative trends, complications, reinterventions and survival after limited versus extended-classic versus modified frozen elephant trunk (mFET) repair for this condition.

METHODS

From 1 January 1978 to 1 January 2018, 879 patients underwent surgery for acute DeBakey type I dissection at Cleveland Clinic. Repairs were limited to the ascending aorta/hemiarch (701.79%) or extended through the arch [extended classic (88.10%) or mFET (90.10%)]. Weighted propensity score matched established comparable groups.

RESULTS

Among weighted propensity-matched patients, mFET repair had similar circulatory arrest times and postoperative complications to limited repair, except for postoperative renal failure, which was twice as high in the limited group [25% (n = 19) vs 12% (n = 9), P = 0.006]. Lower in-hospital mortality was observed following limited compared to extended-classic repair [9.1% (n = 7) vs 19% (n = 16), P = 0.03], but not after mFET repair [12% (n = 9) vs 9.5% (n = 8), P = 0.6]. Extended-classic repair had higher risk of early death than limited repair (P = 0.0005) with no difference between limited and mFET repair groups (P = 0.9); 7-year survival following mFET repair was 89% compared to 65% after limited repair. Most reinterventions following limited or extended-classic repair underwent open reintervention. All reinterventions following mFET repair were completed endovascularly.

CONCLUSIONS

Without increasing in-hospital mortality or complications, less renal failure and a trend towards improved intermediate survival, mFET may be superior to limited or extended-classic repair for acute DeBakey type I dissections. mFET repair facilitates endovascular reintervention, potentially reducing future invasive reoperations and warranting continued study.

Postcardiac Surgery Euglycemic Diabetic Ketoacidosis in Patients on Sodium-Glucose Cotransporter 2 Inhibitors

OBJECTIVES

To evaluate sodium-glucose cotransporter 2 inhibitors (SGLT2i) use and complications (euglycemic diabetic ketoacidosis [eDKA] rate, mortality, infection, hospital, and cardiovascular intensive care unit [CVICU] length of stay [LOS]) in patients undergoing cardiac surgery.

DESIGN

A retrospective study.

SETTING

At an academic university hospital.

PARTICIPANTS

Adult patients undergoing cardiac surgery.

INTERVENTIONS

SGLT2i use versus no SGLT2i use.

MEASUREMENTS AND MAIN RESULTS

The authors evaluated patients undergoing cardiac surgery within 24 hours of hospital admission (between February 2, 2019 to May 26, 2022) for SGLT2i prevalence and eDKA frequency. The outcomes were compared using Wilcoxon rank sum and chi-square testing as appropriate. The cohort included 1,654 patients undergoing cardiac surgery, of whom 53 (3.2%) were prescribed an SGLT2i before surgery; 8 (15.1%) of 53 had eDKA. The authors found no differences between patients with and without SGLT2i use in hospital LOS (median [IQR]: 4.5 [3.5-6.3] v 4.4 [3.4-5.6] days, p = 0.46) or CVICU LOS (median [IQR]: 1.2 [1.0-2.2] v 1.1 [1.0-1.9] days, p = 0.22), 30-day mortality (1.9% v 0.7%, p = 0.31), or sternal infections (0.0% v 0.3%, p = 0.69). Among patients prescribed an SGLT2i, those with and without eDKA had similar hospital LOS (5.1 [4.0-5.8] v 4.4 [3.4-6.3], p = 0.76); however, CVICU LOS was longer in patients with eDKA (2.2 [1.5-2.9] v 1.2 [0.9-2.0], p = 0.042). Mortality (0.0% v 2.2%, p = 0.67) and wound infections (0.0% v 0.0%, p > 0.99) were similarly rare.

CONCLUSIONS

Postoperative eDKA occurred in 15% of patients on an SGLT2i prior to cardiac surgery, and was associated with longer CVICU LOS. Future studies into SGLT2i management perioperatively are important.

Volume-outcome relationship in septal myectomy for hypertrophic obstructive cardiomyopathy

BACKGROUND

Septal myectomy is the gold standard treatment for refractory hypertrophic obstructive cardiomyopathy. The present study characterized the association of septal myectomy volume and cardiac surgery volume with outcomes after septal myectomy.

METHODS

Adults undergoing septal myectomy for hypertrophic obstructive cardiomyopathy were identified in the 2016 to 2019 Nationwide Readmissions Database. Centers were grouped into low-, medium-, and high-volume hospitals by tertiles based on institutional septal myectomy caseload. Overall cardiac surgery volume was similarly assessed. Generalized linear models were used to test the association between hospital septal myectomy or cardiac surgery volume and in-hospital mortality, mitral valve repair, and 90-day non-elective readmission.

RESULTS

Of 3,337 patients, 30.8% underwent septal myectomy at high-volume hospitals, whereas 39.1% were managed at low-volume hospitals. Patients at high-volume hospitals had a similar burden of comorbidities at low-volume hospitals, although congestive heart failure was more prevalent at high-volume hospitals. Despite comparable rates of mitral regurgitation, patients more commonly avoided mitral valve intervention at high-volume hospitals compared with low-volume hospitals (72.9% vs 68.3%; P = .007). After risk adjustment, high-volume hospital status was associated with reduced odds of mortality (0.24; 95% CI, 0.08-0.77) and readmission (0.59; 95% CI, 0.3-0.97). Among cases requiring mitral intervention, high-volume hospital status was associated with greater odds of valve repair (5.33; 95% CI, 2.54-11.13) relative to low-volume hospitals. Overall cardiac surgery volume was not associated with any studied outcome.

CONCLUSION

Greater septal myectomy volume, but not overall cardiac surgery volume, was associated with reduced mortality and greater mitral valve repair relative to replacement after septal myectomy. These findings suggest that septal myectomy for hypertrophic obstructive cardiomyopathy should be performed at centers with expertise in this operation.

24th hour vasoactive inotrope score is associated with poor outcome in adult cardiac surgery

OBJECTIVE

The aim of this study was to investigate the efficacy of vasoactive inotrope score at the 24th postoperative hour for mortality and morbidity in elective adult cardiac surgery.

METHODS

Consecutive patients who underwent elective adult coronary artery bypass and valve surgery in a single tertiary center for cardiac surgery between December 2021 and March 2022 were prospectively included. The vasoactive inotrope score was calculated with the dosage of inotropes that were continuing at the 24th postoperative hour. Poor outcome was defined as any event of perioperative mortality or morbidity.

RESULTS

The study included 287 patients, of whom 69 (24.0%) were on inotropes at the 24th postoperative hour. The vasoactive inotrope score was higher (21.6±22.5 vs. 0.94±2.7, p=0.001) in patients with poor outcome. One unit increase in the vasoactive inotrope score had an odds ratio of 1.24 (95% confidence interval: 1.14-1.35) for poor outcome. The receiver operating characteristic curve of vasoactive inotrope score for poor outcome had an area under the curve of 0.857.

CONCLUSION

Vasoactive inotrope score at the 24th hour can be a very valuable parameter for risk calculation in the early postoperative period.

Cerebral Embolic Risk in Coronary and Structural Heart Interventions: Clinical Evidence

Surgical and endovascular procedures for coronary and structural heart interventions carry a meaningful risk of acute stroke with greatly increased likelihood of disability and long-term neurocognitive sequelae. In the last decade, transcatheter aortic valve replacement procedures have focused our attention on a spectrum of procedure-related neurologic injuries that have led to various efforts to prevent ischemic injury with the use of embolic protection devices. As the number of patients undergoing surgical and transcatheter cardiac procedures in the United States continues to increase, the risk of iatrogenic brain injury is concerning, particularly in patient populations already at increased risk of thromboembolism and cognitive decline. In this study, we reviewed the current estimates of the incidence of iatrogenic cerebral embolization and ischemic infarction after surgical and percutaneous transcatheter interventions for coronary artery disease, stenotic aortic and mitral valves, atrial fibrillation, left atrial appendage and patent foramen ovale closure. Our findings show that every year in the United States, nearly 2 million patients undergo coronary and structural heart interventions, with approximately 8000 at risk of experiencing a symptomatic stroke and 330,225 (95% CI, 249,948-430,377) at the risk of ischemic brain injury after the procedure. Given the increased use of surgical and endovascular cardiac procedures in clinical practice, the risk of iatrogenic cerebral embolism is significant and demands careful consideration through neurologic and cognitive assessments and appropriate risk mitigation.

Isolated Tricuspid Operations: The Society of Thoracic Surgeons Adult Cardiac Surgery Database Analysis

BACKGROUND

Population-level data are limited regarding contemporary practice and outcomes of isolated tricuspid operations. We evaluated this using The Society of Thoracic Surgeons Adult Cardiac Surgery Database.

METHODS

We identified 14,704 isolated tricuspid operations from The Society of Thoracic Surgeons Adult Cardiac Surgery Database from July 1, 2011 to June 30, 2020. After excluding patients with endocarditis, tricuspid stenosis, emergent/emergent salvage status, previous heart transplants, and missing tricuspid operation type, 6507 patients remained. Endpoints were operative mortality and composite major comorbidities (permanent stroke, renal failure, prolonged ventilation > 24 hours, deep sternal wound infection, cardiac reoperations, and new permanent pacemaker implantation).

RESULTS

Isolated tricuspid operations increased from 2012 (983 cases) to 2019 (2155 cases, P < .001). Median annual center volume was 2 cases (range, 1-81). In the final cohort (n = 6507; median age, 65 years; 38.5% men), 40% had New York Heart Association class III/IV heart failure and 24% had nonelective operations. The operative mortality was 7.3% (1.7% in patients without these risk factors), and new permanent pacemaker implant rate was 10.8%. In the multivariable analysis, factors associated with operative mortality included New York Heart Association class III/IV heart failure (odds ratio [OR], 1.57), nonelective operations (OR, 1.91), tricuspid replacement (OR, 1.56), annual center volume ≤ 5 cases (OR, 1.37), and higher model for end-stage liver disease scores (all P < .05). Beating heart operation was associated with a lower adjusted risk of pacemaker implant (OR, 0.69), renal failure (OR, 0.75), and blood transfusions (OR, 0.8) compared with full cardioplegic arrest (all P < .05).

CONCLUSIONS

Isolated tricuspid repair was associated with lower adjusted mortality and morbidities than replacement. Beating heart operation was associated with lower adjusted major morbidities. The preoperative model for end-stage liver disease scores may identify high-risk patients, and early referral to higher volume centers may help improve outcomes.

Current concepts in coronary artery revascularisation

Coronary artery revascularisation can be performed surgically or percutaneously. Surgery is associated with higher procedural risk and longer recovery than percutaneous interventions, but with long-term reduction of recurrent cardiac events. For many patients with obstructive coronary artery disease in need of revascularisation, surgical or percutaneous intervention is indicated on the basis of clinical and anatomical reasons or personal preferences. Medical therapy is a crucial accompaniment to coronary revascularisation, and data suggest that, in some subsets of patients, medical therapy alone might achieve similar results to coronary revascularisation. Most revascularisation data are based on prevalently White, non-elderly, male populations in high-income countries; robust data in women, older adults, and racial and other minorities, and from low-income and middle-income countries, are urgently needed.

Clinical outcomes and quality of life after contemporary isolated coronary bypass grafting: a prospective cohort study

OBJECTIVES

The objective of the European Multicenter Registry to Assess Outcomes in coronary artery bypass grafting (CABG) patients (DuraGraft Registry) was to determine clinical outcomes and quality of life (QoL) after contemporary CABG that included isolated CABG and combined CABG/valve procedures, using an endothelial damage inhibitor (DuraGraft) intraoperatively for conduit preservation. Here, we report outcomes in the patient cohort undergoing isolated CABG.

METHODS

The primary outcome was the composite of all-cause death, myocardial infarction (MI), or repeat revascularization (RR) [major adverse cardiac events (MACE)] at 1 year. Secondary outcomes included the composite of all-cause death, MI, RR, or stroke [major adverse cardiac and cerebrovascular events (MACCE)], and QoL. QoL was assessed with the EuroQol-5 Dimension questionnaire. Independent risk factors for MACE at 1 year were determined using Cox regression analysis.

RESULTS

A total of 2532 patients (mean age, 67.4±9.2 years; 82.5% male) underwent isolated CABG. The median EuroScore II was 1.4 [interquartile range (IQR), 0.9-2.3]. MACE and MACCE rates at 1 year were 6.6% and 7.8%, respectively. The rates of all-cause death, MI, RR, and stroke were 4.4, 2.0, 2.2, and 1.9%, respectively. The 30-day mortality rate was 2.3%. Age, extracardiac arteriopathy, left ventricular ejection fraction less than 50%, critical operative state, and left main disease were independent risk factors for MACE. QoL index values improved from 0.84 [IQR, 0.72-0.92] at baseline to 0.92 [IQR, 0.82-1.00] at 1 year ( P <0.0001).

CONCLUSION

Contemporary European patients undergoing isolated CABG have a low 1-year clinical event rate and an improved QoL.

[Analysis of cardiac surgeries and operative mortality at the National Cardiovascular Institute during 2022]

Objective

To describe cardiac surgeries, their approaches, and determine operative mortality according to the type of surgery and the main complications recorded within 30 days postoperatively, performed at the National Cardiovascular Institute of Peru.

Materials and methods

A descriptive study was conducted on all patients over 18 years of age who underwent cardiovascular surgery at the National Cardiovascular Institute "Carlos Alberto Peschiera Carrillo".

Results

During the year 2022, a total of 503 cardiac surgeries were performed. Of the patients undergoing surgery, 63.6% (320) were males. Isolated valvular surgery, primarily aortic or mitral valve replacement, was the most frequent surgical procedure, with 136 surgeries (27.0%). This was followed by myocardial revascularization surgery with 110 procedures (21.9%). Throughout the year, there were 23 deaths, resulting in an overall mortality rate of 4.5%. The mortality rate for elective surgeries was 2.8%, while for emergency surgeries, it was 14.3%. The most common complication was paroxysmal atrial fibrillation (14.0%), followed by surgical site infection with 52 cases (10.3%).

Conclusions

Valvular surgery, whether isolated or combined with other procedures, was the most frequently performed. The obtained mortality rate is considered acceptable for a reference center.

A Retrospective Evaluation of Endo-Aortic Balloon Occlusion Compared to External Clamping in Minimally Invasive Mitral Valve Surgery

We compare outcomes of endo-aortic balloon occlusion (EABO) vs external aortic clamping (EAC) in patients undergoing minimally invasive mitral valve surgery (MIMVS) in the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database. Adults undergoing mitral valve surgery (July 2017-December 2018) were identified within the STS database (N = 60,607). Total 7,978 patients underwent a minimally invasive approach (including robotically assisted). About 1,163 EABO patients were 1:1 propensity-matched to EAC patients using exact matching on age, sex, and type of mitral procedure, and propensity score average matching for 16 other risk indicators. Early outcomes were compared. Categorical variables were compared using logistic regression; hospital and intensive care unit length of stay were compared using negative binomial regression. In the matched cohort, mean age was 62 years; 35.9% were female, and 86% underwent mitral valve repair. Cardiopulmonary bypass time was shorter for EABO vs EAC group (125.0 ± 53.0 vs 134.0 ± 67.0 minutes, P = 0.0009). There was one aortic dissection in the EAC group and none in the EABO group (P value > 0.31), and no statistically significant differences in cross-clamp time, major intraoperative bleeding, perioperative mortality, stroke, new onset of atrial fibrillation, postoperative acute kidney injury, success of repair. Median hospital LOS was shorter for EABO vs EAC procedures (4 vs 5 days, P < 0.0001). In this large, retrospective, STS database propensity-matched analysis ofpatients undergoing MIMVS, we observed similar safety outcomes for EABO and EAC, including no aortic dissections in the EABO group. The EABO group showed slightly shorter CPB times and hospital LOS.

A mobilization poster stimulates early in-hospital rehabilitation after cardiac surgery: a prospective sequential-group study

BACKGROUND

Patients infrequently mobilize at the surgical ward after cardiac surgery. Inactivity results in prolonged hospital stay, readmissions and increased cardiovascular mortality. Next, the course of in-hospital mobilization activities for patients is unclear. The aim was to evaluate early mobilization after heart surgery with a mobilization poster on the Activity Classification Guide for Inpatient Activities score from the American College for Sports Medicine (ACSM). Second, to develop a Thorax Centrum Twente (TCT) score to assess distinctive activities performed.

METHODS

A poster was developed for the Moving is Improving! study to stimulate hospital mobilization after heart surgery. In this sequential-group study at a cardiothoracic surgery ward, 32 patients were included in the usual care group and 209 patients in the poster mobilization group. Change of ACSM and TCT scores over time were both defined as primary endpoints. Secondary endpoints included length of stay and survival. A subgroup analysis for coronary artery bypass grafting (CABG) was performed.

RESULTS

ACSM score increased during hospital stay (p < 0.001). No significant increase of ACSM score was observed with a mobilization poster (p = 0.27), nor in the CABG subgroup (p = 0.15). The poster increased mobility to chair, toilet, corridor (all p < 0.01) and cycle ergometer (p = 0.02) as measured by the activity-specific TCT scores, without differences in length of stay or survival.

CONCLUSIONS

ACSM score measured day-to-day functional changes, without significant differences between the poster mobilization and usual care group. Actual activities measured with the TCT score did improve. The mobilization poster is now new standard care, and effects in other centers and other departments should be assessed.

TRIAL REGISTRATION

This study does not fall under the ICMJE trial definition and was not registered.

Graft thrombosis after coronary artery bypass surgery and current practice for prevention

Coronary artery bypass grafting (CABG) is the most frequently performed cardiac surgery worldwide. The reported incidence of graft failure ranges between 10% and 50%, depending upon the type of conduit used. Thrombosis is the predominant mechanism of early graft failure, occurring in both arterial and vein grafts. Significant advances have been made in the field of antithrombotic therapy since the introduction of aspirin, which is regarded as the cornerstone of antithrombotic therapy for prevention of graft thrombosis. Convincing evidence now exists that dual antiplatelet therapy (DAPT), consisting of aspirin and a potent oral P2Y12 inhibitor, effectively reduces the incidence of graft failure. However, this is achieved at the expense of an increase in clinically important bleeding, underscoring the importance of balancing thrombotic risk and bleeding risk when considering antithrombotic therapy after CABG. In contrast, anticoagulant therapy has proved ineffective at reducing the occurrence of graft thrombosis, pointing to platelet aggregation as the key driver of graft thrombosis. We provide a comprehensive review of current practice for prevention of graft thrombosis and discuss potential future concepts for antithrombotic therapy including P2Y12 inhibitor monotherapy and short-term DAPT.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2022 Update on Outcomes and Research

The Society of Thoracic Surgeons Adult Cardiac Surgery Database is the most mature and comprehensive cardiac surgery database. It is one of the most respected clinical data registries in health care, providing accurate risk-adjusted benchmarks, a foundation for quality measurement and improvement activities, and the ability to perform novel research. This report encompasses data from the years 2020 and 2021 and is the seventh in a series of reports that provide updated volumes, outcomes, database-related developments, and research summaries using the Adult Cardiac Surgery Database.

Association between hospital-acquired functional decline and 2-year readmission or mortality after cardiac surgery in older patients: a multicenter, prospective cohort study

BACKGROUND

Hospital-acquired functional decline (HAFD) is a new predictor of poor prognosis in hospitalized older patients.

AIMS

We aimed to assess the impact of HAFD on the prognosis of older cardiac surgical patients 2 years after discharge.

METHODS

This multicenter prospective cohort study assessed 293 patients with cardiac disease aged ≥ 65 years who underwent cardiac surgery at 7 Japanese hospitals between June 2017 and June 2018. The primary endpoint was the composite outcome of cardiovascular-related readmission and all-cause mortality 2 years after discharge. HAFD was assessed using the total Short Physical Performance Battery at hospital discharge.

RESULTS

The primary outcome was observed in 17.3% of the 254 included patients, and HAFD was significantly associated with the primary outcome. Female sex (hazard ratio [HR], 2.451; 95% confidence interval [CI] 1.232-4.878; P = 0.011), hemoglobin level (HR, 0.839; 95% CI 0.705-0.997; P = 0.046), preoperative frailty (HR, 2.391; 95% CI 1.029-5.556; P = 0.043), and HAFD (HR, 2.589; 95% CI 1.122-5.976; P = 0.026) were independently associated with the primary outcome. The incidence rate of HAFD was 22%, with female sex (odds ratio [OR], 1.912; 95% CI 1.049-3.485; P = 0.034), chronic obstructive pulmonary disease (OR, 3.958; 95% CI 1.413-11.086; P = 0.009), and the time interval (days) between surgery and the start of ambulation (OR, 1.260, 95% CI 1.057-1.502; P = 0.010) identified as significant factors.

DISCUSSION

HAFD was found to be an independent prognostic determinant of the primary outcome 2 years after discharge.

CONCLUSION

HAFD prevention should be prioritized in the hospital care of older cardiac surgery patients.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.