The IMPACT Score: Does Sex Matter?

OBJECTIVE: The Index for Mortality Prediction After Cardiac Transplantation (IMPACT) score is a quantitative risk index that predicts 1-year mortality risk, derived from United Network for Organ Sharing data in which women are underrepresented. The validity of the IMPACT score in 1-year mortality risk after OHT in women is unknown. The objective of this study was to assess differences in score performance by sex. We hypothesized that the IMPACT score is a poor predictor of 1-year mortality risk after orthotopic heart transplantation (OHT) in women. DESIGN: In this external validation study, demographic and clinical characteristics were compared by sex. The IMPACT score was calculated and regression models were constructed for the entire sample and stratified by sex. Model discrimination was assessed with the area under the receiver operating characteristic curve, and calibration was assessed graphically. PARTICIPANTS: Patients 18 years and older who were first-time single OHT recipients from the International Society for Heart and Lung Transplantation registry from 2009 to 2018. MEASUREMENTS AND MAIN RESULTS: For 1-year mortality, the area under the receiver operating characteristic curve (95% confidence interval) for the full sample was 0.59 (0.57-0.60): 0.58 (0.55-0.61) for women and 0.59 (0.58-0.61) for men. The 1-year mortality was 9.4% in the overall cohort, with no difference in mortality by sex (9.0% v 9.6% women v men, p = 0.22). CONCLUSIONS: The IMPACT score exhibited poor discrimination and calibration in the International Society for Heart and Lung Transplantation 2009-2019 cohort, overall and by sex. There was no difference in 1-year mortality between women and men.

Pulmonary artery catheter use and in-hospital outcomes in cardiac surgery: a systematic review and meta-analysis.

OBJECTIVES: To determine the association of intraoperative pulmonary artery catheter (PAC) use with in-hospital outcomes in cardiac surgical patients. METHODS: MEDLINE, Embase, and Cochrane Library (Wiley) databases were screened for studies that compared cardiac surgical patients receiving intraoperative PAC with controls and reporting in-hospital mortality. Secondary outcomes included intensive care unit length of stay, cost of hospitalization, fluid volume administered, intubation time, inotropes use, acute kidney injury (AKI), stroke, myocardial infarction (MI), and infections. RESULTS: Seven studies (25 853 patients, 88.6% undergoing coronary artery bypass graft surgery) were included. In-hospital mortality was significantly increased with PAC use [odds ratio (OR) 1.57; 95% confidence interval (CI) 1.12-2.20, P = 0.04]; PAC use was also associated with greater intraoperative inotrope use (OR 2.61; 95% CI 1.54-4.41) and costs [standardized mean difference (SMD) = 0.20; 95% CI 0.16-0.23], longer intensive care unit stay (SMD = 0.29; 95% CI 0.25-0.33), and longer intubation time (SMD = 0.44; 95% CI 0.12-0.76). CONCLUSIONS: PAC use is associated with significantly increased odds of in-hospital mortality, but the amount and quality of the available evidence is limited. Prospective randomized trials testing the effect of PAC on the outcomes of cardiac surgical patients are urgently needed.

Gender Differences in Authorship and Quality of Anesthesia Clinical Practice Guidelines From 2016 to 2020 Using the Appraisal of Guidelines for Research and Evaluation II Instrument.

INTRODUCTION: Women continue to be underrepresented in academic anesthesiology. This study assessed guidelines in anesthesia journals over the past 5 years, evaluating differences in woman-led versus man-led guidelines in terms of author gender, quality, and changes over time. We hypothesized that anesthesia guidelines would be predominately man-led, and that there would be differences in quality between woman-led versus man-led guidelines. METHODS: All clinical practice guidelines published in the top 10 anesthesia journals were identified as per Clarivate Analytics Impact Factor between 2016 and 2020. Fifty-one guidelines were included for author, gender, and quality analysis using the Appraisal of Guidelines for Research & Evaluation (AGREE) II instrument. Each guideline was assessed across 6 domains and 23 items and given an overall score, overall quality score, and overall rating/recommendation. Stratified and trend analyses were performed for woman-led versus man-led guidelines. RESULTS: Fifty out of 51 guidelines were included: 1 was excluded due to unidentifiable first-author gender. In total, 255 of 1052 (24%) authors were women, and woman-led guidelines (woman-first author) represented 12 of 50 (24%) overall guidelines. Eighteen percent (9 of 50) of guidelines had all-male authors, and a majority (26 of 50, 52%) had less than one-third of female authors. The overall number and percentage of woman-led guidelines did not change over time. There was a significantly higher percentage of female authors in woman-led versus man-led guidelines, median 39% vs 20% (P = .012), as well as a significantly higher number of female coauthors in guidelines that were woman-led median 3.5 vs 1.0, P = .049. For quality, there was no significant difference in the overall rating or objective quality of woman- versus man-led guidelines. However, there was a significant increase in the overall rating of all the guidelines over time (P = .010), driven by the increase in overall rating among man-led guidelines, P = .002. The overall score of guidelines did not increase over time; however, they increased in man-led but not woman-led guidelines. There was no significant correlation between the percentage of female authors per guideline and either overall score or overall rating. CONCLUSIONS: There is a substantial disparity in the number of women leading and contributing to guidelines which has not improved over time. Woman-led guidelines included more women and a higher percentage of women. There was no difference in quality of guidelines by first-author gender or percentage of female authors. Further systematic and quota-driven sponsorship is needed to promote gender equity, diversity, and inclusion in anesthesia guidelines.

Patient-physician sex concordance and outcomes in cardiovascular disease: a systematic review.

The sex disparity in outcomes of patients with cardiovascular disease is well-described and has persisted across recent decades. While there have been several proposed mechanisms to explain this disparity, there are limited data on female patient-physician sex concordance and its association with outcomes. The authors review the existing literature on the relationship between patient-physician sex concordance and clinical outcomes in patients with cardiovascular disease, the evidence of a benefit in clinical outcomes with female patient-physician sex concordance, and the possible drivers of such a benefit and highlight directions for future study.

Intraoperative Anemia Mediates Sex Disparity in Operative Mortality After Coronary Artery Bypass Grafting.

BACKGROUND: Women undergoing coronary artery bypass grafting (CABG) have higher operative mortality than men. OBJECTIVES: The purpose of this study was to evaluate the relationship between intraoperative anemia (nadir intraoperative hematocrit), CABG operative mortality, and sex. METHODS: This was a cohort study of 1,434,225 isolated primary CABG patients (344,357 women) from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (2011-2022). The primary outcome was operative mortality. The attributable risk (AR) (the risk-adjusted strength of the association of female sex with CABG outcomes) for the primary outcome was calculated. Causal mediation analysis derived the total effect of female sex on operative mortality risk and the proportion of that effect mediated by intraoperative anemia. RESULTS: Women had lower median nadir intraoperative hematocrit (22.0% [Q1-Q3: 20.0%-25.0%] vs 27.0% [Q1-Q3: 24.0%-30.0%], standardized mean difference 97.0%) than men. Women had higher operative mortality than men (2.8% vs 1.7%; P < 0.001; adjusted OR: 1.36; 95% CI: 1.30-1.41). The AR of female sex for operative mortality was 1.21 (95% CI: 1.17-1.24). After adjusting for nadir intraoperative hematocrit, AR was reduced by 43% (1.12; 95% CI: 1.09-1.16). Intraoperative anemia mediated 38.5% of the increased mortality risk associated with female sex (95% CI: 32.3%-44.7%). Spline regression showed a stronger association between operative mortality and nadir intraoperative hematocrit at hematocrit values <22.0% (P < 0.001). CONCLUSIONS: The association of female sex with increased CABG operative mortality is mediated to a large extent by intraoperative anemia. Avoiding nadir intraoperative hematocrit values below 22.0% may reduce sex differences in CABG operative mortality.

Research Concepts and Opportunities for Early-Career Investigators in Cardiac Surgery.

Basic, translational or clinic, research is a key component of cardiac surgery. Understanding basic cellular and molecular mechanisms is key to improving patient outcomes, and cardiac surgical procedures must be compared with nonsurgical alternatives. However, guidance for early-career investigators interested in cardiac surgery research is limited. This opinion piece aims at providing basic guidance and principles based on the authors' experience.

Distal aortic biomechanics after transcatheter versus surgical aortic valve replacement: a hypothesis generating study.

BACKGROUND: Biomechanical effects of transcatheter (TAVR) versus surgical (SAVR) aortic valve interventions on the distal aorta have not been studied. This study utilized global circumferential strain (GCS) to assess post-procedural biomechanics changes in the descending aorta after TAVR versus SAVR. METHODS: Patients undergoing TAVR or SAVR for aortic stenosis were included. Transesophageal (TEE) and transthoracic (TTE) echocardiography short-axis images of the aorta were used to image the descending aorta immediately before and after interventions. Image analysis was performed with two-dimensional speckle tracking echocardiography and dedicated software. Delta GCS was calculated as: post-procedural GCS-pre-procedural GCS. Percentage delta GCS was calculated as: (delta GCS/pre-procedural GCS) × 100. RESULTS: Eighty patients, 40 TAVR (median age 81 y/o, 40% female) and 40 SAVR (median 72 y/o, 30% female) were included. The post-procedure GCS was significantly higher than the pre-procedural GCS in the TAVR (median 10.7 [interquartile range IQR 4.5, 14.6] vs. 17.0 [IQR 6.1, 20.9], p = 0.009) but not in the SAVR group (4.4 [IQR 3.3, 5.3] vs. 4.7 [IQR 3.9, 5.6], p = 0.3). The delta GCS and the percentage delta GCS were both significantly higher in the TAVR versus SAVR group (2.8% [IQR 1.4, 6] vs. 0.15% [IQR - 0.6, 1.5], p < 0.001; and 28.8% [IQR 14.6%, 64.6%] vs. 4.4% [IQR - 10.6%, 5.6%], p = 0.006). Results were consistent after multivariable adjustment for key clinical and hemodynamic characteristics. CONCLUSIONS: After TAVR, there was a significantly larger increase in GCS in the distal aorta compared to SAVR. This may impact descending aortic remodeling and long-term risk of aortic events.

Revascularization strategies for multivessel coronary artery disease based on sex and age.

OBJECTIVES: This study describes coronary revascularization strategies used by sex and age in the USA. METHODS: A sex-stratified cohort study from the National Inpatient Sample from the Agency for Healthcare Research and Quality (USA) including patients admitted for coronary revascularization with primary or secondary diagnoses of chronic coronary syndrome or non-ST elevation myocardial infarction who underwent ≥3-vessel coronary artery bypass grafting or percutaneous coronary intervention from January 2019 to December 2020. The primary outcome was the use rate of coronary artery bypass grafting or multivessel percutaneous coronary intervention. Prespecified subgroups included age and non-ST elevation myocardial infarction. RESULTS: Among 121 150 patients (21.7% women), there were no sex differences in age (women: 66.6 [66.5-66.7], men: 67.6 [67.5-67.7], standardized mean difference: 0.1) or non-ST elevation myocardial infarction incidence (women: 37.4%, men: 45.7%, standardized mean difference: 0.17). The majority of women (74.2%) and men (84.9%) underwent bypass grafting, which was unaffected by age, race or non-ST elevation myocardial infarction. Women were less likely to undergo bypass grafting than percutaneous intervention (adjusted odds ratio 0.49, 95% confidence interval 0.44-0.54; P < 0.001) and a disparity most pronounced in patients >80 years old (adjusted odds ratio 0.31, 95% confidence interval 0.22-0.45; P < 0.001). CONCLUSIONS: Most patients with multivessel coronary artery disease needing revascularization undergo bypass grafting, irrespective of sex, age or clinical presentation. The sex disparity in the use of bypass grafting is mostly seen among patients >80 years old.

Baseline Intraoperative Left Ventricular Diastolic Function Is Associated with Postoperative Atrial Fibrillation after Cardiac Surgery.

BACKGROUND: Detailed understanding of the association between intraoperative left atrial and left ventricular diastolic function and postoperative atrial fibrillation is lacking. In this post hoc analysis of the Posterior Left Pericardiotomy for the Prevention of Atrial Fibrillation after Cardiac Surgery (PALACS) trial, we aimed to evaluate the association of intraoperative left atrial and left ventricular diastolic function as assessed by transesophageal echocardiography (TEE) with postoperative atrial fibrillation. METHODS: PALACS patients with available intraoperative TEE data (n = 402 of 420; 95.7%) were included in this cohort study. We tested the hypotheses that preoperative left atrial size and function, left ventricular diastolic function, and their intraoperative changes were associated with postoperative atrial fibrillation. Normal left ventricular diastolic function was graded as 0 and with lateral e' velocity 10 cm/s or greater. Diastolic dysfunction was defined as lateral e' less than 10 cm/s using E/e' cutoffs of grade 1, E/e' 8 or less; grade, 2 E/e' 9 to 12; and grade 3, E/e' 13 or greater, along with two criteria based on mitral inflow and pulmonary wave flow velocities. RESULTS: A total of 230 of 402 patients (57.2%) had intraoperative diastolic dysfunction. Posterior pericardiotomy intervention was not significantly different between the two groups. A total of 99 of 402 patients (24.6%) developed postoperative atrial fibrillation. Patients who developed postoperative atrial fibrillation more frequently had abnormal left ventricular diastolic function compared to patients who did not develop postoperative atrial fibrillation (75.0% [n = 161 of 303] vs. 57.5% [n = 69 of 99]; P = 0.004). Of the left atrial size and function parameters, only delta left atrial area, defined as presternotomy minus post-chest closure measurement, was significantly different in the no postoperative atrial fibrillation versus postoperative atrial fibrillation groups on univariate analysis (-2.1 cm2 [interquartile range, -5.1 to 1.0] vs. 0.1 [interquartile range, -4.0 to 4.8]; P = 0.028). At multivariable analysis, baseline abnormal left ventricular diastolic function (odds ratio, 2.02; 95% CI, 1.15 to 3.63; P = 0.016) and pericardiotomy intervention (odds ratio, 0.46; 95% CI, 0.27 to 0.78, P = 0.004) were the only covariates independently associated with postoperative atrial fibrillation. CONCLUSIONS: Baseline preoperative left ventricular diastolic dysfunction on TEE, not left atrial size or function, is independently associated with postoperative atrial fibrillation. Further studies are needed to test if interventions aimed at optimizing intraoperative left ventricular diastolic function during cardiac surgery may reduce the risk of postoperative atrial fibrillation.

Postoperative pericardial effusion, pericardiotomy, and atrial fibrillation: An explanatory analysis of the PALACS trial.

BACKGROUND: In the Posterior left pericardiotomy for the prevention of atrial fibrillation after cardiac surgery (PALACS) trial, posterior pericardiotomy was associated with a significant reduction in postoperative atrial fibrillation (POAF) after cardiac surgery. We aimed to investigate the mechanisms underlying this effect. METHODS: We included PALACS patients with available echocardiographic data (n = 387/420, 92%). We tested the hypotheses that the reduction in POAF with the intervention was associated with 1) a reduction in postoperative pericardial effusion and/or 2) an effect on left atrial size and function. Spline and multivariable logistic regression analyses were used. RESULTS: Most patients (n = 307, 79%) had postoperative pericardial effusions (anterior 68%, postero-lateral 51.9%). The incidence of postero-lateral effusion was significantly lower in patients undergoing pericardiotomy (37% vs 67%; P < .001). The median size of anterior effusion was comparable between patients with and without POAF (5.0 [IQR 3.0-7.0] vs 5.0 [IQR 3.0-7.5] mm; P = .42), but there was a nonsignificant trend towards larger postero-lateral effusion in the POAF group (5.0 [IQR 3.0-9.0] vs 4.0 [IQR 3.0-6.4] mm; P = .06). There was a non-linear association between postero-lateral effusion and POAF at a cut-off at 10 mm (OR 2.70; 95% CI 1.13, 6.47; P = .03) that was confirmed in multivariable analysis (OR 3.5, 95% CI 1.17, 10.58; P = 0.02). Left atrial dimension and function did not change significantly after posterior pericardiotomy. CONCLUSIONS: Reduction in postero-lateral pericardial effusion is a plausible mechanism for the effect of posterior pericardiotomy in reducing POAF. Measures to reduce postoperative pericardial effusion are a promising approach to prevent POAF.

Postoperative atrial fibrillation: from mechanisms to treatment.

Postoperative atrial fibrillation (POAF) is the most common type of secondary atrial fibrillation (AF) and despite progress in prevention and treatment, remains an important clinical problem for patients undergoing a variety of surgical procedures, and in particular cardiac surgery. POAF significantly increases the duration of postoperative hospital stay, hospital costs, and the risk of recurrent AF in the years after surgery; moreover, POAF has been associated with a variety of adverse cardiovascular events (including stroke, heart failure, and mortality), although it is still unclear if this is due to causal relation or simple association. New data have recently emerged on the pathophysiology of POAF, and new preventive and therapeutic strategies have been proposed and tested in randomized trials. This review summarizes the current evidence on the pathogenesis, incidence, prevention, and treatment of POAF and highlights future directions for clinical research.

Regional Differences in Outcomes for Patients Undergoing Transcatheter Aortic Valve Replacement in New York State and Ontario.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has become the standard of care for a wide spectrum of patients with severe aortic stenosis. However, there are wide variations in access to TAVR among jurisdictions. It is unknown if such variation is associated with differences in postprocedural outcomes. Our objective was to determine whether differences in health care delivery in jurisdictions with high vs low access of care to TAVR translate to differences in postprocedural outcomes. METHODS: In this observational, retrospective cohort study, we identified all Ontario and New York State residents greater than 18 years of age who received TAVR from January 1, 2012, to December 31, 2018. Our primary outcomes were post-TAVR 30 day in-hospital mortality and all-cause readmissions. Using indirect standardization, we calculated the observed vs expected outcomes for New York patients, had they been treated in Ontario. RESULTS: Our cohort consisted of 16,814 TAVR patients at 36 hospitals in New York State and 5007 TAVR patients at 11 hospitals in Ontario. In Ontario, TAVR access rates increased from ∼18.2 TAVR per million in 2012 to 87.4 TAVR per million in 2018, whereas for New York State, the rates increased from 31.9 to 220.4 TAVR per million. For 30-day mortality, 3.1% of Ontario TAVR patients had an in-hospital death, compared with 2.5% of New York patients. With adjustment, this translated to an observed-expected ratio of 0.70 (95% confidence interval [CI], 0.54-0.92) for New York patients. CONCLUSIONS: Having greater access to TAVR may be associated with improved outcomes, potentially because of intervention earlier in the trajectory of the disease.

Gender Disparities in Cardiac Surgery Trials: Leadership, Authorship, and Patient Enrollment.

BACKGROUND: Studies have highlighted the paucity of women-led randomized controlled trials (RCTs) in cardiovascular medicine. Whether this finding also applies to cardiac surgery has not been evaluated. In this study, we evaluate women authorship, leadership, and women enrollment in cardiac surgery RCTs. METHODS: A systematic literature search was conducted to identify RCTs comparing 2 or more adult cardiac surgical procedures published from 2000 to 2022. Women-led RCTs were defined as those with a woman as either a first or last author. Linear regression and correlation analyses were used. RESULTS: Of 58 RCTs, 8 (13.8%) were women-led; 17 (29.3%) RCTs had no women authors. Overall, 17.9% of all authors were women, but only 1.2% of all authors were women cardiac surgeons and only 19% of the RCTs had a women cardiac surgeon among the authors. The median proportion of women authors was 14.3% by RCT, which was significantly higher in women-led compared with men-led RCTs (28.6% vs 11.8%; P = .01). No significant change in the proportion of women authors was observed during the study period. North American RCTs had a higher proportion of women authors compared with other geographic regions (28.6% vs 12.5%; P = .01). No correlation was found between the proportion of women authors and the proportion of women participants enrolled in individual RCTs. CONCLUSIONS: During the last 2 decades, only a minority of cardiac surgery RCTs were women-led, and no significant increase in women authorship occurred. There are important geographic differences in women authorship.

Characteristics of Postoperative Atrial Fibrillation and the Effect of Posterior Pericardiotomy.

BACKGROUND: Postoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery. However, only a few detailed descriptions of the arrhythmia have been reported. We aim to describe the characteristics, outcomes, and variables associated with POAF and to evaluate how posterior pericardiotomy (PP) affects POAF characteristics. METHODS: In this post hoc analysis of the Posterior left pericardiotomy for the prevention of AtriaL fibrillation After Cardiac Surgery (PALACS) trial, we describe POAF characteristics based on continuous in-hospital telemetry data. RESULTS: Of 420 patients, 103 (24.5%) developed POAF. Median time to onset was 50.3 hours; 70.9% of events occurred within 3 days. Hemodynamic instability and rapid ventricular response occurred in 8.7% and 51.5% of cases, respectively. Most POAF patients received antiarrhythmics (97.1%), 22.3% electrical cardioversion, and 40.8% systemic anticoagulation. Median POAF duration was 24.0 hours; 70.9% of cases resolved within 36 hours. Median POAF burden was 15.9%. All patients were in sinus rhythm at follow-up. POAF was associated with longer hospitalization (7 vs 6 days; P < .001), but not increased mortality or morbidity. PP reduced POAF incidence (17.7% vs 31.3%; P = .001), especially after postoperative day 2 (time to POAF onset 41.9 vs 57.1 hours; P = .01). Age was associated with POAF. Female sex, coronary artery bypass grafting, beta blockers, and PP were inversely associated. CONCLUSIONS: POAF remains frequent after cardiac surgery. Hemodynamic instability is rare, although rapid ventricular response and need for electrical cardioversion are frequent. POAF burden is significant, and the arrhythmias resolve within 30 days. PP reduces POAF especially after postoperative day 2.