Does patient gender affect outcomes after concomitant coronary artery bypass graft and aortic valve replacement? An Australian Society of Cardiac and Thoracic Surgeons Database study

Male-female differences following concomitant coronary artery bypass grafting and aortic valve replacement surgery

AIMS

Combined coronary artery bypass grafting (CABG) and aortic valve replacement (AVR), and female sex are associated with increased perioperative mortality in clinical risk scores. This study investigated male-female differences in short-term outcome stratified by age groups.

METHODS AND RESULTS

All patients undergoing AVR and CABG between January 2001 and June 2021 at our institution were included. 1963 patients were grouped by decades into: 59 years and younger (n = 127), 60-69 (n = 471), 70-79 (n = 1070), and 80 years and older (n = 295). The primary end points of this study were 30 and 180 days mortality. Secondary end points were influence of preoperative risk factors and impact of sex on survival and postoperative major adverse events. Female patients showed higher 30 and 180 days mortality after combined CABG and AVR surgery (8.3% vs. 4.2%, P < 0.01; 15.8% vs. 9.4%, P < 0.01). Stratified by age groups, 30 and 180 days mortality remained significantly higher in septuagenarians (9.6% vs. 2.5%, P < 0.01; 16.3% vs. 7.7%, P < 0.01). Females were significantly older, had better preserved left ventricular function, and higher incidence of diabetes mellitus compared with male patients in this subgroup (P < 0.01; P = 0.01; P < 0.01). Additionally, females received significantly less internal mammary artery (IMA) conduits (P < 0.01). Female sex (OR: 3.33, 95% CI: [1.76-6.31]; 1.93, [1.22-3.06]), higher age (1.28, [1.13-1.45]; 1.16, [1.06-1.26]), diabetes mellitus (1.93, [1.03-3.60]; 1.70, [1.08-2.67]) and LVEF <30% (3.26, [1.48-7.17]; 2.23, [1.24-4.02]) were correlated with 30 and 180 days mortality, respectively. Upon multivariable testing, sex (1.77, [1.21-2.58]) and LVEF <30% (3.71, [2.39-5.76]) remained independent predictors for major adverse postoperative events. Infrequent use of IMA grafts was associated with increased 30 and 180 days mortality as well as adverse events (0.47, [0.25-0.87]; 0.46, [0.29-0.72]; 0.61, [0.42-0.88]).

CONCLUSIONS

Sex disparities in baseline characteristics may delay operative intervention in female patients. The inherent risk profiles might be responsible for outcome differences in septuagenarians.

Trends and outcomes of concomitant aortic valve replacement and coronary artery bypass grafting in the UK and a survey of practices

OBJECTIVES

Concomitant revascularization of coronary artery disease at the same time as treatment for aortic valvopathy favourably impacts survival. However, combined surgery may be associated with increased adverse outcomes compared to aortic valve replacement (AVR) or coronary artery bypass grafting in isolation.

METHODS

We retrospectively analyzed all patients who underwent AVR with bypass grafting between February 1996 and March 2019 using data from the National Adult Cardiac Surgery Audit. We used a generalized mixed-effects model to assess the effect of the number and type of bypass grafts associated with surgical AVR on in-hospital mortality, postoperative stroke, and the need for renal dialysis. Furthermore, we conducted an international cross-sectional survey of cardiac surgeons to explore their views about concomitant AVR with coronary bypass grafting interventions.

RESULTS

Fifty-one thousand two hundred and seventy-two patients were included in the study. Patients receiving 2 or more bypass grafts demonstrated more significant preoperative comorbidity and disease severity. Patients undergoing 2 and >2 grafts in addition to AVR had increased mortality as compared to patients undergoing AVR and only 1 graft [odds ratio (OR) 1.17, 95% confidence interval (CI) [1.05-1.30], P = 0.005 and OR 1.15, 95% CI [1.02-1.30], P = 0.024 respectively]. A single arterial conduit was associated with a reduction in mortality (OR 0.75, 95% CI [0.68-0.82], P < 0.001) and postoperative dialysis (OR 0.87, 95% CI [0.78-0.96], P = 0.006), but this association was lost with >1 arterial conduit. One hundred and three surgeons responded to our survey, with only a small majority believing that the number of bypass grafts can influence short- or long-term postoperative outcomes in these patients, and an almost equal split in responders supporting the use of staged or hybrid interventions for patients with concomitant pathology.

CONCLUSIONS

The number of grafts performed during combined AVR and coronary artery bypass grafting is associated with increased morbidity and mortality. The use of an arterial graft was also associated with reduced mortality. Future studies are needed to assess the effect of incomplete revascularization and measure long-term outcomes. Based on our data, current published evidence, and the collective expert opinion we gathered, we endorse future work to investigate the short and long-term efficacy and safety of hybrid intervention for patients with concomitant advanced coronary and aortic valve disease.

Females have an increased risk of short-term mortality after cardiac surgery compared to males: Insights from a national database

OBJECTIVES

Female sex is considered a risk factor for mortality and morbidity following cardiac surgery. This study is the first to review the UK adult cardiac surgery national database to compare outcomes following surgical coronary revascularisation and valvular procedures between females and males.

METHODS

Using data from National Adult Cardiac Surgery Audit, we identified all elective and urgent, isolated coronary artery by-pass grafting (CABG), aortic valve replacement (AVR) and mitral valve replacement/repair (MVR) procedures from 2010 to 2018. We compared baseline data, operative data and outcomes of mortality, stroke, renal failure, deep sternal wound infection, return to theater for bleeding, and length of hospital stay. Multivariable mixed-effect logistical/linear regression models were used to assess relationships between sex and outcomes, adjusting for baseline characteristics.

RESULTS

Females, compared to males, had greater odds of experiencing 30-day mortality (CABG odd ratio [OR] 1.76, confidence interval [CI] 1.47-2.09, p < .001; AVR OR 1.59, CI 1.27-1.99, p < .001; MVR OR 1.37, CI 1.09-1.71, p = .006). After CABG, females also had higher rates of postoperative dialysis (OR 1.31, CI 1.12-1.52, p < .001), deep sternal wound infections (OR 1.43, CI 1.11-1.83, p = .005) and longer length of hospital stay (β 1.2, CI 1.0-1.4, p < .001) compared to males. Female sex was protective against returning to theater for postoperative bleeding following CABG (OR 0.76, CI 0.65-0.87, p < .001) and AVR (OR 0.72, CI 0.61-0.84, p < .001).

CONCLUSION

Females in the United Kingdom have an increased risk of short-term mortality after cardiac surgery compared to males. This highlights the need to focus on the understanding of the causes behind these disparities and implementation of strategies to improve outcomes in females.

Impact of sex on outcomes after cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Despite advances in cardiac surgery, observational studies suggest that females have poorer post-operative outcomes than males. This study is the first to review sex related outcomes following both coronary artery bypass graft (CABG) and valve surgery with or without combined CABG.

METHODS

We identified 30 primary research articles reporting either short-term mortality (in-hospital/30 day), long-term mortality, and post-operative stroke, sternal wound infection and myocardial infarction (MI) in both sexes following CABG and valve surgery with or without combined CABG. Reported adjusted odds/hazard ratio were pooled using an inverse variance model.

RESULTS

Females undergoing CABG and combined valve and CABG surgery were at higher risk of short-term mortality (odds ratio (OR) 1.40; 95% confidence interval (CI) 1.32-1.49; I² = 79%) and post-operative stroke (OR 1.2; CI 1.07-1.34; I² = 90%) when compared to males. However, for isolated AVR, there was no difference found (OR 1.19; 95% CI 0.74-1.89). There was no increased risk in long-term mortality (OR 1.04; 95% CI: 0.93-1.16; I² = 82%), post-operative MI (OR 1.22; 95%CI: 0.89-1.67; I² = 60%) or deep sternal wound infection (OR 0.92; 95%CI: 0.65-1.03, I² = 87%). No evidence of publication bias or small study effect was found.

CONCLUSION

Females are at a greater risk of short-term mortality and post-operative stroke than males following CABG and valve surgery combined with CABG. However, there is no difference for Isolated AVR. Long-term mortality is equivalent in both sexes. PROSPERO Registration: CRD42021244603.

Sex Differences in Long-Term Survival After Major Cardiac Surgery: A Population-Based Cohort Study

Background

Little attention has been paid to the importance of sex in the long‐term prognosis of patients undergoing cardiac surgery.

Methods and Results

We conducted a retrospective cohort study of Ontario residents, aged ≥40 years, who underwent coronary artery bypass grafting (CABG) and/or aortic, mitral, or tricuspid valve surgery between October 1, 2008, and December 31, 2016. The primary outcome was all‐cause mortality. The mortality rate in each surgical group was calculated using the Kaplan‐Meier method. The risk of death was assessed using multivariable Cox proportional hazard models. Sex‐specific mortality risk factors were identified using multiplicative interaction terms. A total of 72 824 patients were included in the study (25% women). The median follow‐up period was 5 (interquartile range, 3–7) years. The long‐term age‐standardized mortality rate was lowest in patients who underwent isolated CABG and highest among those who underwent combined CABG/multiple valve surgery. Women had significantly higher age‐standardized mortality rate than men after CABG and combined CABG/mitral valve surgery. Men had lower rates of long‐term mortality than women after isolated mitral valve repair, whereas women had lower rates of long‐term mortality than men after isolated mitral valve replacement. We observed a statistically significant association between female sex and long‐term mortality after adjustment for key risk factors.

Conclusions

Female sex was associated with long‐term mortality after cardiac surgery. Perioperative optimization and long‐term follow‐up should be tailored to younger women with a history of myocardial infarction and percutaneous coronary intervention and older men with a history of chronic obstructive pulmonary disease and depression.

Male-female differences in aortic valve and combined aortic valve/coronary surgery: a national cohort study in the Netherlands

Objective

The outcome of female patients after adult cardiac surgery has been reported to be less favourable compared with the outcome of male patients. This study compares men with women with respect to patient and procedural characteristics and early mortality in a contemporary national cohort of patients who underwent aortic valve (AV) and combined aortic valve/coronary (CABG/AV) surgery.

Methods

All patients who underwent AV (n=8717, 56% male) or a combined CABG/AV surgery (n=5867, 67% male) in the Netherlands between January 2007 and December 2011 were included.

Results

In both groups, women were generally older than men (p<0.001) and presented with higher logistic EuroSCORES. In isolated AV surgery, men and women had comparable in-hospital mortality (OR 1.20, 95% CI 0.90 to 1.61; p=0.220). In concomitant CABG/AV surgery, in-hospital mortality was higher in women compared with men (OR 2.00, 95% CI 1.44 to 2.79; p<0.001). The area under the curve for logistic EuroSCORE 1 was systematically higher for men versus women in isolated AV surgery 0.82 (95% CI 0.78 to 0.86) vs 0.75 (95% CI 0.69 to 0.80) and in concomitant CABG/AV surgery 0.78 (95% CI 0.73 to 0.82) vs 0.69 (95% CI 0.63 to 0.74). Finally, (the weight of) risk factors associated with in-hospital mortality differed between men and women.

Conclusions

There are substantial male-female differences in patient presentation and procedural aspects in isolated AV and concomitant CABG/AV surgery in the Netherlands. Further studies are necessary to explore the mechanisms underlying the observed differences. In addition, the observation that standard risk scores perform worse in women warrants exploration of male-female specific risk models for patients undergoing cardiac surgery.Brief title:

A Retrospective Analysis of the Variability in Case Duration for Aortic Valve Replacement and Association With Hospital Facility Types

OBJECTIVE

Currently, there are no large-scale studies that compare differences in case duration of aortic valve replacements (AVRs). The primary objective of this study was to determine associations of hospital facility type, geographic location, case volume per year, and time of day with duration of valve replacement surgery.

DESIGN

Retrospective.

SETTING

Data from the National Anesthesia Clinical Outcomes Registry.

PARTICIPANTS

National data from university and non-university hospitals.

INTERVENTIONS

No interventions.

MEASUREMENTS AND MAIN RESULTS

All AVRs from the National Anesthesia Clinical Outcomes Registry were identified from 2010 to 2014. Mean case duration for all AVRs was 360.8 ± 95.8 minutes and was presented based on facility type (university hospital, large community hospital, medium-sized community hospital, and other); US geographic region; time of day (cases performed after 5 pm and before 7 am v day shift); and case volume per year. A multivariable linear regression model was built to determine the association of various patient, procedural, and facility characteristics with case duration. University hospitals were associated with increased case duration for AVRs (p < 0.0001).

CONCLUSIONS

With this large national database, the authors demonstrated that academic hospitals, time of day of the surgery, US region, and case volume per year for a facility are related to the case duration of AVRs.

Comparison of outcomes and presentation in men-versus-women with bicuspid aortic valves undergoing aortic valve replacement

Gender disparities in short- and long-term outcomes have been documented in cardiac and valvular heart surgery. However, there is a paucity of data regarding these differences in the bicuspid aortic valve (BAV) population. The aim of this study was to examine gender-specific differences in short- and long-term outcomes after surgical aortic valve (AV) replacement in patients with BAV. A retrospective analysis was performed in 628 consecutive patients with BAV who underwent AV surgery from April 2004 to December 2013. To reduce bias when comparing outcomes by gender, propensity score matching obtained on the basis of potential confounders was used. Women with BAV who underwent AV surgery presented with more advanced age (mean 60.7 ± 13.8 vs 56.3 ± 13.6 years, p <0.001) and less aortic regurgitation (29% vs 44%, p <0.001) and had a higher risk for in-hospital mortality (mean Ambler score 3.4 ± 4.4 vs 2.5 ± 4.0, p = 0.015). After propensity score matching, women received more blood products postoperatively (48% vs 34%, p = 0.028) and had more prolonged postoperative lengths of stay (median 5 days [interquartile range 5 to 7] vs 5 days [interquartile range 4 to 6], p = 0.027). Operative, discharge, and 30-day mortality and overall survival were not significantly different. In conclusion, women with BAV who underwent AV surgery were older, presented with less aortic regurgitation, and had increased co-morbidities, lending higher operative risk. Although women received more blood products and had significantly longer lengths of stay, short- and long-term outcomes were similar.

Sex Differences in Aortic Stenosis and Outcome Following Surgical and Transcatheter Aortic Valve Replacement

Aortic stenosis is the commonest valve defect in the developed world and is associated with a high mortality once symptomatic. There is a difference in the way that male and female hearts remodel in the face of chronic pressure overload: women develop a concentrically hypertrophied, small cavity left ventricle (LV), whereas men are more prone to the development of eccentric hypertrophy. At a cellular level, there is an increase in collagen and metalloproteinase gene expression in males suggesting a different regulation of extracellular volume composition according to sex. Male hearts with aortic stenosis appear to have more fibrosis than their female comparators. The trigger for this appears to be in part related to estrogen receptor signaling, but other factors such as renin-angiotensin activation, nitric oxide, and circulating noradrenaline levels may also be implicated. Treatment options include surgical valve replacement (SAVR) and more recently transcatheter aortic valve replacement (TAVR). Female sex may be a risk factor for adverse outcome following SAVR and conversely appears to confer a survival advantage when undergoing TAVR. Whether the lower mortality seen following TAVR in women compared with men (despite their increased age and frailty) reflects their longer life expectancy, smaller annular size (and less post-TAVR aortic regurgitation), more favorable LV reverse remodeling, or more likely, a combination of these factors remains to be established.

Lessons learned from the use of 1,977 in-situ bilateral internal mammary arteries: a retrospective study

Background

We sought to determine the early and long-term results of in-situ bilateral internal mammary artery (BIMA) grafting in patients undergoing coronary artery bypass graft surgery (CABG).

Methods

Between 1992 and 2011, 16,364 patients underwent primary isolated CABG involving at least one in-situ IMA at our institution. Among these, 1,977 patients underwent in-situ BIMA grafting: the right IMA was used to revascularize the right coronary artery system in 1,279, the circumflex system in 454 patients, and the left anterior descending (LAD) in 244. Logistic and Cox regression analyses were used to predict in-hospital mortality and cumulative late death.

Results

Late survival among BIMA patients was negatively and independently influenced by chronic obstructive pulmonary disease (hazard ratio (HR) 2.4, 95% confidence interval (CI) 1.6-3.4, p = 0.0005), age (HR 1.2, 95% CI 1.1-1.3, p < 0.001), and mediastinitis (HR 2.1, 95% CI 1.1-4.2, p < 0.03). Gender, body mass index, diabetes, choice of target for the second (non-LAD) IMA, and conduit grafted to the LAD (RIMA vs. LIMA) did not influence late survival among BIMA patients. A BIMA grafting strategy was significantly beneficial for younger patients. However, it was not associated with superior late survival for patients aged 66 years and above at the time of CABG, and showed a trend to harm among octogenarians (HR 1.05, 95% CI 0.70-1.56, p = 0.80).

Conclusions

Female gender, non-insulin dependent diabetes, and the site of second IMA anastomosis did not influence early and long-term outcomes in patients undergoing CABG with in-situ BIMA grafting. The right and left IMAs are equally effective conduits for the LAD. However, advanced age, chronic obstructive pulmonary disease, and insulin-treated diabetes mellitus have a negative impact on late survival among patients with BIMA grafts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0158-9) contains supplementary material, which is available to authorized users.

Longevity after mechanical aortic root replacement--do men live longer?

OBJECTIVE

To investigate whether longevity after mechanical aortic root replacement is influenced by the patient's gender.

METHODS

From February 1998 to June 2011, 476 patients (376 men, 100 women, mean age, 53±12 years; range, 18-88) underwent composite aortic root replacement. Of these patients, 398 (312 men) were included in the present analysis. The indications for root replacement were aortic valve dysfunction (mostly stenosis) and concomitant aneurysmal disease in 334 (83.9%), acute type A aortic dissection in 51 (12.8%), and infective endocarditis in 10 (2.5%). Other indications were technical or anatomic considerations (0.8%).

RESULTS

The women who presented for surgery were significantly older (men, 52±12 years vs women, 56±12 years; P=.01). However, no significant differences were found with regard to previous cardiac surgery (5.3%, 20 men [6.4%] vs 1 woman [1.2%]; P=.06), concomitant procedures (38%; 117 men [37.5%] vs 35 women [40.7%]; P=.62), or additive EuroSCORE (men, 5.1±2.2; women, 5.2±2.2; P=.55). The mean diameter of the ascending aorta was not significantly different between the 2 groups (men, 54±9 mm; women, 56±14 mm; P=.97). The median follow-up period was 7.4 years (range, 0-13; 2366 cumulative patient-years), with no significant difference in hospital mortality (men, 6.7% vs women, 10.5%; P=.25). Overall, men enjoyed significantly better longevity than did women. After 10 years, 73%±3% of the men and only 60%±6% of the women were alive (P=.03). Although no long-term survival benefit for either gender was found in an age-matched subgroup among young patients (P=.66), men experienced much more favorable longevity after 55 years of age (P=.04). Consequently, the longevity in men-but not in women-was equal to an age-matched normal population.

CONCLUSIONS

Overall, long-term survival after mechanical aortic root replacement was significantly better among men. However, comparing age-matched subgroups≤55 years old, no significantly different life expectancy was found after mechanical root replacement.

Prophylactic epicardial left ventricular lead implantation for biventricular pacing during operations

BACKGROUND

Surgical epicardial left ventricular (LV) lead implantation for biventricular pacing has advantages over the transvenous approach in cardiac surgical patients. We investigated the benefit of concomitant prophylactic LV lead implantation during open heart operations and subsequent lead performance after patients with impaired LV function receive a biventricular device.

METHODS

Retrospective data of 4,844 patients undergoing cardiac operations through a sternotomy between January 2001 and December 2011 were analyzed. Of these, 380 patients (7.8%) had severe impairment of LV function (contrast left ventriculogram showing grade 4 estimated ejection fraction or echocardiogram showing LV ejection fraction<0.30). LV lead implantation was performed in patients in whom recovery of LV function was unlikely. Lead performance data were collected at follow-up.

RESULTS

LV lead implantation occurred in 95 patients (25%), and 29 (30.5%) subsequently received a biventricular device. Of patients with impaired LV function, more patients with prophylactic LV leads underwent biventricular implant than those without LV leads (30.5% vs 1.1%, p<0.0001). The median interval from LV lead implantation to connection to a biventricular device was 30 days (interquartile range, 5.5 to 145 days). At a median follow-up of 437.5 days (interquartile range, 13.8 to 1198 days), the mean pacing threshold (1.25±0.46 vs 1.58±0.66 volts, p=0.069) and impedance (383.81±70.33 vs 448.6±200.1 Ohms, p=0.168) remained stable compared with time of biventricular device connection.

CONCLUSIONS

A significant proportion of patients with poor LV function undergoing cardiac operations may benefit from concomitant LV lead implantation. Subsequent lead performance appears satisfactory. Epicardial LV lead placement is easily accomplished during open heart operations and should be considered before the operation.

Gender differences in clinical outcomes among diabetic patients hospitalized for cardiovascular disease

BACKGROUND

The risk of incident cardiovascular disease (CVD) has been shown to be greater among diabetic women than men, but gender differences in clinical outcomes among diabetic patients hospitalized with CVD are not established. We aimed to determine if hemoglobin A1c (HbA1c) was associated with 30-day and 1-year CVD rehospitalization and total mortality among diabetic patients hospitalized for CVD, overall and by gender.

METHODS

This was a prospective analysis of diabetic patients hospitalized for CVD, enrolled in an National Heart, Lung and Blood Institute-sponsored observational clinical outcomes study (N = 902, 39% female, 53% racial/ethnic minority, mean age 67 ± 12 years). Laboratory, rehospitalization, and mortality data were determined by hospital-based electronic medical record. Poor glycemic control was defined as HbA1c ≥7%. The association between HbA1c and clinical outcomes was evaluated using logistic regression; gender modification was evaluated by interaction terms and stratified models.

RESULTS

Hemoglobin A1c ≥7% prevalence was 63% (n = 566) and was similar by gender. Hemoglobin A1c ≥7% vs <7% was associated with increased 30-day CVD rehospitalization in univariate (odds ratio [OR] = 1.63, 95% CI 1.05-2.54) and multivariable-adjusted models (OR 1.74, 95% CI 1.06-2.84). There was an interaction between glycemic control and gender for 30-day CVD rehospitalization risk (P = .005). In stratified univariate models, the association was significant among women (OR 4.83, 95% CI 1.84-12.71) but not among men (OR 1.02, 95% CI 0.60-1.71). The multivariate-adjusted risk for HbA1c ≥7% versus <7% among women was 8.50 (95% CI 2.31-31.27) and 1.02 (95% CI 0.57-1.80) for men. A trend toward increased 30-day/1-year mortality risk was observed for HbA1c <6% vs ≥6% for men and women.

CONCLUSIONS

Risk of 30-day CVD rehospitalization was 8.5-fold higher among diabetic women hospitalized for CVD with HbA1c ≥7% vs <7%; no association was observed among men. A trend for increased 30-day/1-year mortality risk with HbA1c <6% deserves further study.