Detection of gender differences in incomplete revascularization after coronary artery bypass surgery varies with classification technique

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.

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.

Trends in mortality risks among 94,328 patients surviving 30days after a first isolated coronary artery bypass graft procedure from 1987 to 2006: A population-based study

BACKGROUND

Updated knowledge about survival after coronary artery bypass graft (CABG) surgery is needed. We examined 20-year trends in 4-year survival after a first isolated CABG procedure, compared with that of the general population.

METHODS

We identified 94,328 patients surviving 30days after a first isolated CABG 1987-2006 from the Swedish Inpatient Register.

RESULTS

Crude annual mortality rates remained stable at approximately 1% in patients aged 18-54years and at approximately 2% in those aged ≥55years. After adjustment for comorbidities, 4-year survival in men aged 18-54 and ≥55years improved by 37% (HR: 0.63, 95% CI, 0.46-0.88) and 31% (HR: 0.69, 95% CI, 0.63-0.76), respectively, (1987-1991 vs. 2002-2006). The corresponding estimate for women aged ≥55years was 38% (HR: 0.62, 95% CI, 0.52-0.75), with no significant change in survival in women aged <55years (HR: 1.02, 95% CI, 0.52-2.03). Men and women aged <55years had higher mortality than the general population, with standardized mortality ratios (SMR) of 1.76 (95% CI, 1.35-2.22) in men and 4.49 (95% CI, 2.74-6.68) in women during the last period (2002-2006). In contrast, patients aged ≥55years had better survival with a SMR of 0.74 (95% CI, 0.70-0.78) in men and 0.82 (95% CI, 0.74-0.91) in women during 2002-2006.

CONCLUSION

During 1987-2006, there was a significant improvement in survival after CABG for all categories, except in women aged <55years. Men and women aged ≥55years who survived the first 30days after CABG had a lower mortality risk than the general population.

Applying the Gender Lens to Risk Factors and Outcome after Adult Cardiac Surgery

Background

Applying the gender lens to risk factors and outcome after adult cardiac surgery is of major clinical interest, as the inclusion of sex and gender in research design and analysis may guarantee more comprehensive cardiovascular science and may consecutively result in a more effective surgical treatment as well as cost savings in cardiac surgery.

Methods

We have reviewed classical cardiovascular risk factors (diabetes, arterial hypertension, hyperlipidemia, smoking) according to a gender-based approach. Furthermore, we have examined comorbidities such as depression, renal insufficiency, and hormonal influences in regard to gender. Gender-sensitive economic aspects have been evaluated, surgical outcome has been analyzed, and cardiovascular research has been considered from a gender perspective.

Results

The influence of typical risk factors and outcome after cardiac surgery has been evaluated from a gender perspective, and the gender-specific distribution of these risk factors is reported on. The named comorbidities are listed. Economic aspects demonstrated a gender gap. Outcome after coronary and valvular surgeries as well as after heart transplantation are displayed in this regard. Results after postoperative use of intra-aortic balloon pump are shown. Gender-related aspects of clinical and biomedical cardiosurgical research are reported.

Conclusions

Female gender has become an independent risk factor of survival after the majority of cardiosurgical procedures. Severely impaired left ventricular ejection fraction independently predicts survival in men, whereas age does in females.