Female gender is associated with impaired quality of life 1 year after coronary artery bypass surgery.
Phillips Bute B, Mathew J, Blumenthal JA et al.;
Commented by , 30 Dec 2003
Background
Baseline demographic, physical and psychological characteristics differ between men and women presenting for coronary artery bypass (CABG) surgery. Gender-related differences for two of the most important post-CABG outcomes - quality of life (QOL) and cognitive functioning - remain unclear.
Purpose
Evaluate gender-related differences in QOL and cognitive function 1-year post-CABG.
Methods
280 prospective patients (96 women; 184 men) participated in neurocognitive and QOL evaluation at baseline (preoperatively) and 1-year post-CABG. Cognitive function was measured with a neuropsychological battery of tests, reduced to four cognitive domains with factor analysis.
A subjective measure of cognitive difficulties was also completed. Several valid and reliable measures were used to evaluate QOL parameters: functional capacity, Instrumental Activities of Daily Living (IADL), work activities, general health perception, social activities, social support, depressive and anxiety symptoms, and physical symptom limitations.
The relationship of gender to 1-year QOL and cognitive function was examined by multivariable linear regression. Covariates included age, education, marital status, medical comorbidity, hypertension, diabetes, race, baseline QOL and cognitive status.
Results
At baseline, women were older, less educated, less likely to be married, had higher rates of hypertension, diabetes and higher comorbidity scores, and more likely to be racial minorities. Adjusting for covariates, there were no gender-related differences on baseline cognitive domains. There were significant gender effects in every QOL measure at baseline, with women at a disadvantage.
In most measures, the sample as a whole improved 1 year post-CABG, with the exception of social support and cognitive function. Controlling for baseline differences, women were at greater risk for subjective cognitive difficulties; objectively, women had more problems with ‘concentration/attention’, while men had more difficulty with ‘figural memory’.
Women also had increased anxiety, and reduced functional capacity, IADL and work activities. Women had more depressive symptoms at each time point, with no gender effect at follow-up, controlling for baseline measures.
Discussion
The authors have replicated previous research, demonstrating discrepant gender-related characteristics preoperatively. Women tend to be older, less educated, with greater medical and psychosocial morbidity.
Controlling for these pre-existing risk factors, the findings suggest women do not experience the same long-term benefits in QOL as men. At 1-year post-CABG, women have increased anxiety, and reduced work-related activities, IADL and functional capacity.
The discrepancy in cognitive function at 1-year is less striking. Subjective cognitive difficulties and decreased ‘concentration/attention’ performance may reflect the increased persistence of depression in women, as predicted by preoperative depression.
Attempting to explain the reduced QOL benefits for women postoperatively, the authors point to research demonstrating reduced physical benefit in women post-CABG. While the authors controlled for preoperative risk factors, they did not account for these important medical variables at 1-year, and were therefore unable to account for these important confounds.
An additional limitation was that with the exception of the objective cognitive measures which failed to demonstrate any consistent gender-related differences, the main outcomes were subjective in nature.
Notwithstanding these limitations, the study highlights the importance of QOL as an important postoperative outcome; particularly given recent findings that QOL (1) and depression (2) are associated with post-CABG morbidity and mortality. The research extends beyond previous findings, whereby women appear to not only “start off worse” but may also “finish worse than men” in many QOL domains. Thus, postoperative rehabilitative programs need to take such gender-related differences into consideration and tailor interventions accordingly.
References
1. Rumsfeld JS, MaWhinney S, McCarthy M Jr, et al. Health-related quality of life as a predictor of mortality following coronary artery bypass graft surgery. Participants of the Department of Veterans Affairs Cooperative Study Group on Processes, Structures, and Outcomes of Care in Cardiac Surgery. JAMA 1999; 281: 1298–1303.
2. Connerney I, Shapiro PA, McLaughlin JS, et al. Relation between depression after coronary artery bypass surgery and 12-month outcome: a prospective study. Lancet 2001; 358: 1766–1771