This was a prospective study conducted on 30 men and 30 women with stable ischemic heart disease who had been fully revascularized by PCI with the aim of assessing gender differences in adherence to a 12-week comprehensive cardiac rehabilitation program and differences in the expected benefits from participating in the program.
The main findings of this study are (1) men were more adherent to the cardiac rehabilitation program. (2) Women joined the program following revascularization after a significantly longer period of time (20 days on average) compared to men. (3) After completion of the program, both men and women had a significant reduction in BMI, waist circumference, blood pressure measurements, total cholesterol, triglycerides, LDL-C, HDL-C, HbA1c, and LVEDD with an increase in LVEF. Men had a significant reduction in resting HR while women did not. (4) On comparing magnitude of change after completion of the program, no differences were observed between men and women except that women had more reduction of diastolic BP and HBA1c, while men had more reduction of total cholesterol and triglyceride levels. (5) The proportion of patients in NYHA functional class 1 increased significantly after completion of the program for both men and women.
Cardiac rehabilitation currently has a class 1 recommendation in patients with stable ischemic heart disease following cardiac surgery or PCI [19,20,21]. The benefits of participating in the cardiac rehabilitation program provided at our institution were similar to those widely reported in the literature from other institutions [21,22,23,24].
Secondary findings of this study included differences observed in baseline characteristics of these stable, revascularized ischemic heart disease patients, where a larger proportion of women were hypertensive and diabetic, had a higher BMI, larger waist circumference, higher HbA1c, and smaller LVEDD. These differences persisted even after completion of the program, except for HbA1c level where the difference became non-significant. Smoking was less prevalent among women at baseline and a smaller proportion of women was employed. After completion of the program, there was no difference between men and women regarding the number of active smokers.
It can be concluded from these secondary findings that women have more risk factors for ischemic heart disease in general (diabetes, hypertension, obesity, and unemployment). Cardiac rehabilitation seems to significantly improve better control of diabetes as assessed by HbA1c level in women.
Several clinical studies reported that women participating in cardiac rehabilitation programs tend to have a high-risk burden, namely, hypertension, diabetes mellitus, obesity, dyslipidemia, and to a lesser extent, smoking. Studies also reported that women who complete such programs gain significant benefits [25,26,27,28].
Of note is that compared to other studies, our results show a significantly larger number of active smokers at baseline among men but not among women. This is probably a social and cultural effect as smoking for women is negatively perceived in our society and women are aware of the risks posed by smoking on their children and reproductive health which makes them refrain from smoking. Similar results were found in a study done in Iran [28], while studies performed in Western countries showed no difference between men and women in the proportion of active smokers [25,26,27].
In contrast to other studies, no difference was noted between men and women in the baseline lipid profile, as other studies found that women tend to have higher levels of total cholesterol, LDL-C and HDL-C [29]. The higher level of HbA1c in women at baseline was reported by others [30].
Adherence to cardiac rehabilitation
Women in our study had a longer time to enrollment compared to men (39.17 ± 40.49 vs. 19.77 ± 10.26 days, p = 0.014). In a systemic review and meta-analysis examining the differences between men and women regarding enrollment in a cardiac rehabilitation program that included 297,219 participants from the year 2000 to 2011, it was concluded that women are 36% less likely to be enrolled in a program and thus less likely to achieve the morbidity and mortality benefits of cardiac rehabilitation. The enrollment rate for men was 45 ± 18.5% vs. 38.5 ± 20.7% for women (p < 0.001) [30].
Using the number of sessions attended as an indicator of adherence to the program, we found that women were less adherent as they attended 15.7 ± 5.72 (65.4%) sessions compared to 19.10 ± 4.77 (79.6%) sessions for men (p = 0.015). Local cultural, social, and educational barriers that face women may be responsible for this outcome. A meta-analysis examining the differences between men and women regarding adherence to a cardiac rehabilitation program that included 8176 participants from fourteen studies reported that the mean adherence rate was 68.6% for men and 64.2% for women. It was concluded that, in general, patients adhere to over two thirds of sessions. However, adherence is significantly lower in women (p < 0.001) [31].
Another study examining the reasons for withdrawal from a 12-month cardiac rehabilitation program in Canada examined 1089 women and 4833 men. Researchers reported that women were more likely than men to withdraw from the program. Causes were attributed to medical problems, especially musculoskeletal problems. Family obligations and transportation were important barriers for women, while work and lack of interest were barriers for men [32].
The same message can be concluded from a recent systemic review examining the barriers and possible solutions to the limited participation of women in cardiac rehabilitation programs. Researchers stated that a complex combination of modifiable and non-modifiable social, economic, medical, psychological, demographic, and medical challenges face women and recommended the search for solutions such as providing home-based programs designed for women to work on this gender gap [33].
Changes observed after completion of the program
Several studies reported changes (benefits) after completion of the program similar to ours. Gender disparity was investigated in a study on 12,976 patients of which 69% completed a cardiac rehabilitation program. They reported that both men and women greatly improved but women were less likely to reach target goals of the American Heart Association/American College of Cardiology (AHA/ACC) in serum triglyceride levels and HbA1c, while they were more likely to achieve them for HDL-C. No gender differences were observed regarding achieving AHA/ACC goals of BP, total cholesterol, LDL-C, BMI, smoking cessation, and medication use [34].
Another study on 858 patients assessed the prevalence of women in cardiac rehabilitation programs and their response to the program. They reported that women represented 24% of participants in their program and that improvement was observed in total cholesterol, triglycerides, LDL-C, HDL-C, fasting blood sugar, HbA1c, and N-terminal pro-brain natriuretic peptide levels in the blood, in addition to, improvements in functional capacity and heart rate recovery [29].
Study limitations
The limitations of the current study are that it comes from a single medical center with a relatively small number of patients. We did not measure the quality of life parameters and did not assess depressive symptoms which have been shown to affect outcome and adherence to cardiac rehabilitation programs in other studies. While nutritional and lifestyle advice was provided to all, actual adherence to such measures at home could not be controlled. The results of this study should be considered with the confounding effect of possible changes in the medication regimen during the 3 months period taken into account.