Sex differences in quality of life of patients following percutaneous coronary intervention in Vietnam

Studies regarding the effectiveness of medical treatments and patient recovery from cardiac interventions have attracted growing interest. While mortality and objective measures of morbidity are traditionally considered key clinical outcome measures, health-related quality of life (HRQoL) has been increasingly utilized in contemporary research due to its capability to provide patient-reported outcomes covering both symptoms and the functional impact of the illness and its treatments [1‐3]. Patients therefore provide their own perspectives in defining health status, both in terms of how they feel (distress and well-being) and how they evaluate their own health and future prospects [4, 5].

Sex differences in clinical outcomes after percutaneous coronary intervention (PCI) have been widely documented in current literature, and typically suggest that women have worse post procedural outcomes than men (e.g., higher mortality and morbidity rates) [6‐11]. Among studies that have addressed the gender differences in HRQoL outcomes after PCI, the majority of them have observed poorer post-procedure HRQoL in women patients, especially in the short and medium-term [7, 8, 12‐14], while some publications reported no significant differences between the sexes in HRQoL in the long-term post procedure (3 and 10 years) [6, 12]. Explanations for the sex differences in outcomes in these studies include biological factors such as age and cardiovascular risk factors, and social factors such as social support and health care access [7, 15]. However, such findings are inevitably context-specific, meaning it remains unclear that such explanations can be applied into different populations and cultures. Hence, more comprehensive studies are required to explore this aspect, especially in limited resources countries where the health of women is often prioritised less than that of men.

Our study is the first to utilize data from a PCI registry in Vietnam to examine the HRQoL between men and women at 30 days and 12 months post discharge.

This study is the first using PCI registry data at 30 days and 12 months to compare HRQoL after PCI between men and women in a low-and-middle income country where men are culturally more prioritized than women. The results indicated that women patients experienced poorer HRQoL after PCI in comparison with men. The differences were seen more clearly at 30 days than at 12 months post discharge, perhaps suggesting a higher recovery rate in the women patients. These findings contribute to the literature from developing countries in regard to HRQoL between men and women after an effective revascularization such as PCI. Further, they are potentially beneficial for defining an appropriate intervention strategy targeting patient outcomes after PCI in Vietnam. It appears that women are in greater need, particularly at 30 days suggesting that sex-specific health care approaches should be taken into consideration in providing care for PCI patients.

Available studies in literature that examined the sex differences in HRQoL outcome among PCI patients have utilized a range of HRQoL measurements. Using the same EQ-5D-3L instrument as our study, the Australian state-wide study including data from 30 cardiac centres reported poorer HRQoL outcome of women in comparison with men and confirmed being female was a significant predictor for poor HRQoL at 30 days [7]. In other studies using different HRQoL instruments such as Short-Form 12 questionnaire, 36-Items Short-Form Health Survey and the MacNew Heart Disease Health-Related QoL questionnaire, some reported general worse health condition in women [6, 12], while there were others indicating women were lower in specific areas of physical, disease-specific HRQoL and mental health [13, 29]. Findings in our study are consistent with previous findings regardless the HRQoL instruments, indicating that women had more problems in mobility, personal care and pain/discomfort at 30 days after PCI. In other studies that investigated the HRQoL outcomes between men and women after myocardial infarction or coronary artery diseases, similar results were documented. Women patients were more HRQoL disadvantaged than male counterparts at short and mid-terms such as 30 days, 1 year and 2.5 years [30‐32]. The available evidence suggested that HRQoL declines with the presence and intensity of cardiovascular risk factors such as hypertension, lipid metabolism disorders, diabetes, and sedentary lifestyle. It was also indicated that the more cardiovascular factors present at the same time, the worse the HRQoL score [6, 33]. Furthermore, older age was considered as an associated factor with low HRQoL scores due to the restrictions and difficulties in familial, social and professional life for the elderly [6]. Our results were consistent with these explanations, showing that women undergoing PCI were older, lower in education and income, and had significantly higher rates of cardiovascular risks in comparison with men counterparts. However, our study did not indicate the associated factors for worse HRQoL outcomes, more dedicated studies need to address this issue in future and more sex-specific health care programs should be implemented.

Studies regarding HRQoL of PCI populations have also documented no sex differences in long-term follow-up and have shown that women improved better than men in HRQoL over time. It was reported that HRQoL differences between men and women PCI patients were seen in short and mid-terms such as 1 months and 6 months but not for longer terms such as 3 years or 10 years [6, 12]. Similarly, a study of Włodarczyk showed men performed higher in the physical and emotional aspects of life at 2 and 3 months follow-ups after myocardial infarction, but not at 12 months assessment [34]. This finding was reinforced in our study with no statistically significant difference in HRQoL of the men and women at 12 months. Regarding the HRQoL improvement of patients post discharge, findings remain controversial in current literature. While both sexs reported significant improvement over time, women were more likely to have better recovery in HRQoL [6]. Another study concluded that women patients were reported with slower physical improvement compared to men [29]. In our study, women were found to have better recovery in mobility compared to men. The reason for this change remains unclear and further research should be conducted to investigate this issue further.

This study has some limitations. Our results may not be generalisable to the entire Vietnamese adults because this study was based on registry data collected from only one leading cardiac hospital in Vietnam. Given the hospital is a relatively advanced provider of cardiac intervention, it may be that the outcomes observed elsewhere might be worse, and hence flagging an even greater need for better follow-up care in this patient group. Another limitation is that we could not collect HRQoL before PCI, therefore could not conclude the effect of PCI on HRQoL change. This was because many of the patients were admitted as emergency cases, and there was not an opportunity to collect data prior to PCI. In addition, due to the lack of specific value set for the EQ-5D-3L derived from preferences of the Vietnamese population, the Malaysian value set was used to generate the index score due to the similarity between the two populations. We strongly encourage the development of a specific HRQoL value set for the Vietnamese population to increase the precision of results obtained. Lastly, although potential confounding factors were adjusted, the effect of unmeasured confounders and/or residual confounding cannot be ruled out. This may have obscured the relation between gender and QoL measures, if any.

Our study utilizing data from the first Vietnamese PCI registry provides an opportunity to investigate the sex differences in HRQoL post discharge. Overall, women obtained worse HRQoL after PCI in comparison with men. The differences were seen more clearly at 30 days than at 12 months post discharge, and women were reported to have better recovery in mobility compared to men.