The results of the present qualitative study were divided into five main categories, which are described in detail. The passage of time, the follow-up of treatments, and the improvement of the patients' condition caused the couple's fears and concerns to subside. The results of this part of the present study are in line with the findings of Momennasab et al. They stated in their study that the participants' fears and concerns gradually decreased after undergoing treatment and as their physical conditions improved (
19). Raofie Kalachayeh et al. also showed in their study that although a heart attack causes negative feelings and worries in couples, the use of "self-induction" reduced the patients' fears and worries (
20). The findings of this part of the present study are also in line with the findings of Abbasi et al., who also referred to "removing worries and mental concerns" in their study (
21). In fact, obtaining more information about the disease reduced the incidence of ineffective, immature, and excited reactions to the disease and its consequences.
The results of this part of the present study also showed that resorting to spirituality and having religious beliefs plays an important role in improving couples' relationships after open-heart surgery. A study conducted by Jalali et al. in this field showed that many patients considered their illness to be the will of their God and stated that they could continue their lives by trusting in their God. Thus, they considered the illness as an excuse to strengthen spirituality and have a greater connection with their God (
22). Dahdest and Bagheri also stated in this context that "finding meaning in problems" plays an important role in the individual's adaptation process (
23). Strategies for finding meaning in problems, along with other strategies such as patience, communication with God, satisfaction, and submission, gave couples additional strength to accept and understand the situation (
7). In explaining this finding, it can be stated that when families face difficult situations such as health problems of members, religious beliefs and practices can help them cope with feelings of helplessness and despair, restore meaning and order to their lives, and gain a sense of mastery over the situation (
10). The results of this part of the present study also showed that open-heart surgery can create positive behavioral changes among couples. This process leads to positive changes in self, relationships, well-being, and also reduces disease recurrence (
7). In this regard, Derakhsh and Karaei in their study referred to the concept of getting along and adapting and stated it as one of the components of a successful marriage (
24). Although that study was conducted on couples who were not facing a disease crisis and, in this respect, it is different from the present study, it clearly shows that couples adapt well to each other's habits over time and accept each other as they are.
The results of this part of the present study also showed that open-heart surgery can increase the emotional dependence of couples on each other over time. In this regard, the theory of interdependence states that sometimes in relationships it is necessary for people to give up some of their preferences in favor of the relationship they have with each other (
25). According to this theory, when a person does not act solely based on their own interests and also cares about the needs of their spouse, a kind of motivational transfer occurs in relationships. In this situation, they make sacrifices for their spouse, which aligns with the results of this part of the present study (
7). The results of the present study also showed that couples had changed their life's satisfaction criteria after open-heart surgery. In fact, having a heart attack, due to a sudden change in health status and transition from a healthy person to a sick person, causes a change in the individual's perspective on themselves and life (
7). Derakhsh and Karaei also showed in their study that the result of trying to maintain a marital relationship is satisfaction with life, which includes satisfaction with oneself, one's spouse, and satisfaction with having children, confirming the results of the present study (
24). Based on the definitions presented, marital satisfaction can be defined and identified in two domains: Intrapersonal and interpersonal. In the intrapersonal context, it includes the perception and evaluation of the individual alone, and in the interpersonal context, it includes the state of couple interactions (
7). Therefore, marital satisfaction is a multifactorial and multifaceted phenomenon that can be composed of numerous factors (
26).
Various perspectives have been proposed to explain the revision of life satisfaction criteria after chronic illness, including response displacement. According to this perspective, people with chronic illness try to achieve an acceptable level of quality of life despite the limitations caused by the illness by changing internal standards, values, and revising goals and expectations (
5). Existing evidence also shows that people with chronic illnesses prioritize their goals and expectations to achieve a satisfactory level of life (
10). The results of various studies in this field also show that after open-heart surgery, one of the most frequently used adaptation strategies is positive reappraisal (
7). The results of the present study also showed that after open-heart surgery, couples made every effort to maintain their marital relationship. In this regard, the results of the research by Hashemi-Golmehr and Salari Zare et al. also showed that the individual and couple outcomes of a successful marriage include having a clear and unambiguous marital relationship, satisfaction with the marital relationship, realizing common marital goals, and a sense of peace (
27,
28). The results of this part of the present study also showed that after open-heart surgery, healthy couples make every effort to protect the patient in their marital and couple relationships. The findings of this section of the present study are consistent with the findings of Safaei and Salimi and Pirsaghi et al. They also pointed out in their studies the importance of healthy and appropriate communication between couples (
27,
29,
30).
The results of the present study also showed that after open-heart surgery, spouses try to protect the patient from stress. In this regard, Gullick et al. (2017) also mentioned this issue in their study under the category of "self-protection" and stated that caregivers used strategies aimed at protecting themselves and their partners from greater stress and danger (
31). The results of the present study also showed that healthy couples provide their children with education to protect and support the patient. In this regard, Derakhsh and Karaei showed in their study that parents provide their children with age-appropriate education that leads to the formation of skills in children (
24). Distracting the patient and engaging in social activities were also other strategies used by couples. Sarhadi et al. also showed in their research that when spouses focus on household and real-life tasks, they are less able to understand the seriousness of the situation and are better able to deal with their emotions. Another strategy that couples used was accepting the disease as part of their life together (
10). Accepting the disease caused the couples to accept the complications of the disease and the changes that followed it, and after accepting them, they adopted appropriate strategies. Khansari et al. also referred to the concept of accepting the disease in their study and stated that time can be an effective factor in adapting to the disease (
32).
In this regard, Naseri and Moeeni also showed in their research that when a patient accepts failure, acceptance replaces denial and the disease is accepted (
33). In explaining this finding, it can be stated that adaptation to chronic diseases is a dynamic process, and the patient can achieve self-control by increasing their level of physical and cognitive adaptation, which is considered the ultimate goal in the management of chronic diseases (
34).
This qualitative study, while providing valuable insights, faced several important limitations. First, the purposive sampling method and limited sample size reduce the extensive generalizability of the results to the wider population. Second, the focus on participants from specific medical centers makes the influence of contextual and geographical characteristics on the findings probable. Furthermore, given the reliance on interviews, the possibility of reporting bias (such as the tendency to present a more favorable image) and the inherent influence of the researcher's presence in the data collection and interpretation process are noteworthy. Finally, it should be emphasized that the primary goal of qualitative research, such as the present study, is not statistical generalization, but rather achieving a deep and contextually grounded understanding of the phenomenon under investigation.
5.1. Conclusions
The results of this qualitative study demonstrated that positive dyadic coping is an active and reconstructive process that facilitates adaptation to illness. Couples following open-heart surgery use different approaches individually and as couples to cope with the stress that occurs. The key insight of this research is its emphasis on "preserving dyadic integrity" as the core of this process, whereby couples transform the crisis of illness into an opportunity to strengthen their shared identity. From a clinical implications perspective, these findings reveal the necessity of integrating the assessment of couple relationships into nursing care programs and designing cardiac rehabilitation interventions based on enhancing active couple participation. Therefore, it is suggested that nurses and doctors help reduce couples' anxiety by providing information about surgery, subsequent care, the recovery period, etc. Hospitals should definitely pay attention to couples' coping approaches in their educational, counseling, and rehabilitation programs, and design and implement effective psychological interventions as standard protocols for use at the hospital and cardiac rehabilitation centers level. For future research, the design of structured interventions based on these findings and a longitudinal investigation of the sustainability of these patterns are suggested.