INTRODUCTION

The incidence of premature deaths in Ma­laysia involves 33,623 patients admitted into government hospitals for acute coro­nary syndromes (Malaysian Clinical Prac­tice Guidelines on UA/NSTEMI 2002) with a mortality rate of 15.7% total death in 2006. Coronary artery bypass surgery has increased the survival rate of the individu­als suffering from coronary heart disease (CHD). According to the Ministry of Health (MOH), coronary heart disease is one major cause of premature deaths in Ma­laysia, re­sulting in significant psychosocial and eco­nomic implications in the country (NCVD ACS Registry 1st Annual Report 2006).

Through research and improved treat­ment modalities, the survival rate for those afflicted with CHD has improved but the prevalence of the disease re­mains the same (Rosamond et al. 2007). There is statistical evidence confirming that coronary artery bypass surgery im­proves the survival rate of patients with acute or chronic coronary ar­tery dis­eases. CABG surgery has been touted as the gold standard of treatment for pa­tients with CHD. Being one of the most popular treatments to revascularize blocked coronary arteries, CABG surgery saves lives and reduces angina to im­prove the quality of life (QOL) (Mohamed et al. 2009; Khoo et al. 1997). The multi­dimensional aspects of health re­lated QOL requires a multivariate analysis of the physical, psychological, and emo­tional well-being to evaluate QOL post interventions. The impact of coro­nary artery intervention on the life function­ing post intervention is more important to the patient than being a survivor (Graham et al. 2006; Najafi et al. 2008).  The patient must evaluate their expectations of post operative recovery of CABG. A previous study reported that in most patients, CABG improved their QOL following sur­gery (Barbareschi et al. 2009). However, the recovery period for each individual varies according to their specific level of QOL which is an indicator within a specified period of time. This is not seen with a typical rehabilitation phase (Ballan & Lee 2007; Merkouris et al. 2009).

The Toronto QOL researcher's definition of QOL included the va­riables of the indi­vidual's physical, psycho­logical, and spiri­tual functioning, their con­nections with their environment, and oppor­tunities for main­taining and enhancing skills (Revicki 1989). These variables can also be seen in the World Health Organization's definition of health and health promotion (WHO 1998). Both entities agreed that the definition of QOL is multifaceted and a working definition was drafted to support the area of this study.

This study should provide nurses with the knowledge of a patient's expectations of QOL and an understanding of the value of the QOL domains as valued by the patient. Little is known about percep­tion of QOL for patients who have under­gone CABG surgery when we as nurses are actively involved in patient care. This research was expected to measure the QOL in individuals who have expe­rienced CABG by assessing the patient’s perception of functioning within the physical and mental domains of the Medical Out­comes Short Form 36 (SF-36) (Ware et al. 1994). The main objec­tive of this study was to examine the per­ception of QOL amongst post CABG pa­tients at the National Heart Institute (NHI).

MATERIALS AND METHODS

This cross-sectional descriptive study was conducted to examine the percep­tion of QOL amongst post CABG patients at the National Heart Institute (NHI). Data collection was carried out after approval from the Institutional ethicsand research committee (project code FF-032-2008). The Medical Outcomes Short Form 36 (SF-36) as general health status con­sisted of 36 multiple-choice questions sorted into two components:  physical component summary (PCS) and mental component summary (MCS) (Ware et al. 1994). It comprised of eight assessment scales: 1) physical function­ing measures the limitations in physical activity due to health problems; 2) social functioning measures the limitation of social activities because of physical and emotional problems; 3) role physical items identify limitations in usual role activities because of physical health problems; 4) bodily pain items to assess presence of pain and limitations due to pain; 5) gen­eral medical health include self evaluation of health; 6) mental health items measures psychological distress and well-being; 7) role limitation measures the limitations in usual role activities because of emotional problems; and 8) vitality items to assess energy and fatigue levels of the respon­dents. These domains were used to measure the QOL in post CABG patients at the NHI. The use of the SF-36 scales has been reported in 14 studies researching vari­ous disease processes and social condi­tions using random samples in both the United States and the United Kingdom (Ware et al. 1994). Socio-demographic data in­cluding gender, age, race, marital status, education level, occupation, in­come, du­ration of post CABG, physical exercises and duration of the physical exercises were recorded in the study. A conceptual framework of the study is de­picted in Figure 1.

The inclusion criteria of respondents were patients having CABG surgery in NHI who on agreed to sign a written con­sent. A total of 69 post CABG patients at the NHI, were recruited in this study. Statistical Pack­age for Social Science (SPSS) 12.1 for Windows was used for statistical ana­lyses. Descriptive analyses include fre­quency of the respondents’ socio-de­mo­graphic, mean and standard deviation on the score of QOL. Inferential analysis such as t-test and Analysis of Variance (ANOVA) test were used to compare the relationship between socio- demographic data and QOL of the post CABG respon­dents.

RESULTS

Six nine participants were studied. Res­pondent’s socio-demographic profiles including gender, age, race, marital sta­tus, education level, occupation, income, physical activities and duration of physi­cal activities were depicted in Table 1.

Perceptions of QOL amongst CABG patients were calculated for all compo­nents and the two summary scores for physical health and mental health is pre­sented in Table 2. The mean for each SF-36 subscales, physical domains and mental domains were classified into level of poor QOL with the score of 0-49 and good level of QOL with the score of 50-100. The find­ings showed that post CABG respon­dents possessed a good level of QOL with an average score of 57.80 ± 25.145. In Table 2, the MCS score (64.02 ± 25.470) was found to be higher than PCS score (51.58 ± 24.881). Results of this study it revealed that post CABG patients in NHI were reported to have good QOL.

Student t-test was performed to com­pare the mean of SF-36 subscale and socio-demographic profiles. There were signifi­cant differences between the role func­tioning of sub-components of physical functioning domain with gender (t= .286, p <0.05). Male respondents have higher score in role physical sub-components (56.91±47.119) compared to female (29.55 ±22.001). Gender however, was not significantly different with other sub-domains of SF-36 items (Table 3). 

Duration of physical exercises of more than 20 minutes have positive effects on both the physical component (t=2.738, p < 0.05) and mental component (t=7.326, p < 0.05) (Table 4). Marital status of the respondents was found not signifi­cantly different with other sub-domains of SF-36 items.

Analysis of Variance (ANOVA) test was used to compare the mean of SF-36 subscale and the socio-demographic pro­files. Ethnicity, age groups and post CABG period showed no significant differ­ence with sub-domains of SF-36 items.

The education level showed significant differ­ence with the general health of physi­cal component domain (F= 4.962, p <0.05). The findings showed that the highest score was for tertiary education (60.45±9.28), fol­lowed by primary education (43.17 ± 17.145) and secondary education (41.61 ± 16.835). All other-domains of SF-36 items were found to be not significant with the education level (Table 5).

Respondents’ income showed signifi­cant difference with the role physical (F= 5.300, p <0.05) and physical component summary (F= 3.505, p <0.05) of the SF-36 items. An income of RM1001 to RM 3500 score highest (86.36 ± 32.333), compared with an in­come of RM 3501 (52.27±43.952) and less than RM1000 (38.30±46.582). There were significant differences with the role emotional (F=3.434, p<0.05), mental health (F=3.835, p<0.05) and mental compo­nent sum­mary (F=4.272, p<0.05). The respon­dents’ income of RM 1001 to RM 3500 was found to have the highest score of role emo­tional (90.91±30.151), mental health (88.00±14.311), and men­tal component summary (83.59±20.308) (Ta­ble 6). However, other sub-domains did not show significant difference as de­picted in Table 6.

DISCUSSION

The results of this study showed that post CABG patients in NHI have good QOL. The MCS scores seemed to have better rating than the PCS scores of the SF-36. This result was in accor­dance to earlier findings which reported on the importance of having a structured multi-disciplinary reha­bilitation program with focus on emo­tional support, information and education needs (Merkouris et al. 2009; Järvinen et al. 2003). A previous study revealed that some patients may present with physical health problems which were re­flected in their health related to QOL five to fifteen years post CABG (Herlitz et al. 2009:  Rantanen et al. 2009). In contrast, another study by Peric et al. (2010) about predictive fac­tors for decreasing QOL six months post CABG were female gender, diabetes mellitus, low ejection fraction, and the presence of postoperative com­plications. This could be attributed to different lifestyles among the two popula­tions.

This study reported gender-related dif­ferences in QOL with the role physical functioning among the post CABG res­pondents. There were signifi­cant differ­ences between the role func­tioning sub-components of physical func­tioning do­main with gender. Male res­pondents have higher score in role physical sub-components, compared to female. Ac­cording to Phillips et al. (2003), even af­ter adjusting for known risk factors for compromised QOL, women do not show quality benefits of CABG surgery that men do. However, Koch et al. (2007) empha­sized that attention related to preoperative conditions, such as conges­tive heart failure, anemia, diabetes, and advanced age, were indicative of greater risk in both women and men for lower survival post CABG surgery. Most im­portantly the efforts to reduce or modify such disease prevalence earlier in women, may allow longer survival after surgical intervention. Differ­ences in post­operative survival between women and men were related to gender differences in the distribution of preoperative risk factors (Koch et al. 2003; Peters 2001).

Education levels showed sig­nificant difference with the general health of physical component domains of SF-36 items. Conversely, respondents with ter­tiary education possessed the highest score followed by primary education and lastly secondary education. A study by LeGrand et al. (2006) confirmed that most patients report an improvement in their QOL following coronary ar­tery by­pass surgery. However, the re­covery pe­riod for each individual varies in congru­ent with the above mentioned study.

Consequently, our results showed that physical exercises and its duration have signifi­cant impacts on the QOL as re­ported in this study. Exercises of more than 20 minutes have positive effects on all physical and mental component do­mains except for the physical functioning sub-domain. Physical exercises per­formed by CABG patients enhanced mental health as it entails mental en­gagements which thereby reduce the stress level of the patients. Generally, the

QOL score depend on the per­formance of physical exercises especially for the CABG patients, although, other studies have stated that the survival and QOL benefits should not be re­garded as a substitute for revascularization (Markou et al. 2008; Najafi et al. 2008). A previous study by Järvinen et al. (2003) reported that elderly patients not only have higher mortality and morbidity but also derive less benefit from CABG on certain as­pects of QOL.

The NHI pro­vides cardiac rehabilitation program to pre and post CABG patients whilst hospi­talization. Subsequently, the advance­ment of technology and mass media deployed at the NHI has created awareness to­wards CABG patients with regards their con­dition and continuity of care. Once CHD pa­tients are discharged, they are closely monitored and put on regular follow up. They are contacted via telephone by the car­diac clinic staff if they fail to turn up on the appointment date. Similar findings were reported regarding the importance of having supportive groups which are required to monitor the progression in the physical and mental domains of CHD patients (Bergh et al. 2007).

CONCLUSION

The post CABG patients had good QOLS post operatively. They were able to make comprehensive lifestyle changes through frequent physical exercises to accommo­date their needs. This could be the result of pre and post CABG counseling and health education. This study confirmed the importance of cardiac rehabilitation program as supporting evidence in the improvement of quality of life amongst CABG patients.

ACKNOWLEDGMENTS

The authors would like to express their greatest gratitude to UKM fundamental grant, NHI Manage­ment for granting us the permission to collect the data in this study. The authors sincerely thank the Institution for sanc­tioning the grant FF-032-2008. In addi­tion, the authors are thankful to Assoc Prof. Dr. Srijit Das, and Dr. Tan Aik Kah for their critical comments on the paper.