DISCUSSION
This study compared the quality of life (QoL) of patients with unstable
angina before and after being treated with PCI and investigated the
factors associated with improvement after treatment. The results
indicated that PCI led to improved QoL in most of the health concepts
categorized by the SF-36 questionnaire except for the social functioning
and mental health aspects. The findings are comparable with a study by
Wong et al19 which
demonstrated an increase in all the eight domains after one month of
PCI, and even after 3 months in several domains. Before the
intervention, the patients reported experiencing significant problems
with daily activities due to their physical limitations, moderate bodily
pain, and fatigue. This is in line with another study on Australian and
Danish populations showing quite similar pre-intervention QoL score to
our results.26Moreover, this study also found that 27% of the patients reported a
decrease in the subscale of mental health, which reaffirmed the
patient’s decline of mental health QoL score in our result26. This decrease in
the mental health aspect of quality of life could be due to unstable
mental status and fear of post-operation complications, which led them
to fall into stress and anxiety shortly after the intervention. This
condition would improve over time as the patient’s health stabilized
again. Our results reflected this situation as the QoL score for mental
health, and social functioning aspects dropped remarkably one month from
intervention and started to rise again after three months, even if it
was still lower than before the intervention. Our study shows that QoL
of patients with coronary heart disease may be significantly affected by
patients’ mood disorder even where methods of intervention are
physically beneficial, and more attention to mental and social support
after intervention may be warranted.
In our study, the results also indicated that some demographic factors
were associated with the QoL improvement resulting from PCI. As
expected, older people and people in rural areas had lower QoL across
the time period of the study. It is because they may have more
difficulty to access to better facilities for health care. In Vietnam,
it’s true as the health system that serves the elderly is limited which
could affect health care. This result was found in several previous
studies showing higher mortality rates after PCI in older than in
younger patients. In fact, in several interventions, advanced age was
associated with worse short-term prognosis and higher rates of
complications.28-30 The
justification for this may be that multiple comorbidities, including
chronic kidney diseases, that older patients often suffer from, were
increased risk factors for PCI.31 Besides, in the
study of Shanmugasundaram, physiological factors were also considered to
influence on the outcome after PCI, age caused an increase vascular
stiffness, which in turn results in hypertension, left ventricular
hypertrophy, and decreased left ventricular
function.31 Even
myocardial diastolic function becomes impaired with aging, and
endothelial dysfunction is more
common.31 In addition,
another factor that was related to the QoL improvement resulting from
PCI was occupation. It is true that retirees be more likely not to
improve their QoL after the treatment than the working people (workers,
freelancers, farmers, home-makers, etc.). One justification for this may
be that people being retired would undergo a series of emotional and the
salary level changing. Therefore, they would be less likely to reach a
better outcome after PCI. However, it is not surprising that retirees
living with pension had better QoL than other older age
groups.32 The study of
Isabelle Hansson et al also showed that retirees reported having an
increase in life satisfaction and a higher degree of autonomy due to
sufficient financial capacity after one year of
retirement.33 This
could be explained by the fact that older people with stable financing
would be able to focus more on their regular health care and participate
in social and cultural activities which might enhance their
psychological as well as physical QoL. The working group would have less
time to recover from the intervention than the retirees since they had
to return to their job duties as soon as they could. This elucidates the
similarity of QoL improvement between the groups on the end of the first
month after the treatment, and the higher likelihood of QoL improvement
of the retirees compared to other occupation groups after three months.
Therefore, it is necessary for further research to declare the impact of
this factor on PCI outcome. Our study also found a factor that had
impact on the effectiveness of PCI was the place of residence. The
elderly living in rural area were 4.45 times less likely to improve
their QOL after PCI than the people living in urban area. This result
was similar with the finding of the previous
study.34 They found
that ST-elevation myocardial infarction (STEMI) guidelines recommend
reperfusion by PCI with less than or equal to 90 minutes from time of
first medical contact (FMC). This strategy is challenging in rural areas
with a lack of nearby PCI-capable
hospitals.34 Another
study in China35detected that people living in rural areas had limited access to medical
services. In cases of high-impact conditions, such as acute myocardial
infarction, rural residents are less likely to receive evidence-based
therapies and may experience worse outcomes.
We found that abnormal troponin was associated with the setback of PCI
outcomes, but other sub-clinical factors are not, consistent with a
study by Prasad et al.36 which found that
patients with an elevated troponin after PCI had elevated short-term
mortality risk. The association between an elevation in troponin and
efficacy of cardiovascular diseases treatment was supported by our
study.
This study has several limitations. Some of the interviews were partly
conducted via telephone, which limited the collection of comprehensive
information as we could not observe the facial expression of the
interviewees, and some of the questions might have been difficult for
them to understand compared to direct face-to-face interaction. The
sample may not representative of the concerned population. However, as a
quasi-experiment design with repeated measures on the same patients over
time, the results could present a strong and valid case for informing
both clinical and public health practice.
The results of this study have several implications for care and follow
up in angina patients. Firstly, interventions or health care regimens
that improve the QoL of patients with unstable angina are needed, and
these methods should be prioritized to improve the social functioning
and emotional well-being of the patients, especially within the first
month after the intervention as this is the period that the patients
experience significant drop in their QoL in these two domains. Health
care service providers and caregivers are also expected to deliver
proper rehabilitation methods and guide lifestyles which can provide the
patients with the best recovery after PCI. In addition, healthcare
service providers should establish counselling programs that enhance the
knowledge and practices about post-operation care of patients. Efforts
should also be made to raise patients’ awareness on the adverse impact
of smoking and diabetes on the severity of unstable angina as well as
the efficacy of PCI treatment.