Changes in, and Predictors of, Quality of Life among Patients with Unstable Angina after Percutaneous Coronary Intervention

Rationale and objectives: Changes in, and predictors of, quality of life (QoL) among unstable angina patients are informative for both clinical and public health practice. However, there is little research on this topic, especially in healthcare settings with limited resources. This study aims to detect changes in QoL and its associated factors among patients with unstable angina after percutaneous coronary intervention. Methods: A quasi-experimental design was conducted with two repeated rounds of measurements, one month and three months after intervention, using the generic SF-36 questionnaire, in 120 patients from Vietnam National Heart Institute. A linear mixed-effects model was used to assess changes in patient QoL over time while adjusting for other covariates. Results: Only 2 out of 8 QoL subscales (social functioning and emotional well-being) declined after one month, but these tended to rise again after three months, while scores of all other QoL subscales increased. Adjusting for covariates, QoL increased slightly after one month of intervention (β=0.65, 95%CI=-0.86-2.16) but improved by almost 6 QoL points after 3 months (β=5.99, 95%CI=4.48-7.50). Four confounders significantly associated with a decline in QoL were older age, being retired, living in rural areas, and having abnormal troponin level. Conclusion: QoL of the patients with unstable angina improves significantly three months after intervention, rather than after one month. To increase QoL, it is important to address risk factors and to improve the quality of healthcare delivery.