| Summary: | 碩士 === 國立陽明大學 === 物理治療暨輔助科技學系 === 96 === Background and purpose: Functional capacity (FC) is an important predictor of prognosis and quality of life in cardiac patients. However, FC after heart valve surgery exists variable. Some studies have mentioned the residual cardiac dysfunction and hemodynamic disturbed may be the determinants of functional capacity decrease in the cohort but lack of data evidence directly. The knowledge of special considerations in patients after valvular surgery remains insufficient for clinical practice. The aim of this study is to identify predictors of functional capacity in patients with heart valve surgery four months after surgery and difference between three months after discharge.
Study design: Retrospective follow-up exploratory study
Methods: Patients were referred to heart center if they have been received heart valve surgery. Baseline demographic and clinical characteristics were collected by chart review retrospectively. Symptom-limited exercise tests were done at two weeks and three months after discharge to evaluate FC (Peak oxygen consumption, Peak VO2 ml/kg/min) and exercise cardiopulmonary characteristics. And whether patients choose to attend phase two cardiac rehabilitation (CR II) or not was defined as environmental-behavioral characteristics. By multiple regression, we focused on four domains (personal demographic, clinical characteristics, exercise cardiopulmonary response, and exercise training) to identify the possible predictors for functional capacity.
Results: There were 249 patients recruited for 1st exercise test two weeks after discharge. 178 patients were dropped out during three months due to reasons like lost contact or personal factors and etc. Finally, there were 116 cases included for analysis. FC of 116 cases improved 29% averagely at 3 months after discharge. Around 73% patients with exercise training improved more than 15%, and only 42% patients without exercise training got significant improvement. By multiple regression analysis, variables in personal demographic characteristics, such as age, gender, educational level were significantly associated with FC at three months after discharge (R2=30%), but none for FC change. In clinical characteristics, those with a diagnosis of coronary artery disease (CAD), a higher preoperational triglyceride and a lower forced vital capacity(FVC) had a lower FC at three months after discharge significancely (R2=37%). In exercise responses, only peak VO2, rest systolic blood pressure (SBP) were significantly associated with FC at three months after discharge (R2=49%). Meanwhile, peak VO2, rest SBP, and peak dead space/tidal volume (VD/VT) could predict FC change (R2=30%). When we combine four domains into consideration, only educational level, preoperational triglyceride, and baseline peak VO2 were significant predictors of FC at three months after discharge (R2=58%). Only exercise cardiopulmonary characteristics at baseline, such as peak VO2, rest SBP, peak VD/VT could predict FC change significantly (R2=31%).
Conclusion: Our data showed that functional capacity of patients with heart valve surgery could improve after four months after surgery if they received comprehensive post operation care, including in-patient and out-patient cardiac rehabilitation. Higher educational level, lower preoperational triglyceride and higher baseline FC can predict higher FC at three months after discharge. However, lower FC, lower rest SBP, and higher peak VD/VT at baseline were significant predictors of higher FC change after discharge.
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