Author + information
This study aims to investigate the impact of atrial fibrillation (Af) on the pulmonary function, exercise capacity and health-related quality of life (HRQOL) of the patients who have undergone the minimally invasive mitral valve surgery (MIMVS).
This cross-sectional study enrolled patients who have undergone the MIMVS in Guangdong Cardiovascular Institute between Jan. 2013 and Sept. 2014. All patients signed their informed consent. Patients' demographic information and medical history were recorded in self-made inventory by inquiring patients and checking the medical files. Pulmonary function which indicated by % forced vital capacity (FVC%), % forced expiration volume in one second (FEV1%), and FEV1/FVC ratio were assessed utilizing pulmonary function test (PFT). Peak oxygen consumption (peak VO2/kg) and % peak oxygen consumption (peak VO2%) were evaluated by symptom-limited cardiopulmonary exercise testing (CPET) to investigate the exercise capacity. We used the Medical Outcomes Survey 36-Item Short-Form (SF-36) to examine the HRQOL with physical component summary (PCS) and mental component summary (MCS). All data were computed by SPSS windows 17.0. The significant level was set as p < 0.05.
Fifty patients were enrolled totally with 17 patients in the atrial fibrillation group (Af group) and 33 patients in the sinus rhythm group (SR group). In order to balance the potential confounder, patients were stratified into two layers according to the age more than 40 years or lower than 40 years. Twelve patients aged less than 40 years were with sinus rhythm, so comparison was only conducted among the patients whose age was more than 40 years. There were 17 patients in the Af group and 21 patients in the SR group. No significant differences were observed in age, gender, BMI, smoking history and post-operative duration between two groups. FVC%, FEV1% and FEV1/FVC ratio were not significantly different between two groups (FVC%: 74.12 ± 11.49% vs 81.24 ± 15.55%, p = 0.125; FEV1%: 72.53 ± 12.93% vs 78.81 ± 13.89%, p= 0.162; FEV1/FVC ratio 80.51 ± 6.98% vs 78.63 ± 18.41%, p = 0.693), but FVC% and FEV1% were showed a slightly lower in the Af group than that in the SR group. Peak VO2/kg and peak VO2% were significantly lower in Af group (peak VO2/kg: 17.69 ± 3.21 ml/kg/min vs 20.98 ± 4.14 ml/kg/min, p = 0.011; peak VO2%: 61.83 ± 8.55% vs 71.86 ± 13.21%, p = 0.008). PCS and MCS were not significantly different between the two groups (PCS: 42.62 ± 8.22 vs 42.32 ± 8.89, p = 0.913; MCS: 53.77 ± 11.12 vs 51.92 ± 12.97, p = 0.645).
MIMVS patients with Af demonstrate a lower pulmonary function and exercise capacity than MIMVS patients without Af. HRQOL is not affected by the heart rhythm, but physical related quality of life of overall MIMVS patients is lower than their mental related quality of life. These current findings imply that more attention should be paid to the physical function including exercise capacity and pulmonary function of MIMVS patients with Af in the long-term post-operative management.