Preoperative sarcopenia is associated with late mortality after off-pump coronary artery bypass grafting
Homare Okamura, Naoyuki Kimura, Makiko Mieno, Koichi Yuri, Atsushi Yamaguchi
Abstract
OBJECTIVES: We investigated the association between sarcopenia (a marker of frailty) and outcomes after coronary artery bypass grafting (CABG). METHODS: This study included 304 patients who underwent elective isolated off-pump CABG at our hospital between October 2008 and August 2013. Psoas muscle area was measured on preoperative computed tomography scans. Sarcopenia was defined as the lowest sex-specific quartile of the psoas muscle area index (the psoas muscle area normalized for height). Patients were categorized into a sarcopenia group (76 patients) and a non-sarcopenia group (228 patients). Patients in the sarcopenia group were older and showed a lower body mass index, lower serum haemoglobin and albumin levels and lower prevalence of dyslipidaemia but higher prevalence of renal dysfunction and peripheral artery disease. The mean follow-up period was 4.5 ± 2.3 years. RESULTS: The cut-off values for sarcopenia were psoas muscle area index 215 and 142 mm2/m2 in men and women, respectively. No intergroup difference was observed in the in-hospital mortality and morbidity rates. After risk adjustment using inverse probability weighting analysis, late mortality rates were significantly higher in the sarcopenia group than in the non-sarcopenia group (P = 0.022). Multivariable analysis showed that preoperative sarcopenia was an independent predictor of late mortality (hazard ratio 4.25, 95% confidence interval 2.18-8.28; P < 0.001). Preoperative sarcopenia was not associated with major adverse cardiac and cerebrovascular events during follow-up. CONCLUSIONS: Preoperative sarcopenia (assessed by psoas muscle area index) was associated with late mortality after CABG and effectively predicts postoperative prognosis.