Clinical impact of visceral-to-subcutaneous fat ratio in patients with acute aortic dissection

BACKGROUND: Obesity has increased worldwide. Although the visceral-to-subcutaneous fat ratio (VS ratio) is an established risk factor for cardiovascular disease, its clinical impact on the long-term prognosis of patients with acute aortic dissection (AAD) remains unclear. MATERIALS AND METHODS: This retrospective study included 111 patients with AAD admitted to our hospital from 2013 to 2016. Patients who died during hospitalization, and those diagnosed with Marfan's syndrome were excluded. Visceral and subcutaneous fat accumulation (VFA, SFA) at umbilical level were calculated on a dedicated workstation. Major Adverse Cardiovascular and Cerebrovascular Events (MACCE) and worsening renal function (WRF) at 3 years were evaluated. RESULTS: Patient characteristics were as below: age, 73 ± 13; male, 55%; Stanford type A, 53%. Average VFA, SFA, and VS ratio on admission were 98 (52-145) cm2, 141 (90-185) cm2, and 0.75 (0.47-0.97), respectively. VFA was higher in male than in female (male, 134 [84-179] cm2; female, 71 [46-99] cm2; p < 0.001), whereas SFA was similar (male, 141 [91-174] cm2: female, 134 [90-205] cm2; p = 0.687). VS ratio was also higher in male (male, 0.88 [0.75-1.17]; female, 0.49 [0.39-0.65]; p < 0.001). Both MACCE and WRF at 3 years were observed in 17 (15%) and 32 (29%) patients, respectively. Multivariate Cox regression analysis demonstrated that VS ratio tended to be associated with the 3-year MACCE (HR for an increase of 0.5 unit, 1.49; 95% CI, 0.99-2.24; p = 0.056). This result persisted in male (HR for an increase of 0.5 unit, 1.54; 95% CI, 0.96-2.48; p = 0.073) but not female. The VS ratio was not related to the 3-year WRF. CONCLUSION: The VS ratio tends to be associated with the 3-year MACCE in patients with AAD. This finding is inconclusive owing to a small sample and low incidence of adverse events. Further studies with larger samples are needed to confirm the clinical significance of VS ratio.