Abnormal atrial conduction has been shown to be a substrate for postoperative atrial fibrillation (POAF). This study aimed to determine the relationship between the location of the atrial reentry responsible for POAF, and degree of atrial inflammation. Normal mongrel dogs (n = 18) were divided into 3 groups: anesthesia alone (anesthesia), lateral right atriotomy (atriotomy), and lateral right atriotomy with anti-inflammatory therapy (steroid). Conduction properties of the right and left atria (RA and LA) were examined 3 days postoperatively by mapping. Activation was observed during burst pacing-induced AF. The RA and LA myeloperoxidase activity was measured to quantitate the degree of inflammation. Sustained AF (>2 minutes) was induced in 5 of 6 animals in the atriotomy group, but in none in the anesthesia or steroid groups. All sustained AF originated from around the RA incision. Three of these animals had an incisional reentrant tachycardia around the right atriotomy and 2 had a focal activation arising from the RA during AF. The LA activations in these animals were passive from the RA activation. The RA activation of the atriotomy group was more inhomogeneous than that of the anesthesia group (inhomogeneity index: 2.0 ± 0.2 vs 1.0 ± 0.1, P < .01). Steroid therapy significantly normalized the RA activation after the atriotomy (1.2 ± 0.1, P < .01). The inhomogeneity of the atrial conduction correlated with the myeloperoxidase activity (r = 0.774, P < .001). Reentrant circuits responsible for POAF are dependent on the degree of inflammation and rotate around the atriotomy. Anti-inflammatory therapy decreased the risk of postoperative AF.

This study aimed to explore the flow dynamics factors affecting turbulence formation in the false lumen (FL) of aortic dissection using four-dimensional flow magnetic resonance imaging (4D flow MRI). This study also aimed to uncover risk factors affecting late complications of aortic dissection. Thirty-three aortic dissection patients were examined using 4D flow MRI for quantitative flow dynamics (gross flow, velocity and regurgitant fraction) and turbulence visualization (helix and vortex with three-point visual grading) in the FL. The incidence of late complications (rupture or prophylactic intervention) was also obtained prospectively. The helix grade was correlated with FL gross flow (r_S = 0.55, P < 0.001) and FL velocity (r_S = 0.45, P = 0.008). The vortex grade was also correlated with FL gross flow (r_S = 0.70, P < 0.001) and FL velocity (r_S = 0.67, P < 0.001). Comparative analysis of patients with complications and stable patients revealed that patients with complications exhibited higher FL gross flow [41.7 (interquartile range, IQR 29.1–59.7) vs 17.7 (IQR 9.0–42.0) ml/s; P = 0.01], higher helix grade [2 (IQR 1.25–2) vs 0 (IQR 0–1); P = 0.001] and higher vortex grade [2 (IQR 1–2) vs 0 (IQR 0–2); P = 0.01]. Using 4D flow MRI analysis, we showed that turbulence formation depends on flow volume and velocity in the FL. Patients with high-volume turbulent flow in their FL are at higher risk of late complications; therefore, close follow-up and aggressive prophylactic intervention may improve their survival. Nippon Medical School Hospital Institutional Review Board approved this observational study in September 2018 (No. 30-08-986).

Kawasaki disease (KD) is an acute form of systemic vasculitis that may promote atherosclerosis in adulthood. This study examined the relationships between KD, atherosclerosis, and the long-term effects of HMG-CoA inhibitors (statins). Candida albicans water-soluble fraction (CAWS) was injected intraperitoneally into 5-week-old male apolipoprotein-E-deficient (Apo E-/-) mice to create KD-like vasculitis. Mice were divided into 4 groups: the control, CAWS, CAWS+statin, and late-statin groups. They were sacrificed at 6 or 10 weeks after injection. Statin was started after CAWS injection in all groups except the late-statin group, which was administered statin internally 6 weeks after injection. Lipid plaque lesions on the aorta were evaluated with Oil Red O. The aortic root and abdominal aorta were evaluated with hematoxylin and eosin staining and immunostaining. CAWS vasculitis significantly enhanced aortic atherosclerosis and inflammatory cell invasion into the aortic root and abdominal aorta. Statins significantly inhibited atherosclerosis and inflammatory cell invasion, including macrophages. CAWS vasculitis, a KD-like vasculitis, promoted atherosclerosis in Apo E-/- mice. The long-term oral administration of statin significantly suppressed not only atherosclerosis but also inflammatory cell infiltration. Therefore, statin treatment may be used for the secondary prevention of cardiovascular events during the chronic phase of KD.

Operative mortality after endovascular aneurysm repair (EVAR) has been reported as lower than open surgical repair (OSR) for abdominal aortic aneurysm (AAA) in randomized controlled trials. However, many cohort studies have demonstrated similar mortality rates for both procedures. We compared operative mortality between EVAR and OSR, at our institution. All AAA operations from 2012 to 2017 were reviewed, and baseline characteristics were collected. Outcomes included 30-day mortality, operative data, complications, length of hospital stay (LOS), costs, re-intervention, and survival rates were compared. A multivariable analysis with unbalanced characteristics was performed. We had a total of 162 patients, 100 having OSR and 62 for EVAR. The EVAR group was older, with higher ASA classification. Thirty-day mortality rate did not significantly differ (0/100 for OSR and 2/62 (3%) for EVAR; p = 0.145), while the EVAR group had less blood loss, shorter operative times, and LOS, but higher re-intervention rates (adjusted hazard ratio 6.4 (95%CI: 1.4, 26.8)). Survival rates did not significantly differ between the groups. EVAR cost approximately 1-million yen more. OSR had low 30-day mortality rate in selected low-risk patients whereas EVAR had less blood loss, shorter operative times, LOS and could be done in high-risk patients with low 30-day mortality but with higher re-intervention rate.