Yoshihiro Goto

Perioperative use of a beta blocker in coronary artery bypass grafting

Objectives: Atrial fibrillation after cardiac surgery is associated with increases in the risk of complications, length of intensive care unit stay, and cost of care. Beta blockers are effective for controlling myocardial ischemia and arrhythmia and suppressing inflammatory cytokines. The purpose of this study was to examine the effect of administrating a short-acting beta-adrenoceptor antagonist, landiolol, on postoperative atrial fibrillation. Methods: 136 patients undergoing off-pump coronary artery bypass grafting were single-blindly assigned randomly to landiolol (n = 68) and non-landiolol (control, n = 68) groups. In the landiolol group, the beta blocker was administered from the beginning of the operation until postoperative day 2. The primary endpoint was the incidence of atrial fibrillation until postoperative day 7, and the secondary endpoints were the postoperative levels of troponin I, creatine kinase MB-isoenzyme, and C-reactive protein. Results: The incidence of atrial fibrillation was significantly lower in the landiolol group compared to the control group (13/68, 19% vs. 25/68, 37%, p = 0.02, logrank test). Landiolol also significantly reduced the postoperative peak C-reactive protein level compared to the control group (132 ± 55.4 vs. 161 ± 50.9 mgċL−1, p = 0.004). Conclusion: Low-dose continuous infusion of landiolol reduced the incidence of postoperative atrial fibrillation, and significantly suppressed inflammation.

Continuous postoperative insulin infusion reduces deep sternal wound infection in patients with diabetes undergoing coronary artery bypass grafting using bilateral internal mammary artery grafts: a propensity-matched analysis

OBJECTIVES Deep sternal wound infection (DSWI), especially in patients with diabetes mellitus (DM), is a major concern after coronary artery bypass grafting (CABG) with bilateral internal mammary artery (BIMA) grafts. We evaluated the risk of DSWI and other clinical outcomes between continuous insulin infusion therapy (CIT) and insulin sliding scale therapy (IST) in a cohort of DM patients who underwent CABG with BIMA. METHODS The clinical records of DM patients who underwent isolated CABG with BIMA were retrospectively reviewed. The study population consisted of 95 patients who received CIT and 126 patients who received IST. Furthermore, a one-to-one matched analysis based on estimated propensity scores for patients who received CIT or IST yielded two groups comprising 58 patients each. The proportion of patients with DSWI, overall survival rates and major adverse cardiac events were compared between the two groups in the overall and the propensity-matching cohort. RESULTS The prevalence of DSWI requiring debridement and closure was significantly reduced in the CIT group compared with that in the IST group [1/95 (1.1%) vs 9/126 (7.1%), P = 0.031]; these results were not attenuated even after propensity-matching analysis [0/58 (0%) vs 6/58 (10.3%), P = 0.031]. The mean preoperative glucose levels were similar between the two groups (157.5 ± 54.6 vs 176.1 ± ±70 mg/dl, P = 0.063), whereas the mean glucose values were significantly lower on the first and second operative days in the CIT group than in the IST group (132.9 ± 44.1 vs 197.8 ± 78.6 mg/dl, P < 0.0001; 153.5 ± 58.8 vs 199.6 ± 89.1 mg/dl, P < 0.0001, respectively). The glucose variability levels within 24 h postoperatively were significantly higher in the IST group (46.1 ± 19.4 vs 66.4 ± 26.8 mg/dl, P < 0.0001). The 30-day and 1-year survival rates were similar between the two groups (100 vs 99.2%, P = 0.384; 96.6 vs 94.4%, P = 0.454). No results were changed in the propensity-matching models. CONCLUSIONS The CIT approach reduced the variability in glucose concentration and resulted in fewer instances of DSWI after CABG with BIMA grafts.

Local administration of tranexamic acid in off-pump coronary artery bypass.

Purpose: We administered tranexamic acid locally to patients undergoing off-pump coronary artery bypass, to investigate the hemostatic effects and safety. Patients and methods: The subjects were 100 consecutive patients who underwent off-pump coronary artery bypass between July 2009 and January 2011. We assigned 50 patients in the early phase, in which tranexamic acid was not employed, to group N, and 50 in the late phase, in which tranexamic acid was employed, to group T. In group T, 10 mL of a solution containing 1 g of tranexamic acid in was sprayed into the pericardial cavity and mediastinum before the sternum was closed. We compared the volume of postoperative blood loss, blood transfusion volume, and complications between the 2 groups. Results: The volume of blood loss in 24 h after intensive care unit admission was 492 mL in group N and 303 mL in group T (p < 0.0001); the decrease in blood loss in the group receiving tranexamic acid was approximately 40%. There was no significant difference in the blood transfusion volumes. There were no side effects of tranexamic acid. Conclusion: In patients undergoing off-pump coronary artery bypass, local administration of tranexamic acid may decrease the volume of postoperative blood loss. The local administration method is simple, inexpensive, and safe.

Usefulness of routine aortic valve calcium score measurement for risk stratification of aortic stenosis and coronary artery disease in patients scheduled cardiac multislice computed tomography

Objectives This study sought to investigate the clinical utility of aortic valve calcium score (AVCS) determined by using cardiac multislice computed tomography (MSCT). Methods Data of 1315 consecutive patients who underwent both conventional echocardiography and MSCT were reviewed. Degree of aortic stenosis (AS) was assessed according to mean pressure gradient (mPG) measured by echocardiography. Extent of coronary artery disease (CAD) derived by MSCT also was evaluated in 1173 patients who did not undergo prior coronary treatment. Both AVCS and coronary calcium score (CCS) were defined by Agatston units (AU) according to MSCT findings. Results A total of 613 of 1315 patients were defined as AVCS positive (mean, 100 AU [range, 31.0–380.0 AU]). AVCS showed significant correlations with mPG (Spearmans ρ = 0.81, p < 0.001), and CCS (ρ = 0.53, p < 0.001). Differential adequate cut-off values of AVCS were proved for predicting severe AS with mPG ≥ 40 mmHg (1596.5 AU; AUC, 0.88; sensitivity, 89.7%; specificity, 77.0%), and for predicting moderate AS with mPG ≥ 20 mmHg (886.5 AU; area under the curve [AUC], 0.91; sensitivity, 92.4%; specificity, 78.3%). Mean AVCS was higher with increased extent of CAD (none, 0 AU [range, 0–30 AU]; single vessel, 8.5 AU [range, 0–104 AU]; multivessel, 142 AU [range, 10–525 AU]; p < 0.001). The optimal cut-off value of AVCS for predicting multivessel disease was 49 AU (AUC, 0.77; sensitivity, 68.8%; specificity, 78.0%). Conclusions AVCS might be a surrogate marker not only for AS grading but also for CAD progression. Therefore, routine AVCS assessment could be useful for risk stratification.

Total arch replacement through a median sternotomy for Kommerell’s diverticulum

Kommerell’s diverticulum with a right aortic arch and aberrant left subclavian artery is a rare anomaly, and the optimal operative strategy has not yet been established. In particular, the approach to the diverticulum is controversial, with the greatest concern being whether or not to add a right thoracotomy to the median sternotomy for distal anastomosis. We successfully performed total arch replacement through a median sternotomy only, by referring to preoperative computed tomography. We think that if the aneurysm is in a shallow position from the tracheal bifurcation, total arch replacement is possible with a midline incision only.

Collapsed stent graft and severe malperfusion 2 years after endovascular aortic repair

Late collapsing of a stent graft is an extremely rare event, with one existing report describing this phenomenon. A 65-year-old man with a history of endovascular aortic repair for an abdominal aortic aneurysm presented with paraplegia and bilateral lower limb ischaemia. Contrast-enhanced computed tomography showed a dissection of the descending thoracic aorta and a collapsed stent graft, resulting in bilateral lower limb ischaemia. Subsequent axillo-bifemoral bypass resolved his lower extremity functions. The patient required haemodialysis due to acute kidney failure. The follow-up computed tomography scan demonstrated re-expansion of the collapsed stent graft, and his renal function recovered. The case highlights the rare manifestation of late stent collapse and subsequent re-expansion of the collapsed stent and restoration of visceral and lower extremity perfusions following axillo-bifemoral bypass.

Abnormal mobile structure in the aortic valve due to fibrous strand rupture

Mobile abnormal structures in the aortic valve are difficult to diagnose in some cases. We describe a rare clinical case of fibrous strand rupture in a dialysis patient, which was surgically treated. Preoperative echocardiography showed a mobile structure attached to the noncoronary cusp, and intraoperative findings revealed rupture of the fibrous strand in this cusp. If aortic regurgitation without obvious cause is noted in cases of abnormal mobile structures, fibrous strand rupture could be a differential diagnosis.

MicroRNA and hyperglycemic memory in the diabetic heart

“Hyperglycemic memory” is an interesting term. This hypothesis was first put forward in 1990 by Roy et al . (1), after which this phenomenon was named “metabolic” or “hyperglycemic” memory (2,3). Recently, two-meta analyses showed that intensive glycemic control had no impact on the risk of heart failure in patients with diabetes mellitus (4,5). It is possible that the small benefit on non-fatal myocardial infarctions and microalbuminuria may be offset by a significant increase in the risk of severe hypoglycemia (4), and the detrimental effects of hyperglycemia may persist even after restoration of normal glucose levels, that is, “hyperglycemic” or “metabolic” memory. Collectively, these data suggest that such memories are stored early in the course of diabetes, supporting the hypothesis of hyperglycemic memory.

Impact of glucose control on early vein graft failure after coronary artery bypass grafting: one-month angiographic results

Objectives To identify factors that determine early saphenous vein graft failure (VGF) within 1 month after coronary artery bypass grafting (CABG). Methods Seven hundred forty-nine consecutive patients underwent primary isolated CABG with saphenous vein grafts at three Japanese centres from 1 January 2005 to 31 December 2014. According to angiographic findings within 1 month of CABG surgery, 63 patients (8.4%) developed early VGF. We examined the relationships between variables and early VGF by using multivariable logistic regression analysis. Results The preoperative clinical characteristics were similar between patients with and without early VGF, except for median preoperative haemoglobin A1c levels, which were significantly higher among patients with early VGF (6.7 vs 6.4%, P = 0.046). Additionally, anastomosis to the vessel with chronic total obstruction was performed more frequently among patients with early VGF (22/63 [34.9%] vs 140/686 [20.4%], P = 0.007), and myocardial infarction during the hospital admission occurred more frequently among patients with early VGF (4/63 [6.3%] vs 2/686 [0.3%], P < 0.0001). Results of multivariable analysis showed that the preoperative haemoglobin A1c level was associated with early VGF (odds ratio per unit increase, 1.30; 95% confidence interval, 1.06-1.60; P = 0.013). Conclusions An increased preoperative haemoglobin A1c level was strongly associated with early VGF after CABG. Thus, VGF happened more frequently in patients with poorly controlled diabetes mellitus.

Effect of dipeptidyl peptidase-4 inhibitor in patients undergoing bypass surgery.

Objectives Patients with diabetes mellitus often have more complicated postoperative courses and worse outcomes after coronary artery bypass grafting than those without this condition. Dipeptidyl-peptidase-4 inhibitors are a new class of oral medication for treating type 2 diabetes mellitus. We investigated how these drugs influence the postoperative course after coronary artery bypass in patients with type 2 diabetes mellitus. Methods We retrospectively reviewed the clinical records of 177 patients with type 2 diabetes who has undergone coronary artery bypass surgery between 2009 and 2013; 107 were treated with dipeptidyl-peptidase-4 inhibitors postoperatively, and 70 who did not receive dipeptidyl-peptidase-4 inhibitors served as a control group. The rates of overall survival and major adverse cardiac and cerebrovascular events were compared between groups. Results Analysis of all-cause deaths showed that survival at 4 years was 92.8% and 83.6%, respectively, for the treated and control groups (p = 0.052). There was a lower incidence of major adverse cardiac and cerebrovascular events in the treated group (85.6% vs. 73.1%, p = 0.042). Cox regression analysis of the entire population revealed that dipeptidyl-peptidase-4 inhibitor use (hazard ratio 0.46, p = 0.048) and deep sternal wound infection (hazard ratio 11.89, p = 0.003) were independent predictors of major adverse cardiac and cerebrovascular events. Conclusions Dipeptidyl-peptidase-4 inhibitors reduced the incidence of major adverse cardiac and cerebrovascular events and improved the long-term prognosis after coronary artery bypass in patients with type 2 diabetes mellitus.