Incidence, clinical characteristics, and diagnostic approach in transthyretin amyloid cardiomyopathy: The Kumamoto Cardiac Amyloidosis Survey.

BACKGROUND: In recent years, transthyretin amyloid cardiomyopathy (ATTR-CM) has received increasing attention; however, the epidemiology of ATTR-CM in Japan is not yet understood. In the Kumamoto Cardiac Amyloid Survey, we evaluated the current incidence, clinical characteristics, diagnostic approaches, and treatment strategies for ATTR-CM and compared tafamidis-prescription hospitals with regional hospitals. METHODS: We conducted a retrospective multicenter observational cohort study. The registry included patients with ATTR-CM diagnosed in two tafamidis-prescription hospital institutes [Japanese Circulation Society (JCS)-certified facilities] and 15 regional cardiovascular facilities in Kumamoto between January 2018 and December 2020. RESULTS: In total, 174 patients were diagnosed with ATTR-CM. The incidence of ATTR-CM was estimated to be approximately 1 per 10,000 person-years in the elderly population (>65 years old) in Kumamoto. Compared with that in the JCS-certified facilities cohort (n=115), age at diagnosis was significantly older (84.5 ± 5.6 vs. 77.5 ± 6.3 years old; p<0.01) in the regional hospitals cohort (n=59). Histological (25% vs. 81%; p<0.01) and genetic diagnosis (7% vs. 82%) were also less frequently performed. Probable (as indicated by positive bone scintigraphy findings with confirmation of monoclonal protein absence) and possible (as indicated by positive bone scintigraphy findings without confirmation of monoclonal protein absence) ATTR-CM accounted for the majority of cases (75% vs. 19%; p<0.01) in the regional hospitals cohort compared to the JCS-certified facilities cohort. There were no cases of hereditary ATTR-CM among the patients who underwent TTR genetic testing (n=98). CONCLUSIONS: We confirmed the incidence of ATTR-CM in Kumamoto and the diagnostic approach used in patients with ATTR-CM. Further prospective studies with a larger sample are needed to validate our results and to further shed light on the epidemiology of ATTR-CM in Japan.

Corrigendum to 'A case of severe pulmonary thromboembolism in mycoplasma infection during early pregnancy' [J. Cardiol. Cases 22 (2020) 140-142].

[This corrects the article DOI: 10.1016/j.jccase.2020.06.003.].

A case of severe pulmonary thromboembolism in mycoplasma infection during early pregnancy.

Mycoplasma infection and pregnancy are both characterized by thrombogenesis. A 38-year-old pregnant woman was admitted to a general hospital for mycoplasma pneumonia treatment. She experienced sudden dyspnea and fell into cardiopulmonary arrest. Emergent pulmonary arteriography revealed contrast deficits in the bilateral pulmonary arteries, and she was diagnosed with pulmonary thromboembolism (PTE). Reperfusion treatment and hemodynamic support were initiated. This is a rare case report of PTE attributed to mycoplasma infection during pregnancy. .

Myasthenic crisis and polymyositis induced by one dose of nivolumab.

An 80-year-old man, who developed multiple lymph node and skin metastasis of malignant melanoma, received nivolumab monotherapy. Two weeks after the first dose, he experienced anorexia and fatigue, and suffered from progressive, severe dyspnea and muscle weakness. We diagnosed him with myocarditis, myositis, and myasthenic crisis induced by nivolumab. We commenced steroid therapy, immune absorption therapy, plasma exchange therapy, and i.v. immunoglobulin therapy, and succeeded in saving his life. Because his serum level of anti-acetylcholine receptor antibodies in a sample collected before nivolumab treatment were positive and were elevated significantly after nivolumab, we suspected that nivolumab triggered a severe autoimmune response, which progressed subclinical myasthenia gravis to myasthenic crisis. We carried out T cell receptor repertoire analysis using next-generation sequencing technologies and identified infiltration of clonally expanded T cell populations in the skeletal muscle after nivolumab treatment, implying a very strong T cell immune response against muscular cells. To avoid severe immune-related adverse events, the exclusion of patients with subclinical autoimmune disease is very important for treatment with immune checkpoint inhibitors.

[Two cases of pulmonary embolism in spinal surgeries].

We experienced two cases of pulmonary embolism (PE) in the perioperative period. Although the incidence of perioperative PE is low, it may lead to a critical outcome. The first case is a 59-year-old man without risk factors of PE, scheduled for laminectomy. The end tidal CO2 of 25 mmHg and Pa(CO2) of 48 mmHg developed at the same time during the operation, suggesting PE. He was diagnosed as PE by pulmonary perfusion scan later. The second case was a 71-year-old woman with hypertension and diabetes mellitus, scheduled for laminectomy. Although there were no events during the surgery, she complained of chest pain and dyspnea after the operation. Blood gas analysis showed Pa(O2) of 55 mmHg (FI(O2) 0.4). She was also diagnosed as PE by pulmonary perfusion scan. Both patients made satisfactory progress by appropriate diagnosis and treatment. PE may occur in spite of prevention, and it is important to find out the signs of PE and to prepare for the occurrence of PE.

Prognostic value of plasma von Willebrand factor-cleaving protease (ADAMTS13) antigen levels in patients with coronary artery disease.

High plasma level of von Willebrand factor (VWF) is a marker of future cardiovascular events in patients at high risk of coronary artery disease (CAD). The purpose of this study was to examine the changes and the prognostic value of plasma VWF-cleaving protease (ADAMTS13) levels in patients with CAD. Plasma VWF and ADAMTS13 levels were measured in 225 patients with CAD (152 men and 73 women, age, 70.3 +/- 8.9 years, mean +/- SD) and 100 patients without CAD who were age- and gender-matched to the CAD patients (60 men and 40 women, age, 68.6 +/- 8.9 years). The CAD patients had higher VWF and lower ADAMTS13 antigen levels compared to patients without CAD. During 22.3 +/- 10.4 months follow-up period, 20 major adverse cardiac and cerebrovascular events (MACCE) occurred in 222 patients with CAD who could be followed up. Kaplan-Meier analysis demonstrated that CAD patients with high plasma VWF antigen levels were significantly more likely to develop MACCE. Furthermore, eight cardiac and cerebrovascular thrombotic events [acute coronary syndrome (n=4) and cerebral infarction (n=4)] occurred in CAD patients with both high plasma VWF and low ADAMTS13 antigen levels. Multivariate Cox hazards regression analysis identified high plasma VWF and low ADAMTS13 antigen levels as significant and independent predictors of future MACCE and thrombotic events during the follow-up period in CAD patients. Our findings suggest that low plasma ADAMTS13 as well as high VWF level is a useful predictor of cardiac and cerebrovascular events in CAD patients.

Changes in plasma von Willebrand factor and ADAMTS13 levels associated with left atrial remodeling in atrial fibrillation.

INTRODUCTION: Previous studies have shown raised plasma von Willebrand factor (VWF) levels in patients with atrial fibrillation (AF). However, little is known about changes of VWF associated with VWF-cleaving protease (ADAMTS13) in AF. The aim of this study was to examine the relationship between changes in plasma VWF and ADAMTS13 levels, and left atrial remodeling in AF patients. MATERIALS AND METHODS: We measured plasma VWF and ADAMTS13 antigen levels in 70 paroxysmal AF (PAF) patients, 56 chronic AF (CAF) patients, and 55 control subjects. RESULTS: Plasma VWF levels (mU/ml) were significantly higher in CAF and PAF patients compared with the controls (2103 +/- 743, 1930 +/- 676, 1532 +/- 555, respectively, P < 0.0001 in CAF vs. controls, P = 0.001 in PAF vs. control), while ADAMTS13 levels (mU/ml) were significantly lower in CAF and PAF patients compared with the controls (795 +/- 169, 860 +/- 221, 932 +/- 173, respectively, P = 0.0002 in CAF vs. controls, P = 0.04 in PAF vs. control). The VWF/ADAMTS13 ratio was significantly higher in patients with CAF than PAF or controls (2.81 +/- 1.30, 2.34 +/- 0.92, 1.73 +/- 0.83, respectively; P = 0.01 in CAF vs. PAF, P < 0.0001 in CAF vs. controls). There was a significant correlation between the VWF/ADAMTS13 ratio and left atrial diameter (positive correlation; r = 0.275, P = 0.0002) and left atrial appendage flow velocity (negative correlation; r = -0.345, P = 0.0018). CONCLUSIONS: These findings suggest that the imbalance between plasma VWF and ADAMTS13 levels caused by left atrial remodeling might be closely associated with intra-atrial thrombus formation in AF patients.

Pioglitazone, a peroxisome proliferator-activated receptor-gamma agonist, attenuates myocardial ischemia-reperfusion injury in mice with metabolic disorders.

Although considerable attention has focused on obesity, insulin resistance and abnormal lipid metabolism as coronary risk factors, it remains unclear how these pathogenic factors affect the inflammatory response after myocardial ischemia-reperfusion. This study was conducted to evaluate whether these metabolic disorders exacerbate myocardial ischemia-reperfusion injury, and to determine if ischemia-reperfusion injury could be modified with the thiazolidinedione, pioglitazone. Experiments were performed in KK-A(y) and C57BL/6J mice subjected to 40 min of ischemia followed by reperfusion. Infiltration of inflammatory cells in ischemic myocardium, and infarct size 3 days after reperfusion were significantly higher in KK-A(y) than C57BL/6J mice (p<0.05 and p<0.001, respectively). Furthermore, expression of chemokines, inflammatory cytokines and extracellular matrix proteins in ischemic myocardium was significantly higher in KK-A(y) than C57BL/6J mice 1 day after reperfusion. Pioglitazone treatment of KK-A(y) mice for 14 days significantly reduced the accumulation of inflammatory cells in ischemic myocardium, and infarct size 3 days after reperfusion compared to vehicle treatment (p<0.05 and p<0.05, respectively). Pioglitazone also attenuated expression of chemokines, inflammatory cytokines and extracellular matrix proteins in ischemic myocardium 1 day after reperfusion. In vitro experiments demonstrated that tumor necrosis factor-alpha (TNF-alpha) was significantly higher in cultured peritoneal macrophages from KK-A(y) than C57BL/6J mice, and pioglitazone significantly reduced TNF-alpha in macrophages from both types of mice. These findings suggest that metabolic disorders exacerbate ischemia-reperfusion injury as a result of overexpression of inflammatory mediators, and this effect might be improved, in part by the anti-inflammatory effects of pioglitazone.

Changes in plasma von Willebrand factor-cleaving protease (ADAMTS13) levels in patients with unstable angina.

INTRODUCTION: Increased plasma levels of von Willebrand factor (VWF) have been reported in acute myocardial infarction (AMI). Recently, we showed reduced activity of a VWF-cleaving protease (ADAMTS13) in AMI patients. However, there is no information as to whether ADAMTS13 affects the pathogenesis of unstable angina (UA). Thus, the purpose of this study was to examine changes in plasma VWF and ADAMTS13 levels in UA patients. MATERIALS AND METHODS: Plasma VWF and ADAMTS13 levels (mU/ml) were measured in 45 patients with UA, 55 with stable exertional angina (SEA) and 47 with chest pain syndrome (CPS) at the time of coronary angiography. Levels were also measured in 15 UA patients after 6 months of follow-up. RESULTS: VWF antigen levels (mU/ml) increased significantly in UA patients compared with SEA or CPS (2129.3+/-739.5, 1571.8+/-494.2 and 1569.5+/-487.0, respectively; P < 0.0001 in UA vs. SEA or CPS). ADAMTS13 antigen levels (mU/ml) were significantly lower in UA patients than SEA or CPS (737.3+/-149.5, 875.3+/-229.0 and 867.7+/-195.5, respectively; P < 0.01 in UA vs. SEA or CPS). Furthermore, there was a significant inverse correlation between VWF and ADAMTS13 antigen levels (r = -0.302, P = 0.0002). The antigen levels at 6 months of follow-up were not different compared to the acute phase in the 15 UA patients that had repeated blood sampling. CONCLUSIONS: These findings suggest that there is prolonged thrombogenicity in UA patients represented as an imbalance between VWF and ADAMTS13 activity.

Serial changes in von Willebrand factor-cleaving protease (ADAMTS13) and prognosis after acute myocardial infarction.

Von Willebrand factor (VWF), a cofactor in platelet adhesion and aggregation, increases hemostasis and thrombosis. Recently, a metalloprotease that cleaves VWF multimers has been identified, namely ADAMTS13. The aim of this study was to investigate the relation between serial changes in plasma VWF and ADAMTS13 and the prognosis after acute myocardial infarction (AMI). We measured serial changes of plasma VWF and ADAMTS13 antigen levels in 92 patients with AMI and 40 control subjects. VWF levels were significantly higher in patients with AMI compared with controls (p <0.01) on admission, peaked 3 days after admission, and remained high for 14 days. In contrast, on admission, ADAMTS13 levels were significantly lower in patients with AMI compared with controls (p <0.0001), with minimum antigen levels reached after 3 days, and remained lower for 14 days. The ratio of VWF/ADAMTS13 antigen levels was higher in patients with AMI compared with controls throughout the time course. Cox hazards analysis revealed that the early increase of VWF and VWF/ADAMTS13 ratio levels and the early decrease of ADAMTS13 levels were significant predictors of future thrombotic events during the 1-year follow-up period. Kaplan-Meier analysis demonstrated that patients with major decreases of ADAMTS13 levels and high increases of VWF/ADAMTS13 levels had significantly greater probabilities for development of thrombotic events (p = 0.0104 and 0.0209, respectively). In conclusion, these findings suggest that monitoring the changes of VWF and ADAMTS13 antigen levels in the early phase might be valuable for predicting and preventing thrombosis during 1-year follow-up in patients with AMI.