Naoaki Onishi

Unexpectedly High Prevalence of Acquired von Willebrand Syndrome in Patients with Severe Aortic Stenosis as Evaluated with a Novel Large Multimer Index

AIM Severe gastrointestinal bleeding sometimes occurs in patients with aortic stenosis (AS), known as Heydes syndrome. This syndrome is thought to be caused by acquired von Willebrand syndrome and is characterized by reduced large von Willebrand factor (vWF) multimers. However, the relationship between the severity of AS and loss of large vWF multimers is unclear. METHODS We examined 31 consecutive patients with severe AS. Quantitative evaluation for loss of large vWF multimers was performed using the conventional large vWF ratio and novel large vWF multimer index. This novel index was defined as the ratio of large multimers of patients to those of controls. RESULTS Loss of large vWF multimers, defined as the large vWF multimer index ＜80%, was detected in 21 patients (67.7%). The large vWF multimer ratio and the large vWF multimer index were inversely correlated with the peak aortic gradient (R = -0.58, p=0.0007, and R=-0.64, p＜0.0001, respectively). Anemia defined as hemoglobin ＜9.0 g/dl was observed in 12 patients (38.7%), who were regarded as Heydes syndrome. Aortic valve replacement was performed in 7 of these patients, resulting in the improvement of anemia in all patients from a hemoglobin concentration of 7.5±1.0 g/dl preoperatively to 12.4±1.3 g/dl postoperatively (p＜0.0001). CONCLUSIONS Acquired von Willebrand syndrome may be a differential diagnosis in patients with AS with anemia. The prevalence of AS-associated acquired von Willebrand syndrome is higher than anticipated.

Very long-term clinical outcomes after radiofrequency catheter ablation for atrial fibrillation: A large single-center experience

AIMS Radiofrequency catheter ablation (RFCA) has become widely used for drug-refractory atrial fibrillation (AF). However, there is a paucity of data on the long-term clinical outcomes after RFCA for AF. The aim of the present study was to investigate the very long-term outcomes after RFCA for AF in a large number of consecutive patients. METHODS AND RESULTS In this retrospective single-center study, we evaluated very long-term follow-up results in 1206 consecutive patients undergoing first RFCA for AF. The primary outcomes were adverse outcomes at 30-day as a safety outcome measure and event-free rates from recurrent atrial tachyarrhythmias as efficacy outcome measures. Final follow-up rate reached 99.3% with a mean follow-up duration of 5.0±2.5years. The incidence of overall 30-day adverse outcomes was 3.6% without death. The 10-year event-free rates from recurrent atrial tachyarrhythmias after the initial and last procedures were 46.9% and 76.4%, respectively. Arrhythmia recurrence occurred most commonly during the first year and decreased beyond 3-year, although it continued to occur at an annual rate of 2.0% and 1.3%, respectively, throughout the 10-year follow-up period. The cumulative 10-year incidences of stroke and major bleeding were 4.2% and 3.5%, respectively, with annual rates of 0.3%. Discontinuation rate of oral anticoagulation at 1-, 3-, and 10-year was 34.6%, 53.4%, 58.0% and 61.9%. CONCLUSIONS RFCA for AF provided favorable very long-term arrhythmia-free survival without much safety concerns. The 10-year rates of stroke and major bleeding were low even with discontinuation of oral anticoagulation in a large proportion of patients.

Predictors of Rapid Progression and Clinical Outcome of Asymptomatic Severe Aortic Stenosis.

BACKGROUND The optimal timing of aortic valve replacement (AVR) is controversial in patients with asymptomatic severe aortic stenosis (AS) except when very severe. Prediction of progression of severe AS is helpful in deciding on the timing of AVR. The purpose of this study was to clarify the predictors of progression rate and clinical outcomes of severe AS. METHODSANDRESULTS We retrospectively investigated 140 consecutive patients with asymptomatic severe AS (aortic valve area [AVA], 0.75-1.0 cm(2)). First-year progression rate and annual progression rate of AVA and of aortic jet velocity (AV-Vel) were calculated. Cardiac events were examined and the predictors of rapid progression and cardiac events were analyzed. The median follow-up period was 36 months. The median annual progression rate was -0.05 cm(2)/year for AVA and 0.22 m/s/year for AV-Vel. Dyslipidemia, moderate-severe calcification, and first-year AV-Vel progression ≥0.22 m/s/year were independent predictors of cardiac events. Cardiac event-free rate was lower in patients with AV-Vel first-year progression rate ≥0.22 m/s/year than in those with a lower rate. Diabetes and moderate-severe calcification were related to first-year rapid progression. CONCLUSIONS The annual progression rate of severe AS was -0.05 cm(2)/year for AVA and 0.22 m/s/year for AV-Vel. Patients with first-year rapid progression or severely calcified aortic valve should be carefully observed while considering an early operation. (Circ J 2016; 80: 1863-1869).

Multiple Coronary Artery Aneurysms and Thoracic Aortitis Associated with IgG4-related Disease

A 60-year-old man was admitted due to the onset of right coronary artery (RCA) aneurysms. Coronary angiography showed two RCA aneurysms and focal stenosis with limitations in the blood flow. Balloon angioplasty was performed. However, the follow-up coronary angiography showed restenosis, an enlarged proximal aneurysm and a newly formed aneurysm. The serum immunoglobulin G4 level was elevated to 1,350 mg/dL and fluorodeoxyglucose positron emission tomography showed increased uptake in the ascending aorta, so the patient was diagnosed with immunoglobulin G4-related vascular disease. The prevention of further enlargement of the aneurysms and an improvement in the RCA flow were achieved with steroid therapy. Steroid therapy may therefore be effective for immunoglobulin G4-related vascular disease.

Relationship between plasma dabigatran concentration and activated partial thromboplastin time in Japanese patients with non-valvular atrial fibrillation

Activated partial thromboplastin time (aPTT) is recommended for monitoring anticoagulant activity in dabigatran‐treated patients; however, there are limited data in Japanese patients. To clarify the relationship between plasma dabigatran concentration and aPTT, we analyzed plasma dabigatran concentration and aPTT at various time points following administration of oral dabigatran in a Japanese hospital.

Effect of radiofrequency catheter ablation of persistent atrial fibrillation on the left atrial function: Assessment by 320-row multislice computed tomography

BACKGROUND Atrial fibrillation (AF) increases the left atrial (LA) volume and deteriorates LA function. Whether successful radiofrequency catheter ablation (RFCA) of persistent AF can reverse this process has not been yet established. METHODS Patients with persistent AF undergoing RFCA were evaluated with pre- and post- (at 6-months of follow-up) procedural multislice computed tomography (MSCT). The LA functions were assessed through LA time-volume curves. RESULTS The study population consisted of 44 patients [age 64 (interquartile ranges: 58, 70) years old, 93% male]. Among those, 31 patients (70%) maintained sinus rhythm during the follow-up (no recurrence group; NR group). The remaining 13 patients were classified as the recurrence group (R group). A significant decrease in the minimal and maximal LA volumes was observed in both groups, although this was less pronounced in the R group. Only the NR group had an improvement in the LA expansion index [18% (13, 25) vs. 37% (23, 43), p<0.001], ejection fraction [15% (11, 20) vs. 27% (19, 30), p<0.001] and conduit function [17 ml/m(2) (13, 20) vs. 25 ml/m(2) (20, 34), p<0.001]. An improvement of LV function was also observed only in the NR group. CONCLUSIONS LA anatomical and functional reverse remodeling after RFCA of persistent AF was demonstrated by MSCT during follow-up, which was more pronounced in patients without AF recurrence.

Actual management and prognosis of severe isolated tricuspid regurgitation associated with atrial fibrillation without structural heart disease

BACKGROUND Patients with atrial fibrillation (AF) without structural heart diseases can show severe tricuspid regurgitation (TR), especially among aged people. The aim of this study was to clarify the actual management, prognosis, and prognostic factors for severe isolated TR associated with AF without structural heart diseases. METHODS AND RESULTS We retrospectively investigated actual management in 178 consecutive patients with severe isolated TR associated with AF between 1999 and 2011 in our institution. Prognosis and its predictors were also investigated in 115 patients (68 persistent TR and 47 transient TR) who were followed-up for >1year. During the follow-up period (mean: 5.9years), event free rate from death due to right-sided heart failure (RHF) was 97% at 5years. Persistent TR was associated with higher risk of hospitalization due to RHF than transient TR (log-rank P=0.048) and death due to RHF were all seen in patients with persistent TR who experienced hospitalization due to RHF. Among patients with persistent TR, right ventricular outflow tract dimension >35.3mm, right atrial area >40.3cm2, and tenting height >2.1mm were associated with higher risk of hospitalization due to RHF (adjusted hazard ratio: 3.32, 3.83, and 2.89, respectively; P=0.003, 0.002, and 0.009, respectively). CONCLUSION The prognosis of severe isolated TR associated with AF was good with a focus on cardiac death. However, the incidence of cardiac death increased among patients who experienced hospitalization due to RHF. Larger right ventricular outflow tract dimension, right atrial area and tenting height were predictors of hospitalization due to RHF.

The Influence of Assay Selection on Prothrombin Time Measured in Patients Treated With Rivaroxaban for Nonvalvular Atrial Fibrillation

Prothrombin time (PT) can provide a qualitative assessment of the relative intensity of anticoagulation by rivaroxaban. More than ten types of assay are available for the measurement of PT in clinical settings, but it is not yet fully understood whether their interactions with rivaroxaban are uniform or inconsistent.

Diagnostic accuracy of the Embolic Risk French Calculator for symptomatic embolism with infective endocarditis among Japanese population

BACKGROUND Recently, the Embolic Risk French Calculator (ER-Calculator) was designed to predict symptomatic embolism (SE) associated with infective endocarditis (IE), but external validation has not been reported. This study aimed to determine predictors of SE and the diagnostic accuracy of the ER-Calculator in left-sided active IE among a Japanese population. METHODS This retrospective cohort study included 166 consecutive patients with a definite diagnosis of left-sided IE from 1994 to 2015 in our institution. SE during the period after initiation of antibiotic therapy was defined as new SE and embolism during the period before initiation of antibiotic therapy was defined as previous embolism. The primary endpoint was new SE. RESULTS The mean age of patients was 63±17 years. New SE occurred in 23 (14%) patients at a median of 6 days (interquartile range: 2.5-12.5 days) after initiation of antibiotic therapy. The cumulative incidence of new SE at 12 weeks was 18.2%. The 2-week probability by the ER-Calculator as well as previously reported predictors, such as previous embolism, vegetation length (>10mm), and their combination, were associated with a high risk of new SE. By receiver operating characteristic analysis, the area under the curve of the 2-week probability by the ER-Calculator for prediction of new SE was 0.75 and the optimal cut-off value was 8%. A 2-week probability >8% by the ER-Calculator was the most useful predictor of new SE (hazard ratio 3.63, 95% confidence interval 1.50-8.37; p=0.006), which was more remarkable for fatal embolic events (hazard ratio 13.9, 95% confidence interval 3.19-95.4; p=0.004). CONCLUSIONS The ER-Calculator is a useful predictor of new SE. Predictive ability is more remarkable for critical embolic events.

Efficacy of Intensive Radiofrequency Energy Delivery to the Localized Dense Scar Area in Post-Infarction Ventricular Tachycardia Ablation ― A Comparative Study With Standard Strategy Targeting the Infarcted Border Zone ―

BACKGROUND Several reports have demonstrated the importance of severely low voltage areas as arrhythmogenic substrates of ventricular tachycardia (VT). However, a comparative study of dense scar-targeted and infarcted border zone-targeted strategies has not been reported.Methods and Results:We divided 109 consecutive patients with VT post-infarction from 6 centers into 2 groups according to the ablation strategy used: dense scar-targeted ablation (DS ablation, 48%) or border zone-targeted ablation (BZ ablation, 52%). During DS ablation, we attempted to identify VT isthmuses in the dense scar areas (≤0.6 mV) using detailed pace mapping, and linear ablation lesions were applied mainly to those areas. During BZ ablation, linear ablation of standard low voltage areas (0.5-1.5 mV) was performed along with good pace map sites of the clinical VT. Acute success was defined as complete success (no VTs inducible) or partial success (clinical VT was noninducible). The acute complete success rate was significantly higher for DS ablation than for BZ ablation (62% vs. 42%, P=0.043). During a median follow-up of 37 months, the VT-free survival rate was significantly higher for DS ablation than for BZ ablation (80% vs. 58% at 48 months; log-rank P=0.038). CONCLUSIONS DS ablation may be a more effective therapy for post-infarction VT than BZ ablation in terms of the acute complete success rate and long-term follow-up.