Shigenobu Bando

Efficacy and safety of rivaroxaban in extreme elderly patients with atrial fibrillation: Analysis of the Shikoku Rivaroxaban Registry Trial (SRRT)

BACKGROUND The Shikoku Rivaroxaban Registry Trial (SRRT) is a retrospective survey of the use of rivaroxaban for stroke prevention in elderly patients in Shikoku, Japan. METHODS The SRRT enrolled 1339 patients from 8 hospitals. Patients were divided into two groups according to their age, the extreme elderly group (453 patients aged ≧80 years) and the control group (886 patients aged <80 years). RESULTS In the extreme elderly group, 41.5% of the patients had low body weight (<50kg) and 65.1% had abnormal renal function (creatinine clearance <50ml/min). The mean CHADS2, CHA2DS2-VASc, and HAS BLED scores were 2.7, 4.4, and 2.3, respectively. There were 333 (73.5%) patients who met the dosing criteria, and of these patients, 81.2% received rivaroxaban 10mg daily. Thromboembolic events occurred in 4 patients (0.94%/person year) and intracranial hemorrhage occurred in 4 patients (0.89%/person year). The incidence of these events was not significantly different from the control group. In addition, all patients with cerebral infarction had been treated with a smaller dose of rivaroxaban than recommended by the dosing criteria, suggesting that dosing criteria should be adhered to. CONCLUSION These results suggest that rivaroxaban is effective and safe in extreme elderly patients with atrial fibrillation.

Regional Differences in Frequency of Warfarin Therapy and Thromboembolism in Japanese Patients With Non-Valvular Atrial Fibrillation – Analysis of the J-RHYTHM Registry –

BACKGROUND The proportion of patients with atrial fibrillation (AF) treated with anticoagulation varies from country to country. In Japan, little is known about regional differences in frequency of warfarin use or prognosis among patients with non-valvular AF (NVAF). METHODSANDRESULTS In J-RHYTHM Registry, the number of patients recruited from each of 10 geographic regions of Japan was based on region population density. A total of 7,406 NVAF patients were followed up prospectively for 2 years. At baseline, significant differences in various clinical characteristics including age, sex, type of AF, comorbidity, and CHADS2score, were detected among the regions. The highest mean CHADS2score was recorded in Shikoku. Frequency of warfarin use differed between the regions (P<0.001), with lower frequencies observed in Hokkaido and Shikoku. Baseline prothrombin time international normalized ratio differed slightly but significantly between the regions (P<0.05). On univariate analysis, frequency of thromboembolic events differed among the regions (P<0.001), with the highest rate seen in Shikoku. An inverse correlation was detected between frequency of thromboembolic and of major hemorrhagic events (P=0.062). On multivariate analysis, region emerged as an independent risk for thromboembolism. CONCLUSIONS Thromboembolic risk, frequency of warfarin use, and intensity and quality of warfarin treatment differed significantly between geographic regions of Japan. Region was found to be an independent predictor of thromboembolic events. (Circ J 2016; 80: 1548-1555).

Effects of Verapamil and Magnesium Sulfate on Electrophysiologic Changes During Acute Myocardial Ischemia and Following Reperfusion in Dogs: Comparative Effects of Administration by Intravenous and Coronary Sinus Retroperfusion Routes

The authors evaluated the effects of verapamil (Ve) and magnesium sulfate (Mg) on the electrophysiologic changes induced in dogs during acute myocardial ischemia and following reperfusion. The effects of their intravenous (IV) administration and adminis tration by coronary sinus retroperfusion (CSR) were also compared. Sixty-five dogs were divided into five groups : Ve-IV: 9 dogs, 0.1 mg/kg; Ve-CS: 9 dogs, 0.05 mg/kg; Mg-IV: 12 dogs, 20 mg/kg; Mg-CS: 11 dogs, 10 mg/kg, control: 24 dogs. The left anterior descending coronary artery was ligated for ten minutes, then quickly reopened. The changes in ventricular effective refractory period (ERP) and intramyocardial conduction time (ICT) were determined during ischemia and following reperfusion. The authors observed a shortening of the ERP and a prolongation of the ICT in the control group versus an attenuation of those effects in all other groups. The ERP was shortened to a lesser extent in the Mg-IV group than in the Ve-IV group. Drug adminis tration by CSR inhibited the changes in ERP and ICT to a greater extent than IV admin istration, even though the dose given by CSR was one-half the IV dose. Ventricular fibril lation (Vf) occurred in 12 of 24 dogs (50%) in the control group during ischemia, and in 5 of 12 dogs (41.7%) following reperfusion. Vf occurred during ischemia and following reperfusion, respectively, in 22.2% and 0% in the Ve-IV and Ve-CS groups, in 25% and 22.2% in the Mg-IV group, and in 9.1% and 10% in the Mg-CS group. Thus, verapamil and magnesium sulfate inhibited the electrophysiologic changes and prevented ventric ular arrhythmias during myocardial ischemia and following reperfusion. Administering the antiarrhythmic agent by coronary sinus retroperfusion may be useful for treating patients with acute myocardial infarction with intractable arrhyth mias, according to these experimental results.

Non-valvular atrial fibrillation patients with low CHADS2 scores benefit from warfarin therapy according to propensity score matching subanalysis using the J-RHYTHM Registry

INTRODUCTION Recently, direct-acting oral anticoagulants (DOACs) have been introduced, with increasing use in patients with non-valvular atrial fibrillation (NVAF). However, warfarin continues to be widely used and the benefits and risks of warfarin in NVAF patients warrant closer inspection. MATERIALS AND METHODS Thromboembolism, major hemorrhage, and total and cardiovascular mortalities were analyzed in 7,406 NVAF patients in the J-RHYTHM Registry from January to July 2009, prior to DOAC introduction. Propensity score matching analysis was performed to reduce the differences in clinical characteristics between non-anticoagulant (n=1002) and warfarin (n=6404) cohorts to reassess warfarin outcomes over 2years. RESULTS The incidence of thromboembolism was significantly greater in the non-anticoagulant cohort (3.0%) than in the warfarin cohort (1.5%, P<0.001) with less frequent major hemorrhage in the non-anticoagulant cohort (0.8%) than in the warfarin cohort (2.1%, P=0.009). Using propensity score matching, new subsets (n=896 each) were obtained, with matching of the clinical characteristics between warfarin and non-anticoagulant subsets. The warfarin subset had lower risk factors compared with the total warfarin cohort. The incidence of thromboembolism was higher in the non-anticoagulant subset (2.9%) than in the warfarin subset (0.7%, P<0.001). However, major hemorrhage was not significantly different between the two subsets. CONCLUSIONS Although warfarin was associated with a significantly higher incidence of hemorrhage in the unmatched cohorts, propensity score matching revealed that warfarin reduced thromboembolism without a significant increase in hemorrhage in the matched subsets with lower risks. Propensity score matching reduced selection bias and provided rational comparisons although it had indwelling limitations.

Relationship between liver cirrhosis and arteriosclerosis: Evaluation by pulse wave velocity, carotid arterial echotomography and autonomic nervous activity

Background:  It has been reported that patients with liver cirrhosis (LC) rarely suffer complications from arteriosclerotic disorders such as coronary artery disease. However, recent studies have reported that the measurement of pulse wave velocity (PWV) facilitates objective evaluation of the severity of arteriosclerosis, suggesting a relationship between LC and arteriosclerosis.

Characteristics of coronary flow velocity in constrictive pericarditis

A 50-yr-old man developed constrictive pericarditis following an episode of acute pericarditis. Cardiac catheterization revealed a typical early diastolic dip and plateau configuration in both the right and left ventricular pressure curves. The coronary flow velocity pattern determined using an intracoronary Doppler guidewire showed an abrupt decrease in peak velocity at early diastole and followed by plateau until late diastole, the so-called dip and plateau configuration. After a successful pericardiectomy, cardiac catheterization no longer showed the dip and plateau configuration, but the early diastolic dip in the coronary flow velocity persisted probably because of infiltration of the organic involvement into the myocardium.

Vector U loop in patients with idiopathic cardiomyopathy

The U loops of vectorcardiograms were recorded in 50 normal subjects, 10 patients with dilated cardiomyopathy (DCM group), and 83 patients with hypertrophic cardiomyopathy (HCM group). The HCM group was divided into three subgroups: those with obstructive hypertrophic cardiomyopathy (HOCM), nonobstructive hypertrophic cardiomyopathy (HNCM), and apical hypertrophy (APH). The spatial characteristics of the U loop were examined qualitatively and quantitatively and were correlated with echocardiographic findings. The magnitude of the U loop was significantly larger in the HCM group, especially in the APH subgroup, than in the normal subjects, but it was not larger in the DCM group. The maximum U vector was significantly displaced anteriorly and to the right in the DCM and HCM groups, especially the APH and HNCM subgroups. In the HNCM and APH subgroups, the magnitude of the U loop correlated significantly with the thickness of the posterior wall of the left ventricle, but not with that of the interventricular septum. These findings suggest that the U loop is related to hypertrophy of the apex and the posterior wall of the left ventricle.

U wave of high-speed and magnified electrocardiogram in left ventricular overloading

In this study we examined by high speed and magnified electrocardiography the quantitative characteristics of the U wave and the clinical significance of a negative U wave in patient with left ventricular over loading. This method permitted more quantitative measurement of the U wave than the ECG at normal magnification (standard ECG)