What is Standard Dose of Rivaroxaban in Elderly Asian Patients with Atrial Fibrillation: 20ms versus. 15mg?

Although there is no age criterion for rivaroxaban dose reduction, elderly patients with atrial fibrillation (AF) are often prescribed an off-label reduced dose. We aimed to evaluate whether age is a necessary criterion for rivaroxaban dose reduction in Korean patients with AF. Among 2208 patients who prescribed warfarin or rivaroxaban, 552 patients over 75 years without renal dysfunction (creatinine clearance >50 mL/min) were compared based on propensity score matching. The rivaroxaban group was further divided into a 20 mg (R20; on-label) and a 15 mg (R15; off-label). Primary net clinical benefit (NCB) was defined as the composite of stroke, systemic embolism, major bleeding, and all-cause mortality. Secondary NCB was defined as the composite of stroke, systemic embolism, and major bleeding. Patients were followed for 1 year, or until the first outcome occurrence. Both rivaroxaban groups had comparable efficacy compared with warfarin. However, both R20 (0.9% vs 7.4%, p = .014) and R15 (2.3% vs 7.4%, p = .018) had a significant reduction in major bleeding. There were no differences in efficacy or safety outcomes between R20 and R15. R20 had significantly reduced primary (hazard ratio [HR] 0.33, 95% confidence interval [CI]: 0.12-0.93) and secondary (HR 0.31, 95% CI: 0.10-0.93) NCBs compared with warfarin. However, primary and secondary NCBs were not reduced in R15. In real-world practice with elderly patients with AF, off-label rivaroxaban dose reduction to 15 mg conferred no benefits. Therefore, guideline-adherent rivaroxaban 20 mg is favorable in elderly Korean patients with AF.

Radiofrequency catheter ablation without radiation exposure in a 13th week pregnant woman with Wolff-Parkinson-White syndrome.

A 36-year-old woman with 12-week gestation visited the emergency department, complaining of palpitations. Her electrocardiography (ECG) demonstrated ventricular pre-excitation combined with atrial fibrillation. The polarity of the delta waves in leads V5, V6, I, and aVL were positive and negative in leads V1, III, and aVF, suggesting that the accessory pathway (AP) was located on the right posterior free wall. She did not want to take any medicine to prevent the tachycardia. Moreover, the shortest pre-excited RR interval during the atrial fibrillation was 200 ms, so we decided to ablate the AP without fluoroscopy. An electrophysiology study was performed with guidance of a 3-dimension (3D) navigation system and intracardiac echocardiography (ICE). We ablated the right free wall AP without fluoroscopy. A follow-up ECG no longer exhibited any delta waves. Even in the early period of pregnancy, catheter ablation might be performed safely using ICE and a 3D navigation system without fluoroscopy. Therefore, it could more often be considered as a therapeutic option in pregnant women without concern for radiation exposure.

Tpeak-Tend interval during therapeutic hypothermia can predict upcoming ventricular fibrillation in subjects with aborted arrhythmic sudden cardiac death: 3-years follow-up results.

AIMS: Prolonged Tpeak-Tend interval has been shown to be markers of arrhythmogenesis in various cardiac disorders. However, its dynamicity is one of the obstacles to predict fatal ventricular arrhythmia. This study investigated whether Tpeak-Tend interval during therapeutic hypothermia (TH) is associated with ventricular fibrillation (VF) inducibility and clinical arrhythmia in subjects with aborted arrhythmic sudden cardiac death (SCD). METHODS AND RESULTS: The study group included 31 patients (24 males, age 39.1 ± 17.6 years) presenting with arrhythmic SCD in whom Tpeak-Tend interval and J-wave amplitude were measured in electrocardiogram (ECG) of the earliest medical contact and during TH; these patients underwent programmed ventricular stimulation. The summation of J-wave amplitude and QTc interval increased during TH. However, it was not associated with VF inducibility. Patients with inducible VF showed a small Tpeak-Tend interval dispersion in the baseline 12-lead ECG (68.8 ± 24.7 vs. 94.0 ± 55.6 ms, P = 0.044) and a marked increase of the dispersion during the TH (36.2 ± 51.2 vs. -6.1 ± 45.5 ms, P = 0.039). Twenty-four patients underwent implantable cardioverter defibrillator (ICD) implantation. Among them, the patients with long QTc, Tpeak-Tend, and precordial Tpeak-Tend during the TH developed VF more frequently (QTc, 511.9 ± 53.71 ms vs. 566.5 ± 56.08 ms, P = 0.038; Tpeak-Tend interval, 145.6 ± 38.4 ms vs. 185.7 ± 49.95 ms, P = 0.048; precordial Tpeak-Tend interval, 139.3 ± 35.11 ms vs. 185.7 ± 49.95 ms, P = 0.018). The initial VF inducibility was not related with the VF development in follow-up. CONCLUSION: In patients with aborted arrhythmic SCD, long Tpeak-Tend interval and QTc interval during TH could predict VF development in their follow-up.

Effects of combination therapy of statin and N-acetylcysteine for the prevention of contrast-induced nephropathy in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: Acute myocardial infarction (AMI) is a risk factor for contrast-induced nephropathy (CIN). We investigated whether pretreatment with statin, N-acetylcysteine (NAC) and sodium bicarbonate (NaHCO3) reduces the risk of CIN. METHODS: We conducted a prospective trial and enrolled a total of 334 ST-segment elevation myocardial infarction (STEMI) patients. Patients were divided into four groups: Group I (statin 40mg), Group II (statin 80mg), Group III (statin 80mg plus NAC 1200mg) and Group IV (regimen of group III plus NaHCO3 154mEq/L). CIN was defined as ≥25% or ≥0.5mg/dL increase in serum creatinine from the baseline within the 72h after PCI. RESULTS: CIN occurred in 72 (21.6%) patients. The incidence of CIN was the lowest in the group III (14.3%), and multivariate analysis showed the lower incidence of CIN in group III compared to Group I [odds ratio (OR) 0.29, 95% confidence interval (CI) 0.13-0.64, p=0.002]. Admission hyperglycemia [(AHG)>198mg/dL] (OR 2.20, 95% Cl 1.20-3.68, p=0.011) and the use of intra-aortic balloon pump (IABP) (OR 4.20, 95% CI 1.38-12.78, p=0.016) were independent predictors for CIN. The CIN (OR 9.00, 95% CI 1.30-62.06, p=0.026) was an independent predictor for in-hospital mortality. CONCLUSIONS: Combination of high-dose statin plus NAC was associated with lower incidence of CIN in patients with STEMI who underwent primary PCI compared to statin only.

The effects of QRS duration and pacing sites on the acute hemodynamic changes during right ventricular pacing.

BACKGROUND: Has been reported that patients exhibiting prolonged paced QRS duration tend to have more serious heart disease, and the paced QRS duration can be an effective indicator of impaired left ventricular function. However, the acute and chronic hemodynamic effects of paced QRS duration and pacing sites during right ventricular (RV) pacing remain unknown. METHODS: A total of 14 patients who underwent electrophysiologic study for paroxysmal supraventricular tachycardia were examined. RV pacing was performed at 10 different sites with cycle lengths of 600 ms and 500 ms utilizing a 6-7F deflectable quadripolar electrode catheter. Systolic, diastolic, and mean blood pressures during pacing were measured once the blood pressure was stabilized. RESULTS: During RV pacing, blood pressures (systolic/diastolic/mean) decreased. The change of post-pacing QRS duration and pre-pacing the systolic blood pressure (SBP) were greater in the group with paced QRS duration. The differences overall were greater than 140 ms. The SBP decrease during pacing was larger in the group exhibiting paced QRS duration of greater than 140 ms. The SBP decrease during pacing showed relation to QRS duration during pacing (r = 0.500, p = 0.001), the change of QRS duration post-pacing (r = 0.426, p = 0.001), and SBP during sinus rhythm (r = 0.342, p = 0.001) on linear correlation analysis. The pacing site, on the other hand, did not affect acute hemodynamic changes during pacing. CONCLUSION: Ventricular pacing of less than 40 ms at the area of paced QRS duration is recommended.