A prospective feasibility study of uracil-tegafur and leucovorin as adjuvant chemotherapy for patients aged ≥ 80 years after curative resection of colorectal cancer, the HiSCO-03 study.

PURPOSE: There is no consensus on the safety and effectiveness of adjuvant chemotherapy for patients with stage III colorectal cancer (CRC) aged ≥ 80 years. We conducted a prospective multi-institutional phase II study of uracil-tegafur and leucovorin (UFT/LV) as adjuvant chemotherapy in this population. PATIENTS AND METHODS: Patients with stage III CRC aged ≥ 80 years who underwent curative resection were enrolled. Eligible patients received UFT/LV therapy (UFT, 300 mg/m2 per day as tegafur; LV, 75 mg/day on days 1-28, every 35 days for five courses). Primary endpoint was feasibility, and secondary endpoints were safety and relative dose intensity. RESULTS: Sixty-nine patients were enrolled between 2013 and 2021. Of the 69 patients, 65 were included in the analysis. There were 32 males and 33 females with a median age of 82 years (range 80-88 years). In the primary endpoint, administration completion rate was 67.3% (95% confidence interval 54.9-77.6%), and the lower limit of the 95% confidence interval was below the threshold of 60%. 21 patients discontinued treatment because of adverse events (AEs) and refused treatment. The median relative dose intensities were 84% (range 4-100%) for UFT, and 100% (range 4-100%) for LV. Incidence of grade three or higher AEs were neutropenia (1.5%), aspartate transaminase elevation (3%), alanine transaminase elevation (1.5%), oral mucositis (3%), anemia (1.5%), and diarrhea (4.6%). CONCLUSIONS: The indications for adjuvant UFT/LV therapy for elderly CRC aged ≥ 80 years were considered limited. It is necessary to clarify the background of patients in whom drug administration is discontinued and investigate their impact on long-term prognosis.

Causes of Death in Elderly Patients With Non-Valvular Atrial Fibrillation　- Results From the ANAFIE Registry.

BACKGROUND: Previous studies on mortality in atrial fibrillation (AF) included a limited number of elderly patients receiving direct oral anticoagulants (DOACs). This subanalysis of the ANAFIE Registry evaluated 2-year mortality according to causes of death of elderly non-valvular AF (NVAF) patients in the DOAC era.Methods and Results: The ANAFIE Registry was a multicenter prospective observational study. Mean patient age was 81.5 years and 57.3% of patients were male. Of the 32,275 patients completing the study, 2,242 died. The most frequent causes of death were cardiovascular (CV) death (32.4%), followed by infection (17.1%) and malignancy (16.1%). Incidence rates of CV-, malignancy-, and infection-related death were 1.20, 0.60, and 0.63 per 100 person-years, respectively. Patients aged ≥85 years showed increased proportions of non-CV and non-malignancy deaths and a decreased proportion of malignancy deaths compared with patients aged <85 years. The incidence of death due to congestive heart failure/cardiogenic shock, infection, and renal disease was higher in patients aged ≥85 than those aged <85 years. Compared with warfarin, DOACs were associated with a significantly lower risk of death by intracranial hemorrhage, ischemic stroke, and renal disease. CONCLUSIONS: This subanalysis described the mortality according to causes of death of Japanese elderly NVAF patients in the DOAC era. Our results imply that a more holistic approach to comorbid conditions and stroke prevention are required in these patients.

Tumor budding as a predictive marker for 5-fluorouracil response in adjuvant-treated stage III colorectal cancer.

BACKGROUND: Tumor budding (TB) has been described as an adverse prognostic marker for operable colorectal cancer (CRC); however, a limited number of studies have demonstrated the prognostic significance of TB in patients with drug therapy. This study was conducted to determine the predictive power of TB in stage III CRC patients who received adjuvant chemotherapy. METHODS: We retrospectively collected clinicopathological data including TB of 237 stage III colorectal cancer patients at Hiroshima University Hospital between July 1, 2006 and June 31, 2019. Differential disease-free survival (DFS) was investigated according to TB status. RESULTS: This study included 237 patients with a median age of 67 years, comprising patients who underwent surgery alone (n = 65), 5-fluorouracil (5-FU) monotherapy (n = 129), and oxaliplatin-based chemotherapy (n = 43). Overall, 81 patients developed disease recurrence, and 33 patients died of cancer-related causes. The TB status was categorized into two groups: 99 with low budding (< 5 buds) and 138 with high budding (≥ 5 buds). Overall, the low budding cases demonstrated significantly better DFS. In the 5-FU monotherapy group, low-risk patients (T1, T2, or T3 and N1) with low budding showed a remarkably higher 3-year DFS (91%) compared to high budding (55%). CONCLUSION: Our results indicate that TB could play a subsidiary role in selecting patients who could maintain a favorable prognosis with 5-FU monotherapy in stage III CRC.

Cardiac electrophysiological characteristics of silent paroxysmal atrial fibrillation: What causes asymptomaticity?

BACKGROUND: A diagnosis of silent paroxysmal atrial fibrillation (AF) is highly challenging due to its asymptomatic and intermittent nature. The goal of the present study was to clarify its asymptomaticity with the use of a comprehensive electrophysiological approach. METHODS: We prospectively compared (a) 24-hour Holter monitoring data, (b) invasive cardiac electrophysiological properties, (c) AF inducibility, and (d) outcome of radiofrequency catheter ablation between patients with symptomatic paroxysmal AF and those with silent paroxysmal AF, defined as transient asymptomatic AF detected by chance. RESULTS: Patients with silent paroxysmal AF (N = 57) were more likely than patients with symptomatic paroxysmal AF (N = 282) to be male (75.4% vs 56.7%; P = .009), and to have a previous stroke (17.5% vs 6.7%; P = .008), more prolonged atrio-His interval (114.9 ± 29.1 vs 105.5 ± 24.1 ms; P = .01), longer atrioventricular nodal effective refractory period (352.3 ± 103 vs 318.2 ± 77.2 ms; P = .007), slower Wenckebach cycle length (488.5 ± 83.9 vs 443.3 ± 74.9 ms; P < .001), and lower maximum heart rate during AF (128.7 ± 31.9 vs 143.9 ± 29.6 beats/min; P = .02). Atrial ectopy (median [interquartile range], 385 [88, 2430] vs 207 [73.8, 870.8] beats/24 h; P = .02) and pharmacological AF induction (66.7% vs 43.2%; P = .02) were more common in silent paroxysmal AF patients. There was no difference in the 1-year freedom from AF following the ablation between the two patient groups. CONCLUSIONS: The more attenuated atrioventricular conduction properties in silent paroxysmal AF patients may explain their asymptomatic nature, and their higher likelihood of atrial arrhythmias may increase the chance to detect AF episodes. Whether or not they benefit from catheter ablation is uncertain.

Clinical risk factors of stroke and major bleeding in patients with non-valvular atrial fibrillation under rivaroxaban: the EXPAND Study sub-analysis.

For Japanese patients with non-valvular atrial fibrillation (NVAF), the risk of stroke and major bleeding events was assessed by using the CHADS2, CHA2DS2-VASc, and HAS-BLED scores. The risk factors for embolism and major bleeding under DOAC may be different from current reports. We analyzed the data set of the EXPAND Study to determine the risk factors for events among Japanese NVAF patients in the era of direct oral anticoagulant. Using the data of EXPAND Study, the validity for predictability of the CHADS2, CHA2DS2-VASc, and HAS-BLED scores was identified using the receiver operating characteristic curve analysis. Multivariate analysis was performed with the Cox proportional hazard model to determine the independent risk factors for stroke/systemic embolism and major bleeding among NVAF patients receiving rivaroxaban. Explanatory variables were selected based on the univariate analysis. A total of 7141 patients (mean age 71.6 ± 9.4 years, women 32.3%, and rivaroxaban 15 mg per day 56.5%) were included. Incidence rates of stroke/systemic embolism and major bleeding were 1.0%/year and 1.2%/year, respectively. The multivariate analysis revealed that only history of stroke was associated with stroke/systemic embolism (hazard ratio 3.4, 95% confidence interval 2.5-4.7, p < 0.0001). By contrast, age (1.7, 1.1-2.6, p = 0.0263), creatinine clearance (CrCl) 30-49 mL/min (1.6, 1.2-2.2, p = 0.0011), liver dysfunction (1.7, 1.1-2.8, p = 0.0320), history/disposition of bleeding (1.8, 1.0-3.0, p = 0.0348), and concomitant use of antiplatelet agents (1.6, 1.2-2.3, p = 0.0030) were associated with major bleeding. This sub-analysis showed that some components of the HAS-BLED score were independently associated with major bleeding in Japanese NVAF patients receiving anticoagulation therapy by rivaroxaban. Additionally, CrCl value of 30-49 mL/min was an independent predictor of major bleeding in patients receiving rivaroxaban.

The EXPAND study: Efficacy and safety of rivaroxaban in Japanese patients with non-valvular atrial fibrillation.

AIMS: The EXPAND study examined the real-world efficacy and safety of rivaroxaban for the prevention of stroke and systemic embolism (SE) in Japanese patients with non-valvular atrial fibrillation (NVAF). METHODS AND RESULTS: This multicenter, prospective, non-interventional, observational, cohort study was conducted at 684 medical centers in Japan. A total of 7141 NVAF patients ≥20 years of age (mean, 71.6 ±â€¯9.4 years) who were being or about to be treated with rivaroxaban (10 mg/day, 43.5%; 15 mg/day, 56.5%) were followed for an average of 897.1 (±206.8) days with a high follow-up rate (99.65%). The mean CHADS2 score at baseline was 2.1 (1.3) (0-1, 37%; 2, 29%; ≥3, 34%). The total incidence rate of symptomatic stroke and SE (primary efficacy endpoint) was 1.0%/year, and 0.5%, 0.9%, and 1.7%/year for those with CHADS2 scores of 0-1, 2, and ≥3, respectively. Cumulative incidence rates for major bleeding (primary safety endpoint) and non-major bleeding (secondary safety endpoint) were 1.2%/year and 4.9%/year, respectively. Differences were noted between new and current users only for major bleeding event rate (1.7% vs. 1.1%/year, P = 0.0024). Comparisons with previous studies suggested that rivaroxaban is effective and safe for low-risk patients (0-1 CHADS2), as shown for warfarin in the XANTUS international prospective post-marketing study. CONCLUSIONS: The EXPAND study demonstrated that low dosages of rivaroxaban for Japanese NVAF patients in real-world clinical practice, including those with CHADS2 scores 0-1, resulted in low rates of stroke and SE, and major and non-major bleeding.

Differences in the onset mode of ventricular tachyarrhythmia between patients with J wave in anterior leads and those with J wave in inferolateral leads.

BACKGROUND: The pathophysiological mechanism of J wave in anterior leads (A-leads) and inferolateral leads (L-leads) remains unclear. OBJECTIVE: We investigated the onset mode and circadian distribution of ventricular tachyarrhythmia (VTA) episodes between patients with early repolarization syndrome (ERS) and Brugada syndrome (BrS). METHODS: The study enrolled 35 patients with ERS and 52 patients with type 1 BrS with spontaneous ventricular fibrillation who were divided into 4 groups: ERS(A+L) (n = 15), patients with ERS who had a non-type 1 Brugada pattern electrocardiogram in any A-leads (second to fourth intercostal spaces) in control and/or after drug provocation tests; ERS(L) (n = 20), patients with ERS with J wave only in L-leads; BrS(A) (n = 24), patients with BrS without J wave in L-leads; and BrS(A+L) (n = 28), patients with BrS with J wave in L-leads. The onset mode of 206 VTAs obtained from electrocardiograms or implantable cardioverter-defibrillators and the circadian distribution of 352 VTAs were investigated in the 4 groups. RESULTS: Three groups with J wave in A-leads, ERS(A+L), BrS(A), and BrS(A+L), had higher incidences of nocturnal (63%, 43%, and 47%, respectively) and sudden onset VTAs (67%, 97%, and 86%, respectively) with longer coupling intervals of premature ventricular contractions (388.8, 397.3, and 385.6 ms, respectively) than the ERS(L) group with J wave only in L-leads (25%, P = .0019; 19%, P < .0001; and 330.6 ms, P = .0004, respectively), the last of which mainly displayed VTAs with a short-long-short sequence. CONCLUSION: The onset mode of VTAs was different between patients with J wave in A-leads and patients with J wave in only L-leads. The underlying mechanism of J wave may differ between A-leads and L-leads.

Analyses of the Mode of Termination During Diagnostic Ventricular Pacing to Differentiate the Mechanisms of Supraventricular Tachycardias.

OBJECTIVES: The goal of this study was to determine the diagnostic yield of analyzing the mode of termination during ventricular overdrive pacing (VOP) to differentiate the mechanisms of supraventricular tachycardias (SVTs). BACKGROUND: The majority of the diagnostic criteria for VOP rely on successful entrainment, but termination of SVTs is common during VOP. METHODS: We studied 225 SVTs with a 1:1 atrioventricular relationship, including 34 atrial tachycardias, 67 orthodromic reciprocating tachycardias (ORTs) (including 4 ORTs using accessory pathways [APs] with decremental properties), and 124 atrioventricular nodal re-entrant tachycardias. The total pacing prematurity (TPP) needed to reset or terminate the SVT was calculated by using a simplified method, and the post-pacing interval minus the tachycardia cycle length (PPI - TCL) was predicted from the TPP. RESULTS: VOP terminated 87 SVTs (39%). No atrial tachycardias were terminated by VOP in this study. SVT termination occurred after (n = 71) or before (n = 16) atrial resetting. The predicted PPI - TCL was highly correlated with the measured PPI - TCL (r = 0.96; p < 0.001). The TPP had diagnostic accuracy equivalent to the predicted PPI - TCL. The TPP was measurable irrespective of the termination mode and correctly diagnosed ORTs with decremental APs. All ORTs using septal APs and no atrioventricular nodal re-entrant tachycardias had a TPP <125 ms. Considering other criteria evaluable in terminated SVTs, a combined criteria of a TPP <125 ms and atrial capture/termination within the fusion period were specific for ORTs using free-wall APs, except for left anterolateral/lateral sites. CONCLUSIONS: The termination analyses were useful for differential diagnoses of SVTs terminated during VOP.

Study Design and Baseline Characteristics of the EXPAND Study: Evaluation of Effectiveness and Safety of Xa Inhibitor, Rivaroxaban for the Prevention of Stroke and Systemic Embolism in a Nationwide Cohort of Japanese Patients Diagnosed as Non-Valvular Atrial Fibrillation.

The use of rivaroxaban, a factor Xa inhibitor, has been increasing for prevention of ischemic stroke and systemic embolism in patients with non-valvular atrial fibrillation (AF) in Japan. We conducted the nationwide multicenter study, termed as the EXPAND Study, to address its effectiveness and safety in the real-world practice of patients with non-valvular AF in Japan. The EXPAND Study is a prospective, non-interventional, observational cohort study to evaluate the effectiveness and safety of rivaroxaban in non-valvular AF patients in a real-world clinical practice. A total of 7,178 patients with non-valvular AF were enrolled in 684 medical institutes between November 20, 2012 and June 30, 2014. As for the baseline demographic and clinical characteristics of 7,164 patients, the proportion of female patients was 32.2%, and those of patients with creatinine clearance < 50 mL/min and non-paroxysmal (persistent or permanent) AF were 21.8% and 55.1%, respectively. The proportions of patients complicated with hypertension, congestive heart failure, diabetes mellitus, and a history of ischemic stroke were 70.9%, 25.9%, 24.3%, and 20.2%, respectively. The proportions of patients with a CHADS2 score ≤ 1 and a CHA2DS2-VASc score ≤ 1 were 37.3% and 13.6%, respectively. They were followed up until March 31, 2016 for a mean follow-up period of approximately 2.5 years. The findings of the EXPAND Study will help to establish an appropriate treatment with rivaroxaban for Japanese patients with non-valvular AF.

Current characteristics and management of ST elevation and non-ST elevation myocardial infarction in the Tokyo metropolitan area: from the Tokyo CCU network registered cohort.

Limited data exists on ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) managed by a well-organized cardiac care network in a metropolitan area. We analyzed the Tokyo CCU network database in 2009-2010. Of 4329 acute myocardial infarction (AMI) patients including STEMI (n = 3202) and NSTEMI (n = 1127), percutaneous coronary intervention (PCI) was performed in 88.8 % of STEMI and 70.4 % of NSTEMI patients. Mean onset-to-door and door-to-balloon times in STEMI patients were shorter than those in NSTEMI patients (167 vs 233 and 60 vs 145 min, respectively, p < 0.001). Coronary artery bypass graft surgery was performed in 4.2 % of STEMI and 11.4 % of NSTEMI patients. In-hospital mortality was significantly higher in STEMI patients than NSTEMI patients (7.7 vs 5.1 %, p < 0.007). Independent correlates of in-hospital mortality were advanced age, low blood pressure, and high Killip classification, statin-treated dyslipidemia and PCI within 24 h were favorable predictors for STEMI. High Killip classification, high heart rate, and hemodialysis were significant predictors of in-hospital mortality, whereas statin-treated dyslipidemia was the only favorable predictor for NSTEMI. In conclusion, patients with MI received PCI frequently (83.5 %) and promptly (door-to-balloon time; 66 min), and had favorable in-hospital prognosis (in-hospital mortality; 7.0 %). In addition to traditional predictors of in-hospital death, statin-treated dyslipidemia was a favorable predictor of in-hospital mortality for STEMI and NSTEMI patients, whereas hemodialysis was the strongest predictor for NSTEMI patients.

Mechanisms of postoperative atrial tachycardia following biatrial surgical ablation of atrial fibrillation in relation to the surgical lesion sets.

BACKGROUND: Atrial tachycardia (AT) may develop after biatrial surgical ablation of atrial fibrillation. However, the mechanism has not been determined in detail. OBJECTIVE: We aimed to determine the mechanism and treatment of postoperative AT following biatrial surgical ablation in relation to the design and durability of the surgical lesion sets. METHODS: An electrophysiologic study and radiofrequency ablation were performed in 34 consecutive patients (23 male, mean age of 63 ± 9.4 years) who were referred for AT that developed late after biatrial surgical ablation. RESULTS: The mechanism of a total of 53 ATs was macroreentry in 30, a focal mechanism in 20, and localized reentry in 1, and could not be determined in 2. The cause of the macroreentrant AT was residual conduction across a surgical lesion, most of which was located at the annular end of the mitral (n = 18) or tricuspid isthmus incision (n = 7), where cryoablation was applied during the surgery. We did not find any gaps across the cut-and-sew lesions. Radiofrequency (RF) applications to the gap, or an alternative site to transect the circuit, or the earliest activation site of the focus was effective for 48 ATs (91%). After a total of 1.3 ± 0.6 RF sessions, 27 patients (79%) were free of AT (n = 2) or AF (n = 5) during a follow-up period of 50 ± 49 months. CONCLUSIONS: Macroreentry due to a gap in a surgical lesion and focal AT were the major mechanisms of AT in patients after biatrial surgical ablation. Radiofrequency ablation of those ATs is feasible.

Larger low voltage zone in endocardial unipolar map compared with that in epicardial bipolar map indicates difficulty in eliminating ventricular tachycardia by catheter ablation.

Patients with ischemic and non-ischemic cardiomyopathy often have substrate for ventricular tachycardia (VT) in the endocardium (ENDO), epicardium (EPI), and/or intramural. Although it has been reported that the ENDO unipolar (UNI) voltage map is useful in detecting EPI substrate, its feasibility to detect intramural scarring and its usefulness in radiofrequency catheter ablation (RFCA) remain unclear. To assess the relationship between the left ventricle (LV) ENDO UNI voltage map and the LV EPI bipolar (BIP) voltage map, and to determine the usefulness of the ENDO UNI voltage map to guide RFCA for VT in patients with cardiomyopathy undergoing combined ENDO- and EPI RFCA. Eleven patients with VT undergoing detailed ENDO and EPI electroanatomical mapping of the LV were included (mean age 59 ± 11 years, 9 men). We assessed the value of the LV ENDO UNI voltage map in identifying EPI and/or intramural substrate in these 11 patients with non-ischemic or ischemic cardiomyopathy. The underlying heart disease was dilated cardiomyopathy in 4 patients, cardiac sarcoidosis in 3, hypertrophic cardiomyopathy in 2, and ischemic heart disease in 2 patients. The mean LV ejection fraction was 24 ± 7 %. The low voltage zone (LVZ) was defined as <1.5 mV for LV ENDO BIP electrograms (EGMs), <8.3 mV for LV ENDO UNI EGMs, and <1.0 mV for LV EPI BIP EGMs. The surface area of each LVZ was measured. We also measured the LVZ of the spatial overlap between ENDO UNI and EPI BIP voltage maps using the transparency mode on CARTO software. We performed RFCA at the ENDO and EPI based on activation and/or substrate maps, targeting the LVZ and/or abnormal EGMs. The LVZ was present in the LV ENDO BIP voltage map in 10 of 11 patients (42 ± 33 cm(2)), and in the LV ENDO UNI voltage map in 10 of 11 patients (72 ± 45 cm(2)). The LVZ was present in the EPI BIP voltage map in 9 of 11 patients (70 ± 61 cm(2)), and the LVZ in the ENDO UNI voltage map was also seen in all 9 patients. The location of the LVZ in the EPI BIP map matched that in 45 ± 28 % of ENDO UNI voltage maps. The LVZ in the ENDO UNI voltage map was larger than that in the EPI BIP voltage map in 6 of 11 patients, and RFCA failed in 5 of these 6 patients. In the remaining 5 patients with a smaller LVZ in the ENDO UNI voltage map compared with the EPI BIP voltage map or no LVZ both at ENDO UNI and EPI BIP voltage map, VT was successfully eliminated in 4 of 5 patients. The LV ENDO UNI voltage map is useful in detecting EPI substrate in patients with cardiomyopathy. A larger LVZ in the ENDO UNI voltage map compared to that in the EPI BIP voltage map may indicate the presence of intramural substrate, which leads to difficulty in eliminating VT, even with combined ENDO- and EPI RFCA.

Significance of electrocardiogram recording in high intercostal spaces in patients with early repolarization syndrome.

AIMS: Published reports regarding inferolateral early repolarization (ER) syndrome (ERS) before 2013 possibly included patients with Brugada-pattern electrocardiogram (BrP-ECG) recorded only in the high intercostal spaces (HICS). We investigated the significance of HICS ECG recording in ERS patients. METHODS AND RESULTS: Fifty-six patients showing inferolateral ER in the standard ECG and spontaneous ventricular fibrillation (VF) not linked to structural heart disease underwent drug provocation tests by sodium channel blockade with right precordial ECG (V1-V3) recording in the 2nd-4th intercostal spaces. The prevalence and long-term outcome of ERS patients with and without BrP-ECG in HICS were investigated. After 18 patients showing type 1 BrP-ECG in the standard ECG were excluded, 38 patients (34 males, mean age; 40.4 ± 13.6 years) were classified into four groups [group A (n = 6;16%):patients with ER and type 1 BrP-ECG only in HICS, group B (n = 5;13%):ERS with non-type 1 BrP-ECG only in HICS, group C (n = 8;21%):ERS with non-type 1 BrP-ECG in the standard ECG, and group D (n = 19;50%):ERS only, spontaneously or after drug provocation test]. During follow-up of 110.0 ± 55.4 months, the rate of VF recurrence including electrical storm was significantly higher in groups A (4/6:67%), B (4/5:80%), and C (4/8:50%) compared with D (2/19:11%) (A, B, and C vs. D, P < 0.05). CONCLUSIONS: Approximately 30% of the patients with ERS who had been diagnosed with the previous criteria showed BrP-ECG only in HICS. Ventricular fibrillation mostly recurred in patients showing BrP-ECG in any precordial lead including HICS; these comprised 50% of the ERS cohort.

Number needed to entrain: a new criterion for entrainment mapping in patients with intra-atrial reentrant tachycardia.

BACKGROUND: Measuring postpacing intervals (PPIs) is the standard maneuver for localizing reentrant tachycardia circuits. However, changes or termination of the tachycardia during entrainment pacing, or difficulties in defining the correct local activity, limit the use of PPIs. METHODS AND RESULTS: We hypothesized that the number of pacing stimuli needed to entrain (NNE) was useful for mapping intra-atrial reentrant tachycardias. First, 10 patients with typical atrial flutter were studied to characterize the NNE. Next, 317 entrainment attempts in 30 patients with 76 intra-atrial reentrant tachycardias were analyzed to determine the efficacy of the NNE. The NNE was small at sites within the reentrant circuit (median 2) and large at remote sites during typical atrial flutter. The NNE depended on the pacing cycle length and coupling interval of the initial paced beat, where the NNE became smaller at shorter pacing cycle lengths and coupling intervals. The NNE highly correlated with the difference between the PPI and tachycardia cycle length (r = 0.906; P<0.001). When the pacing cycle length and coupling interval were 16 to 30 ms below the tachycardia cycle length, a NNE ≤2 and >3 predicted a PPI-tachycardia cycle length ≤20 and >20 ms, respectively, with 100% accuracy. Thirty-six (11%) entrainment attempts changed or terminated intra-atrial reentrant tachycardia. Importantly, the NNE remained valid in those cases. Furthermore, the NNE provided additional information in cases with some difficulties with PPI measurements. CONCLUSIONS: The NNE is a simple and reliable criterion, which facilitates mapping intra-atrial reentrant tachycardia. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT001747.

Efficacy of additional radiofrequency applications for spontaneous dissociated pulmonary vein activity after pulmonary vein isolation in patients with paroxysmal atrial fibrillation.

BACKGROUND: The aim is to evaluate the efficacy of additional radiofrequency ablation (RFCA) for spontaneous dissociated pulmonary vein activity (DPV-spike) after PV isolation (PVI) in patients with paroxysmal atrial fibrillation (AF). METHODS: One hundred fifty-two consecutive patients with paroxysmal AF referred for RFCA were enrolled. When DPV-spike was documented after PVI, we randomly assigned these patients to receive additional RFCA for DPV-spike or only PVI. We divided them into 4 groups: 87 patients without DPV-spike after PVI (No-spike group), 31 without DPV-spike after additional RFCA (Successful group), 8 with remaining DPV-spike after additional RFCA (Unsuccessful group), and 26 with DPV-spike after only PVI (Spike group). AF recurrence was evaluated among the 4 groups. RESULTS: After PVI, DPV-spike was documented in 87 PVs (14%) from 65 patients. During 16 ± 9 months of follow-up, the incidence of the freedom from AF was significantly higher in the No-spike group than that in the Spike group and Unsuccessful group (P < 0.05), and tended to be higher in the Successful group than that in the Spike group and Unsuccessful group (P = 0.08 and 0.11, respectively). In a multivariate analysis, the remaining PV-spike after ablation was an independent predictor of AF recurrence (HR 2.44; CI 1.10-5.43, P < 0.05). No major complications including PV stenosis were observed during the follow-up. CONCLUSIONS: DPV-spike after PVI may be associated with higher electrical activity within the PVs and may be one of the risk factors for AF recurrence. Additional RFCA for DPV-spike was effective to reduce the AF recurrence after PVI.