Characterization and antiviral susceptibility of SARS-CoV-2 Omicron BA.2.

The recent emergence of SARS-CoV-2 Omicron (B.1.1.529 lineage) variants possessing numerous mutations has raised concerns of decreased effectiveness of current vaccines, therapeutic monoclonal antibodies and antiviral drugs for COVID-19 against these variants1,2. The original Omicron lineage, BA.1, prevailed in many countries, but more recently, BA.2 has become dominant in at least 68 countries3. Here we evaluated the replicative ability and pathogenicity of authentic infectious BA.2 isolates in immunocompetent and human ACE2-expressing mice and hamsters. In contrast to recent data with chimeric, recombinant SARS-CoV-2 strains expressing the spike proteins of BA.1 and BA.2 on an ancestral WK-521 backbone4, we observed similar infectivity and pathogenicity in mice and hamsters for BA.2 and BA.1, and less pathogenicity compared with early SARS-CoV-2 strains. We also observed a marked and significant reduction in the neutralizing activity of plasma from individuals who had recovered from COVID-19 and vaccine recipients against BA.2 compared to ancestral and Delta variant strains. In addition, we found that some therapeutic monoclonal antibodies (REGN10987 plus REGN10933, COV2-2196 plus COV2-2130, and S309) and antiviral drugs (molnupiravir, nirmatrelvir and S-217622) can restrict viral infection in the respiratory organs of BA.2-infected hamsters. These findings suggest that the replication and pathogenicity of BA.2 is similar to that of BA.1 in rodents and that several therapeutic monoclonal antibodies and antiviral compounds are effective against Omicron BA.2 variants.

Epidemiologic Trends and Distributions of Imported Infectious Diseases Among Travelers to Japan Before and During the COVID-19 Pandemic, 2016 to 2021: A Descriptive Study.

BACKGROUND: Little is known about the trends of imported infectious diseases among travelers to non-endemic countries during the novel coronavirus disease 2019 (COVID-19) pandemic. This article aimed to describe those among travelers to Japan. METHODS: This is a descriptive study based on national surveillance data. Imported infectious disease cases were defined as those with a reported overseas source of infection among 15 diseases pre-selected based on the probability and impact of importation. The number of notified cases from April 2016 to March 2021 were described by disease and time of diagnosis. The relative ratio and absolute difference in case counts-both by number and per arrival-were calculated by disease comparing those from the pandemic period (April 2020-March 2021) to the pre-pandemic period (April 2016-March 2020). RESULTS: A total of 3,524 imported infectious disease cases were diagnosed during the study period, including 3,439 cases before and 85 cases during the pandemic. The proportionate distribution of diseases changed but notification counts of all 15 diseases decreased during the pandemic. Accounting for arrivals, however, seven diseases showed a two-fold or greater increase, with a notable absolute increase per million arrivals for amebiasis (60.1; 95% confidence interval [CI], 41.5-78.7), malaria (21.7; 95% CI, 10.5-33.0), and typhoid fever (9.3; 95% CI, 1.9-16.8). CONCLUSION: The epidemiology of imported infectious diseases changed during the pandemic. While the number of imported infectious disease cases decreased, the number of cases per arrivals increased considerably both in relative and absolute terms for several diseases of public health and clinical importance.

Esophagogastric complications in radiofrequency and cryoballoon catheter ablation of atrial fibrillation.

INTRODUCTION: Direct comparison studies about the incidence of esophagogastric complications between radiofrequency (RF) and cryoballoon (CB) catheter ablation (CA) for atrial fibrillation (AF) have been scarce. We sought to elucidate the relationship between the pulmonary vein isolation (PVI) modalities and esophagogastric complications. METHODS: The study population consisted of 254 patients who underwent CA for AF from November 2017 to October 2018. Finally, 160 patients were enrolled and divided into the RF and CB groups. Esophageal ulcers, gastric hypomotility, and exfoliative esophagitis detected by esophagogastroduodenoscopy were defined as esophagogastric complications in this study. RESULTS: The median age was 68 years old, with 34% being females. Esophagogastric complications were observed in 42.5% of patients who underwent CA. According to the detailed esophagogastric complications, the RF group had a higher prevalence of esophageal ulcers than the CB group (19% vs. 0%, p < .0001). There was no significant difference between the two groups regarding gastric hypomotility and exfoliative esophagitis (18% vs. 28%; p = .15 and 16% vs. 21%; p = .42, respectively). CONCLUSION: Asymptomatic esophagogastric complications were common in CA for AF. The incidence of esophageal ulcers was higher in the RF group than in the CB group, whereas the other esophagogastric complications did not significantly differ.

Catheter contact angle influences local impedance drop during radiofrequency catheter ablation: Insight from a porcine experimental study with 2 different LI-sensing catheters.

BACKGROUND: Local impedance (LI) can indirectly measure catheter contact and tissue temperature during radiofrequency catheter ablation (RFCA). However, data on the effects of catheter contact angle on LI parameters are scarce. This study aimed to evaluate the influence of catheter contact angle on LI changes and lesion size with two different LI-sensing catheters in a porcine experimental study. METHODS: Lesions were created by the INTELLANAV MiFi™ OI (MiFi) and the INTELLANAV STABLEPOINT™ (STABLEPOINT). RFCA was performed with 30 W and a duration of 30 s. The contact force (CF) (0, 5, 10, 20, and 30 g) and catheter contact angle (30°, 45°, and 90°) were changed in each set (n = 8 each). The LI rise, LI drop, and lesion size were evaluated. RESULTS: The LI rise increased as CF increased. There was no angular dependence with the LI rise under all CFs in the MiFi. On the other hand, the LI rise at 90° was lower than at 30° under 5 and 10 g of CF in STABLEPOINT. The LI drop increased as CF increased. Regarding the difference in catheter contact angles, the LI drop at 90° was lower than that at 30° for both catheters. The maximum lesion widths and surface widths were smaller at 90° than at 30°, whereas there were no differences in lesion depths. CONCLUSION: The LI drop and lesion widths at 90° were significantly smaller than those at 30°, although the lesion depths were not different among the 3 angles for the MiFi and STABLEPOINT.

Reduced atrial conduction velocity is associated with the recurrence of atrial fibrillation after catheter ablation.

The recurrence of atrial fibrillation (AF) after catheter ablation (CA) is still an unsolved issue. Although structural remodeling is relatively well defined, the method to assess electrical remodeling of the atrium is not well established. In this study, we evaluated the relationship between atrial conduction properties and recurrence after CA for AF. One hundred six consecutive patients (66 ± 11 years old, male: 68%) who underwent CA for AF with a CARTO system from July 2016 to July 2019 were enrolled in this study. An activation map of both atria was constructed to precisely evaluate the total conduction time, distance, and conduction velocity between the earliest and latest activation sites during sinus rhythm. All parameters were compared between the patients with or without AF recurrence. Of the patients, 27 had an AF recurrence (Rec group). The left atrial (LA) conduction velocity was significantly slower in the Rec group than in the non-Rec group (101.2 ± 17.9 vs. 116.9 ± 18.0 cm/s, P < 0.01). Likewise, the right atrial (RA) conduction velocity was significantly slower in the Rec group than in the non-Rec group (81.1 ± 17.5 vs. 103.6 ± 25.4 cm/s, P < 0.01). A multivariate logistic analysis demonstrated that the LA and RA conduction velocities were independent predictors of AF recurrence, with adjusted odds ratios of 0.95 (95% confidential interval: 0.91-0.98, P < 0.01) and 0.94 (0.89-0.98, P < 0.01), respectively. In conclusion, slower conduction velocity of the atrium was associated with AF recurrence after pulmonary vein isolation.

Effect of an Oral Frailty Measures Program on Community-Dwelling Elderly People: A Cluster-Randomized Controlled Trial.

INTRODUCTION: Oral frailty describes a trivial decline in the oral function and is considered to be related to frailty. Thus, effective management of oral frailty could prevent or ameliorate physical frailty and the need for care. However, there is a lack of consensus regarding specific interventions for oral frailty. In this cluster-randomized controlled trial, we investigated the effects of a newly developed oral frailty measures program mentored by dentists and dental hygienists for elderly people in a clinical setting. METHODS: Of 3,296 participants included in a field survey, 219 who regularly visited dental clinics and met at least 3 of the following 6 criteria for oral frailty were considered eligible: <20 natural teeth, decreased chewing ability, decreased articulatory oral-motor skills, decreased tongue pressure, and substantial subjective difficulties in eating and swallowing. After applying the inclusion and exclusion criteria, we studied 51 patients in the intervention group (14 men and 37 women; mean age, 78.6 years) and 32 patients in the control group (7 men and 25 women; mean age, 78.0 years). We implemented a 12-week oral frailty measures program only for the intervention group. The program included preparatory oral exercises, mouth-opening training, tongue pressure training, prosodic training, and masticatory training. Primary outcome measures were the chewing ability score, articulatory oral motor skill for /ta/, tongue pressure, subjective difficulty in eating tough foods, and subjective difficulty in swallowing. We compared baseline characteristics using the Mann-Whitney U and χ2 tests for continuous and categorical variables, respectively. A repeated-measures two-way ANOVA was used to determine the efficacy of independent intervention variables, following the Wilcoxon signed-rank test. The groups (intervention/control) and time (baseline/week 12) were the independent variables. Oral frailty measures were the dependent variables. RESULTS: Baseline characteristics and assessment results were similar between groups. We observed significant improvements in the intervention group in terms of articulatory oral motor skill for /ta/ and tongue pressure (p < 0.001). No improvements were observed in the control group. DISCUSSION/CONCLUSION: Our results suggest that our oral frailty measures program effectively alleviates oral frailty. Future studies are needed to clarify the impact on preventing physical frailty and improving the nutritional status.

Severe Acute Respiratory Syndrome Coronavirus 2 Infection among Returnees to Japan from Wuhan, China, 2020.

In early 2020, Japan repatriated 566 nationals from China. Universal laboratory testing and 14-day monitoring of returnees detected 12 cases of severe acute respiratory syndrome coronavirus 2 infection; initial screening results were negative for 5. Common outcomes were remaining asymptomatic (n = 4) and pneumonia (n = 6). Overall, screening performed poorly.

Precise Signals with a High-Density Grid Mapping Catheter Are Useful for an Entrainment Study.

Complex atrial tachycardias (ATs) after catheter ablation or a MAZE procedure is sometimes difficult to determine the circuits of the tachycardia. A high-density, grid-shapes mapping catheter has been launched, which can be useful for detecting the detail circuits of tachycardias on three-dimensional mapping systems. The signal quality is also important for performing electrophysiological studies (EPSs), such as entrainment mapping, to identify the circuit. This unique mapping catheter has 1 mm electrodes on 2.5 Fr shafts, which improve the signal quality. The high-quality intracardiac electrograms facilitate differentiating small critical potentials, which allows us to perform detailed entrainment mapping in targeted narrow areas. Here, we describe a patient with a perimetral AT with epi-endocardium breakthrough after a MAZE surgery and catheter ablation, which was treated successfully along with detailed entrainment mapping using the HD Grid. This catheter with high-quality signals could be a significant diagnostic tool for a classic EPS as well as for the construction of 3D mapping.

Prediction of Lethal Arrhythmic Events Through Remote Monitoring Using Heart Rate Variability Analysis in Patients with an Implantable Cardioverter Defibrillator.

We prospectively collected device and heart rate data through remote monitoring (RM) of patients with an implantable cardioverter defibrillator (ICD). The objective was to identify the predictors of lethal arrhythmic events (VT/VF).Thirty-three patients (mean age: 50 years) with ICDs [with functionality of heart rate variability (HRV) analysis] were divided into two groups [VT/VF (+), VT/VF (-) ]. Clinical, device (ventricular lead impedance; amplitude of ventricular electrogram), and HRV data were compared between the two groups. The NN interval-index (SDNNi) was calculated for every 5 minutes, and the mean, maximum, minimum, and standard deviation of SDNNi during the 24-hour period were used.During the observation period of 13 ± 10 months, 10 patients experienced VT/VF events. Total mean, max, and min SDNNi were higher in the VT/VF (+) than the VT/VF (-) group (132.9 ± 9.3 versus 93.5 ± 6.1, P = 0.0013; 214.6 ± 10.6 versus 167.0 ± 7.0, P = 0.0007; 71.2 ± 7.5 versus 43.9 ± 4.9, P = 0.0047). On logistic regression analysis, a total mean SDNNi of 100.1, max SDNNi of 185.0 and min SDNNi of 52.0 as cut-off values for prediction of a VT/VF event demonstrated significant receiver operating characteristic (ROC) curves (AUC = 0.86, P = 0.0007; AUC = 0.84, P = 0.0005; AUC = 0.78, P = 0.0030). The max ΔSDNNi, i.e., difference from baseline SDNNi, and min ΔSDNNi in 7 and 28 days preceding VT/VF events were significant predictors of VT/VF events.Time-domain HRV analysis through a RM system may help identify patients at high risk of lethal arrhythmic events; in addition, it may help predict the occurrence of lethal arrhythmic events in specific cases.

Increasing Incidence of Degenerative Spinal Diseases in Japan during 25 Years: The Registration System of Spinal Surgery in Tohoku University Spine Society.

Spinal disorders affect mainly older people and cause pain, paralysis and/or deformities of the trunk and/or extremities, which could eventually disturb locomotive functions. For ensuring safe and high-quality treatment of spinal disorders, in 1987, the Tohoku University Spine Society (TUSS) was established by orthopedic departments in Tohoku University School of Medicine and its affiliated hospitals in and around Miyagi Prefecture. All spine surgeries have been enrolled in the TUSS Spine Registry since 1988. Using the data from this registration system between 1988 and 2012, we demonstrate here the longitudinal changes in surgical trends for spinal disorders in Japan that has rushed into the most advanced "aging society" in the world. In total, data on 56,744 surgeries were retrieved. The number of spinal surgeries has annually increased approximately 4-fold. There was a particular increase among patients aged ≥ 70 years and those aged ≥ 80 years, with a 20- to 90-fold increase. Nearly 90% of the spinal operations were performed for degenerative disorders, with their number increasing approximately 5-fold from 705 to 3,448. The most common disease for surgery was lumbar spinal stenosis (LSS) (35.9%), followed by lumbar disc herniation (27.7%) and cervical myelopathy (19.8%). In 2012, approximately half of the patients with LSS and cervical myelopathy were ≥ 70 years of age. In conclusion, the number of spinal operations markedly increased during the 25-year period, particularly among older patients. As Japan has a notably aged population, the present study could provide a near-future model for countries with aging population.

Antimicrobial efficacy of combined clarithromycin plus daptomycin against biofilms-formed methicillin-resistant Staphylococcus aureus on titanium medical devices.

In vitro efficacy of combined eradication therapy with clarithromycin and daptomycin against biofilm-formed methicillin-resistant Staphylococcus aureus on the orthopedic titanium devices was evaluated. The bactericidal effect of this antibiotic was investigated by a re-culture test, the scanning electron microscopy, and fluorescence microscopy using a double-staining dyes. Clarithromycin decreased the amount to half in 24 h. Although MRSA biofilms were not eradicated with clarithromycin or daptomycin alone, clarithromycin combined with daptomycin was useful to sterilize titanium devices within 72 h. This in vitro study showed that combined treatment with clarithromycin plus daptomycin is useful to eradicate staphylococcal biofilms formed on orthopedic devices.

Reoperation rates after fenestration for lumbar spinal canal stenosis: a 20-year period survival function method analysis.

PURPOSE: Fenestration is the gold standard surgery for lumbar spinal canal stenosis in Japan. Several previous studies have analyzed the reoperation rates in large numbers of patients undergoing several surgical procedures such as laminectomy with or without instrumented spinal fusion; however, there have been few studies focusing solely on fenestration. The purpose of this study was to calculate the reoperation rates after fenestration using the survival function method. METHODS: Form 1988-2007, 6,998 surgeries for lumbar spinal canal stenosis occurred in Miyagi prefecture, Japan, and these patients were enrolled by the spinal surgery registration system of the Department of Orthopaedic Surgery, Tohoku University. Among these, 5,835 surgeries involved fenestration as a primary surgery and for those who underwent ≥2 lumbar surgeries we analyzed the reoperation rates using the Kaplan-Meier method. RESULTS: Among the 5,835 patients undergoing primary fenestration, 215 patients underwent 221 revisions; 112 included the same spinal levels and 103 were revised only at other levels as primary fenestration. The overall reoperation rates were 0.8% at 1 year, 2.9% at 5 years, 5.2% at 10 years, 7.5% at 15 years and 8.6% at >17.7 years. Reoperation rates for those at the same spinal levels were 0.6% at 1 year, 1.7% at 5 years, 2.7% at 10 years, 3.8% at 15 years, and 4.1% at >17.0 years. CONCLUSIONS: Fenestration can be performed at low cost using standard spinal surgery equipments. The reoperation rates of this procedure were lower than previously reported for several other surgical procedures.

Lesion size index-guided cavotricuspid isthmus linear ablation.

BACKGROUND: The lesion size index (LSI) predicts radiofrequency (RF) ablation lesion size and is an established parameter for pulmonary vein isolation. However, the effectiveness and safety of LSI for cavotricuspid isthmus (CTI) linear ablation remain unclear. METHODS: This single-center retrospective study included 50 of patients (67 ± 10 years, 68% male) who underwent de novo CTI linear ablation between July 2020 and December 2020. The LSI target was set at 5.0 and 4.0 for the anterior 2/3 and posterior 1/3 segments, respectively. Acute procedural parameters of ablation were evaluated. RESULTS: Acute bidirectional CTI block was achieved in all patients with an RF application time of 4.0 min (3.1-5.0 min), RF application number of 15 ± 7, and length of CTI of 36.9 ± 9.3 mm. First-pass bidirectional conduction block of the CTI was achieved in 39/50 (78%) patients. No major complications were observed. The contact force (CF) per application was significantly lower in the gap tag group than in the non-gap tag group (7 g [7-8 g] vs. 10 g [7-12 g], P = 0.0284). CONCLUSIONS: LSI-guided CTI linear ablation is an effective and safe treatment approach. CF affects gap formation, even when the target LSI is the same.

Fracture and contralateral dislocation of the twin facet joints of the lower cervical spine.

PURPOSE: The combination of a facet fracture and a contralateral facet dislocation at the same intervertebral level of the cervical spine (a fracture and contralateral dislocation of the twin facet joints) has not been described in detail. The aims of this study are to report a series of 11 patients with this injury, to clarify the clinical features and to discuss its pathomechanism. METHODS: Among 251 patients with lower cervical spine fractures and/or dislocations surgically treated, 11 (9 males and 2 females, averaged age, 52 years) had this kind of injury. Medical charts and medical images were reviewed retrospectively. RESULTS: Injury levels were C4-5, C5-6 and C6-7 in 1, 4 and 6 patients, respectively. A fracture was found at the superior facet in 6, and at the inferior facet in 5. The anterior displacement of the vertebral body ranged from 7 to 19 mm. The unilateral horizontal facet appearance on an anteroposterior radiograph and the triple image on a CT composed of a separated fracture fragment, the base of the fractured facet, and the neighboring non-fractured facet were characteristic. All patients had neurological deficits from Frankel A to D, and were surgically treated by posterior fusion using wire or cable, or combined anterior and posterior spinal fusion. CONCLUSIONS: The fracture and contralateral dislocation of the twin facet joints can cause severe neurological deficits because of its gross anterior displacement. Its plausible pathomechanism is extension force exerted to the cervical spine when it is maximally bent laterally.

Two-step movement of tsunami boulders unveiled by modified viscous remanent magnetization and radiocarbon dating.

Massive boulders in landslide and tsunami deposits are prominent geomorphic features in various landscapes. Tracking their movement history is important for reconstructing past geologic dynamics; however, the reworking movements of massive boulders remain unresolved. The boulder field on the Ishigaki Island was formed by repeated tsunamis. Although the individual movement histories of boulders contribute to retrodict the history of different magnitude tsunamis, their radiocarbon ages only correspond to the tsunamis that detached boulders from the reef. Viscous remanent magnetization dating methods have been applied in reworking movements. These methods reveal signals associated with remanent magnetization that gradually grew since the reworking event, which helps to determine the passage of time. The methods were verified by comparison to the radiocarbon ages of un-reworked boulders detached by the recent Meiwa tsunami, while the estimated ages of such two boulders based on the classical relaxation theory contradicted the radiocarbon ages. Here, we show that a method based on the stretched exponential function addressed this contradiction. The reworking movement was estimated using an additional boulder, whose, using our method, radiocarbon age indicated that an older tsunami moved it, whereas the remanent magnetization age unveiled a reworking of the boulder attributed to the Meiwa tsunami.

Atrial flutter with an epicardial and endocardial breakthrough in the cavotricuspid isthmus.

We performed cavotricuspid isthmus (CTI) linear ablation for atrial flutter; however, the tachycardia cycle length was not changed at all. In such cases, repeated or broad line ablation is usually performed. We presented that high-density three-dimensional mapping after the first CTI linear ablation, which revealed the complex tachycardia circuit with the epicardial and endocardial breakthrough.

Atrial late potentials are associated with atrial fibrillation recurrence after catheter ablation.

Background: Previous studies have identified noninvasive methods for predicting atrial fibrillation (AF) recurrence after catheter ablation (CA). We assessed the association between AF recurrence and atrial late potentials (ALPs), which were measured using P-wave signal-averaged electrocardiography (P-SAECG). Methods: Consecutive patients with paroxysmal AF who underwent their first CA at our institution between August 2015 and August 2019 were enrolled. P-SAECG was performed before CA. Two ALP parameters were evaluated: the root-mean-square voltage during the terminal 20 ms (RMS20) and the P-wave duration (PWD). Positive ALPs were defined as an RMS20 <2.2 µV and/or a PWD >115 ms. Patients were allocated to either the recurrence or nonrecurrence group based on the presence of AF recurrence at the 1-year follow-up post-CA. Results: Of the 190 patients (age: 65 ± 11 years, 37% women) enrolled in this study, 21 (11%) had AF recurrence. The positive ALP rate was significantly higher in the recurrence group than in the nonrecurrence group (86% vs. 64%, p = .04), despite the absence of differences in other baseline characteristics between the two groups. In the multivariate analysis, positive ALP was an independent predictor of AF recurrence (odds ratio: 3.83, 95% confidence interval: 1.05-14.1, p = .04). Conclusions: Positive ALP on pre-CA P-SAECG is associated with AF recurrence after CA.

Characterization and antiviral susceptibility of SARS-CoV-2 Omicron/BA.2.

The recent emergence of SARS-CoV-2 Omicron variants possessing large numbers of mutations has raised concerns of decreased effectiveness of current vaccines, therapeutic monoclonal antibodies, and antiviral drugs for COVID-19 against these variants1,2. While the original Omicron lineage, BA.1, has become dominant in many countries, BA.2 has been detected in at least 67 countries and has become dominant in the Philippines, India, and Denmark. Here, we evaluated the replicative ability and pathogenicity of an authentic infectious BA.2 isolate in immunocompetent and human ACE2 (hACE2)-expressing mice and hamsters. In contrast to recent data with chimeric, recombinant SARS-CoV-2 strains expressing the spike proteins of BA.1 and BA.2 on an ancestral WK-521 backbone3, we observed similar infectivity and pathogenicity in mice and hamsters between BA.2 and BA.1, and less pathogenicity compared to early SARS-CoV-2 strains. We also observed a marked and significant reduction in the neutralizing activity of plasma from COVID-19 convalescent individuals and vaccine recipients against BA.2 compared to ancestral and Delta variant strains. In addition, we found that some therapeutic monoclonal antibodies (REGN10987/REGN10933, COV2-2196/COV2-2130, and S309) and antiviral drugs (molnupiravir, nirmatrelvir, and S-217622) can restrict viral infection in the respiratory organs of hamsters infected with BA.2. These findings suggest that the replication and pathogenicity of BA.2 is comparable to that of BA.1 in rodents and that several therapeutic monoclonal antibodies and antiviral compounds are effective against Omicron/BA.2 variants.

Novel Predictor for New-Onset Atrial High-Rate Episode in Patients With a Dual-Chamber Pacemaker.

Background: The incidence of new-onset atrial high-rate episode (AHRE) is higher among patients with cardiac implantable electronic devices (CIEDs) than in the general population. We sought to elucidate the clinical factors associated with AHRE in CIED patients, including P-wave dispersion (PWD) in sinus rhythm. Methods and Results: In all, 101 patients with CIEDs newly implanted between 2010 and 2014 were included in the study. PWD was measured at the time of device implantation via a body-surface electrocardiogram. AHRE was defined as any episode of sustained atrial tachyarrhythmia (>170 beats/min) recorded in the device's memory. Patients were divided into an AHRE (n=34) and non-AHRE (n=67) group based on the presence or absence of AHRE within 1 year of device implantation and compared. Mean (±SD) patient age was 75±11 years. A greater incidence of sick sinus syndrome (P=0.05) and longer PWD (62.6±13.1 vs. 38.2±13.9 ms; P<0.0001) were apparent in the AHRE than non-AHRE group. Multivariate analysis revealed that PWD was an independent predictor of new-onset AHRE (odds ratio 1.11; 95% confidence interval 1.06-1.17; P<0.0001). In logistic regression analysis, receiver-operating characteristic curve analysis (area under the curve 0.90; P<0.001) suggested the best cut-off value for PWD was 48 mm (sensitivity 73.8%, specificity 77.9%). Conclusions: PWD is a simple but feasible predictor of new-onset AHRE in patients with CIEDs.

Optimized lesion size index (o-LSI): A novel predictor for sufficient ablation of pulmonary vein isolation.

BACKGROUND: Although the lesion size index (LSI) has been well established, it is sometimes difficult to achieve first-pass pulmonary vein isolation (PVI) and to avoid acute pulmonary vein reconnections, even with LSI-guided procedures. The purpose of this study was to assess the predictive accuracy of a novel parameter, the optimized lesion size index (o-LSI), to perform PVI. METHODS: The voltage maps created by the Advisor™ high-density (HD) grid catheter before PVI in 35 atrial fibrillation (AF) patients were examined for an association between the voltage amplitude and insufficient ablation sites (IAS), which were defined as either (i) spontaneous reconnection sites, (ii) dormant PV conduction sites unmasked with 20 mg of adenosine triphosphate disodium hydrate (ATP) injection, or (iii) PV-LA gap sites after the initial PVI. RESULTS: IAS was observed in 25/1417 of the total ablation sites. IAS was significantly associated with higher bipolar voltage areas (4.20 ± 2.68 vs 2.43 ± 1.93 mV, P < .0001) but not with LSI. A novel index, o-LSI (defined as LSI/bipolar voltage), was significantly lower in IAS than in others (1.14 [0.82, 1.81] vs 2.35 [1.31, 4.80] LSI/mV). By receiver operating characteristic analysis, an o-LSI of 2.04 was the best cutoff value for the prediction of IAS (88% sensitivity and 55% specificity, P < .0001, areas under the curve: 0.742). CONCLUSION: Low o-LSI was strongly associated with IAS, potentially providing a novel index to improve first-pass PV isolation.