Cardiovascular Outcomes after Paclitaxel-Coated Balloon Angioplasty versus Drug-Eluting Stent Placement for Acute Coronary Syndrome: A Systematic Review and Meta-Analysis.

Background: We conducted a systematic review and meta-analysis to examine the feasibility of paclitaxel-coated balloon (PCB) angioplasty for de novo lesions in patients with acute coronary syndrome (ACS) by comparing with drug-eluting stent (DES) placement. Methods: By a systematic literature search, nine (five randomized controlled, two retrospective propensity-score matched, and two retrospective baseline-balanced) studies comparing the midterm clinical and angiographic outcomes after PCB angioplasty and DES placement were included, yielding 974 and 1130 ACS cases in PCB and DES groups, respectively. Major adverse cardiac event (MACE) was defined as a composite of cardiac mortality (CM), all-cause mortality (ACM), myocardial infarction (MI), target vessel revascularization (TVR), and target lesion revascularization (TLR). Late luminal loss (LLL) and bleeding events (BLD) were also estimated. Results: The frequencies of MACE in PCB and DES groups were 8.42% and 10.62%, respectively. PCB angioplasty had no significant impacts on all of MACE (risk ratio: 0.90, 95%CI: 0.68-1.18, p = 0.44), CM, ACM, MI, TVR, TLR, BLD, and LLL, compared to DES placement in random-effects model. Conclusions: The present systematic review and meta-analysis showed the feasibility of PCB angioplasty for the de novo lesions in patients with ACS in comparison with DES placement by the emergent procedures.

Reliable measurement methods for the isovolumic relaxation time: comparisons of dual gate Doppler and seven other methods.

PURPOSE: Isovolumic relaxation time (IVRT) is a useful indicator of diastolic dysfunction. However, a measurement method for IVRT has not been established. The Dual Gate Doppler method, which can record two separate pulse-wave Doppler signals simultaneously using two sample gates, may be ideal for measuring IVRT. This study aimed to evaluate the accuracy of IVRT measured using conventional methods versus that measured using the Dual Gate Doppler method. METHODS: A total of 104 patients (mean age 58 ± 21 years, 48 women) were examined using ultrasound equipment with Dual Gate Doppler at our hospital. In addition to Dual Gate Doppler method, IVRTs were measured using seven different methods: pulsed Doppler (PW method), continuous wave Doppler (CW method), and other methods. The IVRT values obtained using the Dual Gate Doppler method were compared with those measured using other methods. RESULTS: All IVRTs measured using conventional methods showed a strong correlation with the that measured using the Dual Gate Doppler method. However, there were slight deifferences among the IVRTs depending on the method. The PW method and the PW time difference method using only the PW showed small statistical bias and were not complicated. The IVRT measured using the CW method was significantly longer than that measured using the Dual Gate Doppler method. CONCLUSIONS: Among the conventional methods, the PW method was the simplest and most practical method for measuring the IVRT in any conditions as arrhythmias. It is important to recognize the characteristics of IVRTs based on the measurement method.

Chronic Effect of HotBalloon-Based Wide Planar Ablation on Epicardial Adipose Tissue in Persistent Atrial Fibrillation.

Background: Adverse atrial remodeling, including epicardial adipose tissue (EAT) deposition in the left atrium (LA), is implicated in atrial fibrillation (AF). Radiofrequency hotballoon (RHB) ablation can produce wide planar lesions because the balloon is highly compliant; however, chronic effects of RHB ablation on structural remodeling remain unknown. This clinical-experimental investigation characterized chronic effects of RHB ablation on EAT in persistent AF (PsAF). Methods and Results: The clinical study involved 91 patients (obese, n=30; non-obese, n=61) undergoing RHB ablation for PsAF. LA-EAT was assessed from computed tomography images obtained before ablation and 6 months later. Tissue effects of RHB ablation were explored in a chronic swine model. RHB ablation significantly reduced LA volume (mean [±SD] 177.7±29.7 vs. 138.4±29.6 mL; P<0.001) and LA-EAT volume (median [interquartile range] 22.0 [12.4-33.3] vs. 16.5 [7.9-25.8] mL; P<0.001). The reduction in EAT was significantly greater in the pulmonary vein (PV) antrum than in other LA regions (37.9% vs. 15.8%; P<0.001). The percentage reduction in PV antrum EAT was equivalent between obese and non-obese patients, as was the postablation success rate (73% vs. 70%; P=0.77). RHB ablation produced transmural lesions reaching the pigs' epicardial fat region. Conclusions: RHB-based planar-transmural lesions altered the structurally remodeled LA, including EAT. Further studies are needed to determine whether factors other than PV isolation contribute to the clinical success of RHB ablation.

Deep learning-based model detects atrial septal defects from electrocardiography: a cross-sectional multicenter hospital-based study.

Background: Atrial septal defect (ASD) increases the risk of adverse cardiovascular outcomes. Despite the potential for risk mitigation through minimally invasive percutaneous closure, ASD remains underdiagnosed due to subtle symptoms and examination findings. To bridge this diagnostic gap, we propose a novel screening strategy aimed at early detection and enhanced diagnosis through the implementation of a convolutional neural network (CNN) to identify ASD from 12-lead electrocardiography (ECG). Methods: ECGs were collected from patients with at least one recorded echocardiogram at 3 hospitals from 2 continents (Keio University Hospital from July 2011 to December 2020, Brigham and Women's Hospital from January 2015 to December 2020, and Dokkyo Medical University Saitama Medical Center from January 2010 and December 2021). ECGs from patients with a diagnosis of ASD were labeled as positive cases while the remainder were labeled as negative. ECGs after the closure of ASD were excluded. After randomly splitting the ECGs into 3 datasets (50% derivation, 20% validation, and 30% test) with no patient overlap, a CNN-based model was trained using the derivation datasets from 2 hospitals and was tested on held-out datasets along with an external validation on the 3rd hospital. All eligible ECGs were used for derivation and validation whereas the earliest ECG for each patient was used for the test and external validation. The discrimination of ASD was assessed by the area under the receiver operating characteristic curve (AUROC). Multiple subgroups were examined to identify any heterogeneity. Findings: A total of 671,201 ECGs from 80,947 patients were collected from the 3 institutions. The AUROC for detecting ASD was 0.85-0.90 across the 3 hospitals. The subgroup analysis showed excellent performance across various characteristics Screening simulation using the model greatly increased sensitivity from 80.6% to 93.7% at specificity 33.6% when compared to using overt ECG abnormalities. Interpretation: A CNN-based model using 12-lead ECG successfully identified the presence of ASD with excellent generalizability across institutions from 2 separate continents. Funding: This work was supported by research grants from JST (JPMJPF2101), JSR corporation, Taiju Life Social Welfare Foundation, Kondou Kinen Medical Foundation, Research fund of Mitsukoshi health and welfare foundation, Tokai University School of Medicine Project Research and Internal Medicine Project Research, Secom Science and Technology Foundation, and Grants from AMED (JP23hma922012 and JP23ym0126813). This work was partially supported by One Brave Idea, co-funded by the American Heart Association and Verily with significant support from AstraZeneca and pillar support from Quest Diagnostics.

Prognostic Impacts of CHADS2, CHA2DS2-VASc, and CHA2DS2-VASc-HS Scores on Clinical Outcomes After Elective Drug-Eluting Stent Placement for De Novo Coronary Stenosis.

Background: The prognostic impact of CHADS2, CHA2DS2-VASc, and CHA2DS2-VASc-HS scores on clinical outcomes after drug-eluting stent (DES) placement has not been fully elucidated. Methods and Results: The present study was a retrospective, non-randomized, single-center, and lesion-based study. Target lesion failure (TLF), comprising cardiac death, non-fatal myocardial infarction, and target vessel revascularization, occurred in 7.1% of 872 consecutive de novo coronary lesions in 586 patients. These patients were electively and exclusively treated by DESs from January 2016 to January 2022 until July 2022 with a mean (±SD) observational interval of 411±438 days. Multivariate Cox proportional hazard analysis revealed that CHA2DS2-VASc-HS scores ≥7 (hazard ratio [HR] 1.800; 95% CI 1.06-3.05; P=0.029) was a significant predictor of cumulative TLF among 24 variables evaluated. CHADS2 scores ≥2 (HR 3.213; 95% CI 1.32-7.80; P=0.010) and CHA2DS2-VASc scores ≥5 (HR 1.980; 95% CI 1.10-3.55; P=0.022) were also significant in the multivariate analysis. Pairwise comparisons of receiver operating characteristic curves for CHADS2 score ≥2, CHA2DS2-VASc score ≥5, and CHA2DS2-VASc-HS score ≥7 showed they were equivalent in terms of predicting the incidence of TLF, with areas under the curve of 0.568, 0.575, and 0.573, respectively. Conclusions: All 3 cardiocerebrovascular thromboembolism risk scores were strong predictors of the incidence of cumulative mid-term TLF after elective DES placement, with cut-off values of 2, 5, and 7, respectively, and equivalent prognostic impacts.

Clinical and Angiographic Outcomes of Elective Paclitaxel-Coated Balloon Angioplasty in Comparison with Drug-Eluting Stents for De Novo Coronary Lesions in Large Vessels.

We retrospectively examined the feasibility of paclitaxel-coated balloon (PCB) angioplasty for de novo stenosis in large coronary vessels (LV; pre- or postprocedural reference vessel diameter ≥ 2.75 mm) in comparison with placement of drug-eluting stents (DESs).Consecutive de novo stenotic lesions in the LV electively and successfully treated with either PCB (n = 73) or DESs (n = 81) from January 2016 to December 2018 at our center were included. The primary endpoint was the incidence of target lesion failure (TLF), including cardiac death, nonfatal myocardial infarction, and target vessel revascularization. The impact of PCB on TLF was examined using Cox proportional hazards models by including 39 variables. The secondary endpoint, angiographic restenosis, defined as a follow-up percent diameter stenosis > 50, was examined in angiographic follow-up lesions after PCB angioplasty (n = 56) and DES placement (n = 53). This retrospective investigation was conducted in July 2022.The mean PCB size and length were 3.23 ± 0.42 and 18.4 ± 4.3 mm, respectively. The TLF frequency in the PCB group (6.8% during the mean observational interval of 1536 ± 538 days) was not significantly different from that in the DES group (14.6%, 1344 ± 606 days, P = 0.097). PCB was not a significant predictor of TLF in the univariate analysis (hazard ratio: 0.424; 95%CI: 0.15-1.21; P = 0.108). There was no angiographic restenosis after PCB angioplasty.The present observational single-center study showed that PCB for de novo stenosis in the LV had no significant adverse impact on TLF and had favorable angiographic outcomes.

Perinatal and neonatal characteristics of Prader-Willi syndrome in Japan.

BACKGROUND: Prader-Willi syndrome (PWS) is suspected at birth if extreme hypotonia, difficulty in feeding, hypogonadism, and failure to thrive are present. Genetic diagnosis of PWS can generally be made within the first few months of life; however, a delayed diagnosis of PWS is frequently reported. Although the clinical characteristics of perinatal and neonatal patients with PWS have been reported, there are no such reports on the clinical characteristics of these patients in Japan. METHODS: This retrospective, single-center study involved 177 Japanese patients with PWS and their medical data regarding the perinatal and neonatal periods were evaluated. RESULTS: The median maternal age at birth was 34 years; 12.7% of the mothers had a history of assisted reproductive technology (ART). Of the mothers, 13.5% reported polyhydramnios and 4.3% had oligohydramnios. Decreased fetal movement during pregnancy was reported by 76% of the mothers. A total of 60.5% of patients were born by cesarean section. Genetic subtypes included deletions (66.1%), uniparental disomy (31.0%), imprinting defects (0.6%), and other or unknown subtypes (2.3%). The median birth length was 47.5 cm and the median birthweight was 2476 g. Of the 160 patients, 14 (8.8%) were classified as small for gestational age. Most patients had hypotonia (98.8%), and 89.3% required gavage feeding at birth. Breathing problems, congenital heart disease, and undescended testis were noted in 33.1%, 7.0%, and 93.5% of patients, respectively. CONCLUSION: In our study, higher rates of ART, polyhydramnios, decreased fetal movements, cesarean section, hypotonia, feeding difficulties, and undescended testis were observed in PWS.

Comparison of phrenic nerve injury and its effect on the extrapulmonary vein structures with cryoballoon and hot-balloon ablation systems: considering the lesion created on the superior vena cava as a surrogate marker.

Preventing phrenic nerve injury (PNI) during balloon-based ablation is essential. The superior vena cava-right atrial (SVC-RA) junction is located just opposite the balloon position during right superior pulmonary vein (RSPV) ablation, and the phrenic nerve runs nearby on the lateral side. We compared the occurrence of PNI between the two balloon-based ablation systems and also the lesions created at the SVC-RA junction, which were expected to represent the effect on extra-PV structures. Cryoballoon ablation (CBA, n = 110) and hot-balloon ablation (HBA, n = 90) were performed in atrial fibrillation patients. High-density maps of the SVC-RA junction were created in 93 patients (CBA = 53, HBA = 40), and the damaged area (< 1.0 mV) was determined as an "SVC lesion". CBA had a higher occurrence of transient PNI (7.3% vs 1.1%, p = 0.035), but all recovered during the 6-month follow-up. An apparent SVC lesion was documented in 43% of the patients (40/93), and all patients with PNI had this lesion. CBA created a frequent (CBA vs HBA = 55% vs 28%, p = 0.008) and wider (0.8[0.4-1.7] cm2 vs 0.5[0.3-0.7] cm2, p = 0.005) SVC lesion than HBA. A multivariate analysis revealed that the use of a CBA system was a predictive factor of the occurrence of SVC lesions. CBA had a higher occurrence of transient PNI but not a permanent form. Every patient with PNI had lesions on the SVC-RA junction, and CBA revealed more substantial ablation effects at the SVC-RA junction than HBA. This may be caused by the different characteristics of the two balloon-based ablation systems and their balloon positions.

Midterm safety and efficacy of elective drug-coated balloon angioplasty in comparison to drug-eluting stents for unrestrictive de novo coronary lesions: A single center retrospective study.

BACKGROUND: The safety and efficacy of elective drug-coated balloon (DCB) angioplasty for unrestrictive de novo coronary stenosis in daily practice is not fully understood, especially in comparison to those of drug-eluting stents (DESs). METHODS: A total of 588 consecutive de novo coronary stenotic lesions electively and successfully treated with either DCB (n = 275) or DESs (n = 313) between January 2016 and December 2019 at our medical center were included. The primary safety endpoint was the incidence of target lesion failure (TLF), comprising cardiac death, non-fatal myocardial infarction, and target vessel revascularization. The secondary angiographic efficacy endpoint was angiographic restenosis frequency, defined as a follow-up percent diameter stenosis of >50. The endpoints were compared after baseline adjustment using propensity score matching. In addition, the frequency and predictors of late lumen enlargement (LLE), defined as minus late luminal loss, were examined in 201 crude angiographic follow-up lesions after DCB angioplasty. RESULTS: A total of 31 baseline parameters were adjusted to analyze 177 lesions in each group. The TLF frequencies (DCB group: 9.6 % during a mean observational interval of 789 ±â€¯488 days vs. DES group: 10.2 %, 846 ±â€¯484 days, p = 0.202) and cumulative TLF-free ratios of both groups were not significantly different (p = 0.892, log-rank test). The angiographic restenosis frequency in the DCB group (6.3 %, n = 128) was not significantly different from that of the DES group (10.1 %, n = 100, p = 0.593). LLE was observed in 45.3 % of entire lesions, and a type-A dissection was a significant predictor of LLE among 23 variables (odds ratio: 3.02, 95 % CI: 1.31-6.95, p = 0.010). CONCLUSIONS: The present single-center retrospective study revealed statistically equivalent midterm clinical safety and angiographic efficacy among both elective DCB angioplasty and DESs placements in the treatment of unrestrictive de novo coronary lesions. In our daily practice environment, LLE was achieved in approximately half after DCB angioplasty.

Is creation of a fully circumferential lesion set necessary for laser balloon ablation-based pulmonary vein isolation?

BACKGROUND: Despite reports of remote pulmonary vein (PV) stenosis after visually guided laser balloon (VGLB) ablation, circumferential (360°) lesion sets are routinely performed. This study aimed to determine whether fully circumferential lesion creations are required for all PVs to achieve PV isolations (PVIs) and to determine PV's vulnerability to chronic-phase stenosis. METHODS: Fifty-one patients with paroxysmal atrial fibrillation underwent mapping-guided PVIs using circular mapping catheters. VGLB ablation was performed circumferentially beginning at the 12 o'clock position and continued clockwise or counterclockwise. PVIs obtained within the bounds of the first half of the circumferential lesion (≤ 180°) were defined as "early PVIs." RESULTS: "Early PVIs" were documented in real time for 39% (80/204) of the PVs and at a significantly greater frequency among lower PVs than upper PVs (60.1% vs. 17.6%; p < 0.0001). The PV sleeve length, PV diameter, and isolation of ipsilateral PVs within a semicircular lesion set were identified as predictors of an "early PVI" phenomenon. The amount of energy delivered to the lower PVs was significantly less than that to the upper PVs (5553 [5089-6188] vs. 3559 [2793-4380] J; p < 0.0001), but the incidence of narrowing of the lower PVs at 6 months was comparable to that of the upper PVs (p = 0.73). CONCLUSION: Our study revealed electrical isolations of more than 60% of the lower PVs while creating the first half of the circumferential lesions. Crosstalk via the carina region was presumably involved due to the preceding upper PVI. Further study is needed to determine whether energy delivery adjustments are needed for lower PVs to avoid chronic narrowing.

Treatment of secondary mitral regurgitation by transcatheter edge-to-edge repair using MitraClip.

Transcatheter edge-to-edge repair (TEER) is becoming the standard invasive treatment for ventricular functional mitral regurgitation (MR). It is necessary to determine the severity of MR before treatment with MitraClip; however, the severity of secondary MR is usually underestimated compared with that of primary MR and varies temporally. Therefore, to accurately determine the severity of MR, it is important to correctly use the algorithm of the guidelines for valvular heart disease and aggressively perform stress echocardiography. Before performing TEER, the difficulty of the procedure should be evaluated. First, morphological features that make TEER unsuitable, such as cleft of the mitral leaflet, mitral stenosis (MS), or perforation of the mitral leaflet, should be checked. The mitral valve orifice area, transmitral valve pressure gradient, coaptation depth, coaptation length, and posterior leaflet length should be measured to determine the difficulty of the procedure based on the inclusion criteria of Endovascular Valve Edge-to-Edge Repair Study II and the German consensus. After MitraClip implantation, in addition to assessing the severity of MS and residual MR, the pulmonary venous flow pattern and stroke volume should be evaluated to comprehensively assess whether TEER improves the hemodynamics. MitraClip has also been used to treat atrial functional MR, another type of secondary MR. Several reports suggest that MitraClip is effective for atrial functional MR; however, evidence is still being accumulated.

Subtle Cardiovascular Abnormalities in Prader-Willi Syndrome Might Begin in Young Adulthood.

Objective Patients with Prader-Willi syndrome (PWS) are known to have a high mortality rate. However, little is known about the exact reason for this, particularly in adults, because so few reports have been published. The present study examined cardiovascular abnormalities to determine the cause of death in adults with PWS. Methods From September 2017 to April 2019, a total of 18 adults with PWS, and, no history of cardiovascular diseases, were enrolled. We investigated the levels of the cardiovascular biomarkers: high-sensitivity C-reactive protein (hs-CRP) and troponin T (TnT). To estimate the cardiac function, we measured the left ventricular ejection fraction (LVEF), global longitudinal systolic strain (GLS) of the left ventricle, ratio of peak early mitral filling velocity (E) to early diastolic mitral annular velocity (E/e' ratio), mitral annular plane systolic excursion (MAPSE) and tricuspid annular plane systolic excursion (TAPSE) using standard and tissue Doppler echocardiography. Results The mean patient age was 28±9 years old. There were 11 men, and the mean body mass index was 45.1 kg/m2. Dyslipidemia (82%), diabetes mellitus (82%) and hypertension (83%) were commonly found as comorbidities. Most patients had elevated levels of hs-CRP (mean 1.007±0.538 mg/dL). The LVEF (mean 61%±5%) showed normal values, while the GLS (mean 15.0%±3.0%) was decreased. The TAPSE was mildly reduced (mean 16±3 mm). Conclusion These results suggest that subtle cardiovascular abnormalities have already begun in young adults with PWS. We need to manage obesity and the resultant obesity-related disorders in order to prevent heart failure and coronary atherosclerosis in PWS patients.

Cryofreezing for slow-pathway modification in patients with slow-fast AVNRT: Efficacy, safety, and electroanatomical relation between sites of transient AV block and sites of successful cryoablation.

INTRODUCTION: Cryoablation has emerged as an alternative to radiofrequency ablation for treating atrioventricular nodal reentrant tachycardia (AVNRT). The aim of this prospective study was to evaluate the efficacy and safety of cryoapplication at sites within the mid/high septal region of Koch's triangle and the relation between sites of transient AV block (AVB) and sites of successful cryoablation. METHODS AND RESULTS: Included were 45 consecutive patients undergoing slow-fast AVNRT cryoablation. Initial delivery of cryoenergy was to the mid-septal to high septal region of Koch's triangle. Transient AVB occurred during cryoenergy delivery in 62% (28/45) of patients. Median distance between sites at which cryofreezing successfully eliminated slow pathway conduction and sites of AVB was 4.0 (3.25-5.0) mm. Sites of successful cryoablation tended to be to the left and inferior to the AVB sites. The atrial/ventricular electrogram ratio was significantly lower at sites of successful cryoablation than at AVB sites (0.25 [0.17-0.56] vs. 0.80 [0.36-1.25], p < .001). Delayed discrete or fractionated atrial electrograms were recorded more frequently at sites of successful cryoablation than at AVB sites (78% vs. 20%, p < .001). No persistent AV conduction disturbance occurred, and 96% (43/45) of patients showed absence of recurrence at a median follow-up time of 25.0 months. CONCLUSION: Cryoablation of slow-fast AVNRT and targeting the mid/high septal region of Koch's triangle was highly successful. AVB frequently emerged near the site at which the slow pathway was eliminated but always resolved by regulating the energy delivery under careful monitoring, and it may be distinguishable by its local electrogram features.

Utility of hot-balloon-based pulmonary vein isolation under balloon surface temperature monitoring: First clinical experience.

INTRODUCTION: A new hot balloon system that registers balloon surface temperature (BST) during energy delivery is now available for clinical use in Japan. This study sought to investigate the utility of BST measurement for achievement of pulmonary vein isolation (PVI) by a single-shot energy delivery strategy during hot balloon ablation (HBA). METHODS: We applied and tested the system in 30 consecutive patients undergoing HBA for paroxysmal or early-persistent atrial fibrillation (AF). We also performed real-time PV potential monitoring using a circular catheter. RESULTS: Acute PVI was achieved with single hot balloon shots in 88% (106/120) of the PVs. Real-time BSTs and PV potentials were recorded in all cases. Mean BST at documentation of PVI was 49.4°C, and acute reconnections were observed in most cases (86%, 12/14) in which the single-shot technique was ineffective. Time-to-isolation (TTI) (23.1 ± 8.7 s vs. 36.3 ± 9.3 s, p < .01) and median BST (59.9 ± 2.6°C vs. 55.7 ± 1.9°C, p < .01) differed significantly between cases in which PVI was achieved (vs. those in which PVI was not achieved). Multivariable analysis revealed strong association between both TTI and median BST and acute PVI. The best median BST cutoff value for achieving PVI with a single shot was >58.7°C (sensitivity 67.0%, specificity 100%). CONCLUSION: Our data suggest that real-time BST monitoring during energy applications is useful for predicting achievement of acute PVI by a single shot during HBA.

A porcine study of the area of heated tissue during hot-balloon ablation: Implications for the clinical efficacy and safety.

INTRODUCTION: Hot-balloon ablation depends solely on thermal conduction, and myocardial tissue is ablated by only conductive heating from the balloon surface. Despite growing clinical evidence of the efficacy and safety of hot-balloon ablation for atrial fibrillation (AF), the actual tissue temperature and the mechanism of heating during such ablation has not been clarified. To determine, by means of a porcine study, the temperatures of tissues targeted during hot-balloon ablation of AF performed with hot-balloon set temperatures of 73°C or 70°C, in accordance with the temperatures now used clinically. METHODS: After a right thoracotomy, thermocouples with markers were implanted epicardially on the superior vena cava (SVC) and pulmonary veins (PVs) in six pigs. The tissue temperatures during hot-balloon ablation (balloon set temperatures of 73°C and 70°C, 180 s/PV) were recorded, and the maximum tissue temperatures and fluoroscopically measured distance from the balloon surface to the target tissues were assessed. RESULTS: Sixteen SVC- and 18 PV-targeted energy deliveries were performed. Full-thickness circumferential PV lesions were created with all hot-balloon applications. A significant inverse relation was found between the recorded tissue temperatures and distance (r = -.67; p < .001) from the balloon surface. No tissue temperature exceeded either of the balloon set temperatures. The best distance cutoff value for achieving lethal tissue temperatures more than 50°C was 3.6 mm. CONCLUSION: The hot-balloon set temperature, energy delivery time, and tissue temperature data obtained in this porcine study supported the clinical efficacy and safety of the hot-balloon ablation as currently practiced in patients with AF.

Clinical Impact of Size, Shape, and Orientation of the Tricuspid Annulus in Tricuspid Regurgitation as Assessed by Three-Dimensional Echocardiography.

BACKGROUND: Tricuspid annuloplasty for tricuspid regurgitation (TR) depends on the measurements of tricuspid annular diameter (TAD) obtained in an apical four-chamber view on two-dimensional (2D) transthoracic echocardiography (TTE). We performed a combined 2D and three-dimensional (3D) echocardiographic study to understand the impact of the size, shape, and orientation of a dilated annulus on the inconsistencies between measured 2D TTE-TAD and the actual annular diameter. METHODS: A total of 185 patients with grade ≥3+ TR and 50 controls underwent 2D TTE and 3D transesophageal echocardiography (TEE) assessment of the tricuspid valve. The 3D TEE-TAD, defined as the longest dimension, and tricuspid annulus (TA) eccentricity index, defined as the shortest/longest dimension ratio, were obtained. The angle between the major tricuspid annulus axis and interatrial septum parallel to the vertical axis (α°) was measured as an index of TA orientation. RESULTS: Compared with controls, TR subgroups had a larger α° irrespective of TR etiology and cardiac rhythm (P < .05), with the posteriorly displaced TA most frequently noted in patients with atrial fibrillation. An excellent correlation was found between 3D TEE-TAD and 2D TTE-TAD, but 2D TTE-TAD was significantly smaller than 3D TEE-TAD (35.9 ± 5.4 vs 39.8 ± 5.7 mm; P < .001; bias, 3.9 ± 2.6 mm; limits of agreement, -1.1-8.9 mm). After multivariate adjustment, a larger 3D TEE-TAD and larger absolute value of 90° - α° were independent determinants of the bias between 3D TEE-TAD and 2D TTE-TAD (both P < .001). CONCLUSIONS: The inconsistencies between measured 2D TTE-TAD and the actual annular diameter can be explained through morphologic factors such as TA size and orientation.

Atrial reverse remodeling represented by the atrial conduction time in persistent atrial fibrillation patients after catheter ablation: its impact on predicting late atrial fibrillation recurrence.

BACKGROUND: The aim of this study was to examine the reduction in the atrial conduction time during the follow-up phase of catheter ablation in persistent atrial fibrillation (PsAF) patients, which would suggest atrial reverse remodeling, and to investigate its impact on predicting AF recurrence. METHODS: Fifty-seven PsAF patients underwent radiofrequency catheter ablation. The P-wave to left atrial appendage (LAA) conduction time was measured by transthoracic echocardiography using tissue Doppler imaging (P-LAA TDI), within 24 h and 6 months after ablation. RESULTS: The accuracy of the P-LAA TDI was confirmed by measuring the actual electrophysiological data during the ablation (90 ±â€¯13 ms, r = 0.754, p < 0.001). The P-LAA TDI was significantly reduced (170 ±â€¯18 msec to 159 ±â€¯19 msec, p < 0.001) at the 6-month follow-up. Sixteen patients (28%) had an AF recurrence by 12 months of follow-up. The no-AF recurrence group had a significantly reduced P-LAA TDI 6 months later (165 ±â€¯15 msec to 155 ±â€¯18 msec, p < 0.001), while there was no significance in the AF recurrence group (184 ±â€¯21 msec to 174 ±â€¯16 msec, p = 0.091). The P-LAA TDI was a predictive factor of AF recurrence after ablation with a cut-off value of >175 msec (sensitivity = 0.750, specificity = 0.780) when measured within 24 h after ablation and >166 msec (sensitivity = 0.750, specificity = 0.756) when calculated at 6 months of follow-up. CONCLUSIONS: In PsAF patients, a significant reduction in the P-LAA TDI was observed at 6 months of follow-up, which may have represented the occurrence of left atrial reverse remodeling. These findings suggested that the P-LAA TDI time in the follow-up was appropriate for predicting late AF recurrences.

Characterization of Residual Conduction Gaps After HotBalloon-Based Antral Ablation of Atrial Fibrillation　- Evidence From Ultra-High-Resolution 3-Dimensional Mapping.

BACKGROUND: The electrophysiological characteristics of residual conduction gaps between the left atrium (LA) and pulmonary veins (PVs) after HotBalloon-based wide antral ablation (HBWA) of atrial fibrillation (AF) remain incompletely understood. This study aimed to characterize the residual gaps by means of ultra-high-resolution mapping.Methods and Results:A total of 55 AF patients underwent HBWA by a predetermined protocol (6-shot total-based antral approach). LA-PV maps were created using 64-electrode minibasket catheters. In total, 55 residual gaps were identified among 26 (47%) patients. Residual gaps included 33 left superior (LS: 60%), 10 left inferior (18%), 6 right superior (11%), and 6 right inferior (11%) PVs. Those gaps demonstrated both extremely lower bipolar amplitudes (0.11 [interquartile range: 0.06-0.27] mV) and conduction velocities (0.75±0.27 m/s); however, the length was confined (10.3±4.1 mm) except for the LSPV anterior carina (12.2±2.4 mm) region. Among the carina regions, all gaps had far-field potentials consistently added to the PV potentials. Left atrial appendage pacing to split the far-field activity identified confined gap regions (6.7±1.9 mm). Touch-up ablation eliminated the residual PV potentials in all cases. CONCLUSIONS: HBWA resulted in a certain degree of residual gap conduction in particular antral regions. These gaps exhibited narrow lengths with lower amplitudes, and often had far-field recordings from the left atrial appendage. Combined with pacing maneuvers, ultra-high-resolution activation maps could both visualize all confined gaps and ensure a bare minimum of touch-up ablations in all patients with gap conduction.