Multicenter prospective observational study to clarify the current status and clinical outcome in Japanese patients who have an indication for implantable cardioverter defibrillator (ICD) or wearable cardioverter defibrillator (WCD) (TRANSITION JAPAN-ICD/WCD study): Rationale and design of a prospective, multicenter, observational, comparative study.

Background: Despite the positive impact of implantable cardioverter defibrillators (ICDs) and wearable cardioverter defibrillators (WCDs) on prognosis, their implantation is often withheld especially in Japanese heart failure patients with reduced left ventricular ejection fraction (HFrEF) who have not experienced ventricular tachycardia (VT) or ventricular fibrillation (VF) for uncertain reasons. Recent advancements in heart failure (HF) medications have significantly improved the prognosis for HFrEF. Given this context, a critical reassessment of the treatment and prognosis of ICDs and WCDs is essential, as it has the potential to reshape awareness and treatment strategies for these patients. Methods: We are initiating a prospective multicenter observational study for HFrEF patients eligible for ICD in primary and secondary prevention, and WCD, regardless of device use, including all consenting patients. Study subjects are to be enrolled from 31 participant hospitals located throughout Japan from April 1, 2023, to December 31, 2024, and each will be followed up for 1 year or more. The planned sample size is 651 cases. The primary endpoint is the rate of cardiac implantable electronic device implementation. Other endpoints include the incidence of VT/VF and sudden death, all-cause mortality, and HF hospitalization, other events. We will collect clinical background information plus each patient's symptoms, Clinical Frailty Scale score, laboratory test results, echocardiographic and electrocardiographic parameters, and serial changes will also be secondary endpoints. Results: Not applicable. Conclusion: This study offers invaluable insights into understanding the role of ICD/WCD in Japanese HF patients in the new era of HF medication.

Novel simultaneous mapping technique to treat multifocal atrial tachycardia.

Although a high-resolution three-dimensional mapping system has made it possible to treat complicated atrial tachyarrhythmia (AT), there remain cases that are difficult to diagnose and treat. However, when multiple different ATs alternately appear, mapping and diagnosis of those are more difficult. Parallel mapping module is well known as a good option to simultaneously map two or more different ATs when they alternately appear. When performing parallel mapping of two different ATs, one bipolar signal of the reference catheter is used as a timing reference and a cycle length filter is used for differentiating AT1, AT2, and others, including sinus rhythm, fusion beats, or catheter-induced premature atrial complex. Therefore, it has some limitations for differentiating multifocal ATs. We present a case wherein multifocal ATs were successfully eliminated by combining parallel mapping module and dual-chamber intra-cardiac pattern matching technique that we have previously reported. Learning objective: ▪Parallel mapping is a useful tool when two or more tachycardias alternately occur; however, it has some limitations.▪Dual-chamber intra-cardiac pattern matching technique, which combines right atrial and coronary sinus potentials, provides better discrimination than coronary sinus reference alone.▪By combining parallel mapping and dual-chamber intra-cardiac pattern matching, two or more atrial tachycardias could be automatically and simultaneously mapped.

The effect of ablation settings on lesion characteristics with DiamondTemp ablation system: An ex vivo experiment.

Introduction: Creating large lesion in ablations using the DiamondTemp (DTA) ablation system may reduce the frequency of arrhythmia recurrence and allow the treatment of ventricular arrhythmias. Therefore, this study aimed to investigate whether power, application time, contact force (CF), and contact angle affect lesion formation in the ventricles. Methods: Ablations were delivered to porcine myocardial preps to evaluate the lesion characteristics. Ablations were conducted with a maximum power of 50 W, target temperature of 58°C, CF of 10, 20, or 30 g, and contact angle between the catheter tip and tissue. The ablation durations were 15, 30, 60 s, 15 s × 2, or 30 s × 2. Results: Steam pops occurred only in cases with perpendicular contact. The lesion depth was larger in all settings in the perpendicular orientation than in the parallel orientation. The temperatures were lower in all settings in the perpendicular orientation than in the parallel orientation. The lesions became larger as CF increased with perpendicular contact and duration of ≥30 s. The longer application time resulted in larger surface area, depth, and volume of the lesion. Lesion depth was greater with single application of 30 and 60 s than with 15 s × 2 and 30 s × 2, respectively. Conclusion: It is important to perform a single prolonged application as much as possible to create deeper lesions. Parallel contact with the tissue should be maintained to take advantage of the temperature sensor's capabilities to avoid pop phenomenon.

Optimal treatment of biatrial tachycardia diagnosed by one-chamber mapping within an ultrahigh-resolution mapping system.

Biatrial tachycardia (BiAT) is a rare arrhythmia, and identification of the re-entry circuit is often complicated. By creating an activation map of the right atrium, left atrium, and coronary sinus as a single chamber, the LUMIPOINT module of the Rhythmia mapping system (Boston Scientific, Marlborough, MA, USA) can be used in real time to make an accurate diagnosis. Ablation of the Bachmann bundle is a feasible way to terminate BiAT, but might cause interatrial conduction delay and electrical isolation of the left atrial appendage. Chemical ablation into the vein of Marshall might be the more beneficial treatment, avoiding any potential interatrial conduction delay.

Grid-mapping catheters versus PentaRay catheters for left atrial mapping on ensite precision mapping system.

INTRODUCTION: Areas displaying reduced bipolar voltage are defined as low-voltage areas (LVAs). Moreover, left atrial (LA) LVAs after pulmonary vein isolation (PVI) have been reported as a predictor of recurrent atrial fibrillation (AF). In this study, we compared grid mapping catheter (GMC) with PentaRay catheter (PC) for LA voltage mapping on Ensite Precision mapping system. METHODS: Twenty-six consecutive patients with LVAs and border zone within the LA were enrolled. After achieving PVI, voltage mapping under high right atrial pacing for 600 ms was performed twice using each catheter type (GMC first, PC next). Furthermore, LVA was defined as a region with a bipolar voltage of <0.50, and border zone was defined as a region with a bipolar voltage of <1.0, or <1.5 mV. RESULTS: Compared with PC, using GMC, voltage mapping contained more mapping points (20 242 [15 859, 26 013] vs. 5589 [4088, 7649]; p < .0001), and more mapping points per minute(1428 [1275, 1803] vs. 558 [372, 783]; p < .0001). In addition, LVA and border zone size using GMC was significantly less than that reported using PC: <1.0 mV (5.9 cm2 [2.9, 20.2] vs. 13.9 cm2 [6.3, 24.1], p = .018) and <1.5 mV voltage cutoff (10.6 cm2 [6.6, 27.2] vs. 21.6 cm2 [12.6, 35.0], p = .005). CONCLUSION: Bipolar voltage amplitude estimated by GMC was significantly larger than that estimated by PC on Ensite Precision mapping system. GMC may be able to find highly selective identification of LVAs with lower prevalence and smaller LVA and border zone size.

Poor prognosis of heart failure patients with in-hospital worsening renal function and elevated BNP at discharge.

AIMS: Our purpose was to investigate the association between the B-type natriuretic peptide (BNP) level at discharge, the occurrence of worsening renal function (WRF), and long-term outcomes in patients with heart failure (HF). METHODS AND RESULTS: We enrolled hospitalized acute HF patients. We divided patients into four groups on the basis of BNP <250 pg/mL (BNP-) or BNP ≥250 pg/mL (BNP+) at discharge and the occurrence of WRF during admission: BNP-/WRF-, BNP-/WRF+, BNP+/WRF-, and BNP+/WRF+. We evaluated the association between BNP at discharge, WRF, and cardiovascular/all-cause mortality/hospitalization due to HF. Clinical follow-up was completed in 301 patients. At discharge, percentages of the patients with clinical signs of HF were low and similar among four groups. The median follow-up period was 1206 days (interquartile range, 733-1825 days). The composite endpoint of cardiovascular mortality and HF hospitalization was significantly different between the four groups [12.9% (BNP-/WRF-), 22.7% (BNP-/WRF+), 35.8% (BNP+/WRF-), and 55.4% (BNP+/WRF+), P < 0.0001]. All-cause mortality was also different etween the four groups (15.1%, 38.6%, 28.7%, and 39.3%, respectively, P = 0.003). In the multivariate Cox proportional hazards model, the combination of BNP ≥250 pg/mL and WRF showed the highest hazard ratio (HR) for composite endpoint (HR, 5.201; 95% confidence interval, 2.582-11.11; P < 0.0001), and BNP-/WRF+ was associated with increased all-cause mortality (HR, 2.286; 95% confidence interval, 1.089-4.875; P = 0.03). Patients in BNP+/WRF+ had a higher cardiovascular mortality (28.6%), and those in BNP-/WRF+ had a high non-cardiovascular mortality (29.5%). CONCLUSIONS: Heart failure patients with BNP ≥250 pg/mL at discharge and in-hospital occurrence of WRF had the highest risk for the composite endpoint (cardiovascular mortality and HF hospitalization) among groups.

Chronic stent recoil in severely calcified coronary artery lesions. A serial optical coherence tomography study.

Chronic second-generation drug-eluting stent recoil in severely calcified coronary lesions has not been studied. We aimed to evaluate chronic stent recoil by optical coherence tomography (OCT) in severely calcified lesions treated with thin strut stents after rotational atherectomy. In 28 lesions (26 patients with 23% on hemodialysis) treated with everolimus-eluting stents after rotational atherectomy, baseline and 8-month follow-up OCT were compared. Stent recoil was defined as >10% decrease in stent area from baseline to follow-up. Overall, there was no change in minimal stent area (6.0 mm2 [5.0, 8.1] to 6.0 mm2 [4.8, 8.6], p = 0.51) from baseline to follow-up, although neointimal hyperplasia measured 16.3 ± 15.8%. Thirty-six percent of lesions showed stent recoil associated with 6 non-nodular calcifications, 1 calcified nodule, and 3 stent deformations. The overall mean calcium angle with attenuation decreased (54° [29-76] to 31° [19-48], p < 0.0001), and calcium without attenuation increased (28° [21-67] to 64° [34-93], p < 0.0001), but primarily at the location of stent recoil. Furthermore, in the stent recoil segments in 10 recoil lesions, the stent circumference decreased primarily at non-calcium segments rather than at calcium with or without attenuation. One lesion with stent recoil and 2 lesions without stent recoil required repeat revascularization. Thin strut stents can chronically recoil in severely calcified lesions, but this rarely causes restenosis.

RNAs and Gene Expression Predicting Postoperative Atrial Fibrillation in Cardiac Surgery Patients Undergoing Coronary Artery Bypass Grafting.

Postoperative atrial fibrillation (POAF) is linked with increased morbidity, mortality rate and financial liability. About 20-50% of patients experience POAF after coronary artery bypass graft (CABG) surgery. Numerous review articles and meta-analyses have investigated links between patient clinical risk factors, demographic conditions, and pre-, peri- and post-operative biomarkers to forecast POAF incidence in CABG patients. This narrative review, for the first time, summarize the role of micro-RNAs, circular-RNAs and other gene expressions that have shown experimental evidence to accurately predict the POAF incidence in cardiac surgery patients after CABG. We envisage that identifying specific genomic markers for predicting POAF might be a significant step for the prevention and effective management of this type of post-operative complication and may provide critical perspective into arrhythmogenic substrate responsible for POAF.

The impact of worsening renal function with elevated B-type natriuretic peptide at discharge on 1-year prognosis in heart failure patients.

There are a few studies about the clinical impacts of plasma B-type natriuretic peptide (BNP) at discharge with the occurrence of worsening renal function (WRF) on mortality in patients with heart failure (HF). We divided total 301 patients with acute decompensated HF into four groups by the median value (278.7 pg/mL) of BNP level at discharge and by the occurrence of WRF. WRF developed in 100 patients (33.2%). Cardiovascular mortality was significantly different between the four groups (P = 0.0002). Patients with WRF and elevated BNP had a higher cardiovascular mortality than patients without WRF and elevated BNP in Cox proportional hazard models (hazard ratio [HR], 10.48; 95% confident interval [95% CI], 1.27-225.53; P = 0.03). Patients with either WRF or elevated BNP did not have an increased risk of cardiovascular mortality compared to patients without WRF and elevated BNP. Regarding HF readmission and cardiovascular mortality, patients with WRF and elevated BNP had the highest risk (HR, 5.17; 95% CI, 2.07-14.30, P = 0.0003) and patients with either WRF or elevated BNP had a higher risk than patients without WRF and elevated BNP. The occurrence of WRF combined with elevated BNP at discharge was associated with increased 1-year cardiovascular mortality and HF readmission.

Effective Ablation Settings That Predict Chronic Scar After Left Atrial Ablation.

OBJECTIVES: The goal of this study was to find effective parameters that can be used in real-time that result in chronic scar verified by left atrial (LA) late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). BACKGROUND: Automated annotation can be a useful tool while ablating in tagging areas that will result in scar, but the effective settings that best predict chronic scar are still unknown. METHODS: Patients underwent pulmonary vein isolation using a CARTO3 mapping system with a VISITAG Module and 3-month post-ablation LGE-CMR. The electroanatomical map (EAM) was used to retrospectively tag ablated areas with 5 different parameters: catheter stability; stability duration; force over time; minimum contact force; and impedance drop. The ablation tags in EAM were projected to the 3-month post-ablation LGE-CMR. Tags were divided into 2 groups depending on if they correlated with CMR-based scar tags (STAGs) or nonscar tags (NTAGs); the effective parameters were estimated for the 2 groups at different power levels. RESULTS: This study assessed 70 consecutive patients and 28,939 ablation tags. Ablation time and force time integral (FTI) were significantly larger in the STAG group. Mean contact force, change of catheter tip temperature, and impedance were not significantly different between STAGs and NTAGs. The minimum ablation time and FTI to make durable scar lesions were 17.6, 13.6, and 11.0 s and 226.1, 187.4, and 161.4 g at 25, 35, and 50 W, respectively. CONCLUSIONS: Minimum ablation time and FTI values are critical parameters that determine durable atrial scar creation and their minimum values vary with the ablation power setting.

Blanking period after radiofrequency ablation for atrial fibrillation guided by ablation lesion maturation based on serial MR imaging.

BACKGROUND: Recent guidelines recommend a 3-month blanking period after atrial fibrillation (AF) ablations, which are based on clinical observation. Our goal was to quantify the timeline of the radiofrequency ablation lesion maturation using serial late gadolinium enhancement-magnetic resonance imaging (LGE-MRI) and to develop a blanking period estimate based on visible lesion maturation. METHODS: Inclusion criteria targeted patients who underwent AF ablation and at least four MRI scans: at baseline before ablation, within 24 hours after (acute), between 24 hours and 90 days after (subacute), and more than 90 days after ablation (chronic). Central nonenhanced (NE) and surrounding hyperenhanced (HE) area volumes were measured and normalized to chronic lesion volume. RESULTS: This study assessed 75 patients with 309 MRIs. The acute lesion was heterogeneous with a HE region surrounding a central NE region in LGE-MRI; the acute volume of the total (HE + NE) lesion was 2.62 ± 0.46 times larger than that of the chronic lesion. Acute T2-weighted imaging also showed a relatively large area of edema. Both NE and HE areas gradually receded over time and NE was not observed after 30 days. Larger initial NE volume was associated with a significantly greater chronic scar volume and this total lesion volume receded to equal the chronic lesion size at approximately 72.5 days (95% prediction interval: 57.4-92.2). CONCLUSION: On the basis of serial MRI, atrial ablation lesions are often fully mature before the typical 90-day blanking period, which could support more timely clinical decision making for arrhythmia recurrence.

Perioperative Biomarkers Predicting Postoperative Atrial Fibrillation Risk After Coronary Artery Bypass Grafting: A Narrative Review.

Postoperative atrial fibrillation (POAF) after cardiac surgery remains a highly prevalent and costly condition that negatively impacts patient quality of life and survival. Numerous retrospective studies, meta-analysis, and review papers have been reported identifying POAF risk based on patients' risk factors and clinical biomarkers. In this narrative review, the authors report significant variations among selected pre- and perioperative biomarkers used to predict POAF incidence in patients without a history of atrial fibrillation (AF). POAF prediction based on B-type natriuretic peptide, N-terminal pro B-type natriuretic peptide, C-reactive protein, interleukin-6, creatinine, and plasminogen activator inhibitor-1 differs significantly among different studies, thereby limiting their clinical utility to predict POAF risk with high accuracy. Conversely, soluble vascular endothelial cells adhesion molecule-1, soluble CD40 ligand, Galectin-3, and aldosterone show promise for better POAF prediction. However, the current datasets for these selected biomarkers are not of sufficient size to validate the broad clinical application specifically for patients with no prior history of AF.

The Effective Contact Force to Minimize Edema Relative to Chronic Lesion Formation During Radiofrequency Ablation in Ventricular Wall.

Radiofrequency (RF) ablation results in creation of acute edema which can lead to temporary disruption of electrical propagation.The goal of this study was to find the effective contact force (CF) to minimize edema formation in comparison to the lesion size.Ventricular RF lesions (n = 49) were created by a CF-sensing catheter in a canine model (n = 10) with varying force for 30 seconds. Animals underwent T2-weighted (T2w) and late gadolinium enhancement MRI (LGE-MRI) immediately after ablation and at 12 weeks. Acute LGE lesion volume, acute edema, and chronic LGE lesion volume were measured. Acute edema/acute LGE lesion volume ratio was used to divide the lesions into two groups.Mean edema/lesion volume ratio was 5.0 ± 2.8. The lesions were divided into greater edema group (n = 8) and smaller edema group (n = 41) based on a cutoff edema/lesion volume ratio. When comparing the two groups, the CF and force time integral (FTI) were significantly lower in the greater edema group. There was no difference in catheter power setting, tip temperature change, impedance drop, and bipolar electrogram voltage change. Acute LGE volume and chronic lesion depth were significantly smaller in the greater edema group. Moreover, receiver-operator characteristic curve for the smaller edema lesion group showed that the most discriminant cutoff values for CF and FTI were 12.4 g and 584 gs, respectively.To minimize edema size while still forming permanent lesions, ablation should be performed with FTI > 584 gs or CF > 12.4 g.

Changes in atrial electrophysiological and structural substrate and their relationship to histology in a long-term chronic canine atrial fibrillation model.

BACKGROUND: Atrial fibrillation (AF) is related to numerous electrophysiological changes; however, the extent of structural and electrophysiological remodeling with long-term AF is not well characterized. METHODS: Dogs (n = 6) were implanted with a neurostimulator in the right atrium (AF group). No implantation was done in the Control group (n = 3). Electroanatomical mapping was done prior to and following more than 6 months of AF. Magnetic resonance imaging was also done to assess structural remodeling. Animals were euthanized and tissue samples were acquired for histological analysis. RESULTS: A significant increase was seen in the left atrial (LA) volume among all AF animals (22.25 ± 12.60 cm3 vs 34.00 ± 12.23 cm3 , P = .01). Also, mean bipolar amplitude in the LA significantly decreased from 5.96 ± 2.17 mV at baseline to 3.23 ± 1.51 mV (P < .01) after chronic AF. Those significant changes occurred in each anterior, lateral, posterior, septal, and roof regions as well. Additionally, the dominant frequency (DF) in the LA increased from 7.02 ± 0.37 Hz to 10.12 ± 0.28 Hz at chronic AF (P < .01). Moreover, the percentage of fibrosis in chronic AF animals was significantly larger than that of control animals in each location (P < .01). CONCLUSIONS: Canine chronic AF is accompanied by a significant decrease in intracardiac bipolar amplitudes. These decreased electrogram amplitude values are still higher than traditional cut-off values used for diseased myocardial tissue. Despite these "normal" bipolar amplitudes, there is a significant increase in DF and tissue fibrosis.

Effect of cutting balloon after rotational atherectomy in severely calcified coronary artery lesions as assessed by optical coherence tomography.

OBJECTIVES: Using optical coherence tomography (OCT), we evaluated the effect of a cutting balloon (CB) compared with a conventional balloon after rotational atherectomy (RA) and before stenting in severely calcified coronary lesions. BACKGROUND: A CB is designed to create discrete incisions to facilitate fracture of severely calcified plaque. METHODS: OCT was performed preintervention (if possible), post-RA, and poststent implantation. RA modification of calcium was defined as a polished, concave, round-shaped surface. Calcium fracture was defined as a break in the calcium plate. The effects of calcium modification and stent expansion between CB (n = 18) versus conventional balloon (n = 23) following RA were compared. RESULTS: Median patient age was 72 years with 24% on hemodialysis. The amount of calcium and the length of RA modification were comparable between the CB and conventional balloon groups. Final poststent OCT showed that the number and thickness of calcium fracture were greater after CB versus conventional balloon, resulting better stent expansion (78.9% [IQR: 72.4-88.1] vs. 66.7% [IQR: 55.0-76.7], p < 0.01). In the multivariable model, after adjusting for the amount of calcium, CB use was an independent predictor of the presence of calcium fracture (odds ratio 30.0; 95% confidence interval 2.7-994.1, p = 0.004) and an independent predictor for greater stent expansion (regression coefficient 7.4; 95% confidence interval 0.5-14.3, p = 0.04). CONCLUSION: In severely calcified lesions calcium fracture was more often associated with RA followed by CB compared with RA followed by conventional balloon predilation before stenting. CB use was also a determinant of greater stent expansion.

Impact of recanalization of chronic total occlusion on left ventricular electrical remodeling.

BACKGROUND: Successful percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is associated with reduction of cardiac mortality, as well as reducing fatal ventricular arrhythmias. The aim of this study was to evaluate the effect of recanalization of CTO on endocardial left ventricular voltages by paired electrophysiological studies. METHODS: Sixteen consecutive patients who underwent PCI for de novo CTO lesions were included. High-density mapping was performed during sinus rhythm before and 8 months after PCI. According to the amplitude of bipolar electrograms, the left ventricular endocardium was classified into a preserved normal voltage (>1.5 mV), border zone (0.5-1.5 mV), and dense scar areas (<0.5 mV). RESULTS: The border zone area had a significant positive correlation with CTO length, as well as a significant negative correlation observed in the preserved voltage region. In the successful PCI patient, the median dense scar area did not change significantly (reported as [median difference: 95% confidence interval]) between baseline and after PCI (0.1 cm2 : -2.8 to 2.9). However, the area of the border zone decreased (-10.5 cm2 : -16.8 to -4.1) and the preserved voltage area increased significantly (19.2 cm2 : 7.7-30.6). In addition, successful PCI was related to slight, but significant, increase in the amplitude of unipolar and bipolar voltage (1.55 mV: 0.88-3.33, 0.23 mV: 0.08-0.36). CONCLUSIONS: Recanalization of CTO may promote reverse electrical remodeling in the border zone of the left ventricle, without affecting the dense scar tissue.

Safety and Efficacy of Tolvaptan for the Prevention of Contrast-Induced Acute Kidney Injury in Patients with Heart Failure and Chronic Kidney Disease.

BACKGROUND: Tolvaptan is a promising drug for the prevention of contrast-induced acute kidney injury (CI-AKI) because it induces aquaresis without adversely affecting renal hemodynamics. CI-AKI is a major cause of acute renal failure associated with increased morbidity and mortality. OBJECTIVE: To investigate the effectiveness of different doses of tolvaptan for the prevention of CI-AKI. METHOD: Ninety-one consecutive patients with congestive heart failure (CHF) and chronic kidney disease (CKD) were prospectively enrolled as the tolvaptan group in this study (T-group; 7.5-mg: n = 42, 15-mg: n = 49). In addition, 91 consecutive patients with CHF and CKD were collected retrospectively as a control group (C-group, n = 91). All patients received continuous intravenous infusion of isotonic saline, and tolvaptan was administered to the T-group. RESULTS: One patient developed CI-AKI in the T-group versus 3 in the C-group (1.1 vs. 3.3%, p = 0.61). On the other hand, the change of serum creatinine in the T-group was lower than that in the C-group. Additionally, in the 7.5-mg group, serum creatinine was unchanged up to 72 h after contrast administration, showing a significant difference from the 15-mg group (-0.00 ± 0.09 vs. 0.05 ± 0.12 mg/dL, p = 0.009). Similarly, the change of eGFR was significantly smaller in the 7.5-mg group than that in the 15-mg group (0.7 ± 5.4 vs. -2.8 ± 5.1 mL/min/1.73 m2, p = 0.002). No patient required hemodialysis and there was no prolongation of hospitalization due to exacerbation of heart failure. CONCLUSIONS: Compared to hydration alone, tolvaptan combined with hydration could be a safer method for preventing CI-AKI while avoiding exacerbation of heart failure, and a dosage of 7.5-mg might be safer than 15-mg.