Clinical outcomes of catheter ablation for atrial fibrillation, atrial flutter, and atrial tachycardia in wild-type transthyretin amyloid cardiomyopathy: a proposed treatment strategy for catheter ablation in each arrhythmia.

AIMS: Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is often accompanied by atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia (AT), which are difficult to control because beta-blockers and antiarrhythmic drugs can worsen heart failure (HF). This study aimed to investigate the outcomes of catheter ablation (CA) for AF/AFL/AT in patients with ATTRwt-CM and propose a treatment strategy for CA. METHODS AND RESULTS: A cohort study was conducted on 233 patients diagnosed with ATTRwt-CM, including 54 who underwent CA for AF/AFL/AT. The background of each arrhythmia and the details of the CA and its outcomes were investigated. The recurrence-free rate of AF/AFL/AT overall in ATTRwt-CM patients with multiple CA was 70.1% at 1-year, 57.6% at 2-year, and 44.0% at 5-year follow-up, but CA significantly reduced all-cause mortality [hazard ratio (HR): 0.342, 95% confidence interval (CI): 0.133-0.876, P = 0.025], cardiovascular mortality (HR: 0.378, 95% CI: 0.146-0.981, P = 0.045), and HF hospitalization (HR: 0.488, 95% CI: 0.269-0.889, P = 0.019) compared with those without CA. There was no recurrence of the cavotricuspid isthmus (CTI)-dependent AFL, non-CTI-dependent simple AFL terminated by one linear ablation, and focal AT originating from the atrioventricular (AV) annulus or crista terminalis eventually. Twelve of 13 patients with paroxysmal AF and 27 of 29 patients with persistent AF did not have recurrence as AF. However, all three patients with non-CTI-dependent complex AFL not terminated by a single linear ablation and 10 of 13 cases with focal AT or multiple focal ATs originating beyond the AV annulus or crista terminalis recurred even after multiple CA. CONCLUSION: The outcomes of CA for ATTRwt-CM were acceptable, except for multiple focal AT and complex AFL. Catheter ablation may be aggressively considered as a treatment strategy with the expectation of improving mortality and hospitalization for HF.

Clinical, electrocardiographic, and echocardiographic parameters associated with the development of pacing and implantable cardioverter-defibrillator indication in patients with transthyretin amyloid cardiomyopathy.

AIMS: This study aimed to identify factors for attention leading to future pacing device implantation (PDI) and reveal the necessity of prophylactic PDI or implantable cardioverter-defibrillator (ICD) implantation in transthyretin amyloid cardiomyopathy (ATTR-CM) patients. METHODS AND RESULTS: This retrospective single-center observational study included consecutive 114 wild-type ATTR-CM (ATTRwt-CM) and 50 hereditary ATTR-CM (ATTRv-CM) patients, neither implanted with a pacing device nor fulfilling indications for PDI at diagnosis. As a study outcome, patient backgrounds were compared with and without future PDI, and the incidence of PDI in each conduction disturbance was examined. Furthermore, appropriate ICD therapies were investigated in all 19 patients with ICD implantation. PR-interval ≥220 msec, interventricular septum (IVS) thickness ≥16.9 mm, and bifascicular block were significantly associated with future PDI in ATTRwt-CM patients, and brain natriuretic peptide ≥35.7 pg/mL, IVS thickness ≥11.3 mm, and bifascicular block in ATTRv-CM patients. The incidence of subsequent PDI in patients with bifascicular block at diagnosis was significantly higher than that of normal atrioventricular (AV) conduction in both ATTRwt-CM [hazard ratio (HR): 13.70, P = 0.019] and ATTRv-CM (HR: 12.94, P = 0.002), whereas that of patients with first-degree AV block was neither (ATTRwt-CM: HR: 2.14, P = 0.511, ATTRv-CM: HR: 1.57, P = 0.701). Regarding ICD, only 2 of 16 ATTRwt-CM and 1 of 3 ATTRv-CM patients received appropriate anti-tachycardia pacing or shock therapy, under the number of intervals to detect for ventricular tachycardia of 16-32. CONCLUSIONS: According to our retrospective single-center observational study, prophylactic PDI did not require first-degree AV block in both ATTRwt-CM and ATTRv-CM patients, and prophylactic ICD implantation was also controversial in both ATTR-CM. Larger prospective, multi-center studies are necessary to confirm these results.

Malnutrition-associated high bleeding risk with low thrombogenicity in patients undergoing percutaneous coronary intervention.

BACKGROUND AND AIMS: Although antithrombotic treatments are established for coronary artery disease (CAD), they increase the bleeding risk, especially in malnourished patients. The total thrombus-formation analysis system (T-TAS) is useful for the assessment of thrombogenicity in CAD patients. Here, we examined the relationships among malnutrition, thrombogenicity and 1-year bleeding events in patients undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS: This was a retrospective analysis of 300 consecutive CAD patients undergoing PCI. Blood samples obtained on the day of PCI were used in the T-TAS to compute the thrombus formation area under the curve. We assigned patients to two groups based on the geriatric nutritional risk index (GNRI): 102 patients to the lower GNRI group (≤98), 198 patients to the higher GNRI group (98<). The primary endpoint was the incidence of 1-year bleeding events defined by Bleeding Academic Research Consortium criteria types 2, 3, or 5. The T-TAS levels were lower in the lower GNRI group than in the higher GNRI group. Kaplan-Meier analysis showed worse 1-year bleeding event-free survival in the lower GNRI group compared with the higher GNRI group. The combined model of the GNRI and the Academic Research Consortium for High Bleeding Risk (ARC-HBR) had good calibration and discrimination for bleeding risk prediction. In addition, having a lower GNRI and ARC-HBR positivity was associated with 1-year bleeding events. CONCLUSION: A lower GNRI could reflect low thrombogenicity evaluated by the T-TAS and determine bleeding risk in combination with ARC-HBR positivity.

Clinical significance of reactive oxidative metabolites in patients with heart failure with reduced left ventricular ejection fraction.

BACKGROUND: We investigated the clinical significance of the derivative of reactive oxygen metabolites (DROM), a new marker of reactive oxygen species (ROS), in patients with heart failure (HF) with reduced left ventricular ejection fraction (LVEF) (HFrEF). METHODS AND RESULTS: Serum DROM concentrations were measured in 201 consecutive patients with HFrEF (EF < 50%) in stable condition. DROM values were significantly higher in patients with HFrEF than in risk-matched patients without HF (P < 0.01). They also correlated significantly with high-sensitivity C-reactive protein and B-type natriuretic peptide. Kaplan-Meier analysis demonstrated significantly higher probabilities of HF-related events in the high-DROM group than in the low-DROM group (log-rank test, P < 0.01). Multivariable Cox hazard analysis revealed that DROM were independent and significant predictors of cardiovascular events. In a subgroup analysis, DROM levels were also measured at the aortic root and coronary sinus in 49 patients. The transcardiac gradient of DROM values was significantly higher in patients with HFrEF than in patients without HF (P = 0.04), indicating an association between DROM production in the coronary circulation and HFrEF development. Changes in DROM following optimal therapy were significantly associated with LVEF improvement (r = 0.34, P = 0.04). CONCLUSIONS: The higher levels of DROM and their association with cardiovascular events suggest the clinical benefit of DROM measurements in the risk stratification of patients with HFrEF.

Analysis of the preferable site and stability of rotational reentry: its role for the maintenance of atrial fibrillation.

It remains unclear whether AF is maintained by rotor. We evaluated the significance of rotor during atrial fibrillation (AF). Prevalence, location, and stability of rotational reentry (RR) in the left atrium were clarified by endocardial non-contact mapping in 66 AF patients. RR was classified into three categories: RR continued at stable site (Stable-RR), RR observed intermittently at the same site (Intermittent-RR), and RR observed at different locations (Different-RR). Catheter ablation was performed in a stepwise fashion (linear roof lesion and complex fractionated atrial electrogram ablation following pulmonary vein isolation) until AF termination and elucidated the consequence of radiofrequency lesion delivered within RR site on AF termination and recurrence. One hundred and nineteen RRs were observed. There were 54 patients with RR (RR Group) and 22 patients without RR (Non-RR Group). Prevalence of Different-RR (n = 81) was significantly higher than Stable-RR (n = 16, p < 0.001) and Intermittent-RR (n = 22, p < 0.001). The intervals involved in RR occupied only 22.4% of total activation time. There was no significant difference in the prevalence of AF termination nor AF/atrial tachycardia recurrence between RR and non-RR Groups (46 vs. 9 patients, p = 0.317, and 13 vs. 1 patients, p = 0.271) and between patients in whom radiofrequency lesion was involved in RR and those was not (24 vs. 22 patients, p = 0.210, and 6 vs. 7 patients, p = 0.506). In conclusion, most RRs were observed transiently and often shifted its locations. Radiofrequency lesion delivered within RR site did not correlate with AF termination nor recurrence, suggesting that RR is not a driving source during AF.

Successful treatment of deep vein thrombosis caused by iliac vein compression syndrome with a single-dose direct oral anti-coagulant.

BACKGROUND: Although vein stenting is popular for treatment for venous thromboembolism due to mechanical compression, some cases are forced to avoid inserting align agents because of immunodeficiency. CASE PRESENTATION: An 82-year-old man with left extremity redness and swelling presented to a hospital for a medical evaluation. The patient was immunodeficient because of the adverse effects of his treatment for Castleman's disease. A contrast-enhanced computed tomography scan revealed a venous thromboembolism in inferior vena cava and the left lower extremity. Magnetic resonance venography showed that the iliac artery was compressing the iliac vein. We were reluctant to place a stent in the iliac vein has because of the patient's immunodeficient status. Three months of treatment using single-dose edoxaban (30 mg daily) resulted in complete resolution of the thrombus. This is the first report demonstrating that single-dose edoxaban without acute-phase parenteral anticoagulation is effective in the treatment of iliac vein compression. CONCLUSIONS: A single-dose direct oral anti-coagulant without acute-phase parenteral anticoagulation is effective for mechanical compression.

Reduced trans-mitral A-wave velocity predicts the presence of wild-type transthyretin amyloidosis in elderly patients with left ventricular hypertrophy.

Wild-type transthyretin amyloidosis (ATTRwt) is often overlooked in elderly patients with left ventricular hypertrophy (LVH). Impaired atrial function, in addition to ventricular diastolic dysfunction, is one of the hallmarks of cardiac amyloidosis. Here, we assessed the hypothesis that atrial function evaluated by A-velocity in pulse Doppler echocardiography is useful to differentiate ATTRwt in elderly patients with LVH. We analyzed 133 consecutive patients who underwent tissue biopsy to rule out infiltrative cardiomyopathy in our institute. We excluded patients younger than 50 years, without LVH (LV thickness was less than 12 mm), with other types of cardiac amyloidosis and patients with chronic atrial fibrillation, and analyzed remaining 51 patients (ATTRwt: 16, non-ATTRwt: 35). ATTRwt patients were significantly older and had advanced heart failure compared with non-ATTRwt group. In echocardiography, E/A, E/e', and relative wall thickness was significantly higher in ATTRwt group than non-ATTRwt group. A-velocity was significantly decreased in ATTRWT group compared with non-ATTRwt group (40.8 ± 20.8 vs. 78.7 ± 28.2 cm/s, p = 0.0001). Multivariate logistic analysis using eight forced inclusion models identified trans-mitral Doppler A-wave velocity was more significant factor of cardiac amyloidosis in ATTRwt. In receiver operating characteristic (ROC) analysis, the area under the curve (AUC) for A-wave velocity in discrimination between ATTRwt and non-ATTRwt were 0.86 (CI 0.76-0.96, p < 0.001). The cut-off value was 62.5 cm/s, and it yielded the best combination of sensitivity (69.7%) and specificity (87.5%) for prediction of amyloidosis. We concluded that reduced A-velocity predicts the presence of ATTRwt in elderly patients with LVH in sinus rhythm.

Left atrial electrophysiologic feature specific for the genesis of complex fractionated atrial electrogram during atrial fibrillation.

Complex fractionated atrial electrogram (CFAE) has been suggested to contribute to the maintenance of atrial fibrillation (AF). However, electrophysiologic characteristics of the left atrial myocardium responsible for genesis of CFAE have not been clarified. Non-contact mapping of the left atrium was performed at 37 AF onset episodes in 24 AF patients. Electrogram amplitude, width, and conduction velocity were measured during sinus rhythm, premature atrial contraction (PAC) with long- (L-PAC), short- (S-PAC) and very short-coupling intervals (VS-PAC). These parameters were compared between CFAE and non-CFAE regions. Unipolar electrogram amplitude was higher in CFAE than non-CFAE during sinus rhythm, L-, S- and VS-PAC (1.82 ± 0.73 vs. 1.13 ± 0.38, p < 0.001; 1.44 ± 0.54 vs. 0.92 ± 0.35, p < 0.001; 1.09 ± 0.40 vs. 0.70 ± 0.27, p < 0.001; 0.76 ± 0.30 vs. 0.53 ± 0.25 mV, p < 0.001). Laplacian bipolar electrogram amplitude was also higher in CFAE than non-CFAE during sinus rhythm, L-, S- and VS-PAC. Unipolar electrogram width was similar in CFAE and non-CFAE. Laplacian bipolar electrogram width was wider in CFAE than non-CFAE during L-, S- and VS-PAC (85.5 ± 6.8 vs. 79.6 ± 4.5, p < 0.001; 96.1 ± 9.7 vs. 84.5 ± 5.9, p < 0.001; 122.4 ± 16.0 vs. 99.6 ± 9.6 ms, p < 0.001), but not during sinus rhythm. The conduction velocity was slower in CFAE during sinus rhythm, L-, S- and VS-PAC than non-CFAE (1.7 ± 0.3 vs. 2.4 ± 0.4, p < 0.001; 1.4 ± 0.3 vs. 2.0 ± 0.5, p < 0.001; 1.2 ± 0.3 vs. 1.7 ± 0.5, p < 0.001; and 0.9 ± 0.3 vs. 1.4 ± 0.4 m/s, p < 0.001). CFAE was generated in the high amplitude atrial myocardium with slow and non-uniform conduction properties which were pronounced associated with premature activation, suggesting that heterogeneous conduction produced in high amplitude region contributes to the genesis of CFAE.

Overview of the 79th Annual Scientific Meeting of the Japanese Circulation Society ­ Late-Breaking Cardiovascular Medicine From Japan.

The 79th Annual Scientific Meeting of the Japanese Circulation Society was held in Osaka on April 24-26, 2015. The main theme was "Late-breaking Cardiovascular Medicine from Japan". Recently, optimal medical treatment has been guided by evidence-based medicine. We aim to emphasize the research findings and advances in cardiology from Japan, in the hope that Japan will become one of the leaders in the field worldwide. Unlike previous meetings, this annual scientific meeting was held in late April. Approximately 18,000 people, including medical doctors, healthcare professionals, and management staff, attended. The meeting was successfully completed, and included discussions on state-of-the art medicine.

Prognostic Significance of Soluble PD-L1 on Cardiovascular Outcomes in Patients with Coronary Artery Disease.

AIMS: Programmed cell death-1 (PD-1) and its ligand (PD-L1) regulate T cells, leading to immunotolerance. We previously demonstrated that patients with coronary artery disease (CAD) had increased circulating levels of soluble PD-L1 (sPD-L1). However, the prognostic significance of sPD-L1 on cardiovascular outcomes is unknown. In the present study, we evaluated the association between sPD-L1 and cardiovascular events in patients with CAD. METHODS: We prospectively measured sPD-L1 in patients with CAD admitted to Kumamoto University Hospital between December 2017 and January 2020 and observed their cardiovascular event rate. The primary outcome was a composite of death from non-cardiovascular causes, death from cardiovascular causes, non-fatal myocardial infarction, unstable angina pectoris, revascularization, hospitalization for heart failure, and ischemic stroke. RESULTS: Finally, 627 patients were enrolled, and 35 patients were lost to follow-up. The median follow-up duration was 522 days. In total, 124 events were recorded. The Kaplan-Meier curve showed that the event rate was higher in the higher sPD-L1 group (median ≥ 136 pg/dL) than in the lower sPD-L1 group (25.0% vs. 16.9%; p=0.028, log-rank test). Univariate Cox proportional hazards analysis showed that high-sensitivity C-reactive protein, an estimated glomerular filtration rate of ＜60 mL/min/1.73m2, B-type natriuretic peptide, left ventricular ejection fraction, and sPD-L1 were significantly associated with cardiovascular events. Multivariable Cox proportional hazards analysis of factors that were significant in univariate analysis identified that sPD-L1 was significantly and independently associated with cardiovascular events (hazard ratio: 1.364, 95% confidence interval: 1.018-1.828, p=0.038). CONCLUSIONS: Higher sPD-L1 levels were significantly associated with future cardiovascular events in patients with CAD.

A new staging system using right atrial strain in patients with immunoglobulin light-chain cardiac amyloidosis.

AIMS: There are minimal data on the prognostic impact of right atrial strain during the reservoir phase (RASr) in patients with immunoglobulin light-chain (AL) cardiac amyloidosis. METHODS AND RESULTS: Among 78 patients who were diagnosed with AL cardiac amyloidosis at Kumamoto University Hospital from 2007 to 2022, 72 patients with sufficient two-dimensional speckle tracking imaging data without chemotherapy before the diagnosis were retrospectively analysed. During a median follow-up of 403 days, 31 deaths occurred. Age and the rate of male sex were not significantly different between the all-cause death group and the survival group (age, 70.4 ± 8.8 years vs. 67.0 ± 10.0 years, P = 0.14, male sex, 65% vs. 66%, P = 0.91). The estimated glomerular filtration rate (eGFR) was significantly lower, and B-type natriuretic peptide (BNP) and high sensitivity cardiac troponin T (hs-cTnT) were significantly higher, in the all-cause death group versus the survival group (eGFR, 48.2 ± 21.0 mL/min/1.73 m2 vs. 59.4 ± 24.4 mL/min/1.73 m2, P < 0.05, BNP, 725 [360-1312] pg/mL vs. 123 [81-310] pg/mL, P < 0.01, hs-cTnT, 0.12 [0.07-0.18] ng/mL vs. 0.05 [0.03-0.08] ng/mL, P < 0.01). Left ventricular (LV) global longitudinal strain (GLS) (LV-GLS), left atrial strain during the reservoir phase (LASr), right ventricular GLS (RV-GLS), and RASr were significantly lower in the all-cause death group versus the survival group (LV-GLS, 8.5 ± 4.3% vs. 11.8 ± 3.8%, P < 0.01, LASr, 8.8 ± 7.1% vs. 14.3 ± 8.1%, P < 0.01, RV-GLS, 11.6 ± 5.1% vs. 16.4 ± 3.9%, P < 0.01, RASr, 10.2 ± 7.3% vs. 20.7 ± 9.5%, P < 0.01). RASr was significantly associated with all-cause death after adjusting for RV-GLS, LV-GLS and LASr (hazard ratio [HR]: 0.91, 95% confidence interval [95% CI]: 0.83-0.99, P < 0.05). RASr and log-transformed BNP were significantly associated with all-cause death after adjusting for log-transformed troponin T and eGFR (RASr, HR: 0.93, 95% CI: 0.87-1.00, P < 0.05; log-transformed BNP, HR: 2.10, 95% CI: 1.17-3.79, P < 0.05). The optimal cut-off values were RASr: 16.4% (sensitivity: 66%, specificity: 84%, area under curve [AUC]: 0.81) and BNP: 311.2 pg/mL (sensitivity: 83%, specificity: 78%, AUC: 0.82) to predict all-cause mortality using ROC analysis. Kaplan-Meier analysis revealed that patients with low RASr (<16.4%) or high BNP (>311.2 pg/mL) had a significantly high probability of all-cause death (both, P < 0.01). We devised a new staging score by adding 1 point if RASr decreased or BNP levels increased more than each cut-off value. The HR for all-cause death using score 0 as a reference was 5.95 (95% CI: 1.19-29.79; P < 0.05) for score 1 and 23.29 (95% CI: 5.37-100.98; P < 0.01) for score 2. CONCLUSIONS: The new staging system using RASr and BNP predicted prognosis in patients with AL cardiac amyloidosis.

Usefulness of platelet count to predict concomitant valvular heart disease in patients with systemic lupus erythematosus.

Background: Although the prevalence rate of valvular heart disease (VHD) is high in patients with systemic lupus erythematosus (SLE), the predictive factors of concomitant VHD have not been fully evaluated. Methods and results: Among 288 patients with SLE who underwent transthoracic echocardiography at Kumamoto University Hospital from 2016 to 2021, 241 patients with sufficient echocardiographic data were retrospectively analysed. Among them, 22 (9 %) had VHD (10 had mitral regurgitation, 3 had aortic regurgitation, 6 had tricuspid regurgitation, 1 had mitral regurgitation and tricuspid regurgitation, and 2 had a prosthetic cardiac valve). After excluding the two patients with a prosthetic cardiac valve, we divided the remaining patients into two groups: the VHD group and non-VHD group. Multivariate logistic regression analysis revealed that age and the platelet count were significantly and independently associated with having VHD (age: odds ratio, 1.06; 95 % confidence interval, 1.02-1.10; p < 0.01) (platelet count: odds ratio, 0.99; 95 % confidence interval, 0.98-1.00; p < 0.05). After excluding 95 patients aged < 40 years, receiver operating characteristic analysis revealed that the area under the curve of the platelet count for prediction of VHD was 0.73 with an optimal cut-off value of 166.5 × 103/µL (sensitivity: 76.6 %, specificity: 60.0 %). Among patients with a low platelet count (<166.5 × 103/µL), the rate of having VHD was 29 % (12/41 patients). However, among those with a high platelet count (≥166.5 × 103/µL), this rate was only 8 % (8/103 patients). Conclusion: The platelet count is useful to predict concomitant VHD in middle-aged and older patients with SLE.

Human epididymis protein 4 is a useful predictor of post-operative prognosis in patients with severe aortic stenosis.

AIMS: The human epididymis protein 4 (HE4), a novel fibrosis marker, is expressed only in activated fibroblasts and is thought to reflect ongoing left ventricular (LV) fibrosis. LV fibrosis is a feature of severe aortic stenosis (AS) and is related to the post-operative outcome of patients with AS. We investigated the relationship between serum levels of HE4 and the post-operative prognosis of patients with severe AS. METHODS AND RESULTS: We measured the serum HE4 levels of 55 participants (80.8 ± 8.0 years old, male n = 26, 46%) with severe AS prior to surgical aortic valve replacement (n = 31, 56%) or transcatheter aortic valve implantation (n = 24, 44%) at Kumamoto University Hospital in 2018. We followed them for cardiovascular (CV) death or hospitalization for heart failure (HF) for 3 years. Serum HE4 levels were positively correlated with computed tomography-extracellular volume (CT-ECV) values (r = 0.53, P = 0.004). Kaplan-Meier curves demonstrated a significantly higher probability of hospitalization for HF or CV-related death in the patients with high HE4 (greater than the median HE4 value) compared with the patients with low HE4 (lower than the median HE4 value) (log-rank P = 0.003). Multivariate analysis showed HE4 (log(HE4)) to be an independent prognostic factor [hazard ratio (HR): 7.50; 95% confidence interval (CI): 1.81-31.1; P = 0.005]. Receiver operating characteristic (ROC) curve analysis suggested that HE4 is a marker of increased risk of CV-related death or hospitalization for HF at 3 years after surgery, with an area under the curve (AUC) of 0.76 (95% CI: 0.62-0.90; P = 0.003). CONCLUSIONS: We found that HE4 is a potentially useful biomarker for predicting future CV events in patients scheduled for AS surgery. Measuring serum HE4 values could help consider AS surgery.

Electrophysiologic mechanism of typical atrial flutter termination by nifekalant: effect of a pure IKr -selective blocking agent.

BACKGROUND: Little is known about the effect of nifekalant, a pure I(Kr) -selective blocker, on typical atrial flutter (AFL) and its termination mechanism. METHODS: The effects of nifekalant on AFL were elucidated in 17 patients. During AFL, the conduction time from the lateral to septal cavotricuspid isthmus (IS) and that through the reminder of the right atrium (nIS); AFL-cycle length (CL) variability, which was quantified by the standard deviation; and the maximum difference in AFL-CL were measured before and after administration of nifekalant (0.2-0.3 mg/kg). A single extrastimulus was delivered from the lateral cavotricuspid isthmus to elucidate the resetting response curves and atrial effective refractory period (AERP) before and after administration of nifekalant. RESULTS: There was no significant difference in AFL-CL, IS, and nIS before and after nifekalant; however, AERP was increased after nifekalant (155 ± 22 ms vs 184 ± 32 ms, P < 0.001). The standard deviation and the maximum difference in AFL-CL were both increased after nifekalant (1.7 ± 0.7 ms vs 3.6 ± 2.3 ms, P < 0.001 and 4.1 ± 1.9 ms vs 8.5 ± 5.2 ms, P < 0.001). The total excitable gap decreased (94 ± 17 ms vs 66 ± 21 ms, P < 0.001) with rightward shift of the resetting response curves and loss of full excitability after nifekalant. In 11 patients (65%), AFL was terminated spontaneously (n = 7) or by a single extrastimulus (n = 4), which was not observed before nifekalant. Termination was associated with orthodromic block in the cavotricuspid isthmus in all patients. CONCLUSIONS: Nifekalant increases AERP and AFL-CL variability by abolishing a fully excitable gap, without prolongation of AFL-CL. These unique effects facilitate the termination of AFL.

Effect of contact vector direction on achieving cavotricuspid isthmus block.

Cavotricuspid isthmus (CTI) ablation is an important treatment strategy for CTI-dependent atrial flutter (AFL). The location of the catheter contact area is confirmed by the contact vector direction (CVD) through three-dimensional mapping during the procedure. However, the relationship between CVD during radiofrequency ablation and its efficacy in achieving CTI block has not been clarified. This study aimed to investigate the relationship between CVD and efficacy in achieving CTI block. CVDs during radiofrequency ablation were divided into proximal vectors against the distal tip (P-vector) and other vectors (normal-vector). In 39 patients who underwent CTI linear ablation, the CTIs were divided into two segments: the tricuspid valve area (anterior) and inferior vena cava area (posterior). The frequency of the residual conduction gap was compared between segments in which the P- and normal-vectors were observed. P-vectors were observed in 13 of the 78 segments. The median ablation index was not significantly different between segments in which the P-vector and normal-vector were observed (398.2 [384.2-402.2] vs. 393.3 [378.3-400.1], p = 0.15). However, residual conduction gaps were significantly more frequently observed in the segment in which the P-vector was observed than those in which only the normal-vector was observed (6/13, 46.2% vs. 3/65, 4.6%; p < 0.01). During a 6-month follow-up, two patients required a second session of ablation due to AFL recurrence. A residual conduction gap was observed in one patient at the site where the P-vector was observed in the first session. Avoiding the P-vector might be an important factor in improving CTI block and reducing AFL recurrence.

Japanese high bleeding risk criteria status predicts low thrombogenicity and bleeding events in patients undergoing percutaneous coronary intervention.

Although the Japanese high bleeding risk criteria (J-HBR) were established to predict bleeding risk in patients undergoing percutaneous coronary intervention (PCI), the thrombogenicity in the J-HBR status remains unknown. Here, we examined the relationships among J-HBR status, thrombogenicity and bleeding events. This study was a retrospective analysis of 300 consecutive patients who underwent PCI. Blood samples obtained on the day of PCI were used in the total thrombus-formation analysis system (T-TAS) to investigate the thrombus-formation area under the curve (AUC; PL18-AUC10 for platelet chip; AR10-AUC30 for atheroma chip). The J-HBR score was calculated by adding 1 point for any major criterion and 0.5 point for any minor criterion. We assigned patients to three groups based on J-HBR status: a J-HBR-negative group (n = 80), a low score J-HBR-positive group (positive/low, n = 109), and a high score J-HBR-positive group (positive/high, n = 111). The primary end point was the 1-year incidence of bleeding events defined by the Bleeding Academic Research Consortium types 2, 3, or 5. Both PL18-AUC10 and AR10-AUC30 levels were lower in the J-HBR-positive/high group than the negative group. Kaplan-Meier analysis showed worse 1-year bleeding event-free survival in the J-HBR-positive/high group compared with the negative group. In addition, both T-TAS levels in J-HBR positivity were lower in those with bleeding events than in those without bleeding events. In multivariate Cox regression analyses, the J-HBR-positive/high status was significantly associated with 1-year bleeding events. In conclusion, the J-HBR-positive/high status could reflect low thrombogenicity as measured by T-TAS and high bleeding risk in patients undergoing PCI.

Differential effects of overweight/obesity depending on the severity of heart failure complicating acute myocardial infarction in Japan.

BACKGROUND: The existence of a paradoxical association between overweight/obesity and survival benefits, the so-called obesity paradox, in heart failure (HF) as well as coronary artery disease (CAD) remains contentious. Previously, we reported that a past history of CAD negated the obesity paradox in the general population with acute HF. Herein, we further focused on HF complicating acute myocardial infarction (AMI) and compared the prognostic effects of overweight/obesity with respect to the severity of HF. METHODS: We conducted a multicenter retrospective study of 7265 consecutive patients with AMI. The severity of HF was categorized according to the Killip classification. Overweight/obesity was defined as a body mass index (BMI) of ≥25 kg/m2. The interaction between overweight/obesity and the Killip classification for in-hospital mortality was tested in the entire cohort. Multivariable logistic regression analyses were performed to examine the effects of overweight/obesity on in-hospital mortality. RESULTS: Across the entire study cohort, 1931 patients had HF. Overweight/obesity had a significant association with reductions in in-hospital mortality in patients with mild HF (Killip class II; odds ratio [OR], 0.284; P = 0.019). Conversely, overweight/obesity was a significant risk factor for in-hospital mortality in patients with severe HF (Killip class IV; OR, 2.152; P = 0.001). The effects of overweight/obesity on in-hospital mortality in patients with moderate HF (Killip class III) were intermediate between those with mild HF and severe HF. CONCLUSION: Opposing effects of overweight/obesity on in-hospital mortality in patients with mild HF versus severe HF were demonstrated, suggesting a balance between beneficial and deleterious effects of overweight/obesity may be inclined toward the latter with the severity of HF complicating AMI.

Prognostic impact of diabetes mellitus on in-hospital mortality in patients with acute myocardial infarction complicating renal dysfunction according to age and sex.

BACKGROUND: Patients with acute myocardial infarction (AMI) complicating renal dysfunction (RD) are recognized as being at high risk. Although diabetes mellitus (DM) is a major cause of RD, the prognostic impact of coexisting DM on mortality in patients with AMI complicating RD is ill-defined. This study compared the prognostic impact of coexisting DM in patients with AMI complicating RD according to both age and sex. METHODS: A multicenter retrospective study was conducted on 2988 consecutive patients with AMI complicating RD (estimated glomerular filtration rate <60 mL/min per 1.73 m2). Multivariable Cox regression analysis was performed to investigate the effects of DM on in-hospital mortality. RESULTS: Statistically significant interactions between age and DM and between sex and DM for in-hospital mortality were revealed in the entire cohort. Coexisting DM was identified as an independent risk factor for in-hospital mortality (hazard ratio [HR], 2.543) in young (aged <65 years), but not old (aged ≥65 years), patients. DM was identified as an independent risk factor (HR, 1.469) in male, but not female, patients. Kaplan-Meier survival curves showed that DM correlated with significantly low survival rates in patients that were young or male as compared to those who were old or female. CONCLUSIONS: There were significant differences in the prognostic impact of DM on in-hospital mortality between young and old as well as male and female patients with AMI complicating RD. These results have implications for future research and the management of patients with DM, RD, and AMI comorbidities.

Placement of catheters without magnetic sensors in the coronary sinus without fluoroscopic guidance: Feasibility and safety evaluation.

Background: A three-dimensional (3D) mapping system is essential to reduce radiation exposure during catheter ablation. When using the CARTO 3D mapping system, only the catheter with magnetic sensor can visualize its location. However, once target chamber matrix is created using the catheter, even the catheters without magnetic sensors (CWMS) can enable visualization. We aimed to investigate the feasibility and safety of placing a CWMS in the coronary sinus (CS) without fluoroscopic guidance. Methods: The study group comprised 88 consecutive patients who underwent catheter ablation. CWMS placement was performed without fluoroscopic guidance in 47 patients and with fluoroscopic guidance in 41 patients. Placement without fluoroscopic guidance was performed after creating a visualization matrix of the CS, right atrium, and superior vena cava using a catheter with a magnetic sensor. Feasibility and safety were compared between the two groups. Results: Successful catheter placement was achieved in all patients without fluoroscopic guidance, with no inter-group difference in the median procedure time: with guidance, 120.0 [96.0-135.0] min, and without guidance, 110.0 [97.5-125.0] min; p = .22. However, radiation exposure was significantly shorter, and the effective dose was lower without fluoroscopic guidance (0 [0-17.5] s and 0 [0-0.004] mSv, respectively) than with fluoroscopic guidance (420.0 [270.0-644.0] s and 0.73 mSv [0.36-1.26], respectively); both p < .001. Conclusions: CWMS placement without fluoroscopic guidance is feasible, safe to perform, and does not involve complications. Our technique provides an option to decrease radiation exposure during catheter ablation and electrophysiological testing.