Disappearance pattern and the last remaining earliest pulmonary vein potential during cryoballoon ablation in predicting recurrence and conduction gap site of pulmonary veins

Electrophysiological studies have rarely evaluated the sites prone to pulmonary vein (PV) conduction gap during cryoballoon ablation (CBA) for atrial fibrillation (AF). In addition, no studies have analyzed the sequence of PV potentials just before PV isolation during CBA for AF. Of the 238 patients who underwent first-time CBA for paroxysmal AF, 115 PVs of 29 patients who underwent repeat session due to recurrence after the procedure were retrospectively evaluated in the study. We evaluated the disappearance pattern of PV potential and PV reconnection on intracardiac electrograms and investigated whether the conduction gap site of the PV was related to the last remaining earliest PV potential (EP) and sequence pattern during the first-time CBA. Time to isolation was observed in 81 PVs during the first-time CBA. At the repeat session, PV reconnection was only observed in 22 of 81 PVs. PV potentials disappeared with sequence changes in 36 PVs and without sequence changes in 38 PVs. Multivariate analysis demonstrated that disappearance of PV potentials without change in the EP site but with delay or disappearance of other PV potentials was independently associated with PV reconnection (12/22 PVs [55%] vs. 4/59 PVs [6.8%]; odds ratio 14.4; 95% confidence interval 3.75-55.5; p < 0.001). In 19 of 22 (86%) reconnected PVs, PV conduction gap sites at repeat ablation corresponded with the last remaining EP sites during first-time CBA. In conclusion, disappearance pattern of the PV potential and the last remaining EP during the CBA can predict PV reconnection and gap site.

The mechanism and prognosis of acute and late improvement in mitral regurgitation after cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) improves functional mitral regurgitation (MR); however, the mechanism and differences in acute and late improvement in MR are unclear. We aimed to evaluate the factors associated with the acute and late MR improvements and the prognosis of MR improvement after CRT. This retrospective study included 121 patients who underwent CRT implantation with full echocardiography assessment at baseline, 1 week, and 6 months after implantation. MR severity was classified into five grades (0: none to 4: severe). Two-dimensional speckle-tracking echocardiography with radial strain was used to assess dyssynchrony, and the time difference between the lateral and inferior segments at papillary muscle levels (TD_late-inf) was calculated. The MR improved 1 week and 6 months after CRT in 40 (33%) and 45 (37%) patients, respectively. On multivariate analyses, TD_late-inf (baseline-1 week) and SPWMD were independently associated with acute MR improvement. The %reduction in left ventricular end-systolic volume (LVESV) (baseline-6 months) and TD_late-inf (baseline-1 week) were independently correlated with late MR improvement. The patients with pre-MR grades 2-4 and improved MR after CRT showed significantly better prognosis in heart failure hospitalization. Cutoff values of ≥ 19.5 ms of the reduction of TD_late-inf and ≥ 30.8% of the %reduction of LVESV were significantly associated with the decrease in heart failure hospitalization. The improved interpapillary muscle activation time delay and volume reduction after CRT were associated with acute and late MR improvements. There may be different time course of recovery and distinct causes for late MR improvement.

Safety and efficacy of first-line cryoablation for para-hisian ventricular arrhythmias using a cryomapping protocol approach: A case series

A first-line cryoablation for para-Hisian VAs using a strict cryomapping protocol is useful and safe, even if the His bundle potential is recorded on the ablation catheter.

Improved Risk Stratification of Patients With Brugada Syndrome by the New Japanese Circulation Society Guideline - A Multicenter Validation Study

BACKGROUND

The new guideline (NG) published by the Japanese Circulation Society (JCS) places emphasis on previous arrhythmic syncope and inducibility of ventricular fibrillation (VF) by ≤2 extrastimuli during programmed electrical stimulation (PES) for deciding the indication of an implantable cardioverter-defibrillator in patients with Brugada syndrome (BrS). This study evaluated the usefulness of the NG and compared it with the former guideline (FG) for risk stratification of patients with BrS.Methods and Results:This was a multicenter (7 Japanese hospitals) retrospective study involving 234 patients with BrS who underwent PES at baseline (226 males; mean age at diagnosis: 44.9±13.4 years). At diagnosis, 46 patients (20%) had previous VF, 100 patients (43%) had previous syncope, and 88 patients (37%) were asymptomatic. We evaluated the difference in the incidence of VF in each indication according to the new and FGs. During the follow-up period (mean: 6.9±5.2 years), the incidence of VF was higher in patients with Class IIa indication according to the NG (NG: 16/45 patients [35.6%] vs. FG: 16/104 patients [15.4%]), while the incidence of VF in patients with other than class I or IIa indication was similarly low in both guidelines (NG: 2/143 patients [1.4%] vs. FG: 2/84 patients [2.4%]).

CONCLUSIONS

This study validated the usefulness of the NG for risk stratification of BrS patients.

Early improvement of daily physical activity after catheter ablation for atrial fibrillation in an accelerometer assessment: A prospective pilot study

Background

Catheter ablation improves physical activity in patients with atrial fibrillation (AF). However, continuous daily evaluation and time course of improvement in physical activity after ablation have not been fully assessed. This prospective study was conducted to evaluate the daily physical activities and changes in the physical performance in patients undergoing catheter ablation for AF by continuous monitoring of a portable accelerometer.

Methods

Ten patients scheduled for catheter ablation for AF were fitted with a uniaxial accelerometer prior to and 6 months after the procedure. This study evaluated changes in daily steps, activity intensity, and activity duration. We also evaluated changes in activity intensity using a short version of the International Physical Activity Questionnaire (IPAQ).

Results

The maximum daily steps significantly increased from baseline to postablation (baseline, 9,232 [6,716–11,485]; after 1–3 months, 11,605 [8,285–14,802]; and after 4–6 months, 11,412 [8,939–13,808], p = .020). Similarly, Δ maximum‐mean daily steps increased significantly (baseline, 2,431 [1,199–6,181]; after 1–3 months, 4,674 [4,164–6,474]; and after 4–6 months, 4,871 [3,657–6,117], p = .014). These improvements were more pronounced in patients with paroxysmal and symptomatic AF. The total IPAQ score significantly improved from baseline to after 6 months ablation (from 1,170 [693–3,930] to 4,312 [1,865–6,569], p = .037). All patients were recurrence‐free from AF after ablation.

Conclusions

The physical activity improved significantly even in the early phase following catheter ablation. The effect of suppressing AF on activity levels was apparent soon after the procedure.

Autopsy evaluation of the implantation site of a His bundle pacing lead demonstrating selective capture

Evaluations of His bundle pacing (HBP) lead location at autopsy examination have been rarely reported. We report an autopsy case of a 98-year-old man who underwent HBP implantation due to atrioventricular block and heart failure. Although selective HBP was achieved with an acceptable threshold, the stimulus-to-QRS interval was relatively longer without correction of the right bundle-branch block. A macroscopic examination revealed that the HBP lead was inserted on the ventricular side passing through the anteroseptal commissure of the tricuspid valve. Transthyretin cardiac amyloidosis may affect the distal conduction system resulting in a long stimulus-to-QRS interval during selective HBP.

Prothrombotic Responses After Catheter Ablation for Atrial Fibrillation During Uninterrupted Oral Anticoagulant Agent Administration

OBJECTIVES

The aim of this study was to evaluate the extent of changes in prothrombotic responses after catheter ablation for atrial fibrillation (AF) under uninterrupted oral anticoagulant agent (OAC) administration.

BACKGROUND

Catheter ablation for AF has a potential risk for prothrombotic activation and silent thromboembolic events.

METHODS

A total of 814 patients (n = 172 [warfarin], n = 153 [dabigatran], n = 134 [rivaroxaban], and n = 301 [apixaban] patients undergoing AF ablation and a control group of 54 patients undergoing non-AF ablation) were included. Uninterrupted OACs were administered during the procedure in patients with AF. Blood samples were collected the day before and 3 days after the procedure.

RESULTS

At baseline, D-dimer levels were within normal limits (≤1.0 μg/ml) in more than 90% of the patients in all groups. However, after 3 days, this proportion decreased to 67%, 73%, 59%, 68%, and 65% in the warfarin, dabigatran, rivaroxaban, apixaban, and control groups, respectively (p = 0.180). Changes in prothrombin fragment 1+2 levels differed (p < 0.001), whereas fibrin monomer complex levels 3 days after ablation at a trough were equivalent within normal ranges among the groups (p = 0.146). Multivariate analysis revealed that age, CHA₂DS₂-VASc score, first session, and radiofrequency ablation were independent predictors of increased D-dimer levels after the procedure. Various changes in prothrombotic markers were observed between the warfarin and direct OAC groups after propensity score matching analyses.

CONCLUSIONS

The coagulation cascade was activated after catheter ablation for AF under uninterrupted OAC administration. The changes in various prothrombotic markers differed among the OAC groups.

Prospective comparison of periprocedural coagulation markers among uninterrupted anticoagulants for atrial fibrillation ablation

BACKGROUND

The difference in coagulation state during the periprocedural period of atrial fibrillation (AF) ablation among patients with uninterrupted anticoagulation has not been fully elucidated.

OBJECTIVE

The purpose of this study was to compare periprocedural trends in coagulation markers among patients on uninterrupted anticoagulation for AF ablation.

METHODS

In total, 275 consecutive patients who underwent AF ablation were evaluated. These patients were divided according to the anticoagulant they received into the dabigatran group (DG) (n = 64); rivaroxaban group (RG) (n = 62); apixaban group (AG) (n = 60); edoxaban group (EG) (n = 59); and warfarin group (WG) (n = 30). The trends in coagulation markers and the rate of silent stroke (SS) confirmed by postoperative magnetic resonance imaging were evaluated.

RESULTS

The fibrin monomer complex (FMC) level on postoperative day 1 and the prothrombin fragment 1+2 (PF1+2) levels on the operative day and postoperative day 1 were higher in DG than in the other groups (P <.05, <.001, and <.001, respectively). The incidence of SS in DG (17%) was significantly higher than in RG (6%), AG (3%, EG (7%), or WG (4%) (P <.05). Dabigatran use independently predicted the occurrence of SS (odds ratio 4.12; 95% confidence interval 1.37-12.7; P <.05).

CONCLUSION

FMC and PF1+2 levels during the periprocedural period of AF ablation were higher in DG than in the other groups. Dabigatran use independently predicted the occurrence of SS.

Electrocardiogram characteristics of P wave associated with successful pulmonary vein isolation in patients with paroxysmal atrial fibrillation: Significance of changes in P-wave duration and notched P wave

Background

The mechanisms involved in changes in P wave following catheter ablation for atrial fibrillation (AF) are uncertain. This study aimed to assess the relationship between changes in P‐wave morphology and pulmonary vein (PV) reconnection following ablation by the assessment of 12‐lead surface electrocardiogram and signal‐averaged electrocardiogram.

Methods

This retrospective study included 115 consecutive patients with paroxysmal AF that underwent repeat ablation for recurrence following initial ablation. We investigated changes in P‐wave morphology between baseline and repeat procedure in patients with and without PV reconnection. The study also included as validation group without recurrence (n = 67) following initial ablation.

Results

The maximum P‐wave duration (PWD) was significantly decreased from baseline to just after the procedure in all groups. However, for the PV reconnection group (n = 100), the maximum PWD was significantly increased again at the repeat procedure. In contrast, the maximum PWD was significantly reduced between baseline and repeat procedure in the non‐PV reconnection group (n = 15). The signal‐averaged PWD was significantly decreased from baseline to repeat procedure in the non‐PV reconnection group, but, conversely, was increased in the PV reconnection group. In the non‐PV reconnection group, the disappearance of notched P wave was detected in 8 of 15 patients (53%), which was significantly higher than in other groups (p = .001). A new or delayed notched P wave was identified in the PV reconnection group only. These results were confirmed in the validation group.

Conclusions

The reverse dynamics of PWD after initial shortening directly following ablation were significantly associated with PV reconnection.

Study design and protocol for evaluating the long-term prognosis of patients receiving his bundle pacing: A multicenter observational study

BACKGROUND

His bundle pacing (HBP) is a recently developed pacing technique that can achieve an ideal physiological pattern of ventricular activation via stimulation of the native His-Purkinje system. Despite the widespread introduction of HBP in clinical practice, its appropriate indications are yet to be determined clearly. Moreover, the efficacy and safety of HBP and long-term prognosis of patients undergoing such are unknown.

METHODS

We conducted a multicenter observational prospective study in patients undergoing HBP in Japan. Patients with atrioventricular block or conduction delay and estimated ventricular pacing of ≥ 40% scheduled for HBP implantation are included. All patients are followed up until 3 years after the implantation. The primary endpoints are all-cause death, heart failure-related hospitalization, and upgrade to cardiac resynchronization therapy. The secondary endpoint is changes in cardiac function based on echocardiographic findings and laboratory data after the implantation.

RESULTS

The results are currently under investigation.

CONCLUSIONS

This multicenter observational study evaluates the long-term prognosis and changes in cardiac function of patients undergoing HBP implantation in a clinical setting. Considering the large number of patients included, the cumulative results would be helpful in establishing evidence on HBP application in this area and consequently allow accurate management and treatment of patients undergoing HBP.

Long-term prognosis of patients withJ-wave syndrome

OBJECTIVE

Limited data are currently available regarding the long-term prognosis of patients with J-wave syndrome (JWS). The aim of this study was to investigate the long-term prognosis of patients with JWS and identify predictors of the recurrence of ventricular fibrillation (VF).

METHODS

This was a multicentre retrospective study (seven Japanese hospitals) involving 134 patients with JWS (Brugada syndrome (BrS): 85; early repolarisation syndrome (ERS): 49) treated with an implantable cardioverter defibrillator. All patients had a history of VF. All patients with ERS underwent drug provocation testing with standard and high intercostal ECG recordings to rule out BrS. The impact of global J waves (type 1 ECG or anterior J waves and inferolateral J waves in two or more leads) on the prognosis was evaluated.

RESULTS

During the 91±66 months of the follow-up period, 52 (39%) patients (BrS: 37; ERS: 15) experienced recurrence of VF. Patients with BrS and ERS with global J waves showed a significantly higher incidence of VF recurrence than those without (BrS: log-rank, p=0.014; ERS: log-rank, p=0.0009). The presence of global J waves was a predictor of VF recurrence in patients with JWS (HR: 2.16, 95% CI 1.21 to 3.91, p=0.0095), while previously reported high-risk electrocardiographic parameters (high-amplitude J waves ≥0.2 mV and J waves associated with a horizontal or descending ST segment) were not predictive of VF recurrence.

CONCLUSIONS

This multicentre long-term study showed that the presence of global J waves was associated with a higher incidence of VF recurrence in patients with JWS.

T-wave changes of cardiac memory caused by frequent premature ventricular contractions originating from the right ventricular outflow tract

INTRODUCTION

Cardiac memory is recognized as altered T-waves when the sinus rhythm resumes after an abnormal myocardial activation period that recovers slowly over several weeks. The T-wave changes after ablation of frequent premature ventricular contractions (PVCs) as cardiac memory was not known.

OBJECTIVE

This study identified whether cardiac memory exists after successful ablation of PVCs from the right ventricular outflow tract (RVOT).

METHODS

We investigated 45 patients who underwent successful ablation of PVCs from RVOT and 10 patients who underwent unsuccessful ablation. We analyzed the amplitude of the T-wave, QT intervals, and QRST time-integral values of a 12-lead electrocardiogram before ablation and 1 day, 3 days, and 1 month after ablation.

RESULTS

In the successful ablation group, the amplitude of the T-wave and QRST time-integral values of lead II, III, aVR, aVL, and aVF significantly changed after ablation and gradually normalized within 1 month. In addition, if the number of pre-ablation PVCs was small, then the corresponding impact was also small. However, the greater the number of pre-ablation PVCs, the more prominent the changes. Significant changes were not observed in the unsuccessful ablation group.

CONCLUSION

When ablation of PVCs from RVOT was successful, primary T-wave changes because of cardiac memory and the gradual normalization of the amplitude of the T-wave were observed. No significant T-wave changes were detected after unsuccessful ablation.

Atypical Fast-Slow Atrioventricular Nodal Reentrant Tachycardia Utilizing a Slow Pathway Extending to the Inferolateral Right Atrium

Background: The existence of atypical fast-slow (F/S) atrioventricular (AV) nodal reentrant tachycardias (NRT) using slow pathway (SP) variants connected to the right atrial (RA) inferolateral (inf) free wall (FW) along the tricuspid annulus (TA), has been neither confirmed nor precisely characterized.

Methods and Results: We studied 7 patients (mean age, 48±16 years; 5 men) with F/S-AVNRT with long RP intervals and an earliest atrial activation at the RA inf-FW along the TA (inf-F/S-AVNRT). AV reentrant tachycardia was excluded on observation of the transition zone criteria in all 7 patients. Atrial tachycardia was excluded on the observation of a V-A-V activation sequence after the induction or entrainment of the tachycardia from the right ventricle in all. During the tachycardia, low-frequency, fractionated potentials (LP) preceding the local atrial electrogram were recorded near the site of the earliest atrial activation in 6 patients. Observations of conduction delay and block of the LP during ventricular entrainment or ablation of the tachycardia indicated that LP reflect retrograde activation via the inf-SP. Retrograde SP conduction was interrupted at the site of earliest atrial activation in 3 patients, and in the right posterior septum in 4 patients.

Conclusions: inf-F/S-AVNRT are distinct supraventricular tachycardia incorporating an SP variant connected to the RA inf-FW along the TA in the retrograde direction, which were eliminated by ablation.

Myocardial viability as shown by left ventricular lead pacing threshold and improved dyssynchrony by QRS narrowing predicts the response to cardiac resynchronization therapy

INTRODUCTION

Patients with advanced heart failure and dyssynchrony can benefit from cardiac resynchronization therapy (CRT). To predict the response to CRT, myocardial viability and improved dyssynchrony are suggested to be important.

METHODS

We retrospectively investigated 93 patients who underwent CRT implantation in Nagoya University Hospital. We assessed QRS narrowing the day after implantation to measure the improvement in dyssynchrony and measured the left ventricular pacing threshold (LVPT) to determine the local myocardial viability in all patients. Responders to CRT were defined as those having a greater than or equal to 15% decrease in left ventricular end-systolic volume by echocardiography at their 6-month follow-up.

RESULTS

Sixty-two patients (67%) were classified as responders. The QRS width before CRT implantation, QRS narrowing after implantation, left atrial diameter, septal-to-posterior wall motion delay, left ventricular end-diastolic diameter, radial strain, and LVPT were significantly different between the responder and nonresponder groups. On multivariate analysis, QRS narrowing (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.05; P = 0.005) and LVPT (OR, 0.42; 95% CI, 0.22-0.82; P = 0.011) were independent predictors of a response to CRT. We calculated the cutoff values from the receiver operating characteristic curves as 22.5 milliseconds of QRS narrowing and 1.55 V of LVPT. The response rates in patients with both predictive factors (QRS narrowing ≥ 22.5 milliseconds and LVPT ≤ 1.55 V), one factor, and no factors were 91%, 61%, and 25%, respectively (P < 0.001).

CONCLUSION

Both myocardial viability and improved electrical dyssynchrony may be essential to predict a good response to CRT.

Clinical significance of the timing of early recurrence of atrial arrhythmia after pulmonary vein isolation: a two-institution clinical study

Early recurrence of atrial arrhythmia (ERAA) after ablation frequently occurs, but there is limited evidence about ERAA-timing. This study aimed to investigate the association between ERAA-timing and late recurrence. We retrospectively investigated 332 patients who underwent PVI for paroxysmal atrial fibrillation at Nagoya University Hospital and Komaki City Hospital. Seventy-six patients (23%) had ERAA. The cutoff value of the first ERAA for late recurrence was set as 3 days, with a specificity of 77% and sensitivity of 43%. On multivariate analysis, first ERAA beyond 3 days (hazard ratio, 2.477; 95% confidence interval, 1.168-5.25; p = 0.018) and large left atrial diameter (LAD) (hazard ratio, 1.101; 95% confidence interval, 1.024-1.184; p = 0.009) were independent predictors for late recurrence. Patients who had first ERAA within 3 days and no ERAA beyond 3 days showed a significantly higher recurrence-free rate than those who had first ERAA beyond 3 days and those who had ERAA both within 3 days and beyond 3 days (89% versus 39%, 44%; p  < 0.001). Moreover, the patients with ERAA within 3 days and LAD ≤ 37.7 mm showed a significantly higher recurrence-free rate than those with ERAA beyond 3 days and LAD > 37.7 mm, and as compared with the other patients (100% versus 26% and 60%, respectively; p < 0.001). ERAA beyond 3 days after ablation was a predictor for late recurrence. Among patients with ERAA, those with ERAA within 3 days and smaller LAD showed favorable prognosis after ablation.

Uninterrupted Direct Oral Anticoagulant and Warfarin Administration in Elderly Patients Undergoing Catheter Ablation for Atrial Fibrillation: A Comparison With Younger Patients

OBJECTIVES

The goal of this study was to evaluate the efficacy and safety of uninterrupted direct oral anticoagulant (DOAC) use and uninterrupted warfarin administration in elderly patients undergoing catheter ablation for atrial fibrillation (AF).

BACKGROUND

There is limited knowledge regarding the uninterrupted use of oral anticoagulant agents in elderly patients undergoing catheter ablation for AF.

METHODS

This retrospective study included 2,164 patients (n = 325 ≥75 years of age and n = 1,839 <75 years of age) who underwent catheter ablation for AF. All the patients received uninterrupted oral anticoagulant agents during the procedure. We investigated the occurrences of periprocedural events and compared these between the DOAC and warfarin groups of the elderly and younger groups.

RESULTS

Major bleeding events (3.1% vs. 1.3%; p = 0.023) and minor bleeding events (9.2% vs. 5.0%; p = 0.002), except for thromboembolic events (0% vs. 0.8%; p = 0.248), were significantly higher in the elderly group than in the younger group. No significant differences in thromboembolic and bleeding events were found between the DOAC and warfarin groups of both the elderly and younger groups. Adverse complications did not differ between the groups after adjustment using propensity score matching analysis. Multivariate analysis revealed that lower body weight (odds ratio: 0.96; p = 0.010) and antiplatelet drug use (odds ratio: 2.21; p = 0.039) were independent predictors of adverse events in the elderly group.

CONCLUSIONS

The periprocedural bleeding risk during the use of uninterrupted oral anticoagulants was higher in the elderly group than in the younger group. This area needs more attention for these patients in whom caution is required.

Comparison of uninterrupted anticoagulation with dabigatran etexilate or warfarin in the periprocedural period for atrial fibrillation catheter ablation: Results of the Japanese subgroup of the RE-CIRCUIT trial

Background

There are limited data on uninterrupted anticoagulation with direct oral anticoagulants during catheter ablation for atrial fibrillation (AF), particularly in Japan. We planned a subgroup analysis of the RE-CIRCUIT study, comparing the use of uninterrupted dabigatran therapy with warfarin therapy during catheter ablation among the Japanese subgroup and with that in the total population.

Methods

The RE-CIRCUIT study utilized a prospective, randomized, open-label, blinded endpoint design, and the primary endpoint was the incidence of major bleeding events (MBEs). Patients were randomized to uninterrupted dabigatran 150 mg twice daily or warfarin. In this study, we analyzed the results in Japanese patients.

Results

Of 704 enrolled patients in the study, 112 Japanese patients were randomized to dabigatran (n = 65) or warfarin (n = 47). MBEs were experienced by two patients: one in the dabigatran group (1.6%, cardiac tamponade) and one in the warfarin group (2.2%, groin hematoma) (risk difference vs warfarin -0.6%; 95% CI -5.8, 4.7). Within the Japanese subgroup, there were no thromboembolic events in both groups.

Conclusion

While not designed to show statistical difference between two treatment groups, our results from the Japanese subgroup supported those from the overall population. Furthermore, this study provided clinical information regarding MBE, especially cardiac tamponade, in Japanese patients.

Renal function and risk of stroke and bleeding in patients undergoing catheter ablation for atrial fibrillation: Comparison between uninterrupted direct oral anticoagulants and warfarin administration

BACKGROUND

The effect of uninterrupted oral anticoagulant use in patients with chronic kidney disease (CKD) during catheter ablation for atrial fibrillation (AF) is not fully understood.

OBJECTIVE

The present study aimed to evaluate the safety and efficacy of periprocedural uninterrupted direct oral anticoagulant (DOAC) use compared with those of uninterrupted warfarin use in patients undergoing catheter ablation for AF stratified by various renal function groups.

METHODS

A total of 2091 patients were retrospectively included in this study. The study population was divided into 4 groups: creatinine clearance level ≥80 mL/min (n = 1086), 50-79 mL/min (n = 774), 15-49 mL/min (n = 209), and <15 mL/min (n = 22). We investigated periprocedural complications and compared them between uninterrupted DOAC and warfarin groups.

RESULTS

There was no significant difference in thromboembolic events among the 4 groups (0.6%, 0.6%, 1.0%, and 0%, respectively; P = .792). However, major bleeding events (0.9%, 1.4%, 4.8%, and 4.5%; P < .001) and minor bleeding events (4.1%, 6.1%, 11.5%, and 13.6%; P < .001) primarily occurred in patients with CKD. The rate of periprocedural complications in the DOAC group was similar to that in the warfarin group for each renal function category. Adverse events did not differ after adjustment using propensity score-matched analysis. Multivariate analysis showed that lower body weight, antiplatelet drug use, initial ablation session, and CKD were independent predictors of adverse events.

CONCLUSION

The periprocedural bleeding risk was increased in patients with CKD. Uninterrupted DOAC and warfarin administration during catheter ablation for AF in patients with CKD is feasible and effective.

An ECG Index of P-Wave Force Predicts the Recurrence of Atrial Fibrillation after Pulmonary Vein Isolation

BACKGROUND

Although several prognostic factors of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) have been investigated, the accurate prediction of AF recurrence remains difficult. We propose an electrocardiogram (ECG) index, the P-wave force (PWF), which is the product of the amplitude of the negative terminal phase of the P wave in the V1 electrode and the filtered P-wave duration, obtained by a signal-averaged P-wave analysis. This study was conducted to evaluate the impact of the PWF on the recurrence of AF after PVI.

METHODS

We retrospectively evaluated 79 paroxysmal AF patients (64 ± 9 years, 56 males) who underwent PVI by cryoballoon ablation. Standard 12-lead ECG and a P-wave signal-averaged electrocardiogram (SAECG) were recorded the day before and 1 month after the PVI procedure.

RESULTS

During the mean follow-up of 10.2 months, AF recurred in 11 (14%) patients. The PWF 1 month after ablation was significantly higher in the recurrence group compared to that in the nonrecurrence group (8.8 ± 3.1 mVms vs 6.5 ± 2.9 mVms, P = 0.017). The patients with a PWF value ≥9.3 mVms had a significantly greater risk of recurrence after the ablation compared to the patients with a PWF value <9.3 mVms (log-rank test, P < 0.001).

CONCLUSION

Higher PWF after cryoballoon ablation was associated with poor prognosis during follow-up. The PWF may be a useful and noninvasive marker to predict the recurrence of AF.

Effect and Significance of Early Reablation for the Treatment of Early Recurrence of Atrial Fibrillation After Catheter Ablation

There are few reports on early reablation (ER) for early recurrence of atrial fibrillation (AF) after catheter ablation. The present study evaluated the efficacy and significance of ER for early recurrence within a blanking period of 3 months after ablation of both paroxysmal and persistent AF, using a propensity-matched analysis. Of 874 patients who underwent catheter ablation of AF, 389 (45%) had early recurrence. Of these, 78 patients underwent an ER procedure. A total of 132 matched patients (66 in the ER and 66 in the non-ER groups, 82 patients with paroxysmal AF) were included in the analysis. During a mean follow-up of 15.4 months, the patients who underwent ER had a significantly lower recurrence rate than those who did not (29 [44%] vs 42 patients [64%], p = 0.023). The benefit of ER was especially apparent in patients with paroxysmal AF (p = 0.008) but not in those with persistent AF (p = 0.774). However, 24 patients (36%) in the non-ER group did not experience recurrence after a blanking period without any reablation procedure. The total number of reablation sessions was higher in the ER group than in the non-ER group (1.2 ± 0.5 vs 0.4 ± 0.6, p <0.001). Nonetheless, mean number of arrhythmia outpatient clinic visits at follow-up was significantly fewer in the ER group than in the late reablation group. In conclusion, ER for early recurrence of AF after catheter ablation might be effective for preventing recurrence during follow-up, especially for paroxysmal AF.

Elevated Red Blood Cell Distribution Width Predicts Recurrence After Catheter Ablation for Atrial Fibrillation in Patients With Heart Failure - Comparison With Non-Heart Failure Patients

BACKGROUND

Elevated red blood cell distribution width (RDW) predicts poor prognosis in patients with cardiovascular diseases. However, little is known about the association between RDW and outcomes after catheter ablation of atrial fibrillation (AF).

METHODS AND RESULTS

A total of 757 patients who underwent radiofrequency catheter ablation of AF were divided into heart failure (HF, n=79) and non-HF (n=678) groups; RDW was assessed as a predictor after catheter ablation in each. During a 22.3-month follow-up period, the baseline RDW in the HF group was greater in the recurrence group than in the non-recurrence group (14.5±2.0% vs. 13.5±0.9%, P=0.013). In contrast, no significant difference in RDW at baseline was found in the non-HF group between the recurrence and non-recurrence groups (13.3±0.8% vs. 13.2±0.8%, P=0.332, respectively). Multivariate analysis demonstrated that RDW (hazard ratio 1.20, 95% confidence interval 1.01-1.40, P=0.034) was an independent predictor of AF recurrence in the HF group. The cut-off values of RDW for the recurrence of AF and major adverse events in the HF group were 13.9% and 14.8%, respectively.

CONCLUSIONS

High RDW is an independent predictor for the recurrence of AF and major adverse events in patients with HF after catheter ablation. RDW is a potential noninvasive marker in AF patients complicated with HF. (Circ J 2016; 80: 627-638).

Feasibility and safety of uninterrupted dabigatran therapy in patients undergoing ablation for atrial fibrillation

OBJECTIVE

Uninterrupted oral warfarin strategy has become the standard protocol to prevent complications during catheter ablation (CA) for the treatment of atrial fibrillation (AF). However, little is known about the safety and efficacy of uninterrupted dabigatran therapy in patients undergoing CA for AF. Therefore, this study investigated the safety and efficacy of uninterrupted dabigatran therapy and compared the findings with those for uninterrupted warfarin therapy.

METHODS

Bleeding and thromboembolic events during the periprocedural period were evaluated in 363 consecutive patients who underwent CA for AF at Nagoya University Hospital, and received uninterrupted dabigatran (n=173) or uninterrupted warfarin (n=190) for periprocedural anticoagulation.

RESULTS

A total of 27 (7%) patients experienced either bleeding or thromboembolic complications. Major bleeding complications occurred in 2 (1%) patients in the dabigatran group (DG) and 2 (1%) patients in the warfarin group (WG). Eight (5%) patients in the DG and 9 (5%) patients in the WG experienced groin hematoma, a type of minor bleeding complication. Meanwhile, no patient in the DG and 1 (1%) in the WG developed cerebral ischemic stroke. Overall, there was no significant difference between the groups for any category. The activated partial thromboplastin time (APTT) independently predicted periprocedural complications in the DG.

CONCLUSION

Uninterrupted dabigatran therapy in CA for AF thus may be a safe and effective anticoagulant therapy, and appears to be closely similar to continuous warfarin; however, it is essential to pay close attention to the APTT values when using dabigatran during CA.

Efficacy and safety of apixaban in the patients undergoing the ablation of atrial fibrillation

INTRODUCTION

Apixaban, a factor Xa (FXa) inhibitor, is a new oral anticoagulant for stroke prevention in atrial fibrillation (AF). However, little is known about its efficacy and safety as a periprocedural anticoagulant therapy for patients who had undergone catheter ablation (CA) for AF.

METHODS AND RESULTS

We evaluated 342 consecutive patients who underwent CA for AF between April 2013 and March 2014 and received apixaban (n = 105) and warfarin (n = 237) for uninterrupted periprocedural anticoagulation. We retrospectively investigated the occurrence of bleeding and thromboembolic complications during the procedural period and compared them between the apixaban group (AG) and warfarin group (WG). Thromboembolic complications occurred in one (0.4%) patient in the WG. Major and minor bleeding complications occurred in one (1%) and four (4%) patients in the AG, and three (1%) and 12 (5%) patients in the WG. No significant difference in complications was observed between the AG and WG. Of importance, adverse event rates did not differ between the two groups after adjusting by a propensity score analysis. In preoperative tests of blood coagulation, there were significant differences in the prothrombin time, activated partial thromboplastin time, FXa activity, and prothrombin fragment 1 + 2 (F1+2) levels between the AG and WG.

CONCLUSION

The use of apixaban during the periprocedural period of AF ablation seemed as efficacious and safe as warfarin.

Clinical characteristics and predictors of super-response to cardiac resynchronization therapy: a combination of predictive factors

BACKGROUND

Patients with greater improvement of cardiac function after cardiac resynchronization therapy (CRT) implantation are identified as "super-responders." However, it remains unclear which kind of preimplant assessments could accurately predict outcomes after CRT. Thus, we aimed to examine the essential predicting factors for super-response to CRT, and to construct an accurate predictable model.

METHODS

We retrospectively analyzed the CRT patients who underwent implantation at Nagoya University Hospital. Super-responders are defined as those who show a relative reduction in left ventricular end-systolic volume ≥30% after 6 months of CRT.

RESULTS

Eighty patients (mean age, 67.8 ± 10.2 years) were included. Twenty-two patients received upgrading procedure to CRT implantation. Six months after the implantation, 29 patients (36%) were super-responders. Multiple logistic regression analysis shows that consistent right ventricular pacing with a previous device (odds ratio [OR] 7.28, 95% confidence interval [CI] 1.52-34.9; P = 0.013), lack of prior history of ventricular arrhythmia (OR 5.32, 95% CI 1.52-18.6; P = 0.009), and smaller left atrial diameter (LAD) (OR 0.92, 95% CI 0.86-0.98; P = 0.014) are independent predictors for CRT super-responders. The use of a combination of these predictive factors could increase the certainty with which a greater response to CRT is predicted and the presence of such a combination could improve prognosis.

CONCLUSION

Greater response to biventricular pacing occurs more frequently in patients with consistent right ventricular pacing, lack of prior history of ventricular arrhythmia, and smaller LAD. An association between patient background characteristics and a super-response to CRT was also identified.

Clinical usefulness of measuring prothrombin time and soluble fibrin levels in Japanese patients with atrial fibrillation receiving rivaroxaban

BACKGROUND

Rivaroxaban is currently used to prevent stroke in patients with atrial fibrillation. Measuring coagulation function may help clinicians to understand the effects of this drug and the associated risk of bleeding.

METHODS AND RESULTS

Rivaroxaban was given to 136 patients with non-valvular atrial fibrillation. Mean age was 74.5±9.0 years (men: 63.2%) and mean CHADS2 score (±SD) was 1.8±1.2. Prothrombin times (PTs) and plasma soluble fibrin (SF) levels were examined in 84 out of 136 patients at baseline and at least 2 weeks thereafter. In 48 patients we were able to collect blood at exact times, namely just before and 3h after rivaroxaban administration, corresponding to the trough and peak concentrations. Mean peak PT in 48 patients was 17.1±3.6s and median peak SF level was 1.46μg/mL. Multiple regression analysis showed that female sex, high brain natriuretic peptide, and high dose were independent factors prolonging the peak PT. Patients with peak PTs ≥20s experienced significantly more bleeding events. Among 29 of 46 patients newly treated with rivaroxaban without any previous anticoagulant, we examined coagulation function at the exact trough and peak times. In 29 patients, peak PT was significantly more prolonged than the baseline or trough PT (p<0.001 for both), whereas trough PT was comparable to the baseline PT. In contrast, both trough and peak SF levels in these newly treated patients were significantly reduced than at baseline (p=0.003 and p<0.001, respectively).

CONCLUSIONS

In Japanese patients with non-valvular atrial fibrillation receiving rivaroxaban, a prolonged peak PT (≥20s) could indicate increased risk of bleeding, and both trough and peak SF levels were reduced relative to baseline. PT and SF are both valuable measures of coagulation status in patients receiving rivaroxaban, regardless of prior anticoagulant history.

Acute improvement of left ventricular relaxation as a predictor of volume reduction after cardiac resynchronization therapy: a pilot study assessing the value of left ventricular hemodynamic parameter

BACKGROUND

Cardiac resynchronization therapy (CRT) improves cardiac function, but CRT recipients with advanced heart failure (HF) do not always respond well. Because the best parameters for the prediction of CRT response are not established, we investigated whether improvement of invasive left ventricular (LV) hemodynamic diastolic parameters could identify CRT responders.

METHODS

A total of 34 consecutive patients (age, 69 ± 9 years; 70% men) who received CRT devices for HF were assessed as to whether acute invasive hemodynamic parameters with and without CRT function could predict LV volume responders.

RESULTS

These patients demonstrated an improvement in LV dP/dtmax (11.1 ± 11.7%), LV dP/dtmin (4.6 ± 12.1%), and tau (3.7 ± 11.6%) by biventricular pacing. Nineteen patients (55%) were classified as CRT responders, which was defined by a >15% decrease in LV end-systolic volume (ESV) at the 6-month follow-up evaluation. The area under the receiver operator characteristic curve to detect CRT volume response was 0.93 for the shortening of tau, which was superior to any other hemodynamic parameter. The multivariate analysis revealed that this improvement in tau was the strongest predictive factor for identifying CRT volume responders. Of note, the magnitude of tau shortening during biventricular pacing was significantly correlated with the reduction in LVESV at the 6-month follow-up evaluation.

CONCLUSIONS

The extent of acute improvement in LV isovolumic relaxation time, as assessed by tau, was associated with favorable response to CRT. The assessment of invasive diastolic function could provide valuable information about CRT volume response.

Comparison of the change in the dimension of the pulmonary vein ostia immediately after pulmonary vein isolation for atrial fibrillation-open irrigated-tip catheters versus non-irrigated conventional 4 mm-tip catheters

INTRODUCTION

A difference in the lesion formation between open irrigated-tip (OITC) and non-irrigated 4-mm-tip catheters (NITC) may result in a difference in the dimension of the pulmonary vein (PV) ostia after PV isolation of atrial fibrillation (AF). This study evaluated the difference using intracardiac echocardiography (ICE) before and immediately after an extensive encircling PV isolation (EPVI) with an OITC and with an NITC.

METHODS AND RESULTS

We studied 100 consecutive patients (OITC group, 54; NITC group, 46) who received EPVI. Changes in the vessel, lumen, and wall thickness areas of the PVs were evaluated at the PV ostia by ICE. There were no significant differences in the baseline characteristics and acute success rate of the EPVI between the OITC and NITC groups. The energy delivered to achieve EPVI was higher in the OITC group than that in the NITC group (34,967 ± 13,222 J vs. 28,300 ± 10,614 J; p=0.01). After the ablation, the reduction in the vessel and lumen cross-sectional areas was significantly smaller in the OITC group than that in the NITC group (-9.05 ± 28.4 % vs. -21.2 ± 28.8 %, p<0.001; -8.76 % vs. -17.7 ± 26.9 %, p=0.003). The wall thickness area slightly decreased in the OITC group, but increased in the NITC group (-2.96 ± 38.4 % vs. 10.5 ± 76.6 %, p=0.591). During a median follow-up of 234 days, there was no significant difference in the AF recurrence after the initial ablation procedure between the two groups.

CONCLUSION

Greater PV ostial narrowing occurred with the NITC than OITC immediately after the EPVI. PV ostial wall edema was noted with only the NITC. These findings suggested that an OITC might reduce any acute PV narrowing and wall edema as compared with an NITC.

Serum albumin levels predict clinical outcomes in chronic kidney disease (CKD) patients undergoing cardiac resynchronization therapy

OBJECTIVE

A low level of serum albumin is common in chronic kidney disease (CKD) patients with heart failure (HF). Cardiac resynchronization therapy (CRT), a novel therapeutic option, improves cardiac performance in patients with severe HF. In addition, CKD has recently been found to be associated with outcomes after CRT; however, the associations of the serum albumin levels with adverse events and the long-term prognosis in CKD patients who have undergone CRT are unknown. In this study, we investigated whether the albumin levels can be used to the predict mortality rate and incidence of cardiovascular events in CKD patients treated with CRT.

METHODS

A retrospective chart review was conducted in 102 consecutive CKD patients receiving a CRT device for the treatment of advanced HF. The long-term outcomes following device implantation were assessed according to the albumin levels.

RESULTS

During a median follow-up of 2.6 years, 34 patients (33.3%) died and 66 patients (64.7%) experienced cardiovascular events. A Kaplan-Meier survival analysis revealed that the CKD patients with decreased albumin levels exhibited significantly higher rates of all-cause mortality and cardiovascular events, including hospitalization for progressive HF, than the CKD patients without hypoalbuminemia. Importantly, a multivariate Cox regression analysis of confounding factors showed a low serum albumin level to independently predict all-cause death and cardiovascular events.

CONCLUSION

Hypoalbuminemia independently predicts cardiac morbidity and mortality in CKD patients receiving CRT. Assessing the albumin levels provides valuable information regarding the long-term prognosis in CKD patients who undergo CRT.

Mechanisms with clinical implications for atrial fibrillation-associated remodeling: cathepsin K expression, regulation, and therapeutic target and biomarker

BACKGROUND

The cysteine protease cathepsin K (CatK) has been implicated in the pathogenesis of cardiovascular disease. We sought to determine the link between atrial fibrillation (AF) and plasma CatK levels and to investigate the expression of and therapeutic target for CatK in vivo and in vitro.

METHODS AND RESULTS

Plasma CatK and extracellular matrix protein peptides (intact procollagen type I of N-terminal propeptide; carboxyl-terminal telopeptide of type I collagen [ICTP]) were measured in 209 consecutive patients with AF (paroxysmal AF, 146; persistent AF, 63) and 112 control subjects. In addition, the regulation of CatK expression was investigated in vivo and vitro. Patients with AF had higher plasma CatK and ICTP levels than did control subjects. Patients with persistent AF had higher levels of plasma CatK and ICTP than did patients with paroxysmal AF. CatK was correlated with ICTP concentration and left atrial diameter in all subjects. In rabbits, superoxide production, CatK activity, fibrosis, and the levels of atrial tissue angiotensin II, angiotensin type 1 receptor, gp91phox, phospho-p38 mitogen-activated protein kinase, and CatK were greater in those with tachypacing-induced AF than in controls, and these changes were reversed with angiotensin type 1 receptor antagonist. Olmesartan and mitogen-activated protein kinase inhibitor decreased the CatK expression induced by angiotensin II in rat neonatal myocytes.

CONCLUSIONS

These data indicated that increased plasma CatK levels are linked with the presence of AF. Angiotensin type 1 receptor antagonist appears to be effective in alleviating atrial fibrosis in a rabbit AF model, partly reducing angiotensin type 1 receptor-p38mitogen-activated protein kinase-dependent and -independent CatK activation, thus preventing AF.

Clinical outcome of implantable cardioverter defibrillators with recalled and non-recalled leads in Japanese patients. Increased failure rate of the Sprint Fidelis lead

BACKGROUND

In recent years, there has been a series of recalls of popular implantable cardioverter defibrillators leads, and several reports have demonstrated an increasing rate of failure of such leads over time in Caucasian patients. However, little is known about the performance of these leads in Asian patients. The aim of this study was to investigate the rate of failure of the recalled leads and the characteristics as compared with non-recalled leads in Japanese patients.

METHODS AND RESULTS

A retrospective chart review was conducted in 214 patients (75 Sprint Fidelis, 8 Riata, and 131 Sprint Quattro leads) who underwent implantation and follow-up at Nagoya University Hospital. During the follow-up period, 14 Sprint Fidelis leads (19%) and 1 Riata lead (13%) failed, but no abnormality was found in the Sprint Quattro, non-recalled leads. Five patients (4 Sprint Fidelis and 1 Riata, 33% of lead failure patients) received inappropriate shocks. The 3-, 4-, and 5-year lead survival rates in Sprint Fidelis leads were 95.1% (95% confidence interval [CI]: 89.6%-100%), 89.8% (95% CI: 82.1%-97.6%), and 88.0% (95% CI: 79.6%-96.4%), respectively. A previous device implantation before Sprint Fidelis lead was the only significant predictor for lead fracture (hazard ratio, 5.33; 95% CI: 1.55-18.4; P=0.008).

CONCLUSIONS

The rate of Sprint Fidelis lead failure continues to increase over time in Japanese patients.  

Prospective evaluation of corrected QT intervals and arrhythmias after exposure to epirubicin, cyclophosphamide, and 5-fluorouracil in women with breast cancer

BACKGROUND

Corrected QT (QTc) interval prolongation can induce fatal arrhythmias such as torsade de pointes.

PATIENTS AND METHODS

To assess the characteristics of QTc intervals and arrhythmias in women with early breast cancer who received FEC100 adjuvant chemotherapy, electrocardiograms (ECGs) were recorded before and after each chemotherapy. Associations between QTc interval prolongation and single nucleotide polymorphisms (SNPs) of potassium channel genes were also investigated.

RESULTS

A total of 131 ECG records were obtained in 34 patients who received 153 cycles of FEC100. QTc intervals could be measured in 127 records. There was a significant trend toward QTc interval prolongation after each treatment, persisting through four cycles of chemotherapy (P < 0.001). Median QTc interval prolongations were 13, 11, 18, and 14 ms in the first through fourth cycles of chemotherapy, respectively. QTc intervals differed significantly between cycles 1 and 4 before treatment as well as after treatment (P < 0.05). A single supraventricular premature contraction was noted in 3 (2.3%) of the 131 cycles in 2 (5.9%) of the 34 patients. There was no significant association between QTc interval prolongation and SNPs of potassium channel genes.

CONCLUSION

This prospective study confirmed that FEC100 is associated with significant QTc interval prolongation in women with early breast cancer.

Relation of plasma catecholamine levels with pulse wave velocity in hypertensive patients compared with normotensive subjects

Although the circadian variation of catecholamine has been reported, that of the pulse wave velocity (PWV) has not. Brachial ankle (ba) PWV is associated with well-established indices of central stiffness. It is not known whether arterial stiffness is associated with catecholamine. The aim of the present study was to evaluate the changes in baPWV and those on the plasma epinephrine and norepinephrine levels in the morning and evening in hypertensive patients (HPs) and normotensive subjects (NSs). The baPWV and blood pressure (BP) were measured in 14 NSs (14 males, 39 ± 5 years) and 10 HPs (9 males and 1 female, 55 ± 13 years) at 06:00 h, noon, 18:00 h, and midnight, respectively. The plasma epinephrine and norepinephrine levels were measured in 14 NSs and 5 HPs at 06:00 h and 18:00 h, respectively. There was no significant difference in BPs at 06:00 h, noon, 18:00 h, and midnight in either NSs or HPs. The baPWV at 06:00 h was significantly lower than that at noon, 18:00 h, and midnight in NSs (P = 0.01, 0.04, and 0.0008, respectively). The plasma epinephrine and norepinephrine levels at 06:00 h were markedly lower than those at 18:00 h in NSs (P = 0.002 and 0.003, respectively). There were no significant changes in the baPWV of HPs at 06:00 h, noon, 18:00 h, or midnight. The plasma epinephrine and norepinephrine levels at 06:00 h were notably lower than those at 18:00 h in HPs (P = 0.004 and 0.01, respectively). Only NSs showed a significant reduction in the baPWV with a decrease in the plasma catecholamine levels in the morning, suggesting that the baPWV of NSs may be correlated with the variation of the plasma catecholamine levels.