Survival and Heart Failure Hospitalization in Patients With Cardiac Resynchronization Therapy With or Without a Defibrillator for Primary Prevention in Japan　- Analysis of the Japan Cardiac Device Treatment Registry Database.

BACKGROUND: Randomized control trials comparing the effectiveness of cardiac resynchronization therapy devices, with (CRT-D) or without (CRT-P) a defibrillator, are scarce in heart failure patients with no prior sustained ventricular tachyarrhythmias.Methods and Results:The Japan Cardiac Device Treatment Registry (JCDTR) has data for 2714 CRT-D and 555 CRT-P recipients for primary prevention with an implantation date between January 2011 and August 2015. Of these patients, follow-up data were available for 717. Over the mean follow-up period of 21 months, Kaplan-Meier curves of survival free of combined events for all-cause death or heart failure hospitalization (whichever came first) diverged between the CRT-D (n=620) and CRT-P (n=97) groups with a rate of 22% vs. 42%, respectively, at 24 months (P=0.0011). However, this apparent benefit of CRT-D over CRT-P was no longer significant after adjustment for covariates. With regard to mortality, including heart failure death or sudden cardiac death, there was no significant difference between the 2 groups. CONCLUSIONS: In patients without sustained ventricular tachyarrhythmias enrolled in the JCDTR, there was no significant difference in mortality between the CRT-D and CRT-P groups, despite a lower trend in CRT-D recipients. This study was limited by large clinical and demographic differences between the 2 groups.

Catheter ablation of atrial fibrillation in patients with severely impaired left ventricular systolic function.

Little is known about the outcome of catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) and a severely reduced left ventricular ejection fraction (LVEF). We aimed to clarify the effectiveness of catheter ablation of AF in patients with a severely low LVEF. This retrospective study included 18 consecutive patients with HF and an LVEF of ≤ 35 % who underwent catheter ablation of AF. We investigated the clinical parameters, echocardiographic parameters and the incidence of hospitalizations for HF. During a median follow-up of 21 months (IQR, 13-40) after the final procedure (9 with repeat procedures), 11 patients (61 %) maintained sinus rhythm (SR) (6 with amiodarone). The LVEF and NYHA class significantly improved at 6 months after the CA in 12 patients (67 %) who were in SR or had recurrent paroxysmal AF (from 25.8 ± 6.3 to 37.0 ± 11.7 %, P = 0.02, and from 2.3 ± 0.5 to 1.5 ± 0.7, P < 0.01, respectively) but not in patients who experienced recurrent persistent AF. The patients with SR or recurrent paroxysmal AF had significantly fewer hospitalizations for HF than those with recurrent persistent AF after the AF ablation (log-rank test; P < 0.01). Catheter ablation of AF improved the clinical status in patients with an LVEF of ≤ 35 %. A repeat ablation procedure and amiodarone were often necessary to obtain a favorable outcome.

Left atrial appendage flow velocity and time from P-wave onset to tissue Doppler-derived A' predict atrial fibrillation recurrence after radiofrequency catheter ablation.

BACKGROUND: Atrial fibrillation (AF) is associated with atrial remodeling. We investigate the abilities of preprocedural echocardiographic parameters reflecting atrial remodeling to predict AF recurrence after radiofrequency catheter ablation (RFCA) for paroxysmal AF (PAF). METHODS: Preprocedural echocardiographic parameters were measured during sinus rhythm in 105 patients with PAF undergoing RFCA. Electrical remodeling was assessed by the time from the onset of the P-wave to the peak A'-wave on the tissue Doppler imaging (PA-TDI), functional remodeling was assessed by the left atrial appendage flow velocity (LAAFV), and structural remodeling was assessed by the left atrial volume index (LAVI). PA-TDI, LAAFV, and LAVI values were divided into tertiles, and their abilities to predict AF recurrence were assessed using Cox regression analysis. RESULTS: AF recurrence occurred in 39/105 (37.1%) patients. After adjustment for confounders, the rate of AF recurrence was significantly higher in the highest tertile of PA-TDI compared with the lowest tertile (≥151.3 msec vs. <131.0 msec; hazard ratio [HR]: 2.477, 95% confidence interval [CI]: 1.031-5.950; P = 0.042), and in the lowest tertile of LAAFV compared with the highest tertile (<48.5 cm/sec vs. ≥64.9 cm/sec; HR: 2.680, 95% CI: 1.136-6.318; P = 0.024). The risk of AF recurrence was also higher in the highest tertile of LAVI (≥34.2 mL/m(2) ) compared with the lowest tertile, but this difference was not significant (HR: 2.146, 95% CI: 0.834-5.523; P = 0.113). CONCLUSIONS: LAAFV (reflecting functional remodeling) and PA-TDI (reflecting electrical remodeling) are independent predictors of AF recurrence after RFCA for PAF.

Impact of atrial remodeling on the outcome of radiofrequency catheter ablation of paroxysmal atrial fibrillation.

BACKGROUND: Both the left atrial volume index (LAVI) and estimated total atrial conduction time measured using tissue Doppler imaging of the atria (PA-TDI duration) are echocardiographic parameters reflecting atrial remodeling. We investigated their prognostic value for atrial tachyarrhythmia (AF/AT) recurrence after radiofrequency catheter ablation (RFCA) of paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: We analyzed the data for 100 consecutive patients with drug-refractory PAF who underwent RFCA. The correlation between the LAVI and PA-TDI was extremely weak (r=0.26, P<0.01). We categorized the patients into 4 groups based on the median LAVI and PA-TDI duration: group 1 (LAVI <29ml/m(2)/PA-TDI duration <143ms), group 2 (LAVI ≥29ml/m(2)/PA-TDI duration <143ms), group 3 (LAVI <29ml/m(2)/PA-TDI duration ≥143ms), and group 4 (LAVI ≥29ml/m(2)/PA-TDI duration ≥143ms). With a mean follow-up of 20.2±8.9 months after a single RFCA procedure, 60 patients (60%) were in sinus rhythm without any antiarrhythmic drugs. Multivariate analysis using a Cox proportional hazards model demonstrated that the group was an independent predictor of AF/AT recurrence after RFCA (P=0.0017). The patients in groups 2, 3, and 4 had a 4.0-fold (P=0.048), 6.8-fold (P=0.0034) and 10.9-fold (P=0.0001) increase, respectively, in the probability of recurrent AF/AT as compared with group 1. CONCLUSIONS: Preprocedural echocardiographic estimation of atrial remodeling was a useful predictor of AF/AT recurrence following a single RFCA of PAF.

Unusual "ratchet syndrome": spontaneous lead retraction after a generator exchange.

A 72-year-old female with idiopathic dilated cardiomyopathy underwent a generator exchange for a cardiac resynchronization therapy defibrillator with a full-pocket capsulectomy. The lead position after the operation was identical to that before the operation on the chest X-ray. After 4 months, a subacute exacerbation of her heart failure was caused by cardiac resynchronization therapy failure due to a dislodgement of the left ventricular lead. An aggressive adhesiotomy of the connective tissue around the leads made it possible for the lead to retract by a ratchet-like movement through the suture sleeve, so-called "ratchet syndrome", after the generator exchange.

Localized reentrant tachycardia in the aorta contiguity region mimicking perimitral atrial flutter in the context of atrial fibrillation ablation.

We describe a case with a focal atrial tachycardia (AT) masquerading as perimitral atrial flutter revealed after circumferential pulmonary vein antral isolation for atrial fibrillation. It was successfully terminated and became noninducible by a point ablation on the left atrial anterior wall (LAAW) near the mitral annulus in contact with the aortic root and on the left superior pulmonary vein-left atrial appendage ridge, without any linear ablation, using electroanatomical mapping and conventional precise mapping with a maximum amplified gain within the low-voltage area. The AT revealed in our case was an LAAW-aorta contiguity area-related AT.

Long-term results of a cardiovascular implantable electronic device wrapped with an expanded polytetrafluoroethylene sheet.

The use of an expanded polytetrafluoroethylene (ePTFE) sheet wrapping device for patients with pacemaker contact dermatitis is still controversial. This study aimed to retrospectively investigate the occurrence rate of allergies and other complications after implantation of a cardiovascular implantable electronic device (CIED) wrapped with an ePTFE sheet. A total of 4,497 procedures of CIED implantation were performed at our institution between January 1993 and April 2010. Among 19 patients who underwent implantation of an electronic cardiac device wrapped with an ePTFE sheet, device implantation was performed in 11 patients for secondary prevention of device contact sensitivity, in 7 patients for primary prevention of device contact sensitivity, and in 1 patient for avoiding over-sensing of myopotentials. During follow-up periods (mean 46 ± 34 months), there were no allergic or inflammatory reactions to components of the device or ePTFE itself. Among 11 patients with a device wrapped with an ePTFE sheet for secondary prevention, 5 patients completed device replacement due to battery depletion and 3 patients had infections from the device. Wrapping implantable devices with an ePTFE sheet is an effective way of preventing device sensitivity in patients who require CIED therapy. However, the risk of infection from the device should be taken into consideration.

Feasibility evaluation of a remote monitoring system for implantable cardiac devices in Japan.

The number of implanted cardiac devices has been growing steadily over the last several years. Systems to monitor device data remotely have been introduced with the goal of reducing follow-up burden for both patients and physicians. Since the introduction of telemedicine depends greatly on the situations that are unique to each country, the acceptance of cardiac device remote monitoring in Japan was analyzed.A total of 203 patients who had previously undergone cardiac device implantation were enrolled. The subjects were provided with a CareLink Monitor that performed interrogation and transmission of device data at home, and then the physicians reviewed the data via a website at one and 3 months after baseline visits. A total of 470 transmissions were made. Questionnaires were completed by subjects and physicians to evaluate acceptance, ease of use, and satisfaction with the system. More than 87% of the subjects felt the Monitor was easy to use and nearly all of the physicians were satisfied with the system. A majority of patients felt reassured by having their devices assessed from a remote location and preferred the decreased number of clinic visits that were possible when using the Monitor. The patients spent an average of 168.2 minutes per clinic visit, whereas follow-up time was reduced to 13.0 minutes by remote monitoring. Physician consultation time was reduced by 2.7 minutes.The CareLink Network was well accepted by both the patients and physicians. Underlying issues did emerge, but once they are overcome, the system appears to have great potential to improve the quality of care given by healthcare providers.

Successful catheter ablation and documentation of the activation and propagation pattern during a left atrial focal tachycardia in a patient with cor triatriatum sinister.

We report a case of an atrial tachycardia (AT) originating from the left atrium (LA) associated with cor triatriatum sinister. Electroanatomical mapping of the 2 subdivided chambers of the LA during the AT revealed a centrifugal activation pattern from the posterior wall of the accessory chamber near the left superior pulmonary vein. The propagation map on the CARTO system revealed that the AT wave front spread centrifugally over the "accessory chamber," turned around the edge of the membrane subdividing the LA, and then spread over the "main chamber." A single radiofrequency application successfully abolished the AT.

Image integration of three-dimensional cone-beam computed tomography angiogram into electroanatomical mapping system to guide catheter ablation of atrial fibrillation.

AIMS: To evaluate the feasibility of integrating three-dimensional images created by intra-procedural cone-beam computed tomography (CBCT) into three-dimensional electroanatomical maps (EAM) and compare its accuracy with that of pre-procedural multi-slice CT (MSCT). METHODS AND RESULTS: In 24 patients with drug-refractory atrial fibrillation (AF), atriography using CBCT with pulmonary arterial contrast injection was performed at the beginning of the AF ablation procedure. Intra-procedural CBCT images and pre-procedural MSCT images were individually imported into the EAM system and compared their integration accuracy (point-to-surface distance) of each image and EAM just before ablation. The CBCT images were assessed qualitatively and quantitatively in comparison with MSCT images. All CBCT images were graded as optimal or useful in delineating the left atrium-pulmonary vein anatomy and were successfully integrated with the EAM. Overall, integration accuracy was similar for CBCT and MSCT. However, in 11 patients, the MSCT was performed 5 or more days prior to EAM, resulting in significantly shorter surface-to-point distance in CBCT than that in MSCT (P = 0.047). Radiation exposure with CBCT was significantly reduced compared with MSCT (P < 0.001). CONCLUSION: It is feasible to integrate CBCT image into EAM, and the integration is relatively accurate. Intra-procedural atriography by CBCT may replace pre-procedural MSCT as the imaging source for image integration.

Prevalence and persistence of depression in patients with implantable cardioverter defibrillator: a 2-year longitudinal study.

BACKGROUND: It is unclear whether depression persists in patients with implantable cardioverter defibrillators (ICDs). We evaluated the prevalence and persistence of depression in ICD patients over a 2-year period. METHODS: The study included 90 consecutively hospitalized patients. Patients underlying heart disease was 24% coronary artery disease, 29% idiopathic dilated cardiomyopathy, 24% hypertrophic cardiomyopathy, 13% idiopathic VF/long QT syndrome and miscellaneous conditions 11%. A secondary indication for ICD implantation was present in 20 patients. All patients completed the Zung Self-Rating Depression Scale (SDS) at study baseline and at the their routine follow-up visit 2 years after the baseline questionnaire. Delivery of ICD therapies was tracked throughout the 2 years. RESULTS: Depression, indicated by a Zung SDS index score exceeding 60, was present in 29 (32%) of patients at study baseline. Depression was present in 11/51 (21%) patients scheduled to undergo ICD implantation, 2/2 (100%) patients whose device was upgraded to a CRT-D, 3/14 (21%) patients who had undergone pulse generator replacement, 7/14 (50%) patients who experienced electrical storm and 6/9 (66%) patients hospitalized with acute decompensated heart failure. NYHA functional class III was significantly associated with depression at baseline (HR 6.7, 95% CI 1.68-27.2, p = 0.0007). No differences were noted for female gender, demographics, ß-blocker use, or LVEF ≤35% (p = ns). Depression was present in 25 (28%) of patients at 2 years follow-up, persisting in 21 (72%) of patients whose Zung SDS scores were elevated at baseline. The median time from ICD shock therapy to completion of the 2 year questionnaire was 9 months (range, 1-22). Patients who were depressed (9/25, 36%) experienced more shocks than non-depressed patients (6/65, 9%) after 2 years (p = 0.002). CONCLUSIONS: Depression is not uncommon among patients who meet criteria for ICD implantation and persists over time particularly when functional status is impaired. Depression is associated with a higher incidence shock therapy.

Gender difference in arrhythmic occurrences in patients with nonischemic dilated cardiomyopathy and implantable cardioverter-defibrillator.

Previous studies indicated that women were less likely to experience ventricular arrhythmia recurrence than men among patients with coronary artery disease and implantable cardioverter defibrillator (ICD). However, it is not clear whether the risk for ventricular tachyarrhythmia is gender-dependent in patients with nonischemic dilated cardiomyopathy. This study included 173 consecutive nonischemic dilated cardiomyopathy patients with a left ventricular ejection fraction of <45% (122 men and 51 women), who received ICD therapy between 1990 and 2008. The average follow-up period was 33 +/- 28 months. There was no significant difference in event-free rates of appropriate ICD therapy between genders for all patients (P = 0.15) and by indication of ICD (primary prevention: P = 0.43, secondary prevention: P = 0.24). There was also no significant difference in event-free rates of electrical storm between genders (P = 0.17). In high-risk patients with nonischemic dilated cardiomyopathy who received ICD, there was no gender difference in the incidence of appropriate ICD therapy or electrical storm.

Targeted endomyocardial biopsy using electroanatomical voltage mapping in the early stage of arrhythmogenic right ventricular cardiomyopathy.

Endomyocardial biopsy (EMB) is useful for making a diagnosis of cardiomyopathy. However, the sensitivity of conventional EMB specimens from the interventricular septum is low in arrhythmogenic right ventricular cardiomyopathy (ARVC), especially in the early stage, because of the limited location of the affected tissue. Therefore, it is important to be able to target only the affected tissue in order to improve the sensitivity of the EMB, especially in the early stage of ARVC. A significant correlation between the low voltage areas identified by the electroanatomical voltage mapping (EVM) and abnormal findings from the EMB in ARVC has been reported. We describe an innovative strategy for performing EMB, using EVM to identify the local affected area and to perform a selective EMB from that area.

Impact of renal dysfunction on appropriate therapy in implantable cardioverter defibrillator patients with non-ischaemic dilated cardiomyopathy.

AIMS: To examine the effect of renal dysfunction on the occurrence of life-threatening ventricular arrhythmia in patients with non-ischaemic dilated cardiomyopathy and implantable cardioverter defibrillator (ICD). METHODS AND RESULTS: Subjects were 274 consecutive patients with non-ischaemic dilated cardiomyopathy who received ICD implantation. Estimated glomerular filtration rate (eGFR) was calculated using the modification of diet in renal disease formula. Renal dysfunction was defined as eGFR <60 mL/min/1.73 m(2). Differences in survival, appropriate ICD therapy and electrical storm in patients with and without renal dysfunction were compared. The effect of worsening renal function (decrease of eGFR of at least 15 mL/min/1.73 m(2) within 1 year) on appropriate ICD therapy was also evaluated. There was a higher incidence of appropriate ICD therapy in patients with eGFR <60 mL/min/1.73 m(2) than in those with eGFR >or=60 mL/min/1.73 m(2) (P = 0.0001). Patients with eGFR <60 mL/min/1.73 m(2) also showed a significantly higher rate of electrical storm (P = 0.003). Renal dysfunction with eGFR <60 mL/min/1.73 m(2) was an independent predictor of appropriate ICD therapy (HR 1.85, 95% CI 1.24-2.77, P = 0.003). Patients with worsening renal function within 1 year after implantation were at increased risk for appropriate ICD therapy (HR 2.50, 95% CI 1.39-4.52, P = 0.002). CONCLUSION: Our results suggested that renal dysfunction is an independent risk factor for occurrence of life-threatening arrhythmia even in high-risk patients with non-ischaemic dilated cardiomyopathy.

Transverse shifting of the esophagus according to the patient's position helped achieve a safe and successful pulmonary vein isolation procedure.

Although the incidence of causing an atrioesophageal fistula during pulmonary vein isolation is very low, this type of injury results in a very high mortality rate. To prevent this complication, keeping a safe distance from the esophagus to the ablation lesion is a simple but safe method. We report a case in which we were able to shift the position of the esophagus by positioning the patient in a lateral posture in order to keep the esophagus at a safe distance from the pulmonary vein antrum, resulting in performance of a safe and successful pulmonary vein antrum isolation.

Successful radiofrequency catheter ablation of atrial fibrillation late after modified Fontan operation.

The mechanisms responsible for atrial fibrillation (AF) in post-operative Fontan patients are unclear, and the role of catheter ablation for treating AF is not well defined. We present a case of an 18-year-old woman who experienced drug-resistant paroxysmal AF late after the Fontan operation. We eliminated the AF by the radiofrequency catheter ablation of atrial substrates with complex fractionated atrial electrograms (CFAEs). The patient remains on anti-arrhythmic therapy and has not experienced any recurrence since the catheter ablation. Right atrial substrate modification via a CFAE-targeted catheter ablation might be an adjunct therapeutic option for selected post-Fontan patients with AF.

Prognostic significance of nonsustained ventricular tachycardia in patients receiving cardiac resynchronization therapy for primary prevention: Analysis of the Japan cardiac device treatment registry database.

Background: Whether nonsustained ventricular tachycardia (NSVT) is a marker of increased risk of sustained ventricular tachyarrhythmias (VTAs) remains to be established in patients receiving cardiac resynchronization therapy with a defibrillator (CRT-D) for primary prevention. Methods: Among the follow-up data of the Japan cardiac device treatment registry (JCDTR) with an implantation date between January 2011 and August 2015, information regarding a history of NSVT before the CRT-D implantation for primary prevention had been registered in 269 patients. Outcomes were compared between two groups with and without NSVT: NSVT group (n = 179) and No NSVT group (n = 90). Results: There was no significant difference with regard to age, gender, and NYHA class between the two groups. Left ventricular ejection fraction (LVEF) was 25.6% in the NSVT group and 28.0% in the No NSVT group (P = .046). The rate of appropriate therapy at 24 months was 26.0% and 18.4% in the NSVT and No NSVT groups (P = .22), respectively. Survival free from heart failure death was reduced in the NSVT group, as compared with the No NSVT group, with the rate of 90.2% vs 97.2% at 24 months (P = .030). A multivariate analysis identified a history of NSVT, anemia, and no use of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin-receptor blocker (ARB) as predictors of heart failure death. Conclusions: NSVT appears to be a surrogate marker of severe heart failure rather than a substrate for subsequent sustained VTAs in patients with CRT-D for primary prevention.

Inappropriate implantable cardioverter defibrillator shocks-incidence, effect, and implications for driver licensing.

PURPOSE: Patients with implantable cardioverter defibrillators (ICDs) have an ongoing risk of sudden incapacitation that may cause traffic accidents. However, there are limited data on the magnitude of this risk after inappropriate ICD therapies. We studied the rate of syncope associated with inappropriate ICD therapies to provide a scientific basis for formulating driving restrictions. METHODS: Inappropriate ICD therapy event data between 1997 and 2014 from 50 Japanese institutions were analyzed retrospectively. The annual risk of harm (RH) to others posed by a driver with an ICD was calculated for private driving habits. We used a commonly employed annual RH to others of 5 in 100,000 (0.005%) as an acceptable risk threshold. RESULTS: Of the 4089 patients, 772 inappropriate ICD therapies occurred in 417 patients (age 61 ± 15 years, 74% male, and 65% secondary prevention). Patients experiencing inappropriate therapies had a mean number of 1.8 ± 1.5 therapy episodes during a median follow-up period of 3.9 years. No significant differences were found in the age, sex, or number of inappropriate therapies between patients receiving ICDs for primary or secondary prevention. Only three patients (0.7%) experienced syncope associated with inappropriate therapies. The maximum annual RH to others after the first therapy in primary and secondary prevention patients was calculated to be 0.11 in 100,000 and 0.12 in 100,000, respectively. CONCLUSIONS: We found that the annual RH from driving was far below the commonly cited acceptable risk threshold. Our data provide useful information to supplement current recommendations on driving restrictions in ICD patients with private driving habits.

Correlation between left atrial appendage morphology and flow velocity in patients with paroxysmal atrial fibrillation.

AIMS: Reduction of left atrial appendage (LAA) flow velocity (FV) is a risk factor for thrombus formation and increases the risk of stroke in patients with atrial fibrillation (AF). Furthermore, LAA morphology is correlated with stroke in patients with AF. The aim of this study was to correlate LAAFV with LAA morphology in patients with AF. METHODS AND RESULTS: We studied 96 patients (age 59.0 ± 10.2 years, 75% male) referred for radiofrequency catheter ablation for paroxysmal AF. All patients underwent computed tomography (CT) and transthoracic and transoesophageal echocardiography during sinus rhythm. LAA morphology was classified as one of the four types (chicken wing, windsock, cactus, and cauliflower) on CT images. There were significant differences in LAAFV among LAA morphologies (chicken wing 73.7 ± 21.9 cm/s, windsock 61.9 ± 19.6 cm/s, cactus 55.3 ± 14.1 cm/s, cauliflower 52.7 ± 18.1 cm/s, P = 0.008). Post hoc multiple comparisons showed that LAAFV was higher in patients with chicken wing than in those with cactus (P = 0.006, vs. chicken wing) and cauliflower (P = 0.006, vs. chicken wing), but not with windsock (P = 0.102). After adjustment for clinical and LAA anatomical covariates (orifice area, volume, and trabeculation), multiple linear regression analyses revealed that LAA morphology was an independent determinant of LAAFV [chickens wing: standardized partial regression coefficients (ß) = 0.317, P = 0.0014; windsock: ß = 0.303, P = 0.038]. CONCLUSION: LAA morphology is a significant determinant of LAAFV, suggesting an underlying mechanism for the association between LAA morphology and embolic events.