Introduction: Reliable automatic pacing threshold determination functions offer a reduced follow-up examination time and safe remote monitoring. Further, the success rate and accuracy of the automatic pacing threshold determination function have not been sufficiently clarified. Methods: We evaluated 456 patients (male/female: 269/187, age: 70.4±13.3 years, pacemakers/defibrillators: 341/115) with cardiac implantable devices that had an automatic pacing threshold measurement function (the atrium and ventricle/ ventricle only: 298/158). We measured their pacing thresholds with both the automatic and manual methods at periodic device examination visits. Patients who had a high threshold (>4.0V/0.4ms) or out-of-range lead impedance (>2000 or <200Ω) were excluded from the analysis. Results: An automatic pacing threshold was obtained successfully in 206/274 (75.2%) patients in the atrium and in 392/443 (88.5%) in the ventricle. The automatic pacing threshold differed from the manual threshold by more than 1.0mV at the same pulse width in 12 (4.0%) patients in the atrium and in 5 (1.1%) in the ventricle. The success rate of the automatic pacing threshold determination differed depending on which generator manufacturer was used. The success rate for each manufacturer (Medtronic, St. Jude Medical, Biotronik and Sorin) was 167/173 (96.5%), 9/64 (14.1%), 30/37 (81.1%), and 0/0 in the atrium, and 223/224 (99.6%), 79/102 (77.5%), 68/85 (80.0%), and 22/32 (68.8%) in the ventricle, respectively. Regarding the success rate, Medtronic devices were superior to the others in both the atrium and ventricle (P<0.001-P=0.039). St. Jude Medical devices were inferior to the others in the atrium (p<0.001). There were no other significant factors affecting the success rate. The correlation between the pacing threshold measured by the automatic method and that by the manual method was significant in the atrium (r=0.558, P<0.001) and ventricle (r=0.779, P<0.001). Conclusions: The success rate of the automatic pacing threshold determination depended on which generator manufacturer was used. The measurable threshold values using the automatic method were acceptably correlated with those measured by the manual method.
Abstract Aims The MADIT‐ICD benefit score is used to stratify the risk of life‐threatening arrhythmia and non‐arrhythmic mortality. We sought to develop an implantable cardioverter defibrillator (ICD) benefit‐prediction score for Japanese patients with ICDs. Methods Patients who underwent ICD implantation as primary prophylaxis were retrospectively enrolled. Based on their MADIT‐ICD benefit scores, we developed a modified MADIT‐ICD benefit score adapted to the Japanese population. The primary endpoints were appropriate ICD therapy and all‐cause death without appropriate ICD therapy (non‐arrhythmic death). We used the Fine and Gray multivariate model and Cox proportional hazard regression to identify factors for adjusting the MADIT‐ICD benefit–risk score specifically for the Japanese population. The scoring points for the original MADIT‐ICD benefit score were adjusted to optimal points based on the multivariate analysis results in the population. Results The study enrolled 167 patients [age, 61.9 ± 12.3 years; male individuals, 138 (82.6%); cardiac resynchronization therapy, 73 (43.7%); ischaemic cardiomyopathy, 53 (31.7%)]. Fourteen patients received anti‐tachycardia pacing (ATP) therapy, and 23 received shock therapy as the initial appropriate ICD therapy. Non‐arrhythmic deaths occurred in 37 patients. The original MADIT‐ICD benefit score could not stratify non‐arrhythmic mortality in the Japanese population. The patients were reclassified into three groups according to the modified MADIT‐ICD benefit score. The modified MADIT‐ICD benefit score could effectively stratify the incidence of appropriate ICD therapy and non‐arrhythmic mortality. In the highest‐benefit group, the 10 year cumulative rates of appropriate ICD therapy and non‐arrhythmic mortality were 56.8% and 12.9%, respectively ( P < 0.01). In the intermediate‐benefit group, these rates were 20.2% and 40.2% ( P = 0.01). In the lowest‐benefit group, the incidence of non‐arrhythmic deaths was 68.1%, and no patient received appropriate ICD therapy. Conclusions The modified MADIT‐ICD benefit score may be useful for stratifying ICD candidates in the Japanese population.
Patient-reported outcomes of implantable cardioverter defibrillator (ICD), such as those with shock anxiety, have emerged as important endpoints that are related to quality of life (QOL), but they have not been well studied in a sample of the Japanese population. Therefore, we prospectively examined changes in shock anxiety in a large sample of Japanese patients with an ICD.We recruited 214 consecutive patients with an ICD who visited the outpatient clinic. At registration and 12 months later, all patients completed the Florida Shock Anxiety Scale (FSAS) questionnaire to allow us to examine changes in shock anxiety over the course of the first year after registration.During the 12-month follow-up period, 10.5% of the patients received ICD shock therapy. Female sex, secondary prevention, and experience of ICD shock therapy were associated with high FSAS scores at registration. The FSAS scores in both patients with appropriate and inappropriate shock were significantly higher at the 12-month follow-up interval than at registration, and there was no significant difference in the extent of changes in FSAS scores (Δ = 5.2 ± 5.1 and Δ = 6.3 ± 9.9, respectively, P = 0.62).Female sex, secondary prevention, and experience of ICD shock therapy are important risk factors affecting shock anxiety in Japanese patients. Attention should be paid to the after-effects of ICD shock in these patients, regardless of the shock type, with particular attention to women and patients who require secondary prevention.
Abstract Funding Acknowledgements Type of funding sources: None. Aim The purpose of this study was to evaluate the association of RV function and appropriate therapy of ICD.Methods: This study was a single-center retrospective cohort study. Consecutive patients who underwent ICD implantation for any diseases were enrolled except for non-dilated phase hypertrophic cardiomyopathy and channelopathy. Transthoracic echocardiographic parameters including left ventricular ejection fraction (LVEF), RV basal diameter, RV end-diastolic area, and right ventricular fractional area change (RVFAC) were evaluated. RV systolic dysfunction was defined as RVFAC <35%. Cox regression analysis was used to analyze the effects of those parameters on appropriate ICD therapy after the implantation. Results In total, 151 patients (60.9 ± 13.6 years, 117 males) consisting of 67 old myocardial infarction, 34 dilated cardiomyopathy, 19 cardiac sarcoidosis, and 31 others were enrolled. Eighty patients received an ICD as a secondary prophylaxis. Mean LVEF and RVFAC were 37.8 ± 13.9% and 33.2 ± 10.8%, respectively. RV systolic dysfunction was present in 86 (57.0%) patients, which was significantly associated with ICD therapy (odds ratio 2.313; 95% confidence interval 1.067-5.014; P = 0.034) according to a univariate analysis. There was no correlation between RVFAC and LVEF (correlation coefficient =0.064). Regarding the subjects LVEF > 35%, RV systolic dysfunction was an independent predictor of ICD therapy in a multivariate analysis. Conclusion RV systolic dysfunction was independently associated with increased ICD therapy despite of relatively preserved LVEF.
Background: The association between atrial fibrillation (AF) detected by implanted cardiac implantable electronic devices (CIEDs) and the incidence of embolic stroke has been reported. However, the cut-off value of new-onset AF duration detected by CIEDs for embolic stroke is still unknown. In previous studies regarding the cut-off value of AF duration, patients who had a history of AF or had received anticoagulant therapies were also included. Therefore, the solo effect of AF on the risk of embolic stroke cannot be reliably evaluated on these studies. The aim of this study is to identify the incidence of embolic stroke in Japanese patients with a CIED and examine the cut-off value of AF duration detected by CIEDs as a risk factor for embolic stroke. Methods: We retrospectively analyzed the database of our CIEDs clinic. Every 6 months, AF events were checked by CIEDs. Patients who had a history of AF or had received anticoagulant therapies before and after a CIED implantation were excluded. We examined the characteristics and incidence of embolic stroke and investigated the relationship between new-onset AF detected by CIEDs and the incidence of embolic stroke. Results: We enrolled 710 consecutive patients who were followed-up at our CIED clinic. We excluded 360 patients who had a history of AF or had received anticoagulant therapies. Finally, 350 patients (follow-up period, 75±58 months; age, 70±16 years) were included in this study. During the follow-up period, 24 patients (6.9%) had embolic stroke. Receiver-operating characteristic curve analysis confirmed that 30 seconds was the best cut-off value of AF duration detected by CIEDs for embolic stroke (AUC = 0.72). Multivariate analysis demonstrated that independent predictors for embolic stroke were left atrial diameter ≥40mm (p=0.019), new-onset AF ≥ 30 seconds (p = 0.0016). Conclusion: AF episodes lasting for ≥ 30 seconds was the risk factor of embolic stroke. We should evaluate AF burden carefully in this population.
Abstract Background We analyzed the influence of the QRS duration (QRSd) to LV end‐diastolic volume (LVEDV) ratio on cardiac resynchronization therapy (CRT) outcomes in heart failure patients classified as III/IV per the New York Heart Association (NYHA) and with small body size. Hypothesis We proposed the hypothesis that the QRSd/LV size ratio is a better index of the CRT substrate. Methods We enrolled 114 patients with advanced heart failure (NYHA class III/IV, and LV ejection fraction >35%) who received a CRT device, including those with left bundle branch block (LBBB) and QRSd ≥120 milliseconds ( n = 60), non‐LBBB and QRSd ≥150 milliseconds ( n = 30) and non‐LBBB and QRSd of 120−149 milliseconds ( n = 24). Results Over a mean follow‐up period of 65 ± 58 months, the incidence of the primary endpoint, a composite of all‐cause death and hospitalization for heart failure, showed no significant intergroup difference (43.3% vs. 50.0% vs. 37.5%, respectively, p = .72). Similarly, among 104 patients with QRSd/LVEDV ≥ 0.67 ( n = 54) and QRSd/LVEDV < 0.67 ( n = 52), no significant differences were observed in the incidence of the primary endpoint (35.1% vs. 51.9%, p = .49). Nevertheless, patients with QRSd/LVEDV ≥ 0.67 showed better survival than those with QRSd/LVEDV < 0.67 (14.8% vs. 34.6%, p = .0024). Conclusion Advanced HF patients with a higher QRSd/LVEDV ratio showed better survival in this small‐body–size population. Thus, the risk is concentrated among those with a larger QRSd, and patients with a relatively smaller left ventricular size appeared to benefit from CRT.
