Two-Year Outcomes of Primary Prophylactic Use of Defibrillators for Ischemic and Non-Ischemic Cardiomyopathy　- Propensity Score-Matched Analysis From the Nippon Storm Study.

BACKGROUND: In 2016, the DANISH study reported negative results regarding the efficacy of implantable cardioverter-defibrillators (ICDs) in patients with non-ischemic cardiomyopathy (NICM) and reduced left ventricular ejection fraction (LVEF). In this study we determined the efficacy of using ICDs for primary prophylaxis in patients with NICM.Methods and Results: We selected 1,274 patients with underlying cardiac disease who were enrolled in the Nippon Storm Study. We analyzed the data of 451 patients with LVEF ≤35% due to NICM or ischemic cardiomyopathy (ICM) who underwent ICD implantation for primary prophylaxis (men, 78%; age, 65±12 years; LVEF, 25±6.4%; cardiac resynchronization therapy, 73%; ICM, 33%). After propensity score matching, we compared the baseline covariates between groups: NICM (132 patients) and ICM (132 patients). The 2-year appropriate ICD therapy risks were 27.7% and 12.2% in the NICM and ICM groups, respectively (hazard ratio, 0.390 [95% confidence interval, 0.218-0.701]; P=0.002). CONCLUSIONS: This subanalysis of propensity score-matched patients from the Nippon Storm Study revealed that the risk of appropriate ICD therapy was significantly higher in patients with NICM than in those with ICM.

Effectiveness of Implantable Cardioverter Defibrillator in Patients With Non-Ischemic Heart Failure With Systolic Dysfunction　- Subanalysis of the Nippon Storm Study.

BACKGROUND: The prospective observational Nippon Storm Study aggregated clinical data from Japanese patients receiving implantable cardioverter-defibrillator (ICD) therapy. This study investigated the usefulness of prophylactic ICD therapy in patients with non-ischemic heart failure (NIHF) enrolled in the study.Methods and Results: We analyzed 540 NIHF patients with systolic dysfunction (left ventricular ejection fraction <50%). Propensity score matching was used to select patient subgroups for comparison; 126 patients were analyzed in each of the primary (PP) and secondary (SP) prophylaxis groups. The incidence of appropriate ICD therapy during follow-up in the PP and SP groups was 21.4% and 31.7%, respectively (P=0.044). The incidence of electrical storm (ES) was higher in SP than PP patients (P=0.024). Cox proportional hazard analysis revealed that increased serum creatinine in SP patients (hazard ratio [HR] 1.18; 95% confidence interval [CI] 1.02-1.33; P=0.013) and anemia in PP patients (HR 0.92; 95% CI 0.86-0.98; P=0.008) increased the likelihood of appropriate ICD therapy, whereas long-lasting atrial fibrillation in PP patients (HR, 0.64 [95% CI, 0.45-0.91], P=0.013) decreased that likelihood. CONCLUSIONS: In propensity score-matched Japanese NIHF patients, the incidence of appropriate ICD therapy and ES was significantly higher in SP than PP patients. Impaired renal function in SP patients and anemia in PP patients increased the likelihood of appropriate ICD therapy, whereas long-lasting atrial fibrillation reduced that likelihood in PP patients.

High platelet reactivity is a predictor of left ventricular remodelling in patients with acute myocardial infarction.

AIMS: Acute myocardial infarction (AMI) is associated with left ventricular remodelling (LVR), which leads to progressive heart failure. Platelets play a pivotal role in promoting systemic and cardiac inflammatory responses during the complex process of myocardial wound healing or repair following AMI. This study aimed to investigate the impact of platelet reactivity immediately after primary percutaneous coronary intervention (PCI) on LVR in AMI patients with ST-segment (STEMI) and non-ST-segment elevation (NSTEMI). METHODS AND RESULTS: This prospective, single-centre, observational study included 182 patients with AMI who underwent primary PCI (107 patient with STEMI and 75 patients with NSTEMI). Patients were administered a loading dose of aspirin plus prasugrel before the procedure, and platelet reactivity was assessed using the VerifyNow P2Y12 assay immediately after PCI. Echocardiography was performed before discharge and during the chronic phase (8 ± 3 months after discharge). LVR was defined as a relative ≥20% increase in left ventricular end-diastolic volume index (LVEDVI). LVR in chronic phase was found in 34 patients (18.7%) whose platelet reactivity was significantly higher than those without LVR (259.6 ± 61.5 and 213.1 ± 74.8 P2Y12 reaction units [PRU]; P = 0.001). The occurrence of LVR did not differ between patients with STEMI and patients with NSTEMI (21.5% and 14.7%; P = 0.33). The optimal cut-off value of platelet reactivity for discriminating LVR was ≥245 PRU. LVEDVI significantly decreased at chronic phase in patients without high platelet reactivity (<245 PRU) (from 49.2 ± 13.5 to 45.4 ± 15.8 mL/m2 ; P = 0.02), but not in patients with high platelet reactivity (≥d245 PRU) (P = 0.06). Multivariate logistic analysis showed that high platelet reactivity was an independent predictor of LVR after adjusting for LVEDVI before discharge (odds ratio, 4.13; 95% confidence interval, 1.85-9.79). CONCLUSIONS: High platelet reactivity measured immediately after PCI was a predictor of LVR in patients with AMI during the chronic phase. The role of antiplatelet therapy on inflammation in the myocardium is a promising area for further research.

Electrical Storm as an Independent Mortality Risk in Patients with Preserved or Moderately Reduced Left Ventricular Function.

Electrical storm (ES), defined by 3 or more occurrences of ventricular arrhythmias within 24 hours, has been shown to be associated with an increased risk of mortality; however, detailed information remains lacking. We aimed to examine the incidence and determinants of ES and its impact on mortality in patients enrolled in the nationwide implantable cardioverter-defibrillator (ICD) registry.We studied 1,256 patients (age 65 ± 12 years) who had structural heart disease with an ICD. The patients were classified into reduced ejection fraction (EF < 35%; 657 (52%) patients) and preserved or moderately reduced EF (EF ≥ 35%; 599 (48%) patients).ES occurred in 49 (7%) and 36 (6%) patients in the EF < 35% and EF ≥ 35% groups (log-rank P = 0.297) during the median follow-up of 2.3 years. ICD with resynchronization therapy was associated with a lower incidence of ES in patients with EF < 35%. Non-ischemic heart disease and diuretics were associated with ES in patients with EF ≥ 35%. During the follow-up, 10/49 (20%) patients with ES and 80/608 patients (13%) without ES died in patients with EF < 35%, while 7/36 (19%) patients with ES and 38/563 patients (7%) without ES died in those with EF ≥ 35%. We have created 4 Cox multivariate models. All models showed approximately 2-fold higher hazard ratios in patients with EF ≥ 35% compared to EF < 35%.Our study showed that the determinants of ES differed between EF < 35% and EF ≥ 35%. The impact of ES for mortality was numerically higher in EF ≥ 35% than in EF < 35%, although a significant interaction was not detected.

Anti-tachycardia pacing for non-fast and fast ventricular tachycardias in individual Japanese patients: From Nippon-storm study.

BACKGROUND: Anti-tachycardia pacing (ATP) delivered from an implantable device is a useful tool to terminate ventricular tachycardia (VT). But its real-world efficacy for those patients having multiple VTs with varying VT rates has not been fully studied. METHODS: Using the Nippon-storm study database, efficacy of patient-by-patient basis ATP programing for Japanese patients having both non-fast (120-187 bpm) and fast VT (≥188 bpm) was assessed. According to the useful criteria of ≥50% success termination by ATP, patients were divided into three subgroups; success ≥50% for both non-fast and fast VT (both useful), ≥50% only for non-fast VT (non-fast VT useful), or ≥50% for neither non-fast nor fast VT (neither useful). RESULTS: During a median follow-up of 28 months, ATP terminated 184 of the 203 non-fast VT episodes (91%) and 86 of the 113 fast VT episodes (76%) in all 41 patients. In the patient-by-patient analysis, efficacy of ATP was not different between non-fast and fast VT in most of the patients (36/41 = 88%); 32 patients were in the both useful and four other patients in the neither useful. Neither ischemic nor non-ischemic structural heart disease was associated with the ATP efficacy, whereas LVEF more than 37.0% and non-prescribed amiodarone were characteristics of the patients classified into the both useful. CONCLUSIONS: ATP well terminated both non-fast and fast VT occurring in individual Japanese patients with various structural heart diseases in the real-world device treatment and this finding further supports ATP programing for all device tachycardia detection zones in most patients with multiple VTs.

Comparison of 2-year outcomes between primary and secondary prophylactic use of defibrillators in patients with coronary artery disease: A prospective propensity score-matched analysis from the Nippon Storm Study.

BACKGROUND: The Nippon Storm Study was a prospective observational study designed to gather clinical data on implantable cardioverter-defibrillator (ICD) therapy in Japanese patients. OBJECTIVE: The purpose of this subanalysis was to compare the incidence of ICD therapy in patients with left ventricular dysfunction owing to coronary artery disease (CAD) for primary and secondary prophylaxis of sudden cardiac death. METHODS: We analyzed data of 493 patients with CAD and ICDs (men, 87%; age, 68 ± 10 years; left ventricular ejection fraction, 36% ± 13%; primary prophylaxis, 36%). All patients were followed up for at least 2 years. Propensity score matching was used to select patient subgroups for comparison: 133 patients with ICD for primary prophylaxis and 133 with ICD for secondary indications. RESULTS: There were no significant differences between primary and secondary prophylaxis groups with respect to the incidence of appropriate ICD therapy within 2 years (0.153 vs 0.239; hazard ratio, 1.565 [95% confidence interval (CI), 0.898-2.727]; P = .114). Two-year electrical storm risks were 3.3% and 9.6% with HR = 3.236 (95% CI, 1.058-9.896; P = .039) in patients with primary and secondary prophylaxis, respectively. CONCLUSION: The incidence of ICD therapy received by patients with CAD for primary and secondary prophylaxis was not significantly different based on our propensity score-matched analysis. However, secondary-prophylaxis ICD therapy seems to be associated with a significantly higher risk for electrical storm than primary-prophylaxis ICD therapy.

Impact of atrial fibrillation/flutter on outcomes of patients with implantable cardioverter defibrillators: A sub-analysis of the Nippon Storm study.

BACKGROUND: Implantable cardioverter-defibrillator and cardiac resynchronization therapy using a defibrillator (ICD/CRT-D) are established means of reducing mortality due to ventricular arrhythmia. Although atrial fibrillation/flutter (AF) is the most common cardiac arrhythmia in patients with heart disease, the impact of AF on the prognosis of patients with ICD/CRT-D remains controversial. METHODS AND RESULTS: We analyzed data from the Nippon Storm Study, a prospective observational study of 1570 patients that was conducted at 48 Japanese ICD centers. We allocated 1549 participants to AF and non-AF groups, compared their clinical data at the time of enrollment, and monitored the incidences of mortality, hospitalization, and appropriate and inappropriate ICD/CRT-D therapy during a median 28 months. When the AF (n = 257, 16.6%) and non-AF-(n = 1292, 83.4%) groups were compared, the AF group was older (67.7 vs. 61.4 years; p<0.0001), and had lower left ventricular ejection fraction (38.0 ± 17.0% vs. 43.5 ± 18.9%; p<0.0001). During follow up, mortality was significantly higher in the AF than the non-AF group (p<0.0001). In multivariate analysis, AF was significantly associated with all-cause mortality [p = 0.013; hazard ratio (HR)=1.62]. Inappropriate ICD/CRT-D therapy occurred in 40/257 patients (15.6%) and AF was associated with a higher prevalence of inappropriate ICD/CRT-D therapy (p<0.0001; HR=2.25). CONCLUSION: The presence of AF at ICD/CRT-D implantation carries subsequent independent risks of 1.62-fold for death and 2.25-fold for inappropriate therapy.

Risk factors for the first and second inappropriate implantable cardioverter-defibrillator therapy.

INTRODUCTION: Various risk factors for the first inappropriate implantable cardioverter-defibrillator (ICD) therapy event have been reported, including a history of atrial fibrillation/atrial flutter (AF/AFL), younger age, and multiple zones. Nonetheless, which factors are concordant with real-world data has not been clarified, and risk factors for the second inappropriate ICD therapy event have not been well examined. This study aimed to clarify the risk factors for the first and second inappropriate ICD therapy events. METHODS: We conducted a post-hoc secondary analysis of data from a multicenter, prospective observational study (the Nippon Storm Study) designed to clarify the risk factors for electrical storm. RESULTS: The analysis included data from 1549 patients who received ICD or cardiac resynchronization therapy with defibrillator (CRT-D). Over a median follow-up of 28 months, 293 inappropriate ICD therapy events occurred in 153 (10.0%) patients. On multivariate Cox regression analysis, the risk factors for the first inappropriate ICD therapy event were younger age (hazard ratio [HR], 0.986; p = 0.028), AF/AFL (HR, 2.324; p = 0.002), ICD without CRT implantation (HR, 2.377; p = 0.004), and multiple zones (HR, 1.852; p = 0.010). "No-intervention" after the first inappropriate ICD therapy event was the sole risk factor for the second inappropriate ICD therapy event. CONCLUSIONS: Risk factors for the first inappropriate ICD therapy event were similar to those previously reported. Immediate intervention after the first inappropriate ICD therapy event could reduce the risk of the second inappropriate event.

Efficacy of antitachycardia pacing for electrical storms in patients with implantable defibrillators.

INTRODUCTION: Although antitachycardia pacing (ATP) is effective in terminating ventricular tachyarrhythmias in patients with implantable cardioverter defibrillators (ICDs), the efficacy of ATP during an electrical storm (ES) and the positive impact on all-cause mortality have not been fully elucidated. METHODS AND RESULTS: From 2010 to 2012, 1570 patients who underwent ICD implantation in 48 ICD centers in Japan were enrolled in the study and prospectively followed up. Patients with long QT syndrome, Brugada syndrome, and idiopathic ventricular fibrillation were excluded. The prevalence of shocks during ESs and impact on the all-cause mortality were evaluated. During a median follow-up of 28 months, there were 127 ESs in 84 patients. Of those 127 ESs, 80 ESs (63%) in 37 patients were treated by only ATP and the remaining 47 ESs in 47 patients required at least one shock. The lower ventricular rate of the initial arrhythmia during ES (odds ratio [OR]: 1.02 per unit; 95% confidence interval [CI]: 1.00-1.04; p = .02) and narrower QRS complex (OR: 1.03 per unit; 95% CI: 1.01-1.06; p < .01) were the independent predictors of ATP success during the ES. The patients treated with ATP alone tended to have lower all-cause mortality compared to those that required shocks during the ES (log-rank p = .10). CONCLUSIONS: ATP was effective in patients suffering from ESs as it avoided painful shocks in more than half of the cases. Patients who received only ATP during ES tended to have lower mortality compared to those who received the shock.

Comparison of second appropriate defibrillator therapy occurrence in patients implanted for primary prevention and secondary prevention - Sub-analysis of the Nippon Storm Study.

BACKGROUND: Patients with implantable cardioverter defibrillator (ICD) use for primary prevention (primary prevention patients) of sudden cardiac death have lower incidence of appropriate ICD therapy (app-Tx) compared with those with ICD use for secondary prevention (secondary prevention patients). However, detail analysis of a second app-Tx after a first app-Tx is still lacking. OBJECTIVE: This study aimed to compare the incidence of a second app-Tx in primary vs secondary prevention patients. METHODS: We conducted sub-analysis of the Nippon Storm Study, which was a prospective, observational study involving 985 patients with structural heart disease (left ventricular ejection fraction ≤ 50%). Of these, we selected 251 patients (62 ± 14 years old, 82% men) who experienced at least one appropriate ICD therapy, and compared occurrence of a second app-Tx between primary (n = 116) and secondary (n = 135) prevention patients. RESULTS: There was no significant difference in the incidence of a second app-Tx between primary and secondary prevention patients (the cumulative incidence for a second app-Tx was 59% at 1 year and 79% at 3 years in primary prevention patients vs the cumulative incidence for the second app-Tx was 59% at 1 year and 75% at 3 years in secondary prevention patients).Additionally, we evaluated the incidence of a second app-Tx according to basal structural disease (ischemic and non-ischemic cardiomyopathy) and found no significant difference between primary and secondary prevention patients. CONCLUSION: Once app-Tx occurs, primary prevention patients acquire the high risk of subsequent ventricular arrhythmias because there is a comparable incidence of a second app-Tx in secondary prevention patients.

Systematic Evaluation of KCNQ1 Variant Using ACMG/AMP Guidelines and Risk Stratification in Long QT Syndrome Type 1.

Background - Mutation/variant-site specific risk stratification in long-QT syndrome type 1 (LQT1) has been well investigated, but it is still challenging to adapt current enormous genomic information to clinical aspects caused by each mutation/variant. We assessed a novel variant-specific risk stratification in LQT1 patients. Methods - We classified a pathogenicity of 141 KCNQ1 variants among 927 LQT1 patients (536 probands) based on the American College of Medical Genetics and Genomics (ACMG) and Association for Molecular Pathology (AMP) guidelines and evaluated whether the ACMG/AMP-based classification was associated with arrhythmic risk in LQT1 patients. Results - Among 141 KCNQ1 variants, 61 (43.3%), 55 (39.0%), and 25 (17.7%) variants were classified into pathogenic (P), likely pathogenic (LP), and variant of unknown significance (VUS), respectively. Multivariable analysis showed that proband (HR = 2.53; 95%CI = 1.94-3.32; p <0.0001), longer QTc (≥500ms) (HR = 1.44; 95%CI = 1.13-1.83; p = 0.004), variants at membrane spanning (MS) (vs. those at N/C terminus) (HR = 1.42; 95%CI = 1.08-1.88; p = 0.01), C-loop (vs. N/C terminus) (HR = 1.52; 95%CI = 1.06-2.16; p = 0.02), and P variants [(vs. LP) (HR = 1.72; 95%CI = 1.32-2.26; p <0.0001), (vs. VUS) (HR = 1.81; 95%CI = 1.15-2.99; p = 0.009)] were significantly associated with syncopal events. The ACMG/AMP-based KCNQ1 evaluation was useful for risk stratification not only in family members but also in probands. A clinical score (0~4) based on proband, QTc (≥500ms), variant location (MS or C-loop) and P variant by ACMG/AMP guidelines allowed identification of patients more likely to have arrhythmic events. Conclusions - Comprehensive evaluation of clinical findings and pathogenicity of KCNQ1 variants based on the ACMG/AMP-based evaluation may stratify arrhythmic risk of congenital long-QT syndrome type 1.

Patient-by-patient basis anti-tachycardia pacing for fast ventricular tachycardia with structural heart diseases.

BACKGROUND: Anti-tachycardia pacing (ATP) delivered from an implantable device is an important tool to terminate ventricular tachycardia (VT). But its real-world efficacy for fast VT has not been fully studied. METHODS: Using the database of Nippon-storm study, effect of patient-by-patient basis ATP programming for fast VT (≥188 bpm) was assessed for the patients with structural heart diseases. Fast VTs were divided into three groups depending on heart rate (HR); Group A was 188-209 bpm, and Group-B and Group-C were 210-239 bpm and ≥240 bpm, respectively. RESULTS: During a median follow-up of 28 months, 202 fast VT episodes (209 ± 19 bpm) were demonstrated in the 85 patients. ATP terminated 151 of the 202 episodes (74.8%) in total. The success rate of the ATP was not different among the three groups: 73.3% in Group A, 80.6% in Group B, and 66.7% in Group C. ATP success rate of >50% and >70% was 77.6% and 64.7% of the patients, respectively. Left ventricular ejection fraction (LVEF) was significantly higher in the patients with rather than without successful ATP therapy, and receiver operating characteristic (ROC) analysis revealed that LVEF of 23% was the optimal cut-off value. ATP was less effective in patients taking amiodarone, but etiology of the structural heart diseases, indication of the device implantation, and all Electrocardiogram (ECG) parameters were not useful predictors for successful ATP therapy. CONCLUSIONS: ATP highly terminated fast VT with wide HR ranges in patients with structural heart diseases, and should be considered as the first-line therapy for fast VT except for patients with very low LVEF.

Successful Nonsurgical Treatment of Acute Peritonitis Caused by a Large Thrombosis of the Superior Mesenteric Vein in a 25-year-old Woman.

Superior mesenteric venous thrombosis (SMVT), which results from various etiologies, including coagulation disorders, can be diagnosed early using advanced imaging technology. However, few reports have described the nonsurgical treatment of acute peritonitis caused by SMVT. We encountered a young woman whose history included abdominal pain and daily oral contraceptives and who presented with acute peritonitis caused by SMVT. We administered nonsurgical treatment that included thrombolysis and anticoagulation for the peritonitis (without mesenteric ischemia as confirmed by contrast-enhanced computed tomography). In addition, we showed the importance of investigating persistent risk factors for thromboembolism in young patients to determine the duration of anticoagulation.

Association of Genetic and Clinical Aspects of Congenital Long QT Syndrome With Life-Threatening Arrhythmias in Japanese Patients.

Importance: Long QT syndrome (LQTS) is caused by several ion channel genes, yet risk of arrhythmic events is not determined solely by the responsible gene pathogenic variants. Female sex after adolescence is associated with a higher risk of arrhythmic events in individuals with congenital LQTS, but the association between sex and genotype-based risk of LQTS is still unclear. Objective: To examine the association between sex and location of the LQTS-related pathogenic variant as it pertains to the risk of life-threatening arrhythmias. Design, Setting, and Participants: This retrospective observational study enrolled 1124 genotype-positive patients from 11 Japanese institutions from March 1, 2006, to February 28, 2013. Patients had LQTS type 1 (LQT1), type 2 (LQT2), and type 3 (LQT3) (616 probands and 508 family members), with KCNQ1 (n = 521), KCNH2 (n = 487) and SCN5A (n = 116) genes. Clinical characteristics such as age at the time of diagnosis, sex, family history, cardiac events, and several electrocardiographic measures were collected. Statistical analysis was conducted from January 18 to October 10, 2018. Main Outcomes and Measures: Sex difference in the genotype-specific risk of congenital LQTS. Results: Among the 1124 patients (663 females and 461 males; mean [SD] age, 20 [15] years) no sex difference was observed in risk for arrhythmic events among those younger than 15 years; in contrast, female sex was associated with a higher risk for LQT1 and LQT2 among those older than 15 years. In patients with LQT1, the pathogenic variant of the membrane-spanning site was associated with higher risk of arrhythmic events than was the pathogenic variant of the C-terminus of KCNQ1 (HR, 1.60; 95% CI, 1.19-2.17; P = .002), although this site-specific difference in the incidence of arrhythmic events was observed in female patients only. In patients with LQT2, those with S5-pore-S6 pathogenic variants in KCNH2 had a higher risk of arrhythmic events than did those with others (HR, 1.88; 95% CI, 1.44-2.44; P < .001). This site-specific difference in incidence, however, was observed in both sexes. Regardless of the QTc interval, however, female sex itself was associated with a significantly higher risk of arrhythmic events in patients with LQT2 after puberty (106 of 192 [55.2%] vs 19 of 94 [20.2%]; P < .001). In patients with LQT3, pathogenic variants in the S5-pore-S6 segment of the Nav1.5 channel were associated with lethal arrhythmic events compared with others (HR, 4.2; 95% CI, 2.09-8.36; P < .001), but no sex difference was seen. Conclusions and Relevance: In this retrospective analysis, pathogenic variants in the pore areas of the channels were associated with higher risk of arrhythmic events than were other variants in each genotype, while sex-associated differences were observed in patients with LQT1 and LQT2 but not in those with LQT3. The findings of this study suggest that risk for cardiac events in LQTS varies according to genotype, variant site, age, and sex.

Association between changes in platelet reactivity during elective percutaneous coronary intervention and periprocedural myocardial infarction: A pilot study.

BACKGROUND: High platelet reactivity before percutaneous coronary intervention (PCI) reportedly increases the risk of PCI-related myocardial infarction (PMI) following elective PCI. We conducted a pilot study to evaluate changes in platelet reactivity during PCI and their association with the incidence of PMI. METHODS: In total, 133 consecutive patients undergoing elective PCI after pretreatment with dual antiplatelet therapy for at least 7 days were prospectively enrolled. Platelet reactivity was measured by the VerifyNow® assay (International Technidyne Corporation, Edison, NJ, USA) immediately before and after PCI. RESULTS: Platelet reactivity significantly increased from 177.3 ± 53.4 P2Y12 reaction units (PRU) before PCI to 203.4 ± 52.8 PRU immediately after PCI (p < 0.001). Absolute changes in platelet reactivity were significantly greater in patients with than without PMI (32.4 ± 29.0 vs. 21.2 ± 24.8 PRU, respectively; p = 0.021). In the multivariable logistic regression analysis, the absolute change in PRU was an independent predictor of the incidence of PMI. Receiver operating characteristic curve analysis of the change in PRU during PCI for discriminating PMI showed a sensitivity, specificity, and the cut-off value of 46%, 76%, and 37 PRU, respectively (area under the curve = 0.607, p = 0.0235). When the patients were divided into two groups, namely a greater (change in PRU ≥ 37) and smaller (change in PRU < 37) increase group, the incidence rate of PMI was significantly higher in the greater than smaller increase group (59.1% vs. 34.8%, respectively; p = 0.008). Additional exploratory analyses by intracoronary imaging demonstrated that the proximal reference lumen area in the greater increase group was significantly smaller than that in the smaller increase group (6.5 ± 2.4 vs. 7.7 ± 3.1 mm2, respectively; p = 0.032). CONCLUSION: An increase in platelet reactivity after elective PCI is possibly associated with PMI. This finding should be validated by a larger-scale study.

Significant impact of electrical storm on mortality in patients with structural heart disease and an implantable cardiac defibrillator.

BACKGROUND: Electrical storm (E-Storm), defined as multiple episodes of ventricular arrhythmias within a short period of time, is an important clinical problem in patients with an implantable cardiac defibrillator (ICD) including cardiac resynchronization therapy devices capable of defibrillation. The detailed clinical aspects of E-Storm in large populations especially for non-ischemic dilated cardiomyopathy (DCM), however, remain unclear. OBJECTIVE: This study was performed to elucidate the detailed clinical aspects of E-Storm, such as its predictors and prevalence among patients with structural heart disease including DCM. METHODS: We analyzed the data of the Nippon Storm Study, which was a prospective observational study involving 1570 patients enrolled from 48 ICD centers. For the purpose of this study, we evaluated 1274 patients with structural heart disease, including 482 (38%) patients with ischemic heart disease (IHD) and 342 (27%) patients with DCM. RESULTS: During a median follow-up of 28months (interquartile range: 23 to 33months), E-Storm occurred in 84 (6.6%) patients. The incidence of E-Storm was not significantly different between patients with IHD and patients with DCM (log-rank p=0.52). Proportional hazard regression analyses showed that ICD implantation for secondary prevention of sudden cardiac death (p=0.0001) and QRS width (p=0.015) were the independent risk factors for E-storm. In a comparison between patients with and without E-Storm, survival curves after adjustment for clinical characteristics showed a significant difference in mortality. CONCLUSION: E-Storm was associated with subsequent mortality in patients with structural heart disease including DCM.

Impact of premature activation of the right ventricle with programmed stimulation in Brugada syndrome.

BACKGROUND: In Brugada syndrome (BrS), it has been reported that delayed activation in the RV is related to the development of type-1 ECG, which is more critical than type-2. On the other hand, the coexistence of complete right bundle-branch block (CRBBB), which also causes delayed activation in the RV, sometimes makes typical BrS ECG misleading. We hypothesized that premature stimulation of the RV can unmask the influence of delayed activation in the RV and convert the morphology of ECG in BrS patients. METHODS AND RESULTS: In 35 BrS patients with type-1 ECG including 8 patients with concomitant CRBBB and 6 control subjects with CRBBB, progressively premature single stimulations were delivered from the RV apex on electrophysiological study. Then we evaluated QRS morphology of fusion beats created by single premature stimulation in each patient. In 29 (83%) of 35 of the BrS patients, conversion from type-1 to type-2 ECG was observed during the process of single premature stimulation. Additionally, in all 8 BrS patients with concomitant CRBBB, type-1 or type-2 BrS ECG was revealed by premature stimulation with relief of CRBBB. These findings were not observed in any of the control subjects with CRBBB. CONCLUSION: Single premature stimulation of the RV converts ECG from type-1 to type-2 in most BrS cases and unmasks type-1 ECG in all BrS cases with CRBBB. Our results could suggest that type-1 ECG is associated with delayed activation of the RV compared with type-2 ECG.