Morimasa Takayama

Chest Compression-Only Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest With Public-Access Defibrillation A Nationwide Cohort Study

Background—It remains unclear which is more effective to increase survival after out-of-hospital cardiac arrest in those with public-access defibrillation, bystander-initiated chest compression–only cardiopulmonary resuscitation (CPR) or conventional CPR with rescue breathing. Methods and Results—A nationwide, prospective, population-based observational study covering the whole population of Japan and involving consecutive out-of-hospital cardiac arrest patients with resuscitation attempts has been conducted since 2005. We enrolled all out-of-hospital cardiac arrests of presumed cardiac origin that were witnessed and received shocks with public-access automated external defibrillation (AEDs) by bystanders from January 1, 2005, to December 31, 2009. The main outcome measure was neurologically favorable 1-month survival. We compared outcomes by type of bystander-initiated CPR (chest compression–only CPR and conventional CPR with compressions and rescue breathing). Multivariable logistic regression was used to assess the relationship between the type of CPR and a better neurological outcome. During the 5 years, 1376 bystander-witnessed out-of-hospital cardiac arrests of cardiac origin in individuals who received CPR and shocks with public-access AEDs by bystanders were registered. Among them, 506 (36.8%) received chest compression–only CPR and 870 (63.2%) received conventional CPR. The chest compression–only CPR group (40.7%, 206 of 506) had a significantly higher rate of 1-month survival with favorable neurological outcome than the conventional CPR group (32.9%, 286 of 870; adjusted odds ratio, 1.33; 95% confidence interval, 1.03–1.70). Conclusions—Compression-only CPR is more effective than conventional CPR for patients in whom out-of-hospital cardiac arrest is witnessed and shocked with public-access defibrillation. Compression-only CPR is the most likely scenario in which lay rescuers can witness a sudden collapse and use public-access AEDs.

Delayed hyper-enhancement of myocardium in hypertrophic cardiomyopathy with asymmetrical septal hypertrophy: comparison with global and regional cardiac MR imaging appearances.

To evaluate the relationship between delayed hyper‐enhancement of the myocardium and global and regional cardiac abnormalities in hypertrophic cardiomyopathy (HCM) with asymmetrical septal hypertrophy using magnetic resonance (MR) imaging.

Duration of Prehospital Resuscitation Efforts After Out-of-Hospital Cardiac Arrest.

Background— During out-of-hospital cardiac arrest, it is unclear how long prehospital resuscitation efforts should be continued to maximize lives saved. Methods and Results— Between 2005 and 2012, we enrolled 282 183 adult patients with bystander-witnessed out-of-hospital cardiac arrest from the All-Japan Utstein Registry. Prehospital resuscitation duration was calculated as the time interval from call receipt to return of spontaneous circulation in cases achieving prehospital return of spontaneous circulation or from call receipt to hospital arrival in cases not achieving prehospital return of spontaneous circulation. In each of 4 groups stratified by initial cardiac arrest rhythm (shockable versus nonshockable) and bystander resuscitation (presence versus absence), we calculated minimum prehospital resuscitation duration, defined as the length of resuscitation efforts in minutes required to achieve ≥99% sensitivity for the primary end point, favorable 30-day neurological outcome after out-of-hospital cardiac arrest. Prehospital resuscitation duration to achieve prehospital return of spontaneous circulation ranged from 1 to 60 minutes. Longer prehospital resuscitation duration reduced the likelihood of favorable neurological outcome (adjusted odds ratio, 0.84; 95% confidence interval, 0.838–0.844). Although the frequency of favorable neurological outcome was significantly different among the 4 groups, ranging from 20.0% (shockable/bystander resuscitation group) to 0.9% (nonshockable/bystander resuscitation group; P<0.001), minimum prehospital resuscitation duration did not differ widely among the 4 groups (40 minutes in the shockable/bystander resuscitation group and the shockable/no bystander resuscitation group, 44 minutes in the nonshockable/bystander resuscitation group, and 45 minutes in the nonshockable/no bystander resuscitation group). Conclusions— On the basis of time intervals from the shockable arrest groups, prehospital resuscitation efforts should be continued for at least 40 minutes in all adults with bystander-witnessed out-of-hospital cardiac arrest. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/. Unique identifier: 000009918.

Characterization of predictors of in-hospital cardiac complications of takotsubo cardiomyopathy: Multi-center registry from Tokyo CCU Network

BACKGROUND Takotsubo cardiomyopathy (TC) is an acute cardiac syndrome characterized by transient left ventricular dysfunction and relatively good prognosis after discharge. However, cardiac complications during hospitalization remain to be fully determined. We attempted to determine features characterizing patients with adverse clinical outcome by comparing those with cardiac complication and without cardiac complication during hospitalization. METHODS AND RESULTS We investigated 107 patients with TC from the Tokyo CCU Network database, comprising 67 cardiovascular centers in the metropolitan area during January 1 to December 31, 2010. Cardiac complications were defined as cardiac death, pump failure (Killip grade≥II), sustained ventricular tachycardia or fibrillation (SVT/VF), and advanced atrioventricular block (AVB). Cardiac complications were observed in 41 patients (37 pump failure complicated by 3 cardiac deaths and 2 SVT/VF and 2 AVB without pump failure), and there was no cardiac complication in the remaining 66 patients. There was no difference in age, peak creatinine kinase level, C-reactive protein level and ST elevation on electrocardiogram. Multiple logistic regression analysis showed that white blood cell count (p=0.039) and brain natriuretic peptide (p=0.001) were independent predictors of in-hospital adverse cardiac complications. CONCLUSIONS Cardiac complications are relatively high in patients with TC during hospitalization. High white blood cell count and brain natriuretic peptide level are associated with poor clinical outcome in patients with TC.

Optimal cutoff value of P2Y12 reaction units to prevent major adverse cardiovascular events in the acute periprocedural period: Post-hoc analysis of the randomized PRASFIT-ACS study☆ , ☆☆

BACKGROUND Few studies have examined the effects of on-treatment platelet reactivity on the risk of major adverse cardiovascular events (MACE). We aimed to determine the optimal cutoff value of P2Y12 reaction units (PRUs) to prevent MACE occurring within 3days after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). METHODS We performed post-hoc analyses of 1363 patients enrolled in PRASFIT-ACS, which compared the effects of a prasugrel regimen adjusted for Japanese patients (loading dose/maintenance dose: 20mg/3.75mg) with those of clopidogrel (300mg/75mg) on MACE and bleeding events for 24-48weeks after PCI in ACS patients. PRU was serially measured using the VerifyNow® P2Y12 assay and we assessed the relationship between PRU and MACE. RESULTS Receiver operating characteristic curve analysis showed that PRU ≤262 at 5-12h after ADP receptor antagonist loading was the optimal cutoff value for preventing MACE at up to 3days after PCI. The incidences of MACE were 5.2% and 10.8% in patients with PRU ≤262 or >262, respectively (odds ratio 0.50, 95% confidence interval 0.25-0.99, p<0.01). Significantly more prasugrel-treated patients had lower on-treatment platelet reactivity (defined as PRU ≤262) compared with clopidogrel-treated patients (79.9% vs. 30.4%, p<0.0001). Similar differences were observed between the prasugrel and clopidogrel groups for patients with normal or reduced-function CYP2C19 alleles. CONCLUSIONS The optimal PRU cutoff value for preventing MACE was 262 in Japanese ACS patients. Prasugrel rapidly reduced PRU with a large proportion of patients having low on-treatment platelet reactivity.

First direct comparison of clinical outcomes between European and Asian cohorts in transcatheter aortic valve implantation: The Massy study group vs. the PREVAIL JAPAN trial

BACKGROUND The efficacy and safety of transcatheter aortic valve implantation (TAVI) in Asian populations were unknown. The purpose of this study was to compare directly the clinical outcomes of the first Japanese trial and a European single-center experience after TAVI. METHODS AND RESULTS Between April 2010 and October 2011, 64 patients were included in the PREVAIL JAPAN multicenter trial which was set up to evaluate the safety and efficacy of the Edwards SAPIEN XT™ (Edwards Lifesciences, Irvine, CA, USA) in high-risk Japanese patients with severe aortic stenosis. Between March 2010 and January 2012, 237 consecutive patients treated with TAVI using the Edwards SAPIEN XT™ prosthesis at Institut Cardiovasculaire Paris Sud were prospectively included in the Massy cohort. We compared the clinical outcomes of these two cohorts. Patients were of similar age (83.4±6.6 years vs. 84.5±6.1 years, p=0.25), but logistic EuroSCORE was higher in the Massy cohort (20.2±11.7% vs. 15.6±8.0%, p<0.01). Body surface area was smaller in the PREVAIL JAPAN cohort (1.41±0.14m(2) vs. 1.72±0.18m(2); p<0.01) as was the annulus diameter (20.4±1.46mm vs. 22.0±1.84mm, p<0.01). The transfemoral approach was used in 57.8% in the Japanese cohort vs. 51.5% in the Massy cohort. Device success was similar (89.1% vs. 94.1%, p=0.21, respectively), as well as 30-day and 6-month survival rates (92.2% vs. 90.7% and 89.1% vs. 83.1%, p=0.71 and p=0.25, respectively). The incidence of major vascular complications was not significantly different between the two groups (9.4% vs. 5.9%, p=0.23, respectively). A higher post-procedural mean pressure gradient was observed in the PREVAIL JAPAN cohort (12.7±11.4mmHg vs. 10.1±3.6mmHg, p=0.01), but satisfactory improvement in 6-month functional status was obtained in both cohorts (76.5% vs. 77.2%, p=0.91). CONCLUSIONS Clinical outcomes after TAVI in the patients included in the PREVAIL JAPAN trial were acceptable and as safe as that of a single-center European cohort.

Gender Differences in Patients with Takotsubo Cardiomyopathy: Multi-Center Registry from Tokyo CCU Network

Background The clinical features of gender differences in takotsubo cardiomyopathy (TC) remain to be determined. The aim of this study was to evaluate the differences in clinical characteristics of male and female patients with TC. Methods We obtained the clinical information of 368 patients diagnosed with TC (84 male, 284 female) from the Tokyo CCU Network database collected from 1 January 2010 to 31 December 2012; the Network is comprised of 71 cardiovascular centers in the Tokyo (Japan) metropolitan area. We attempted to characterize clinical differences during hospitalization, comparing male and female patients with TC. Results There were no significant differences in apical ballooning type, median echocardiography ejection fraction, serious ventricular arrhythmias (such as ventricular tachycardia or fibrillation), or cardiovascular death between male and female patients. Male patients were younger than female patients (median age at hospitalization for male patients was 72 years vs. 76 years for female patients; p = 0.040). Prior physical stress was more common in male than female patients (50.0% vs.31.3%; p = 0.002), while emotional stress was more common in female patients (19.0% vs. 31.0%; p = 0.039). Severe pump failure (defined as Killip Class > III) (20.2% vs. 10.6%; p = 0.020) and cardiopulmonary supportive therapies (28.6% vs. 12.7%, p < 0.001) were more common in male than female patients. Multivariate analysis revealed that male gender (odds ratio = 4.32, 95% CI = 1.41–13.6, p = 0.011) was an independent predictor of adverse composite cardiac events, including cardiovascular death, severe pump failure, and serious ventricular arrhythmia. Conclusions Cardiac complications in our dataset appeared to be more common in male than female patients with TC during their hospitalization. Further investigation is required to clarify the underlying mechanisms responsible for the observed gender differences.

Autopsy finding of the Sapien XT valve from a patient who died suddenly after transcatheter aortic valve replacement

An 89-year-old woman with severe aortic stenosis underwent transfemoral aortic valve replacement. The postoperative course was uneventful except transient bradycardia immediately after the procedure. Echocardiographic finding showed excellent valvular function. After discharge, the patient died suddenly. Autopsy findings showed compression of the atrioventricular conduction system region at the septum by the stent strut. Microscopic examination showed atrophy of the conduction fibers with eosinophilic degeneration of the cytoplasm or coagulation necrosis with pyknosis in the bundle of His and the left bundle branch. Compression by the stent strut triggering dysfunction of the conduction system could have caused fatal arrhythmic event.

The combination of external high-frequency oscillation and pressure support ventilation in acute respiratory failure

Background: Effective gas exchange can be maintained in animals by using external high‐frequency oscillation (EHFO). The present study evaluates the effect of relatively long‐term duration EHFO combined with pressure support ventilation (PSV) in patients with acute respiratory failure.

Late stent malapposition with marked positive vascular remodeling observed only at the site of drug-eluting stents after multivessel coronary stenting

A 74-year-old woman presented with effort-induced chest pain. Diagnostic coronary angiography revealed three-vessel disease. A successful angioplasty was performed with two sirolimus-eluting stents placed in the left anterior descending artery (LAD) and left circumflex artery (LCX). The right coronary artery (RCA) was treated with a bare-metal stent. Follow-up angiography and intravascular ultrasound (IVUS) assessment were performed 8 months later, which showed late stent malapposition (LSM) with marked positive vascular remodeling around the drug-eluting stents (DES) in both LAD and LCX lesions, but there was no evidence of ectatic area around the BMS in the RCA lesion. Compared with the baseline IVUS, a significant increase in external elastic membrane (EEM) cross-sectional area was found. Twenty-seven months later, we performed repeat follow-up angiography. Intravascular ultrasound still showed vessel malapposition. A previous report showed that aneurysmal dilatation of the stented segment with severe localized hypersensitivity reaction could be a potential cause of late thrombosis after DES implantation. If LSM is related to hypersensitivity of the DES, it may have a potential risk of adverse events. Although there is a paucity of data regarding malapposition as the cause of adverse events, careful long-term follow-up of patients with vessel enlargement after DES placement is recommended.