Background: Mobile cloud electrocardiography (C-ECG) can reduce the door-to-balloon time of acute coronary syndrome (ACS) patients, so we hypothesized it would also assist in transporting ACS-suspected patients to the optimal institutes.

Methods and Results: Initially, 10 fire departments in Oita had 10 ambulances equipped with C-ECG. Ambulance crews recorded a 12-lead ECG from the patient at the first point of contact and transmitted them to 18 hospitals (13 institutions (PCII) with 24-h availability for percutaneous coronary intervention (PCI) and 5 regional core hospitals (RCH) without 24-h PCI) for analysis by a cardiologist. During 41 months, 476 ECGs suspected to be ACS were transmitted and analyzed. Of these, 24 ECGs transmitted to PCII were judged as not requiring PCI, and the patients were directly transported to a RCH (PCII-RCH); 35 ECGs sent to a RCH were judged as requiring PCI, and the patients were directly transported to a PCII (RCH-PCII). The prevalence of cardiovascular disease was significantly higher in the RCH-PCII group than in the PCII-RCH group (P<0.01). There was no significant difference in the door-to-balloon time between the RCH-PCII and the group in which the C-ECG was sent to a PCII and the patients were transported directly to PCII (PCII-PCII) (49±14 vs. 59±20 min, P=0.14).

Conclusions: Prehospital 12-lead ECG can assist in transporting ACS-suspect patients to the optimal treatment facility.

Background:The incidence of sudden cardiac death (SCD) after discharge in Japanese acute myocardial infarction (AMI) patients with reduced left ventricular ejection fraction (LVEF) treated with primary percutaneous coronary intervention (PCI) remains unknown.

Methods and Results:The study population included 1,429 AMI patients (199 with LVEF ≤35% and 1,230 with LVEF >35%) admitted to the Hirosaki University Hospital, treated with primary PCI within 12 h after onset, and survived to discharge. LVEF was evaluated in all patients before discharge, and the patients were followed up for a mean of 2.6±0.8 years. The Kaplan-Meier survival curves revealed LVEF ≤35% was associated with all-cause death and SCD. The incidence of SCD was 2.6% at 1 year and 3.1% at 3 years in patients with LVEF ≤35%, whereas it was 0.1% at 1 year and 0.3% at 3 years in patients with LVEF >35%. Sixty-seven percent of SCDs in patients with LVEF ≤35% occurred within 4 months after discharge, and the events became less frequent after this period. A Cox proportional hazard model indicated LVEF ≤35% as an independent predictor for all-cause death and SCD.

Conclusions:The incidence of SCD was relatively low in Japanese AMI patients treated with primary PCI, even in patients with LVEF ≤35% upon discharge. Careful management of patients with reduced LVEF is required to prevent SCD, especially in the early phase after discharge.

Background: The role of left atrial (LA) function in the long-term prognosis of ST-elevation acute myocardial infarction (STEMI) is still unclear.

Methods and Results: Percutaneous coronary intervention (PCI) was performed in 433 patients with the first episode of STEMI within 12 h of onset. The patients underwent echocardiography 24 h after admission. LA reservoir strain and other echocardiographic parameters were analyzed. Follow up was performed for up to 10 years (mean duration, 91 months). The primary endpoint was major adverse cardiovascular events (MACE): cardiac death or hospitalization due to heart failure (HF). MACE occurred in 90 patients (20%) during the follow-up period. Multivariate Cox hazard analyses showed LA reservoir strain, global longitudinal strain (GLS), age and maximum B-type natriuretic peptide (BNP) were the significant predictors of MACE. Kaplan-Meier curves demonstrated that LA reservoir strain <25.8% was a strong predictor (Log rank, χ²=76.7, P<0.0001). Net reclassification improvement (NRI) demonstrated that adding LA reservoir strain had significant incremental effect on the conventional parameters (NRI and 95% CI: 0.24 [0.11–0.44]) . When combined with GLS >−11.5%, the patients with LA reservoir strain <25.8% were found to be at extremely high risk for MACE (Log rank, χ²=126.3, P<0.0001).

Conclusions: LA reservoir strain immediately after STEMI onset was a significant predictor of poor prognosis in patients, especially when combined with GLS.

Background: The aim of this study was to create a risk scoring model to differentiate obstructive coronary artery (CA) from CA spasm in the etioology of acute coronary syndrome (ACS).

Methods and Results: We included 753 consecutive patients with ACS without persistent ST-segment elevation (p-STE). The exclusion criteria were: (1) out-of-hospital cardiac arrest; (2) cardiogenic shock; (3) hemodialysis; (4) atrial fibrillation/flutter; (5) severe valvular disease; (6) no coronary angiography; (7) non-obstructive coronary artery without “definite” vasospastic angina definition; and/or (8) missing data. From the multivariate logistic regression analysis for prediction of obstructive CA, an integer score of 2 to each 0.5 increment in odds ratio was given, and values were divided into quartiles according to the total score. The scores were as follows: age >70 years (6 points), non-STE myocardial infarction (9 points), diabetes mellitus (5 points), B-type natriuretic peptide >90 pg/mL (7 points), neutrophil to lymphocyte ratio >2 (5 points), and high-density lipoprotein cholesterol <50 mg/dL (5 points). CA spasm-induced ACS occurred in 50.0% in Quartile 1 (total score: 0–13), 20.5% in Quartile 2 (total score: 14–19), 4.9% in Quartile 3 (total score: 20–26), and 2.2% in Quartile 4 (total score: 27–37) (P<0.001), indicating that a total score of <20 was a potential clinical indicator of CA spasm-induced ACS.

Conclusions: CA spasm-induced ACS should be suspected if a total score of <20, and a spasm provocation test was being considered.

Background: As severity of acute myocardial infarction (AMI) varies widely, several risk stratifications for AMI have been reported. We have introduced a novel AMI risk stratification system linked to a rehabilitation program (novel AMI risk stratification; nARS), which stratified AMI patients into low (L)-, intermediate (I)-, and high (H)-risk groups. The purpose of this retrospective study was to compare the long-term clinical outcomes in patients with AMI among L-, I-, H-risk groups.

Methods and Results: This study included 773 AMI patients, and assigned them into the L-risk group (n=332), the I-risk group (n=164), and the H-risk group (n=277). The primary endpoint was major cardiovascular events (MACE), defined as the composite of all-cause death, readmission for heart failure, non-fatal myocardial infarction, and target vessel revascularization after the discharge of index admission. The median follow-up duration was 686 days. MACE was most frequently observed in the H-risk group (39.4%), followed by the I-risk group (23.2%), and least in the L-risk group (19.9%) (P<0.001). The multivariate Cox hazard analysis revealed that the H-risk was significantly associated with MACE (HR 2.166, 95% CI 1.543–3.041, P<0.001) after controlling for multiple confounding factors.

Conclusions: H-risk according to nARS was significantly associated with long-term adverse events after hospital discharge for patients with AMI. These results support the validity of nARS as a risk marker for long-term outcomes.

Background: Most patients with acute myocardial infarction (AMI) present in the emergency department in a hemodynamically stable condition (i.e., non-cardiogenic shock) (AMI-NCS). However, few studies specifically focused on the clinical characteristics and outcomes of AMI-NCS patients. Temporal trends in clinical characteristics, in-hospital occurrence of in-hospital adverse outcomes, and the effect of primary percutaneous coronary intervention (PPCI) were examined.

Methods and Results: Between April 2012 and March 2018, 176,275 AMI-NCS patients (67.7% of the total AMI population; 25.4% female; mean age 68.6±13.1 years) were identified in a nationwide Japanese administrative database. During the 6-year study period, AMI-NCS patients have been getting older and had an increasing burden of comorbidities. The rates of 30-day all-cause mortality and in-hospital complications were 2.6% and 30.5%, respectively. Thirty-day all-cause mortality did not change significantly over time, whereas in-hospital complications, especially major non-cardiac events, increased progressively. On multivariable analyses, higher age, higher Killip class, atrial fibrillation, chronic renal failure, and malignancy were independently associated with both increased 30-day mortality and in-hospital complications. PPCI was independently associated with lower mortality and in-hospital complications.

Conclusions: The clinical background of AMI-NCS patients has been becoming more complex with increasing age and the burden of comorbidities, with increased in-hospital complications. More active and appropriate application of PPCI may further decrease adverse events and improve survival of AMI-NCS patients.

Background: Aortic valve stenosis (AS) leads to increased cardiovascular mortality and morbidity, and recent studies reported that even mild-to-moderate AS was associated with poor prognosis in the general population. This study investigated the prognostic impact of mild or moderate AS, defined as 2.0 m/s ≤ peak aortic jet velocity (Vmax) ≤3.9 m/s using echocardiography in acute myocardial infarction (AMI) patients.

Methods and Results: This study enrolled 3,049 AMI patients using data from the Mie ACS registry. Patients were divided into 2 groups according to Vmax: Group 1: Vmax <2.0 m/s and/or visually intact aortic valve in which all 3 leaflets are fully and evenly open; Group 2: 2.0 m/s ≤ Vmax ≤ 3.9 m/s. There were 2,976 patients in Group 1and 73 patients in Group 2. The Group 2 patients were older, had a higher percentage of males and had lower body mass index and Killip ≥2 than the Group 1 patients. Angiographic data, door-to-balloon time, and mechanical support were not different between the 2 groups. The Group 2 patients demonstrated a significantly higher all-cause mortality rate (P<0.01) and composite of cardiovascular death and heart failure hospitalization (P<0.01), and Kaplan-Meier analysis showed the same tendency in propensity score-matched patients.

Conclusions: The present study revealed that mild or moderate AS based on Vmax is associated with poor prognosis following AMI.

Background: The clinical benefits of neurohormonal antagonists for patients with heart failure (HF) with mid-range and preserved ejection fraction (HFmrEF and HFpEF) are uncertain.

Methods and Results: This study analyzed 858 consecutive patients with HFmrEF (EF: 40–49%) or HFpEF (EF ≥50%), who were hospitalized for acute HF, and who were discharged alive, and were not taking angiotensin-converting enzyme inhibitors (ACE)-I/ angiotensin II receptor blockers (ARB) or β-blockers at admission. The study population was classified into 4 groups according to the status of prescription of ACE-I/ARB and β-blocker at discharge: no neurohormonal antagonist (n=342, 39.9%), ACE-I/ARB only (n=128, 14.9%), β-blocker only (n=189, 22.0%), and both ACE-I/ARB and β-blocker (n=199, 23.2%) groups. The primary outcome measure was a composite of all-cause death or HF hospitalization. The cumulative 1-year incidence of the primary outcome measure was 41.2% in the no neurohormonal antagonist group, 34.0% in the ACE-I/ARB only group, 28.6% in the β-blocker only group, and 16.4% in the both ACE-I/ARB and β-blocker group (P<0.001). Compared with the no neurohormonal antagonist group, both the ACE-I/ARB and β-blocker groups were associated with a significantly lower risk for a composite of all-cause death or HF hospitalization (HR: 0.46, 95% CI: 0.28–0.76, P=0.002).

Conclusions: In hospitalized patients with HFmrEF and HFpEF, starting both ACE-I/ARB and a β-blocker was associated with a reduced risk of the composite of all-cause death or HF hospitalization compared with patients not starting on an ACE-I/ARB or β-blocker.

Background: Heart rate (HR) predicts outcomes in patients with acute coronary syndrome (ACS), whereas the impact of HR on outcomes after out-of-hospital cardiac arrest (OHCA) remains unclear. This study aimed to investigate the impact of HR after resuscitation on outcomes after OHCA and whether the impact differs with OHCA etiology.

Methods and Results: Of 16,452 patients suffering from OHCA, this study analyzed 741 adults for whom HR after resuscitation was recorded by 12-lead electrocardiogram upon hospital arrival. Etiology of OHCA was categorized into 3 groups: ACS, non-ACS, and non-cardiac. Patients in each etiology group were further divided into tachycardia (>100 beats/min) and non-tachycardia (≤100 beats/min). The impact of HR on outcomes was evaluated in each group. Among the 741 patients, the mean age was 67.6 years and 497 (67.1%) patients were male. The primary outcome – 3-month all-cause mortality – was observed in 55.8% of patients. Tachycardia after resuscitation in patients with ACS was significantly associated with higher all-cause mortality at 3 months (P=0.002), but there was no significant association between tachycardia and mortality in non-ACS and non-cardiac etiology patients. In a multivariate analysis model, the incidence of tachycardia after resuscitation independently predicted higher 3-month all-cause mortality in OHCA patients with ACS (hazard ratio: 2.17 [95% confidence interval: 1.05–4.48], P=0.04).

Conclusions: Increased HR after resuscitation was associated with higher mortality only in patients with ACS.

Background: Current guidelines emphasize the indispensability of high-quality chest compression for improving survival in patients who experience out-of-hospital cardiac arrest (OHCA). However, chest compression can cause thoracic injuries that may contribute to poor prognosis; therefore, the purpose of this study is to identify the predictors of thoracic injuries and evaluate the association between thoracic injuries and prognosis.

Methods and Results: Between June 2017 to July 2019, Utstein-style data on 384 consecutive adult patients who experienced non-traumatic OHCA and who were transferred to our hospital (Aso Iizuka Hospital) were collected. Each patient underwent a full-body computed tomography scan. Two-hundred and thirty-four patients (76%) had thoracic injuries (Group-T). The duration of chest compression was significantly longer in Group-T than in patients without thoracic injuries (Group-N; 43 vs. 32 min, respectively, P<0.001). Multivariate analysis revealed that older age and longer chest compression duration were predictors of thoracic injuries (odds ratios 1.03 and 1.07, respectively, P≤0.005). Among patients who achieved return of spontaneous circulation, Kaplan-Meier curves showed a significantly higher cumulative survival rate in Group-N than in Group-T at the 30-day follow up (log-rank test P=0.009).

Conclusions: Older age and longer chest compression duration were independent predictors of thoracic injuries due to chest compression in patients who experienced non-traumatic OHCA. Moreover, the presence of thoracic injuries was associated with worse short-term prognosis.

Background: The coronavirus disease (COVID-19) pandemic may have influenced the prehospital emergency care and deaths of individuals experiencing an out-of-hospital cardiac arrest (OHCA).

Methods and Results: We analyzed the registry data of 2,420 and 2,371 OHCA patients in Osaka City, Japan in 2019 and 2020, respectively, according to the 3 waves of the COVID-19 pandemic. Patient outcomes were compared using multivariable logistic regression analyses with the 2019 data as the reference. Bystander cardiopulmonary resuscitation (CPR) was initiated significantly less frequently in 2020 than in 2019 (2019: 48.0%, 2020: 42.7%, P<0.001), particularly during the first wave (2019: 47.2%, 2020: 42.9%, P=0.046) and second wave (2019: 48.1%, 2020: 41.2%, P=0.010), but not during the third wave (2019: 49.2%, 2020: 44.1%, P=0.066). The public-access automated external defibrillator was less frequently applied during the first wave (2019: 12.6%, 2020: 9.9%, P=0.043), with no significant difference during the second wave (2019: 12.5%, 2020: 12.8%, P=0.863) and third wave (2019: 13.7%, 2020: 13.0%, P=0.722). There was a significant difference in 1-month survival with favorable neurological outcomes (2019: 4.6%, 2020: 3.3%, P=0.018), with a 28% reduction in the adjusted odds ratio in 2020 (0.72; 95% confidence interval: 0.52–0.99, P=0.044).

Conclusions: Bystander CPR and neurologically favorable outcomes after OHCA decreased significantly during the COVID-19 pandemic in Japan.