Background: The Impella^®percutaneous left ventricular assist device has been available in Japan since 2017. This is the first large-scale registry study to analyze the efficacy and safety of Impella in Japanese patients with acute myocardial infarction with cardiogenic shock (AMICS).

Methods and Results: The Japanese registry for Percutaneous Ventricular Assist Device (J-PVAD) has registered all consecutive Japanese patients treated with Impella. We extracted data for 593 AMICS patients from J-PVAD and analyzed 30-day survival and safety profiles. Overall 30-day survival was 63.1%. The 30-day survival of the Impella alone and Impella plus venoarterial extracorporeal membrane oxygenation (ECPELLA) groups was 80.9% and 45.7%, respectively. The Impella alone group was older and had a lower rate of cardiac arrest, milder consciousness disturbance, less inotrope use, lower serum lactate concentrations, higher B-type natriuretic peptide concentrations, and higher left ventricular ejection fraction (LVEF) than the ECPELLA group. Cox regression analysis revealed that older age and comorbid renal disturbance were common risk factors affecting 30-day mortality in both groups. Major adverse events were hemolysis (10.8%), hemorrhage/hematoma (7.6%), peripheral ischemia (4.4%), stroke (1.3%), and thrombosis (0.7%). LVEF improved in both groups during support.

Conclusions: AMICS treatment with Impella showed favorable 30-day survival and safety profiles. The survival rate of patients treated with Impella alone was particularly high. Further studies are needed to improve outcomes of patients with ECPELLA support.

Background: In modern critical care, extracorporeal membrane oxygenation (ECMO) is crucial in the management of severe respiratory and cardiac failure. Nationwide studies of the relationship between hospital volume and outcomes of ECMO use are unavailable.

Methods and Results: Using Taiwan’s National Health Insurance Research Database, we identified 11,734 adult patients who received ECMO support in 101 hospitals between January 1, 2001, and December 31, 2017. Outcomes included in-hospital mortality, 1-year mortality, and ECMO-related complications. Cox proportional hazards model, locally estimated scatterplot smoothing, and restricted cubic spline regression were used to analyze the volume–outcome relationship. The overall in-hospital mortality rate was 65.5%, and the 1-year mortality rate was 70.6% in this database. The 101 hospitals were divided into 4 groups based on annual volume. The in-hospital and 1-year mortality rates were significantly lower in the high-volume group (annual volume >40) than in the low-volume group (annual volume <10).

Conclusions: For critical care, high-volume hospitals have superior short-term and mid-term outcomes. To make the medical system equitable and reasonable, establishing a rapid and efficient nationwide referral system should be considered.

Background: Fulminant myocarditis (FM) is rare but has an extremely poor prognosis. Impella, a catheter-based heart pump, is a new therapeutic strategy, but reports regarding its health economics are lacking.

Methods and Results: This retrospective cohort study compared Impella treatment (Group I) with existing treatments (Group E) using medical data collected from October 2017 to September 2021, with a 1-year analysis period. Cost-effectiveness indices were life-years (LY; effect index) and medical fee amount (cost index). Results were validated using probabilistic sensitivity analysis. The incremental cost-effectiveness ratio (ICER) was calculated using quality-adjusted LY (QALY) and medical costs. Each group included 7 patients, and more than half (57.1%) received combined Impella plus extracorporeal membrane oxygenation. There was no significant difference between Groups I and E in 1-year mortality rates (28.6% vs. 57.1%, respectively) or LY (mean [±SD] 163.1±128.3 vs. 107.8±127.3 days, respectively), but mortality risk was significantly lower in Group I than Group E (95% confidence interval 0.02–0.96; P<0.05). Compared with Group E, Group I had higher total costs (9,270,597±4,121,875 vs. 6,397,466±3,801,364 JPY/year; P=0.20) and higher cost-effectiveness (32,443,987±14,742,966 vs. 92,637,756±98,225,604 JPY/LY; P=0.74), which was confirmed in the sensitivity analysis. ICER probability distribution showed 23.2% and 51.5% reductions below 5 million and 10 million JPY/QALY, respectively.

Conclusions: Impella treatment is more cost-effective than conventional FM treatments. Large-scale studies are needed to validate the added effects and increasing costs.

Background: The vessel healing process after implantation of biodegradable polymer (BP) and durable polymer (DP) everolimus-eluting stent (EES) in ST-elevation myocardial infarction (STEMI) lesions remains unclear.

Methods and Results: We conducted a multicenter prospective randomized controlled trial to compare early (2 weeks) and mid-term (12 months) vascular responses after implantation of BP-EES vs. DP-EES in STEMI patients. In this prespecified subanalysis, serial coronary angioscopy (CAS) analysis was performed in 15 stents in the BP-EES arm (n=10 patients) and 14 stents in the DP-EES arm (n=10 patients). At the 2-week follow-up, there was no significant difference in the estimated marginal means of the neointimal coverage grade (primary endpoint) between the 2 arms (mean [±SE] 0.00±0.00 in both arms; P>0.999). There were no significant differences between the BP-EES and DP-EES groups in the yellow color grade (1.046±0.106 vs. 0.844±0.114, respectively; P=0.201) or the presence of thrombus (77.8% vs. 88.8%, respectively; P=0.205). At 12 months, competent strut coverage, defined as yellow color grade ≤1, no thrombus, and a neointimal coverage grade ≥1 was achieved more frequently in the BP-EES than DP-EES arm (85.2% vs. 53.1%; adjusted odds ratio 2.11 [95% confidence interval 1.26–3.53]; P=0.023).

Conclusions: Neointimal coverage 2 weeks after implantation of BP-EES and DP-EES in STEMI lesions was comparable on CAS evaluation. However, at 1 year, BP-EES was independently associated with competent strut coverage.

Background: The simple risk index recorded in the emergency room (ER-SRI), which is calculated using the formula (heart rate × [age / 10]²) / systolic blood pressure, was shown to be able to stratify the prognosis in ST-elevation myocardial infarction (STEMI) patients. However, the prognostic impact of the prehospital simple risk index (Pre-SRI) remains unknown.

Methods and Results: This study enrolled 2,047 STEMI patients from the Mie Acute Coronary Syndrome (ACS) registry. Pre-SRI was calculated using prehospital data and ER-SRI was calculated using emergency room data. The primary endpoint was 30-day all-cause mortality. The cut-off values of Pre-SRI and ER-SRI for predicting 30-day mortality were 34.8 and 34.1, with accuracies of 0.816 and 0.826 based on receiver operating characteristic analyses (P<0.001 for both). There was no difference in the accuracy of the 2 indices. Multivariate Cox regression analysis demonstrated that a High Pre-SRI (≥34) was a significant independent predictor of 30-day mortality. With combined Pre-SRI and ER-SRI assessment, patients with High Pre-SRI/High ER-SRI showed significantly higher mortality than those with High Pre-SRI/Low ER-SRI, Low Pre-SRI/High ER-SRI, and Low Pre-SRI/Low ER-SRI (P<0.001). The addition of High Pre-SRI to High ER-SRI showed incremental prognostic value of the Pre-SRI.

Conclusions: Pre-SRI can identify high-risk STEMI patients at an early stage and combined assessment with Pre-SRI and ER-SRI could be of incremental prognostic value for risk stratification in STEMI patients.

Background: In patients with acute myocardial infarction (AMI), elevated natriuretic peptide (NP) concentrations are reportedly associated with worse clinical outcomes. This study evaluated the prognostic value of NP concentrations and in-hospital heart failure (HF) events after AMI.

Methods and Results: The present bicenter registry included 600 patients with AMI undergoing percutaneous coronary intervention. HF was evaluated at 3 different time points after AMI: on admission, during hospitalization, and at the short-term follow-up at 1 month. When HF was present at each time point, 1 point was assigned to the “HF time points” (HFTP) risk scoring system; possible total scores on this system ranged from 0 to 3. The primary endpoint was a composite of all-cause death and HF rehospitalization after discharge. Among the 600 patients who survived to discharge, the primary outcome occurred in 69 (11.5%) during a mean follow-up period of 488 days. HF on admission, during hospitalization, and at the short-term follow-up were all significantly associated with subsequent clinical outcomes. Higher scores on the HFTP scoring system were related to an increased risk of the primary endpoint. Multivariable analysis indicated scores of 2 and 3 were independently associated with outcome events in a stepwise manner.

Conclusions: Among patients with AMI, HF evaluation at different time points was useful in stratifying risks of mortality and HF rehospitalization after discharge.

Background: Although a door-to-balloon (D2B) time ≤90 min is recognized as a key indicator of timely reperfusion for patients with ST-segment elevation myocardial infarction (STEMI), it is unclear whether regional disparities in the prognostic value of D2B remain in contemporary Japan.

Methods and Results: We retrospectively analyzed 17,167 STEMI patients (mean [±SD] age 68±13 years, 77.6% male) undergoing primary percutaneous coronary intervention. With reference to the Japanese median population density of 1,147 people/km², patients were divided into 2 groups: rural (n=6,908) and urban (n=10,259). Compared with the urban group, median D2B time was longer (70 vs. 62 min; P<0.001) and the rate of achieving a D2B time ≤90 min was lower (70.7% vs. 75.4%; P<0.001) in the rural group. In-hospital mortality was lower for patients with a D2B time ≤90 min than >90 min, regardless of residential area, whereas multivariable analysis identified prolonged D2B time as a predictor of in-hospital death only in the rural group (adjusted odds ratio 1.57; 95% confidence interval 1.18–2.09; P=0.002). Importantly, the rural-urban disparity in in-hospital mortality emerged most distinctively among patients with Killip Class IV and a D2B time >90 min.

Conclusions: These data suggest that there is a substantial rural-urban gap in the prognostic significance of D2B time among STEMI patients, especially those with cardiogenic shock and a prolonged D2B time.

Background: The REAL-CAD trial, reported in 2017, demonstrated a significant reduction in cardiovascular events with high-intensity statins in patients with chronic coronary syndrome. However, data are scarce on the use of high-intensity statins in Japanese patients with acute coronary syndrome (ACS).

Methods and Results: In STOPDAPT-2 ACS, which exclusively enrolled ACS patients between March 2018 and June 2020, 1,321 (44.2%) patients received high-intensity statins at discharge, whereas of the remaining 1,667 patients, 96.0% were treated with low-dose statins. High-intensity statins were defined as the maximum approved doses of strong statins in Japan. The incidence of the cardiovascular composite endpoint (cardiovascular death, myocardial infarction, definite stent thrombosis, stroke) was significantly lower in patients with than without high-intensity statins (1.44% vs. 2.69% [log-rank P=0.025]; adjusted hazard ratio [aHR] 0.48, 95% confidence interval [CI] 0.24–0.94, P=0.03) and the effect was evident beyond 60 days after the index percutaneous coronary intervention (log-rank P=0.01; aHR 0.38, 95% CI 0.17–0.86, P=0.02). As for the bleeding endpoint, there was no significant difference between the 2 groups (0.99% vs. 0.73% [log-rank P=0.43]; aHR 0.96, 95% CI 0.35–2.60, P=0.93).

Conclusions: The prevalence of high-intensity statins has increased substantially in Japan. The use of the higher doses of statins in ACS patients recommended in the guidelines was associated with a significantly lower risk of the primary cardiovascular composite endpoint compared with lower-dose statins.