Effect of early metoprolol on infarct size in ST-segment-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention: the Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction (METOCARD-CNIC) trial.

BACKGROUND: The effect of ß-blockers on infarct size when used in conjunction with primary percutaneous coronary intervention is unknown. We hypothesize that metoprolol reduces infarct size when administered early (intravenously before reperfusion). METHODS AND RESULTS: Patients with Killip class II or less anterior ST-segment-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention within 6 hours of symptoms onset were randomized to receive intravenous metoprolol (n=131) or not (control, n=139) before reperfusion. All patients without contraindications received oral metoprolol within 24 hours. The predefined primary end point was infarct size on magnetic resonance imaging performed 5 to 7 days after STEMI. Magnetic resonance imaging was performed in 220 patients (81%). Mean ± SD infarct size by magnetic resonance imaging was smaller after intravenous metoprolol compared with control (25.6 ± 15.3 versus 32.0 ± 22.2 g; adjusted difference, -6.52; 95% confidence interval, -11.39 to -1.78; P=0.012). In patients with pre-percutaneous coronary intervention Thrombolysis in Myocardial Infarction grade 0 to 1 flow, the adjusted treatment difference in infarct size was -8.13 (95% confidence interval, -13.10 to -3.16; P=0.0024). Infarct size estimated by peak and area under the curve creatine kinase release was measured in all study populations and was significantly reduced by intravenous metoprolol. Left ventricular ejection fraction was higher in the intravenous metoprolol group (adjusted difference, 2.67%; 95% confidence interval, 0.09-5.21; P=0.045). The composite of death, malignant ventricular arrhythmia, cardiogenic shock, atrioventricular block, and reinfarction at 24 hours in the intravenous metoprolol and control groups was 7.1% and 12.3%, respectively (P=0.21). CONCLUSIONS: In patients with anterior Killip class II or less ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention, early intravenous metoprolol before reperfusion reduced infarct size and increased left ventricular ejection fraction with no excess of adverse events during the first 24 hours after STEMI. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01311700. EUDRACT number: 2010-019939-35.

Out-of-hospital pediatric cardiorespiratory arrest in Galicia: impact of the 2005 resuscitation guidelines.

INTRODUCTION: Pediatric out-of-hospital cardiorespiratory arrest (CRA) is a rare event but has a high mortality and morbidity among survivors. In 2005, an international consensus on science and treatment recommendations has been released, with the aim of improving the assistance of patients who had and, eventually, increasing survival without neurologic sequelae. Our objective was to assess the impact of the 2005 guidelines on the initial prehospital assistance of children with out-of-hospital CRA in a community with scattered population. METHODS: This is a prospective observational study following the Utstein-style guidelines of pediatric CRA in 2 periods: group 1 (pre-2005), from July 2002 to February 2005 (32 months); and group 2 (post-2005), from January 2007 to December 2008 (24 months). Patients aged from 0 months to 16 years who had an out-of-hospital respiratory or cardiac arrest were included in the study. RESULTS: There were 31 patients (84% cardiac) who had CRA in group 1 and 21 patients (62% cardiac) who had CRA in group 2 (P = 0.073). Both groups were comparable in age, sex, CRA cause, place of CRA incident, management of airway, fluid administrations, and defibrillation attempts. A significant increment in the number of bystander cardiopulmonary resuscitation (CPR) was observed in group 2 (13 [62%] vs 7 [29%], P = 0.004). The intraosseous access was more frequently used in the post-2005 group (8 [38%] vs 5 [16%], P = 0.021). In group 2, a higher percentage of patients received more than 1 adrenaline dose (95% vs 61%, P = 0.006), were treated with bicarbonate (7 [33%] vs 3 [10%], P = 0.045), and were not treated with atropine (5 [24%] vs 17 [55%], P = 0.020). Survival to hospital admission, sustained return of spontaneous circulation, and survival to hospital discharge were comparable in both groups. CONCLUSIONS: In cases of pediatric out-of-hospital CRA in a community with scattered population, after the introduction of the 2005 international CPR recommendations, there was an increase in bystander CPR and changes in immediate treatment were detected. However, these changes did not result in a significant outcome improvement.

Influence of the Covid-19 pandemic on out-of-hospital cardiac arrest. A Spanish nationwide prospective cohort study.

AIMS: The influence of the COVID-19 pandemic on attendance to out-of-hospital cardiac arrest (OHCA) has only been described in city or regional settings. The impact of COVID-19 across an entire country with a high infection rate is yet to be explored. METHODS: The study uses data from 8629 cases recorded in two time-series (2017/2018 and 2020) of the Spanish national registry. Data from a non-COVID-19 period and the COVID-19 period (February 1st-April 30th 2020) were compared. During the COVID-19 period, data a further analysis comparing non-pandemic and pandemic weeks (defined according to the WHO declaration on March 11th, 2020) was conducted. The chi-squared analysis examined differences in OHCA attendance and other patient and resuscitation characteristics. Multivariate logistic regression examined survival likelihood to hospital admission and discharge. The multilevel analysis examined the differential effects of regional COVID-19 incidence on these same outcomes. RESULTS: During the COVID-19 period, the incidence of resuscitation attempts declined and survival to hospital admission (OR = 1.72; 95%CI = 1.46-2.04; p < 0.001) and discharge (OR = 1.38; 95%CI = 1.07-1.78; p = 0.013) fell compared to the non-COVID period. This pattern was also observed when comparing non-pandemic weeks and pandemic weeks. COVID-19 incidence impinged significantly upon outcomes regardless of regional variation, with low, medium, and high incidence regions equally affected. CONCLUSIONS: The pandemic, irrespective of its incidence, seems to have particularly impeded the pre-hospital phase of OHCA care. Present findings call for the need to adapt out-of-hospital care for periods of serious infection risk. STUDY REGISTRATION NUMBER: ISRCTN10437835.

QRS distortion in pre-reperfusion electrocardiogram is a bedside predictor of large myocardium at risk and infarct size (a METOCARD-CNIC trial substudy).

BACKGROUND: QRS distortion is an electrocardiographic (ECG) sign of severe ongoing ischemia in the setting of ST-segment elevation acute myocardial infarction (STEMI). We sought to evaluate the association between the degree of QRS distortion and myocardium at risk and final infarct size, measured by cardiac magnetic resonance (CMR). METHODS: A total of 174 patients with a first anterior STEMI reperfused by primary angioplasty were prospectively recruited. Pre-reperfusion ECG was used to divide the study population into three groups according to the absence of QRS distortion (D0) or its presence in a single lead (D1) or in 2 or more contiguous leads (D2+). Myocardium at risk and infarct size were determined by CMR one week after STEMI. Multiple regression analysis was used to study the association of QRS distortion with myocardium at risk and infarct size, with adjustment for relevant clinical and ECG variables. RESULTS: 101 patients (58%) were in group D0, 30 (17%) in group D1, and 43 (25%) in group D2+. Compared with group D0, presence of QRS distortion (groups D2+ and D1) was associated with a significantly adjusted larger extent of myocardium at risk (group D2+: absolute increase 10.4%, 95% CI 6.1-14.8%, p<0.001; group D1: absolute increase 3.3%, 95% CI 1.3-7.9%, p=0.157) and larger infarct size (group D2+: absolute increase 10.1%, 95% CI 5.5-14.7%, p<0.001; group D1: absolute increase 4.9%, 95% CI 0.08-9.8%, p=0.046). CONCLUSIONS: Distortion in the terminal portion of the QRS complex on pre-reperfusion ECG in two or more leads is independently associated with larger myocardium at risk and infarct size in the setting of primary angioplasty-reperfused anterior STEMI. QRS distortion in only one lead is independently associated with larger infarct size in this setting. Our findings suggest that QRS distortion analysis could be included in risk-stratification of patients presenting with anterior STEMI.