A counterpoint paper: Comments on the electrocardiographic part of the 2018 Fourth Universal Definition of Myocardial Infarction endorsed by the International Society of Electrocardiology and the International Society for Holter and Noninvasive Electrocardiology

The Fourth Universal Definition of Myocardial Infarction (FUDMI) focuses on the distinction between nonischemic myocardial injury and myocardial infarction (MI), along with the role of cardiovascular magnetic resonance, in order to define the etiology of myocardial injury. As a consequence, there is less emphasis on updating the parts of the definition concerning the electrocardiographic (ECG) changes related to MI. Evidence of myocardial ischemia is a prerequisite for the diagnosis of MI, and the ECG is the main available tool for (a) detecting acute ischemia, (b) triage, and (c) risk stratification upon presentation. This review focuses on multiple aspects of ECG interpretation that we firmly believe should be considered for incorporation in any future update to the Universal Definition of MI.     

Evolocumab Effects on Lipoproteins,Measured by High-Performance Liquid Chromatography

Aims: Profiling of lipoproteins can predict risk of cardiovascular disease; gel permeation high-performance liquid chromatography (HPLC) improves prediction accuracy by providing detailed data for specific lipoprotein subclasses. This study applied HPLC to examine the effects of evolocumab, which effectively treats hyperlipidemia and mixed dyslipidemia, on lipoprotein subclasses, specifically the number and size of lipoprotein particles.Methods: This post-hoc analysis used patient blood samples from YUKAWA-2, a phase 3 trial evaluating the efficacy of evolocumab in Japanese adult patients with hyperlipidemia or mixed dyslipidemia and at high risk for cardiovascular disease. We used HPLC to assess observed values and percent change from baseline in cholesterol and triglyceride (TG) concentrations, number of particles in lipoprotein subclasses to week 12, and mean observed values and mean percent change from baseline in variables to weeks 10 and 12. HPLC was also compared with conventional methods in assessing low-density lipoprotein (LDL) cholesterol (LDL-C) values.Results: Data for all 404 patients were analyzed. Evolocumab significantly decreased cholesterol and TG concentrations, and total particle count, in very low-density lipoprotein (VLDL) and LDL subclasses. Particle size increased slightly in LDL, high-density lipoprotein (HDL), and VLDL, but data varied widely. At very low L-DLC, HPLC measurements were higher than those from conventional methods.Conclusion: This research used HPLC to assess the effects of evolocumab in 20 lipid subclasses. By lowering lipid content and improving the lipid profile, evolocumab may reduce atherogenicity. This reduction is better quantified by HPLC than by conventional methods in the very low LDL-C range.     

Abnormal Coronary Anatomy in Patients with Transposition of the Great Arteries and Atrial Switch: A Predictor of Serious Cardiac Adverse Events?

Sudden cardiac death and heart failure are well known long-term complications after atrial switch for D-transposition of the great arteries (D-TGA). Right systemic ventricular dysfunction is common and myocardial ischemia has been implicated as a putative mechanism for sudden death, with coronary anomalies prevalent in 30% of cases. We sought to assess an association between adverse events and coronary anomalies in patients with D-TGA and atrial switch surgery. An observational study was conducted in 3 tertiary centers (Montreal Heart Institute, Canada, Nationwide Children’s hospital, Chicago, USA and Hopital cardiologique Louis Pradel de Lyon, France). Adults with D-TGA and atrial switch surgery qualified for inclusion if they had a major adverse cardiovascular event (MACE), i.e., ventricular arrhythmia, sudden cardiac death, heart failure, cardiac transplantation, or cardiovascular death. The prevalence of coronary anomalies was compared to historical controls. Forty-five patients were included. Twenty-one (46.7%) patients experienced a ventricular arrhythmia and 35 (77.8%) suffered from symptomatic heart failure and/or severe right ventricular dysfunction. Twelve patients (26.7%) had congenitally abnormal coronary arteries. There was no difference in the prevalence of coronary anomalies between the cohort with a MACE and a pooled population of 647 historical controls with D-TGA (28.7%, p = 0.89). In conclusion, the prevalence of congenital coronary anomalies is not higher in patients with D-TGA and atrial switch surgery who had adverse cardiovascular events. It could be hypothesized that ischemic complications in this patient population are more likely to be related to a supply-demand mismatch of the distal microvasculature rather than proximal coronary anomalies.