ABC | Volume 114, Nº3, March 2020

Review Article Oliveira The Top 10 Original Articles Published in the ABC Cardiol and in the RPC in 2019 Arq Bras Cardiol. 2020; 114(3):564-570 validation in other cohorts of patients to be then implemented in clinical practice. 14 The Takotsubo syndrome is a differential diagnosis for patients suspected of having ACS, and has gained increasing attention. 15 This year, the Rev Port Cardiol published the results of a Portuguese multicenter study that has assessed the characteristics of 234 patients diagnosed with Takotsubo syndrome. 16 That study has shown that the Takotsubo syndrome has a good short- and medium-term prognosis (in-hospital mortality of 2.2%), but the rate of in-hospital complications (namely heart failure, atrial fibrillation, ventricular arrhythmias and stroke) is high (33%). Aiming at assessing the expression of the transcriptional factors NF- κ B and Nrf2 and PPAR β / δ in chronic coronary syndrome (CCS), 35 patients with CAD (17 men; mean age, 62.4 ± 7.55 years) and 12 patients without CAD (5men; mean age, 63.50± 11.46 years) were studied. Peripheral blood mononuclear cells (PBMC) were isolated and processed for the mRNA expression of Nrf2, NF- κ B, NADPH:quinone oxidoreductase 1 (NQO1) and PPAR β / δ by use of real-time quantitative polymerase chain reaction. The authors have reported a higher mRNA expression of PPAR β / δ in the PBMC of patients with CAD as compared to that of the control group, while the mRNA expressions of Nrf2 and NF- κ B did not differ. Such findings might indicate possible target-therapies for future research in CCS. 17 Another study on CCS has evaluated 5526 obese patients without known CAD referred for CPM-SPECT assessment between January 2011 and December 2016. The factors associated with abnormal myocardial perfusion in obese patients without known ischemic heart disease after adjusting for the relevant variables (multivariate analysis) were: age (2% risk increase for each year of age); diabetes mellitus (57% risk increase); typical angina (245% risk increase in patients with typical angina as compared to asymptomatic patients); need for pharmacologic stress during testing (61% risk increase as compared to physical stress by use of exercise testing); less physical effort evaluated in metabolic equivalents (METs - 10% risk reduction for each additional MET during exercise testing); and left ventricular ejection fraction (LVEF) after stress (1% risk reduction for each 1% addition in LVEF). Such data support the association of obesity and CCS. 18 Cardiac arrhythmias and devices The association between atrial fibrillation and the risk of stroke is complex and multifactorial. Even more challenging is understanding the mechanisms involved in the occurrence of stroke in patients undergoing anticoagulation. In a very interesting study, Fernandes et al. 19 have assessed 60 consecutive patients with nonvalvular atrial fibrillation, chronically medicated with an oral anticoagulant and admitted due to ischemic stroke. For most of those patients, stroke occurrence despite anticoagulation appears to be explained by subtherapeutic dosage, poor treatment adherence or non-cardioembolic etiology, and not by inefficacy of the anticoagulants, because 90% of the patients on vitamin K antagonists had an admission INR < 2, and subtherapeutic prescriptions were found in 43% of those on novel oral anticoagulants. Implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT) reduce the risk of death and hospitalization and promote an improvement in the quality of life of patients with heart failure and reduced LVEF. Bonhorst et al. have published in the Rev Port Cardiol the results of the Síncrone study, 20 an observational, prospective, multicenter registry conducted in 16 centers in Portugal that included 486 patients with a diagnosis of heart failure, LVEF < 35% and indication for ICD or CRT devices. In that study, most patients treated with devices had a class I recommendation of the guidelines, the overall mortality at one year being low (3.6%), as was the number of hospitalizations (11%). That study helps understand the reality of the treatment with devices for heart failure in Portugal. In addition, it evidences the need to improve the pharmacological treatment of those patients, because the drug use rates were suboptimal (76% angiotensin- converting-enzyme inhibitor/aldosterone receptor antagonist; 77% beta-adrenergic blockers; 34% aldosterone antagonist). Heart failure and cardiomyopathies For patients with hypertrophic cardiomyopathy (HCM), the European guidelines recommend assessing the risk of sudden death according to the ESC-SCD score. 21 However, that score has come under criticism, and new risk stratification models are required for those patients. Ruivo C et al. 22 have published in the Rev Port Cardiol a study based on data from the Portuguese National Registry of HCM, which includes 1022 patients with HCM. After identifying the major determinants of the risk of sudden death, the authors have built a new risk model, the SHIFT score, which includes four variables: unexplained syncope; signs of heart failure; septal thickness ≥ 19 mm; and fragmented QRS complex. In that population of patients, the SHIFT score, which includes relatively simple clinical, electrocardiographic and echocardiographic parameters, showed a better predictive value (C-index, 0.81) than the ESC-SCD score. Thus, that new score might play an important role in selecting patients with HCM with indication for ICD in primary prevention. Regarding dilated cardiomyopathy, the Rev Port Cardiol published in 2019 a multicenter study aimed at providing the molecular and genetic characterization of 107 patients with dilated cardiomyopathy. 23 The authors have reported large genetic complexity and diversity in those patients, having identified 31 rare variants in eight different genes, mainly involving sarcomeric genes (MYBPC3, TNNT2 and LMNA). That study emphasizes the importance of the new genomic analysis techniques, mainly next-generation sequencing techniques, to better understand the etiology of dilated cardiomyopathy. Cardiovascular magnetic resonance has played an increasing role in the assessment of patients with myocarditis, being currently the non-invasive test of choice to diagnose that pathology. 24 A study 25 published in the Rev Port Cardiol in 2019 has assessed the role of quantifying myocardial deformation by using tissue tracking as an objective measure of myocardial function quantification in 78 patients with myocarditis. Significant correlations were found between all deformation parameters (strain, strain rate, velocity and displacement) and LVEF, regional wall motion abnormalities, 567