ABC | Volume 112, Nº6, June 2019

Review Article Mesquita et al HFmrEF - state of the art Arq Bras Cardiol. 2019; 112(6):784-790 Clinical history Physical examination EKG + chest radiography Clinical Suspicion of Heart Failure Low Medium High If available Yes No Normal Alterado Natriuretic peptides BNP > 35-50 pg/mL* or NT-proBNP > 125 pg/mg Echocardiogram for structural evaluation, LVEF and diastolic function Heart failure unlikely, Evaluate again; Consider other diagnosis; Heart failure likely; Evaluate phenotype: HFmrEF, HFpEF or HFrEF? LVEF < 40% LVEF between 40% and 50% HFrEF HFmrEF HFpEF LVEF > 50% Figure 1 – Diagnostic algorithm in the clinical suspicion of heart failure. Adapted from: Brazilian Guideline for Chronic and Acute Heart Failure of 2018; 5 HFrEF: heart failure with reduced ejection fraction; HFmrEF: heart failure with mid-range ejection fraction; HFpEF: heart failure with preserved ejection fraction; EKG: electrocardiogram; BNP: brain natriuretic peptide; NT-proBNP: amino-terminal fragment of pro-brain natriuretic peptide; LVEF: left ventricular ejection fraction. to establishing the HF clinical phenotype, since the clinical signs and patients’ symptoms with HFrEF, HFmrEF and HFpEF are similar.³ A relevant aspect regarding the HFmrEF diagnosis involves methodological aspects related to the cardiac imaging techniques. The LVEF evaluation by echocardiography has been the standard method used to categorize patients with HF; however, it is common that the values obtained are different in relation to other methods, such as cardiac magnetic resonance imaging, radioisotope ventriculography and angiocardiography. 19,20 In addition, the ejection fraction evaluation by echocardiography shows considerable intra and inter-observer variability over time, as well as under therapeutic intervention effect. 19,20 Clinical-epidemiological characteristics Previous studies have shown that patients with HFmrEF had clinical characteristics that, although intermediate between the HFrEF and HFpEF groups, were more similar to those of HFpEF. 8,9,13,21 Nevertheless, in relation to the presence of ischemic disease, different studies have found that HFmrEF resembles HFrEF, showing a higher prevalence. 7,22-24 In the study by Kapoor et al., 7 based on the GWTG-HF (Get With The Guidelines - Heart Failure) registry, patients with HFmrEF were older (mean age of seventy-seven years) and showed a higher percentage of females (48%) when compared to patients with HFrEF, being more similar to HFpEF. Moreover, HFmrEF showed a high prevalence of comorbidities such as DM (50%), atrial fibrillation (AF) (42%), chronic obstructive pulmonary disease (COPD) (36%), anemia (27%) and renal failure (26%), "also similar to HFpEF to HFpEF. However, there was a higher prevalence of ischemic heart disease in up to two thirds of the patients, similar to what as observed with HFrEF. However, in the meta-analysis published by Lauritsen et al., 25 patients with HFmrEF had entirely intermediate characteristics, and there were significant differences between patients with HFmrEF and HFrEF and between patients with HFmrEF and HFpEF. Patients with HFmrEF were older than those with HFrEF (p < 0.001) but were younger than those with HFpEF (p < 0.001). The proportion of men and the prevalence of ischemic heart disease in patients with HFmrEF were lower than in those with HFpEF (p < 0.001 and p < 0.034, respectively), but higher than in those with HFpEF (p < 0.001 and p < 0.034 respectively). Hypertension was more frequent in patients with 785