Heart Failure with Mid-Range Ejection Fraction - State of the Art

Abstract In 2016, the European Society of Cardiology (ESC) recognized heart failure (HF) with ejection fraction between 40 and 49% as a new HF phenotype, HF with mid-range ejection fraction (HFmrEF), with the main purpose of encouraging studies on this new category. In 2018, the Brazilian Society of Cardiology adhered to this classification and introduced HFmrEF in Brazil. This paper presents a narrative review of what the literature has described about HFmrEF. The prevalence of patients with HFmrEF ranged from 13 to 24% of patients with HF. Analyzing the clinical characteristics, HFmrEF shows intermediate characteristics or is either similar to HF with preserved ejection fraction (HFpEF) or to HF with reduced fraction (HFrEF). Regarding the prognosis, HFmrEF’s all-cause mortality is similar to HFpEF’s and lower than HFrEF’s. Studies that analyzed cardiac mortality concluded that there was no significant difference between HFmrEF and HFrEF, both of which were lower than HFpEF. Despite the significant increase of publications on HFmrEF, there is a great scarcity of prospective studies and clinical trials that allow delineating specific therapies for this new phenotype. To better treat HFmrEF patients, it is fundamental that cardiologists and internists understand the differences and similarities of this new phenotype.

摘要 2016年，欧洲心脏病学会（European Society of Cardiology, ESC）将射血分数介于40%至49%之间的心力衰竭（heart failure, HF）认定为一种新型心力衰竭表型——射血分数中间值心力衰竭（HF with mid-range ejection fraction, HFmrEF），其核心目的是推动针对这一新分类的相关研究。2018年，巴西心脏病学会采纳了该分类标准，并在巴西引入了HFmrEF这一概念。本文针对现有文献中关于HFmrEF的相关描述展开叙述性综述。
HFmrEF患者在全部心力衰竭患者中的患病率为13%至24%。对临床特征进行分析后可见，HFmrEF呈现出中间表型特征，或与射血分数保留型心力衰竭（HF with preserved ejection fraction, HFpEF）、射血分数降低型心力衰竭（HF with reduced fraction, HFrEF）相似。
就预后而言，HFmrEF的全因死亡率与HFpEF相当，且低于HFrEF。针对心源性死亡率的研究结果显示，HFmrEF与HFrEF之间无显著差异，且二者的死亡率均低于HFpEF。尽管针对HFmrEF的发表文献数量已显著增加，但目前仍极度缺乏能够明确该新型表型特异性治疗方案的前瞻性研究与临床试验。为实现对HFmrEF患者的更优化治疗，心脏病学家与内科医师充分了解该新型表型的异同点至关重要。