New heart failure reclassification: are we left with more questions than answers?

New heart failure reclassification: are we left with more questions than answers? Angel López-Candalesa , Paula M. Hernández Burgosb and Pedro E. Vargasa aCardiovascular Medicine Division at the University of Puerto Rico School of Medicine, Medical Sciences Campus, San Juan, Puerto Rico; bUniversity of Puerto Rico School of Medicine, San Juan, Puerto Rico ARTICLE HISTORY Received 27 February 2018; Accepted 24 May 2018 KEYWORDS Cardiovascular disease; diastolic heart failure; ejection fraction; preserved ejection fraction; reduced ejection fraction; left ventricle; systolic heart failure; recovered ejection fraction Cardiovascular diseases continue to be the leading cause of death, accounting for approximately 31% of all deaths worldwide with heart failure (HF) being a growing epidemic since 1997 [1,2]. Current estimates indicate that over 37.7 million people are afflicted with HF worldwide [3,4]. In the US alone, 5.8 million patients carry a diagnosis of HF and 875,000 additional new HF cases are expected each year [5]. The complexity of HF as a chronic long-term condition that continues to deteriorate and is associated with inordinate morbidity and mortality and whose intricate pathophysiology and ever-changing left ventricular (LV) cardiac mechanics are beginning to be comprehended; it has become apparent that the old concept of HF being simply viewed as ‘a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the LV to fill or eject blood’ is no longer applicable [6–8]. The introduction of the HF stage classification was an attempt to better understand the interaction existing between potential risk factors and underlying cardiac structural elements needed for the natural progression of LV dysfunction and symptom development to occur [9]. Not only this stage classification was useful to identify individuals along the natural continuum from those at risk of developing HF to those eventually reaching an advanced HF stage, but also provided physicians with treatment options depending on each individual stage while complementing the already useful New York Heart Association, primarily used to gauge symptom severity and functional limitation [10]. Unfortunately, these steps were not enough as the previously held concept of LV systolic versus diastolic HF continued to be a significant source of controversy and confusion, particularly when both of these mechanical abnormalities could coexist in any given HF patient [11,12]. This debate continued until the American College of Cardiology and the American Heart Association both agreed on making the much easier distinction between preserved (HFpEF) and reduced (HFrEF) not only based on left ventricular ejection fraction (LVEF) but also driven by a wealth of existing data clearly identifying two patient populations with different patient demographics, comorbid clinical profile, response to therapy, and overall prognosis [13]. However, it soon became apparent that a number of patients whose previous LVEF values have ranged 40%, 45%, 50%, and ≥55% did not necessarily fit this new reclassification scheme. Therefore, for the sake of convenience, these patients were further subgrouped. A HFpEF borderline subgroup identified patients with an LVEF between 41% and 49% and whose clinical profile, treatment patterns, and outcomes appeared to be similar to patients with HFpEF, while a HFpEF improved subgroup included patients not only previously diagnosed as HFrEF who now have LVEFs 40% but also are now considered to be clinically distinct from those with persistently preserved or reduced LVEF [13]. Even though this new reclassification is useful as it tries to ease patient identification, it still does not solve the main issue of impact on clinical outcomes, as novel HF therapies have not been up to par with the progression and natural evolution of the disease process and most contemporary HF trials have failed to improve outcomes above standard medical therapy [14,15]. This is certainly relevant among HFpEF as both diagnosis and management of this clinical entity not only has been always clinically challenging, but also therapeutic interventions to reduce symptoms and improve functional capacity as well as other patient-reported outcomes have not shown any significant clinical benefit. An additional burden now being recognized is the overall impact of non-cardiac comorbidities among HF patients. Undoubtedly, as the general population continues to age, survival rates after myocardial infarction leading to LV remodeling continue to increase and a greater proportion of individuals are afflicted with obesity, diabetes, and poorly controlled hypertension and a greater number of HF cases will continue to emerge. This is particularly distressing as approximately 25% of Americans are known to have multiple chronic conditions, an estimate that increases significantly to up 75% in patients with 65 years of age and older [16]. Unfortunately, the clinical impact of chronic comorbid conditions though almost universal among HF patients, it is CONTACT Angel López-Candales Division of Cardiovascular Medicine, University of Puerto Rico School of Medicine, San Juan, 365067, Puerto Rico POSTGRADUATE MEDICINE 2018, VOL. 130, NO. 5, 449–451 © 2018 Informa UK Limited, trading as Taylor & Francis Group significantly more relevant in HFpEF patients when compar