Acute heart failure (AHF) is defined as the rapid onset or worsening of the signs and symptoms of heart failure. AHF can present as the first manifestation of heart failure (de novo) or, more typically, as the consequence of an acute decompensation of chronic heart failure and can be caused by a primary cardiac dysfunction or triggered by extrinsic factors, more commonly in patients with chronic heart failure.1 AHF is a life-threatening condition that requires emergency assessment and treatment and typically entails hospitalization. In Spain, AHF is the leading cause of hospitalization for individuals older than 65 years,2 although 24% of patients with AHF are discharged from hospital emergency departments without requiring hospitalization.3

In this issue of Revista Clínica Española, García, Sarasola et al.4 present the results of the de novo Acute Heart Failure study (Insuficiencia Cardiaca Aguda de novo, NOVICA), a secondary and retrospective analysis of the Epidemiology of Acute Heart Failure in Emergency Departments (EAHFE) registry, a multicenter, multipurpose, analytical, noninterventional registry, with a prospective follow-up that consecutively included all patients treated for AHF in 34 Spanish hospital emergency departments. This study included 8647 patients from EAHFE-1 (2007) to EAHFE-4 (2014)5 for which the variable “first episode of AHF or HF decompensation in patients with a previous AHF episode” was available. The patients were differentiated between de novo acute heart failure (NOAHF, n = 3288) and acute decompensated heart failure (ADHF, n = 5359). Patients were considered to have NOAHF if they had an initial decompensated AHF that required emergency care. The study’s primary objective was two-fold: 1) to report the clinical characteristics and conduct with the patients treated in the hospital emergency departments for NOAHF and compare them with those who were treated for ADHF and 2) to assess the prognosis of the patients with NOAHF compared with that of the patients with ADHF in terms of survival (hospital, at 30 days and at 12 months) and emergency department readmission for AHF 30 after the discharge. In terms of the results, NOAHF was associated with lower comorbidity, better baseline condition, lesser severity of the acute episode and lower hospitalization rate. The patients with NOAHF were more often admitted to the cardiology departments or intensive care units than those with ADHF, who were more often managed in short-stay units. Rates of raw mortality at 30 days and 12 months and readmission at 30 days were lower for the patients with NOAHF. In the adjusted analysis, however, only the rate of readmission at 30 days was lower for NOAHF (p < .001).

The epidemiology and risk factors of AHF have merited the attention of various registries (ADHERE, OPTIMIZE-HF, EHFS I AND II, ESC-HF and ALARM-HF, among others). These registries have observed data similar to that found in NOVICA,4 given that the mean age at presentation was approximately 70 years, with approximately 50% women, arterial hypertension being the most common comorbidity and with a proportion of patients with ADHF of 65–75%.6

An important point is that the pathophysiology and profile of patients with NOAHF are different from those of patients with ADHF. NOAHF usually presents as acute pulmonary edema within a sudden increase in intracardiac filling pressure and/or in the presence of acute myocardial dysfunction. ADHF presents as the result of chronic neurohormonal deregulation, which leads to the onset of congestive signs and symptoms in patients with already known cardiomyopathy.7 Patients with ADHF are also older, with a higher proportion of women and a higher prevalence of arterial hypertension, diabetes mellitus, pulmonary disease and atrial fibrillation.8

As in previous studies, the raw mortality in NOVICA for the patients with ADHF was higher than that for those with NOAHF, due in part to the fact that patients with ADHF are in a more advanced stage of disease. However, the weight of a history of heart failure varies from one study to another. For example, the FINN-AKVA registry analyzed 620 patients with AHF and found that a history of heart failure was an independent predictor of mortality at 5 years.9 In the EHFS II registry, which included 2981 patients with AHF, the factors independently associated with increased mortality were age, previous myocardial infarction, serum creatinine and hyponatremia.10 The main finding of NOVICA4 is that all-cause mortality during the year following the emergency department visit was similar for the patients with ADHF and for those with NOAHF, when the analysis was performed adjusted to the baseline characteristics and those of the acute episode. Unfortunately, we do not have the causes of death (cardiac vs. non-cardiac), whose analysis would have been very interesting. One of the reasons that could have contributed to these results and a strength of NOVICA is that it provides a holistic view of the problem, because it includes all patients who were admitted to an emergency department for AHF, while most registries that compare both forms of the AHF presentation have an approach limited to patients hospitalized in certain medical departments.11,12

The authors openly recognized 2 obvious limitations of the registry: exclusion of patients with acute coronary syndrome and the lack of the sample size calculation, given that this was a secondary analysis.

In conclusion, NOVICA once more demonstrates that AHF is an entity with a somber prognosis. We therefore need to continue researching strategies, both pharmacological and organizational, that can contribute to preventing episodes of decompensation.