We have read with interest the recent clinical practice guidelines for the diagnosis and treatment of heart failure (HF) by the European Society of Cardiology (ESC), published in Spanish in Revista Española de Cardiología,1 as well as the comments on these guidelines by the expert group and Guidelines Committee of the Spanish Society of Cardiology.2 First, we would like to praise the authors of this document for their deep and nuanced analysis of the ESC guidelines, which stresses their most important aspects and helps to clarify their most controversial recommendations.2

We would like to make some comments on the role of ivabradine in HF treatment and its consideration in the 2 documents. As noted by the authors of the Spanish Society of Cardiology document,2 the recommendation for ivabradine use in patients with chronic HF and reduced ejection fraction has undergone subtle changes to more closely reflect the design and results of the study that informed the guidelines (SHIFT),3 as well as its use in patients unable to tolerate beta-blockers (IIb in 2012 and IIa C in the current 2016 guidelines1). Ivabradine is also listed as a second-line treatment, after beta-blockers, for patients with HF and angina pectoris in the “Comorbidities” section. However, in the translation published in Revista Española de Cardiología, made using the original English-language ahead of print version, there was a sentence on the doubts raised by the results of the SIGNIFY study4 that said, “in the SIGNIFY study, in patients with limiting angina without HF, ivabradine increased the risk of cardiovascular death and nonfatal myocardial infarction, which is why it is not recommended in this context”. Although we agree with the conclusion of the cited article concerning patients with angina and without HF, we believe that this comment is not applicable to patients with HF and reduced ejection fraction because the SIGNIFY trial, in addition to using an ivabradine dose higher than that used for HF, excluded patients with HF, which could be a source of confusion in this matter. Indeed, this sentence has been removed from the latest corrected version of the ESC guidelines,5 as well as from the translation of the guidelines.1

Finally, we would like to thank the authors of the Spanish document for having cited our article on the potential benefits of ivabradine administration during the hospitalization of patients with acute HF.6 In our work, the first published study of this drug in the acute HF field, the combined use of ivabradine and beta-blockers between 24 and 48hours after patient admission for HF decompensation was as safe as the usual approach, namely, beta-blockers alone and use of ivabradine only in patients with heart rate > 70 bpm after maximum beta-blocker dose. The patients randomized to the ivabradine + beta-blocker group had a significantly lower heart rate 28 days after discharge, which was associated with a highly significant increase in ejection fraction at 4 months after discharge and a better functional class.6 At 1-year follow-up, the left ventricular ejection fraction continued to be significantly higher in the patients who underwent early treatment with ivabradine during hospitalization. These data indicate the potential beneficial effects of this strategy for acute HF, which is of paramount importance given that no clinical trial has shown a favorable effect of any intervention (pharmacological or nonpharmacological) in this setting, as stated in the 2016 guidelines.1,2