To estimate the percentage of heart failure patients in Spain that received the European Society of Cardiology recommended treatments, and in those that did not, to determine the reasons why.

The study included 2834 consecutive ambulatory patients with heart failure from 27 Spanish hospitals. We recorded general information, the treatment indicated, and the reasons why it was not prescribed in some cases. In patients who met the criteria to receive a certain drug, true undertreatment was defined as the percentage of patients who, without justification, did not receive the drug.

In total, 92.6% of ambulatory patients with low ejection fraction received angiotensin converting enzyme inhibitors or angiotensin receptor blockers, 93.3% beta-blockers, and 74.5% mineralocorticoid receptor antagonists. The true undertreatment rates were 3.4%, 1.8%, and 19.0%, respectively. Target doses were reached in 16.2% of patients receiving angiotensin converting enzyme inhibitors, 23.3% of those with angiotensin receptor blockers, 13.2% of those prescribed beta-blockers, and 23.5% of those with mineralocorticoid receptor antagonists. Among patients who could benefit from ivabradine, 29.1% received this drug. In total, 36% of patients met the criteria for defibrillator implantation and 90% of them had received the device or were scheduled for implantation, whereas 19.6% fulfilled the criteria for resynchronization therapy and 88.0% already had or would soon have the device. In patients who met the criteria, but did not undergo device implantation, the reasons were not cost-related.

When justified reasons for not administering heart failure drugs were taken into account, adherence to the guideline recommendations was excellent. Exclusive use of the percentage of treated patients is a poor indicator of the quality of healthcare in heart failure. Measures should be taken to improve the attainment of optimal dosing in each patient.