How many heart failure patients do not take adequate doses of beta-blockers even though they could?

Methodology and Study Objectives

The recommendation to use beta-blockers in the treatment of HFrEF stems from the results of numerous randomized controlled trials that demonstrated their benefits at recommended doses, especially in terms of left ventricular remodeling, hospitalization rates, and lifespan. The aim of the presented research was to determine the proportion of HFrEF patients not receiving the optimal BB dose, evaluate their treatment outcomes, and attempt to identify the main reasons for administering a lower dose.

This was a prospective cohort study that analyzed data from 390 outpatient heart failure patients with a left ventricular ejection fraction (LVEF) ≤ 45% examined between 2006 and 2009 at university hospitals in Leeds, UK. These patients underwent clinical and echocardiographic examinations at study entry and then after 1 year. They were subsequently followed until 2018 or until their death, if it occurred earlier.

Findings

An optimal dose of beta-blockers corresponding to ≥ 5 mg bisoprolol/day was used by 61% of patients at the 1-year follow-up. In another 18%, the BB dose could not be titrated upward due to low heart rate (< 60/min) or low systolic blood pressure (< 100 mmHg). The remaining 21% did not use an optimal BB dose even though they could have.

During the average follow-up period of 7.6 years, 59.3% of the observed patients died. Patients on an optimal BB dose showed lower mortality. After adjusting for age and sex, the optimal BB dose at the 1-year follow-up was associated with a significant 5% reduction in mortality (p = 0.004) compared to patients who did not take the optimal BB dose. This statistically significant difference persisted even in multivariate analysis, accounting for other differences between groups at study entry and during follow-up, amounting to 4% (p = 0.029). Higher mortality was observed in both patients unable to take the optimal BB dose and those who could have but did not receive it.

Compared to patients on an optimal BB dose, those not receiving an adequate BB dose despite the possibility were older and more frequently suffered from ischemic heart disease, renal dysfunction, and were 4 times more likely to have chronic obstructive pulmonary disease.

Conclusion

Despite meticulous hospital and community care, approximately 40% of patients with heart failure and reduced LVEF do not receive an optimal dose of beta-blockers, and in more than half of these, the reason is neither bradycardia nor hypotension. Patients with insufficient BB dosage achieve worse outcomes regardless of whether or not they can take the optimal dose. For the majority, no reason for suboptimal BB dosing could be found among clinical characteristics. It seems that unexplored or inadequately assessed factors must be the reason.

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Source: McGinlay M., Straw S., Byrom-Goulthorp R. et al. Suboptimal dosing of β-blockers in chronic heart failure: a missed opportunity? J Cardiovasc Nurs 2021 Jul 26, doi: 10.1097/JCN.0000000000000847 [Epub ahead of print].