Background. In spite of the evidence that good adherence to guidelines can improve clinical outcomes many studies demonstrate suboptimal implementation of guideline-based heart failure (HF) treatment into real clinical practice. The aim of our study was to evaluate the impact of physicians’ adherence to guideline-recommended therapy on the rate of HF re-hospitalizations at 12-months of follow-up.
Methods. This study was part of an international multicenter Optimize Heart Failure Care Program and included 740 patients hospitalized due to worsening HF (mean age 61.9 ± 11.8 years, 70% male, 77.7% with sinus rhythm, NYHA II-IV, mean 2.7 ± 0.6, mean LVEF 35.1 ± 9.9%). To assess physicians’ adherence to the medications recommended by the 2016 ESC HF guidelines, a five-class guideline adherence score for angiotensin converting enzyme inhibitors (ACEIs), beta-blockers (BBs), angiotensin receptor blockers (ARBs), mineralocorticoid receptor antagonists (MRAs), and ivabradine was used.
The score was calculated for each patient by summing the points: 0 for non-prescription of medication in the absence of contraindications and one point each for the use of ACEIs/ARBs, BBs, MRAs and ivabradine. Three types of adherence were defined: good adherence (use of all guideline-recommended medications; score=1); moderate adherence (use of >50% recommended medications; score >0.5-<1); poor adherence (use of 50% recommended medications; score =0.5). To analyze the adherence to the recommended doses of HF medications the score was calculated for each patient by summing the points: 0 for non-prescription of medication, 0.5 points for use of <50% of target doses and 1 point for the each prescribed medication at =50% target dose.
Results. The score of adherence to guideline-recommended medications was good in 80%, moderate in 16%, and poor in 4% of HF patients. However, at discharge from hospital, the proportion of patients at target doses and = 50% of target doses was low (17.7% and 47% for ACEIs/ARBs, 15% and 42% for BBs, 14% and 35% for ivabradine, respectively). 70% of HF patients were at recommended doses of MRAs. The score of adherence to the recommended doses of HF medications was good in 35%, moderate in 63%, and poor in 2% of HF patients without a tendency for improvement during 12 months of follow-up. Poor adherence to guideline-recommended HF medications and to the recommended doses was associated with significantly higher HF hospitalization rates (HR 1.46, 95% CI, 1.18-1.76, p=0.0001 and HR 1.46, 95% CI, 1.18-1.76, p=0.0001, respectively) (Figure).
Conclusion. Regardless of the prevalence of good scores of physicians’ adherence to guideline-recommended HF medications, in most cases the doses of these agents continue to be suboptimal. Poor adherence to guideline-recommended therapy is associated with a higher rate of HF re-hospitalizations. New educational initiatives improving physicians’ adherence to guidelines are required.