Clinical and Social Determinants of Guideline-Directed Medical Therapy Optimization in Heart Failure with Reduced Ejection Fraction

Background: Heart failure with reduced ejection fraction (HFrEF) is associated with high morbidity and mortality. Guideline-directed medical therapy (GDMT) for HFrEF has been shown to improve outcomes, with higher GDMT scores at hospital discharge being associated with lower mortality, fewer rehospitalizations and reduced healthcare costs. Yet, disparities in the utilization of GDMT remain. In this study, we examined the effect of various clinical, demographic, and socioeconomic factors on the utilization of GDMT in HFrEF patients referred to Cardiology in a tertiary care safety net hospital, using a standardized GDMT scoring system. Methods: We conducted a single-center cross-sectional retrospective analysis of patients who had an index HFrEF 40% diagnosis between January 1, 2024, to December 31, 2024, and who were referred to Cardiology at a tertiary care safety net hospital. Baseline characteristics, laboratory investigations, health care utilization, and GDMT score data were extracted at the ambulatory care visit nearest to 90 days from the index HF diagnosis. GDMT score ranges from 0 to 9 factored in doses of beta-blocker (BB), angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEi/ARB), mineralocorticoid receptor antagonist (MRA), sodium-glucose cotransporter 2 inhibitor (SGLT2i), angiotensin receptor-neprilysin inhibitor (ARNI), isosorbide dinitrate/hydralazine (ISDN/HYD). Multivariable logistic regression was performed to examine associations between low GDMT scores (0-4) nearest to 90 days from new onset HFrEF diagnosis and several clinical, demographic, and socioeconomic variables. Results: In 200 patients meeting entry criteria, mean age was 62.7 years, 64.0% were male, 47.5% were classified as white and 42.0% as Black. 39.5% had a low GDTM score (<5). The following were less likely to be associated with low GDMT score: diabetes mellitus (adjusted OR: 0.41, 95%CI=0.18-0.91) and frequent medical appointments (adjusted OR: 0.37, 95% CI=0.25-0.54), while higher serum eGFR was more likely to be associated with low GDMT score (adjusted OR: 1.02, 95%CI=1.00-1.03). There was no significant association between GDMT score and age, sex, race, or payer status. Conclusion: In patients with HFrEF referred to Cardiology in our safety net tertiary care center, higher utilization of GDMT at 90 days was achieved in those who have diabetes mellitus, more frequent medical appointments, or lower serum eGFR. There was no difference in GDMT utilization according to age, sex, race, or payer status predictive of lower GDMT scores. Contrary to findings from previous studies, no significant differences were observed across demographic or payer groups, emphasizing the role of healthcare access and utilization.