Pharmacist Intervention Increases Optimization Of Guideline-directed Medical Therapy In Heart Failure Patients With Medication Intolerances

Introduction Patients with heart failure with reduced ejection fraction (HFrEF) are frequently not prescribed target doses of guideline-directed medical therapy (GDMT) due to a documented history of medication intolerances. Clinical pharmacist involvement in multidisciplinary HF clinics improves GDMT uptake through assistance with patient education and monitoring of drug safety/efficacy. Hypothesis We hypothesized that a pharmacist-led GDMT titration protocol would increase rates of GDMT use and optimization in patients with previously documented medication intolerances. Methods Patients with HFrEF were referred by HF Cardiologists to a pharmacist-led GDMT titration protocol between June 2019-February 2021. Those with ACC/AHA Stage D HF, NYHA class IV symptoms, or contraindications to medication titration were excluded. Interventions included initiating potassium-lowering therapies, implementing therapeutic interchanges, counseling on diet and adverse effects, and outreach to review symptoms and vital signs. In patients with previously reported medication intolerances, the rate of successful GDMT initiation or uptitration was assessed after pharmacist intervention. Results Among the 79 patients referred to the protocol, 26 (33%) had documented intolerance at enrollment to ACEI/ARB/ARNI, beta-blocker, or MRA. Hyperkalemia (N=11) and symptomatic hypotension (N=11) were the most common previously reported adverse effects. In our cohort, mean age was 59 years, 21 (27%) were female, and mean LVEF was 27%. Compared to those without a prior intolerance, patients with an intolerance were less likely to be prescribed MRA (35% vs. 62%, p = 0.02), but other baseline characteristics were similar. After pharmacist intervention, 20 of the 26 (77%) patients with prior intolerance were able to be initiated or uptitrated on the respective medication class, with high rates of success in those with prior hyperkalemia or symptomatic hypotension but not in those with symptomatic bradycardia from beta-blockers (Figure). Conclusions In a referral cohort of HFrEF patients, one-third of patients were thought to be intolerant to specific GDMT drug classes, but pharmacist involvement facilitated successful initiation or uptitration on these medications in the majority of patients, particularly when the intolerance was related to hyperkalemia or symptomatic hypotension. If this model is applied more broadly in the HFrEF population, these simple and practical interventions could enhance GDMT uptake and improve long-term outcomes.