Evaluation of a guideline directed medical therapy titration program in patients with heart failure with reduced ejection fraction

Abstract

Introduction: Heart failure is associated with recurrent hospitalizations and high mortality. Guideline directed medical treatment (GDMT), including beta blockers (BBs), angiotensin converting enzyme inhibitors (ACE-Is), angiotensin receptor blockers (ARBs) and aldosterone antagonists (AAs) has shown to improve outcomes. Current guidelines recommend the use of these medication classes at maximally tolerated dosages. Despite the evidence, < 25% of patients with heart failure with reduced left ventricular ejection fraction (HFrEF) are on the appropriate medical regimen titrated to the target doses. As such, we sought to assess the utility of a focused GDMT clinic to reduce this gap.

Methods: We conducted a retrospective chart review through existing patient data in a single center teaching hospital of patients referred to a focused GDMT clinic primarily staffed with heart failure trained nurse specialists, physician assistants and cardiologists. Management guidelines were developed with protocols for the initiation and uptitration of all therapeutic agents considered as GDMT.Our primary objective was to determine whether enrollment into a dedicated nursing led guideline directed medical therapy clinic would increase the proportion of patients with heart failure with reduced ejection fraction on appropriate medications as well as medication dosages in patients, the percentage of patients on the following medications and percentage at target doses: Renin-Angiotensin-Aldosterone System Blockers, Evidence Based Beta Blockers, and Aldosterone Antagonists. Our secondary objective was to determine if there was any clinical benefit on objective measures including renal function, hospital admissions, mortality and implantable defibrillator shocks.

Results: Between October 2015 and March 2017, 63 patients were identified by requisition forms, in which 61 were able to be identified based on legibility of identifying information. Mean duration of follow up was 264.44 ± 162.68 days over 7 ± 3.94 days. Mean ejection fraction was 21.8 ± 7.3%. New onset cardiomyopathies (diagnosed within 30 days) compiled 21% of the patient population while those with demonstrated cardiomyopathies (> 90 days) compiled 48% of the patient population. Patients with NYHA class III heart failure compiled 65% of the patient population.There was a statistically significant increase in the mean number of GDMT at any dose (2.31 ± 0.76 to 2.74 ± 0.66; p < 0.001) and mean number of GDMT at target doses (0.54 ± 0.79 to 1.52 ± 1.1; p < 0.001). Percentage of the population that were on no target doses at initial visit was 62% which was reduced to 18% after intervention.Clinical improvement was reflected in significant improvement in ejection fraction from 21.8 ± 7.8% to 36.2 ± 14.3% (p < 0.001). Increases in sodium and chloride were statistically small but significant. There a significant reduction in heart failure hospitalizations in comparison to a year prior to after the initial encounter in the clinic (p < 0.001).

Conclusion: This pilot study showed that a nurse directed GDMT titration program successfully increased the number of GDMT that patients were able to tolerate in a timely fashion, all the while enhancing ejection fraction, sodium and chloride levels, with a reduction in rehospitalization rates.

Fig. 1

Proportion of patients tolerating medical therapy at maximal doses before and after nursing directed up titration.

Fig. 2

Proportion of patients tolerating medical therapy by class at maximal dosage before and after nursing directed up titration.