Purpose: Mineralocorticoid Receptor Antagonists (MRA) have been proven to lower hospitalization rates for worsening heart failure, have a significant improvement in heart failure symptoms and are recommended in selected patients by current ESC guidelines. Managing a mostly older cohort of patients with advanced heart failure and multiple co morbidities including chronic kidney disease can be challenging. One such challenge is the difficulty in up- titrating MRA's to the recommended daily dose. There is limited data on the effectiveness of lower dose MRA's in reducing hospitalisations or NYHA class. We examined the effectiveness of lower doses of Eplerenone (<225mgs OD- mean dose = 22.5mg) and Spironolactone (<25 mgs OD mean dose = 12.5mg) in 37 patients attending an outpatient heart failure service.
Method: A retrospective study examined 37 patients currently attending the heart failure service in the last quarter of 2014 (average age 77 years, 13 female, 24male) in NYHA class 2 to 4, 24 with reduced EF (<40%) and 13 patients with HFPEF (EF 50%). All patients attending the service observed to be on lower dose MRA's were included in the study. All available patient records were examined pre and post introduction of lower dose MRA's to determine EF, EGFR, Creatinine level, Systolic BP, NYHA class and admission rates. Admission rates also included episodes of decompensating heart failure managed in an ambulatory setting with IV diuretics from 2011 to 2014.
Results: The mean number of admissions per patient prior to introduction of MRA's was 1.16 compared to 0.37 post introduction. The results indicate a significant reduction in admission rates post introduction of lower dose MRA's (p = 0.001). NYHA class was shown to be reduced significantly (p = 0.0001). Prior to introducing lower dose MRA's the mean NYHA class was 3.2 compared to 2.5 post introduction of MRA. There were no significant changes in EF, Creatinine level, EGFR or Systolic BP. Potassium levels were not significantly different post introduction. However the mean Potassium level prior to introduction of low dose MRA was 3.8mmols compared to 4mmols post introduction.
Conclusion: This study suggests the use of lower dose MRA's in patients unable to tolerate recommended daily doses will still benefit from a reduction in admission rates and an improvement in NYHA class.