2006 HSR&D National Meeting Abstract
3094 — Serum Potassium Monitoring in Veterans Using Renin-Angiotensin-Aldosterone Inhibition
Sauer BC (SLC VAMC (IDEAS))
Kapoor D (SLC VAMC (IDEAS))
Nebeker J (SLC VAMC (IDEAS))
Beddhu S (University of Utah)
Samore MH (SLC VAMC (IDEAS))
Lack of adequate monitoring is a common cause of adverse drug events. ACE-inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) are frequently used in the VA setting, and they are known to cause hyperkalemia in some patients. The objective of this study was to evaluate monitoring practices after initiating ACE-I or ARB therapy.
A retrospective cohort study was performed using the SLC VISTA database. The study population included patients who were initiated on an ACE-I or ARB 10/01/2003 and 08/31/2005. The National Kidney Foundation (NKF) guidelines were used to evaluate monitoring practices of serum K with regards to glomerular filtration rates. Depending on baseline renal function and serum K levels, the NKF guidelines recommend a 12, 4, or 2 week initial monitoring interval.
During the study period 2,936 veterans received a new outpatient ACE-I or ARB prescription. 569 (19%) did not have a baseline serum K and creatinine (Cr) tests. 1,655 (56%) were not followed according to the NKF guidelines. The frequency of veterans who were not monitored within the recommended interval are as follows; 12 week category (50%), 4 week category (67%), and 2 week category (73%). In exploratory logistic regression analysis, factors associated with departure from NKF monitoring recommendations included: having less than 6 outpatient encounters (OR: 1.9; 95% CI: 1.5-2.3), and driving distance >30 miles (OR: 1.19; 95% CI: 1.03-1.4). Initial prescription by a non-cardiologist also tended to increase the likelihood of not being tested according to the recommended interval (OR: 1.3, 95% CI: 0.98-1.77). Current enrollment priority and treatment at satellite clinic were not significant.
More than half of veterans treated with ACE-I/ARB therapy were not receiving recommended baseline and follow-up monitoring. Furthermore, patients with the most baseline renal impairment and/or the highest baseline serum K were least likely to be monitored within the recommended interval.
Use of ACE-I and ARBs are common among veterans. A better understanding of monitoring strategies can help to improve appropriate testing and potentially reduce hyperkalemia and related adverse effects.