Clinical relevance of serum ionized magnesium concentration in dogs with myxomatous mitral valve disease

Abstract

Background: Hypomagnesemia is associated with a poor prognosis in humans with congestive heart failure (CHF), but studies in veterinary medicine are limited. Hypothesis: Serum ionized magnesium concentration [iMg2+] would decrease as CHF progresses compared with the initial diagnostic levels and that lower [iMg2+] would be negatively associated with prognosis in dogs with CHF. Animals: A total of 181 client-owned dogs with myxomatous mitral valve disease (MMVD) were included. They were classified into the preclinical stage (NO-CHF, n = 108), stage C (n = 42), and stage D (n = 31) based on the American College of Veterinary Internal Medicine MMVD classification. Methods: This is a retrospective study from 2 referral centers. The [iMg2+] was compared among the NO-CHF, stage C, and stage D groups. Kaplan-Meier curves and the log-rank test were used to compare the incidence of death between groups. Multivariable Cox regression analysis was used to estimate the association of hypomagnesemia with the death. Results: In the stage D group, the [iMg2+] was lower than that in the NO-CHF (P