Evaluation of red blood cell distribution width as a prognostic indicator in cats with acquired heart disease, with and without congestive heart failure.

Objectives Congestive heart failure secondary to cardiomyopathy is a common manifestation of cardiac disease in cats, carrying a variable prognosis. The objective of this retrospective study was to evaluate the relationship between red blood cell distribution width (RDW) and survival time in feline patients with acquired heart disease with and without congestive heart failure (CHF). Methods Three hundred and forty-nine client-owned cats with echocardiograms and complete blood count, including RDW measurement, performed between March 2006 and December 2011, were included in the study. Patient characteristics, including signalment, hematocrit, RDW, echocardiographic parameters and survival, were recorded. Comparisons between RDW in cats with asymptomatic acquired heart disease and those with CHF were made. Survival was documented and compared at 30 days and 6 months. Results CHF was present in 80 cats and absent in 269 cats. Cats with CHF had an increase in mortality compared with cats without CHF at 30 days and 6 months ( P = 0.007 and P = 0.04, respectively). RDW was not significantly associated with survival in cats with or without CHF at 30 days or 6 months. A significant difference was found between median RDW values in cats with CHF vs cats without CHF (16.3% vs 15.8%; P = 0.02). The median RDW value was significantly higher in cats with unclassified cardiomyopathy compared with cats with other types of cardiomyopathy (16.3% vs 15.8%; P = 0.03). Conclusions and relevance Single RDW values did not predict mortality in cats with acquired heart disease but may be useful in determining if cats have decompensated heart disease and CHF. Human studies indicate that incremental increases in serial RDW measurements are associated with decreased survival; serial RDW measurements in cats may be an area of future study.

Assessment of the responsiveness of the Cats' Assessment Tool for Cardiac Health (CATCH) Questionnaire.

OBJECTIVES: To evaluate the responsiveness and optimal timing of a validated health-related quality of life questionnaire, and to assess the relationship between quality of life, severity of disease, and N-terminal pro B-type natriuretic peptide (NT-proBNP) in cats with acute congestive heart failure (CHF). ANIMALS: Thirty client-owned cats with acute CHF. METHODS: Echocardiography, International Small Animal Cardiac Health Council (ISACHC) stage, and NT-proBNP were assessed in cats within 36 h of admission. The Cats' Assessment Tool for Cardiac Health (CATCH) Questionnaire (range of 0-80, with 80 being the worst possible score) was completed by cat owners and ISACHC stage was assessed at the time of hospital discharge, 3 days after discharge, and 7-14 days after discharge. NT-proBNP concentration was reassessed 7-14 days after discharge. RESULTS: The ISACHC stage at time of admission improved significantly by reevaluation 7-14 days after discharge (P < 0.001). The decrease in median NT-proBNP concentration from time of admission (655 pmol/L; range, 188 to >1500 pmol/L) to reevaluation (583 pmol/L; range, 41 to >1500 pmol/L) was not significant (P = 0.59). Median CATCH score was 26 (range, 0-70) at baseline, 19 (range, 0 to 61) at discharge, and 19 (range, 2-49) 7-14 days after discharge (P = 0.89). CATCH scores did not correlate with NT-proBNP concentrations or ISACHC stage. CONCLUSIONS: These results suggest that the CATCH questionnaire requires further refinement for uses requiring a responsive instrument in cats with acute CHF.

Pharmacokinetics of N-acetylcysteine after oral and intravenous administration to healthy cats.

OBJECTIVE: To describe the pharmacokinetics of N-acetylcysteine (NAC) in healthy cats after oral and IV administration. ANIMALS: 6 healthy cats. PROCEDURES: In a crossover study, cats received NAC (100 mg/kg) via IV and oral routes of administration; there was a 4-week washout period between treatments. Plasma samples were obtained at 0, 5, 15, 30, and 45 minutes and 1, 2, 4, 8, 12, 24, 36, and 48 hours after administration, and NAC concentrations were quantified by use of a validated high-performance liquid chromatography-mass spectrometry protocol. Data were analyzed via compartmental and noncompartmental pharmacokinetic analysis. RESULTS: Pharmacokinetics for both routes of administration were best described by a 2-compartment model. Mean ± SD elimination half-life was 0.78 ± 0.16 hours and 1.34 ± 0.24 hours for the IV and oral routes of administration, respectively. Mean bioavailability of NAC after oral administration was 19.3 ± 4.4%. CONCLUSIONS AND CLINICAL RELEVANCE: The pharmacokinetics of NAC for this small population of healthy cats differed from values reported for humans. Assuming there would be similar pharmacokinetics in diseased cats, dose extrapolations from human medicine may result in underdosing of NAC in cats with acute disease. Despite the low bioavailability, plasma concentrations of NAC after oral administration at 100 mg/kg may be effective in the treatment of chronic diseases.