Abstract
Background: Changes in clinical variables associated with the administration of pimobendan to dogs with preclinical myxomatous mitral valve disease (MMVD) and cardiomegaly have not been described. Objectives: To investigate the effect of pimobendan on clinical variables and the relationship between a change in heart size and the time to congestive heart failure (CHF) or cardiac-related death (CRD) in dogs with MMVD and cardiomegaly. To determine whether pimobendan-treated dogs differ from dogs receiving placebo at onset of CHF. Animals: Three hundred and fifty-four dogs with MMVD and cardiomegaly. Materials and Methods: Prospective, blinded study with dogs randomized (ratio 1:1) to pimobendan (0.4-0.6 mg/kg/d) or placebo. Clinical, laboratory, and heart-size variables in both groups were measured and compared at different time points (day 35 and onset of CHF) and over the study duration. Relationships between short-term changes in echocardiographic variables and time to CHF or CRD were explored. Results: At day 35, heart size had reduced in the pimobendan group: median change in (D) LVIDDN -0.06 (IQR: -0.15 to +0.02), P < 0.0001, and LA: Ao -0.08 (IQR: -0.23 to +0.03), P < 0.0001. Reduction in heart size was associated with increased time to CHF or CRD. Hazard ratio for a 0.1 increase in DLVIDDN was 1.26, P - 0.0003. Hazard ratio for a 0.1 increase in DLA: Ao was 1.14, P = 0.0002. At onset of CHF, groups were similar. Conclusions and Clinical Importance: Pimobendan treatment reduces heart size. Reduced heart size is associated with improved outcome. At the onset of CHF, dogs treated with pimobendan were indistinguishable from those receiving placebo.
| Item Type: | Journal article |
|---|---|
| Faculties: | Veterinary Medicine |
| Subjects: | 600 Technology > 610 Medicine and health |
| ISSN: | 1939-1676 |
| Language: | English |
| Item ID: | 65874 |
| Date Deposited: | 19. Jul 2019 12:18 |
| Last Modified: | 04. Nov 2020 13:46 |
