Prognostic relevance of short-term changes in body weight, renal indices, and echocardiographic variables after intravenous diuretic therapy in dogs with myxomatous mitral valve disease hospitalized for pulmonary edema

Congestive heart failure (CHF) secondary to myxomatous mitral valve disease (MMVD) is managed with diuretics, yet the prognostic value of short-term hemodynamic responses remains unclear. This retrospective study evaluated 50 dogs with ACVIM stage C or D MMVD hospitalized for CHF. We assessed changes in body weight, echocardiographic parameters, and renal values before and after intravenous (IV) diuretic therapy to determine their association with survival. IV diuretic therapy led to significant reductions in body weight and echocardiographic indices, including the left atrium-to-aortic root ratio (LA/Ao), normalized left ventricular internal diameter in diastole (LVIDDN), and early diastolic transmitral flow velocity (all P < 0.005). Conversely, blood urea nitrogen and creatinine concentrations significantly increased (P < 0.001). However, neither short-term changes in these variables nor post-treatment values were associated with long-term survival. Baseline LA/Ao and LVIDDN were related to survival in univariable analysis, while prior oral diuretic therapy was the only independent predictor in the multivariable model (Hazard Ratio 4.21; P < 0.001). Dogs with prior diuretic use had shorter median survival (194 days) than those without (459 days). Thus, short-term echocardiographic improvements reflect effective decongestion rather than long-term prognosis. Prognostic evaluation should prioritize baseline assessments and treatment history.