1029-17 Long-term Oral Vasopressin V1 Receptor Antagonist Therapy Prevented Chronic Ventricular Remodeling in Conscious Dogs

We assessed the long-term effects of oral vasopressin V1 antagonist, OPC-21268 (1-1-[4-(3-acetylaminopropoxy)benzoyl]-4-piperidyl-3.4-dihydro-2(1H)quinolinone) in conscious dogs with regional myocardial damage by repetitive DC-shocks. Methods Study design includes three groups: without DC shock (•, C, n = 6). DC-shock (z, DC, n = 7). and DC-shock with OPC-21268 100 mg/kg twice daily (▴, V1A, n = 7). Cardiac catheterizations were performed at baseline and at 4 and 16 weeks 1 after DC shocks. At sacrifice LV was fixed with constant pressure and the cavity size was measured. Results LVEDP was higher in DC. Mean aortic pressure was lower in V1A. Stroke volume did not change among the groups. LV long axis and cross-sectional cavity area were larger in DC, however, they were significa ntly smaller in VlA Download : Download high-res image (69KB) Download : Download full-size image C DC V1A Long axis (cm/kg) 4.9 ± 04 6.1 ± 0.4 * 5.5 ± 0.4 # Cavity area (cm2/kg) 0.49 ± 0.04 0.72 ± 0.10 * 0.58 ± 0.12 # * p l 0.05 vs. C, # p l 0.05 vs. DC Conclusions Stroke volume was preserved through increased LV volume and elevated LVEDP in dogs with DC shocks. OPC-21268 effectively reduced preload and afterload, resulting in smaller LV cavity and normal LVEDP while maintaining stroke volume