The effect of initial flush for cooling and coronary vascular washout in heart preservation

Abstract

Initial flush for cooling and coronary vascular washout using University of Wisconsin (UW) solution has presented some problems. We used a separate solution for initial flush and for subsequent storage, and evaluated the effect of initial flush for prolonged heart preservation. Following potassium arrest, the initial flush was performed using UW solution (UW group) or Physiol · 3^® solution with additional potassium (PK group). In the PK group, an additional flush with the UW solution was done prior to preservation. The hearts of both groups were stored in the cold UW solution for 12 hours. Myocardial high-energy phosphates were measured using phosphorus 31 nuclear magnetic resonance spectroscopy (UW group: n = 7, PK group: n = 5). Adenosine triphosphate (ATP) levels in the UW group decreased to 23% of the control after storage. ATP levels in the PK group were well maintained for up to 6 hours, and then decreased to 51% (p < 0.01). Orthotopic transplantation was performed in 10 pairs of dogs (UW group: n = 7, PK group: n = 3). Preserved grafts in the PK group (74%) tended to show better recovery of left ventricular pressure than those in the UW group (52%). These results suggest that the introduction of an initial flush may prevent ATP level reduction during cold storage, and may provide good results after transplantation. An initial flush for cooling and coronary vascular washout is important for prolonged heart preservation.