Cardiac function after eight hour storage by using polyethylene glycol hemoglobin versus crystalloid perfusion

Area of Science:

• Cardiovascular Science
• Transplantation Biology
• Biomedical Engineering

Background:

• Crystalloid perfusion for myocardial preservation is limited by edema and compromised function.
• Hypothermic perfusion preservation using novel solutions may extend preservation times for donor hearts.

Purpose of the Study:

• To compare cardiac function after 8-hour hypothermic continuous perfusion preservation using a crystalloid solution with or without polyethylene glycol (PEG) conjugated hemoglobin (Hb).

Main Methods:

• Rabbit hearts underwent cold cardioplegic arrest and were then continuously perfused for 8 hours at 20°C and 30 mm Hg.
• Group I hearts received a hypocalcemic, normokalemic 3% bovine PEG-Hb solution; Group II received an identical crystalloid solution without PEG-Hb.
• Cardiac function was assessed post-preservation using a left ventricular force transducer under standard Langendorff conditions at 37°C.

Main Results:

• Left ventricular developed pressure, peak dP/dt, and peak -dP/dt were significantly superior in the PEG-Hb preserved group (Group I).
• Heart rate and coronary blood flow were similar between the PEG-Hb and crystalloid groups.
• Myocardial edema, measured as percent water of total ventricular weight, was comparable between groups.

Conclusions:

• Hypothermic perfusion preservation with PEG-Hb solution yields superior cardiac function compared to crystalloid solutions alone, despite similar edema and flow.
• This PEG-Hb based solution shows promise for extended cardiac perfusion preservation and warrants further investigation.
• Future studies should compare this novel solution against traditional cardioplegic preservation methods.