Effects of diaspirin crosslinked haemoglobin during coronary angioplasty in the swine

Objective: Percutaneous transluminal coronary angioplasty produces a transient interruption of coronary blood flow during balloon inflation, giving rise to temporary regional myocardial ischaemia. Diaspirin crosslinked haemoglobin (DCLHb™) transports oxygen in a similar way to whole blood and can be perfused through the angioplasty catheter during balloon occlusion. The aim of this study was to test the hypothesis that DCLHb may increase myocardial oxygenation and reduce myocardial ischaemia during coronary angioplasty. Methods: The effect of DCLHb on cardiac function was measured in diazepam sedated swine. Mean arterial blood pressure, peak systolic left intraventricular pressure, maximum rate of left ventricular pressure development (dP/dtmax), pressure-rate product, cardiac output (CO), and ECG were monitored continuously. Variables were compared during control, during 1 min balloon occlusion of the proximal left anterior descending coronary artery with a 2.5-3.5 F angioplasty catheter, during 1 min of DCLHb perfusion (40 ml·min−1) without balloon occlusion, and during 4 min balloon occlusion with DCLHb perfusion (40 ml·min−1) of the occluded region. Measurements were made during balloon occlusion plus DCLHb at 1 min (B + D1). 2 min (B + D2), and 4 min (B + D4). Results: Balloon occlusion decreased cardiac function as compared to control: arterial blood pressure -16%, intraventricular pressure -14%, dP/dt,max -34%, and pressure-rate product -40%. DCLHb alone did not significantly change haemodynamic measurements from control. At B + D4 haemodynamic variables were increased as compared to balloon occlusion alone: arterial blood pressure +32%, intraventricular pressure +29%, dP/dtmax + 20%, and pressure-rate product +19%. Only intraventricular pressure and mean arterial pressure were increased compared to control. The S-T segment of the ECG was depressed by 0.109(SEM 0.019) mV during balloon occlusion without DCLHb, while only decreasing by 0.069(0.027) mV at B + D1, by 0.046(0.018) mV at B + D2, and by 0.058(0.018) mV at B + D4. Conclusions: There is an improvement in cardiac function and a lessening of S-T segment depression during percutaneous transluminal coronary angioplasty balloon occlusion with DCLHb perfusion. Cardiovascular Research 1994; 28 :1188-1192