Intra-aortic Balloon Counterpulsation in Cardiogenic Shock During Acute Myocardial Infarction

Forty-one patients (aged 42-78 years) with cardiogenic shock due to acute myocardial infarction (AMI) who required intra-aortic balloon counterpulsation (IABP) were included in the study. The patients were followed between December 1990 and April 1993. IABP was administered in 20 patients (group A); 21 patients in whom IABP was not installed for various reasons were followed up medically (group B). No significant difference between the two groups was found other than a history of previous angina, higher initial pulse rates and higher CPK peak values in group A. Fourteen patients in group A and 15 patients in group B died (statistically not significant). When the 6 surviving patients in group A and 14 dead patients were compared, the surviving patients were found to be younger, had a faster pulse on admission, lower pulmonary capillary wedge pressures. Furthermore, IABP was administered earlier to the surviving patients. These prognostic factors, were not observed in group B. The parameters measured to evaluate the clinical and hemodynamic benefit of IABP in group A revealed an increase in arterial PO2 from 57.8±13.6 to 79.5±16.8 mmHg (p<0.005) and a decrease in mean pulmonary artery pressure and pulmonary capillary wedge pressure from 33±5.3 and 22±4.6 mmHg to 27.3±5.9 and 18.5±5.1 mmHg (p<0.025, p<0.05), respectively. Complications were observed in 3 patients: Two femoral emboli between days 2-5 and one threat of gangrene. It was concluded that the in-hospital mortality was unchanged by IABB. The observation that IABP administration for treating cardiogenic shock during acute MI led to an increase in arterial PO2 and a decrease in mean pulmonary artery pressure and pulmonary capillary wedge pressure suggests that it might have a beneficial effect on prognosis especially in young patients with moderately evelated pulmonary capillary wedge pressure.