Abstract 3471: Intra-Aortic Balloon Pumping Does Not Increase Early Coronary Flow Following PCI in High Risk Patients: Observations from a Prospective, Randomised Study
The intra aortic balloon pump (IABP) is the most commonly used temporary cardiac assist device that has immediate beneficial haemodynamic effects. The role and mechanism of its potential benefit in non shocked high risk patients undergoing angioplasty (PCI) have not been fully resolved. We hypothesized that the use of an IABP following PCI in such patients would increase coronary blood flow and preserve left ventricular function.
Methods Predefined high risk but non shocked patients were randomised to either an IABP or no IABP following PCI. Angiography was obtained pre PCI, post PCI and 10 minutes after the completion of the procedure. We studied TIMI flow grade (TFG), TIMI frame count (TFC), myocardial blush grades (MBG). Serial ECG and echocardiographic wall motion index (WMI) was measured on days 1 and 30 following PCI.
Results Of 33 patients, 18 patients were randomised to the IABP arm and 15 into the no IABP arm. There were no significant differences in the baseline clinical and angiographic characteristics between the two groups. At final angiography the TFG was 2.8±0.7 and 2.9±0.3 (p=0.7), the TFC was 19.2±22.5 and 17.7±17.3 (p=0.8) and the MBG was 2.6±0.8 and 2.5±0.7 (p=0.7) in the IABP and the no IABP groups. The WMI on day 1 was 1.7±0.4 and 1.7±0.5 (p=0.6), and on day 30 it was 1.5±0.4 and 1.5 ±0.4 (p=0.9). There was no difference in the total sum of ST segment elevation prior to PCI (13.5±8.2 vs. 12.6±7.2, p=0.8) nor in the summed ST change in subsequent ECGs to 48 hours. All of the IABP patients had some degree of ST resolution by 24hrs; 2 in the control group had no resolution (p=0.1). Whether an IABP is beneficial in non shocked but high risk patients undergoing PCI remains to be established, but any potential benefit does not appear to be associated with early improvement in coronary flow and did not affect subsequent left ventricular wall motion index in this study. Whether it improves coronary flow beyond ten minutes is not known.