No Role for Elective IABP in High-risk PCI
Abstract & Commentary
By Andrew J. Boyle, MBBS, PhD
Source: Perera D, et al. Elective Intra-aortic balloon counterpulsation during high-risk percutaneous coronary intervention. JAMA. 2010;304:867-874.
Patients with extensive coronary artery disease (CAD) and left ventricular (LV) dysfunction are at high risk during revascularization. Whether elective placement of an intra-aortic balloon pump (IABP) reduces the risk of complication during high-risk percutaneous coronary intervention (PCI) remains unknown. Thus, Perera and colleagues performed a prospective, randomized, controlled trial of electively using IABP in patients undergoing PCI with LV dysfunction.
They enrolled patients who were undergoing high-risk single- or multi-vessel PCI to native coronary arteries or bypass grafts. High-risk was defined as LV ejection fraction ≤ 30% and a large amount of myocardium subtended by the stenosed vessel, or a left main stenosis, or a target vessel supplying collaterals to an occluded second vessel that, in turn, supplied more than 40% of the myocardium. Patients were randomized to receive elective IABP or no planned IABP. The primary outcome was major adverse cardiac and cerebrovascular event (MACCE) defined as death, myocardial infarction (MI), stroke, further revascularization with PCI or CABG after the index procedure to hospital discharge, or 28 days, whichever came first.
Results: A total of 301 patients were randomized to elective IABP (n = 151) vs. no planned IABP (n = 150). One patient in each group underwent coronary artery bypass graft (CABG) surgery instead of PCI. Three patients in the elective IABP group did not receive an IABP due to vascular access issues, and two in the no IABP group did receive an IABP prior to the PCI. Analysis was performed on an intention-to-treat basis. Baseline demographics were similar between groups with high-risk clinical features in both: mean age of 71 years, 35% diabetes, and mean LV ejection fraction 24%. There were no differences in the number of lesions attempted (2.15 vs. 2.05), the number of stents used (2.56 vs. 2.31), use of glycoprotein IIb/IIIa inhibitors (39.3% vs. 43.3%), or the procedural success rate (93.9% vs. 93.0%) in the elective IABP and no IABP groups, respectively. Two-thirds of all stents used were drug-eluting stents.
The primary endpoint occurred in 15.2% of the elective IABP group vs. 16.0% of the no IABP group (p = 0.85). There also was no difference between any of the individual components of the composite primary endpoint. There were fewer procedural complications in the elective IABP group (1.3% vs. 10.7%; p < 0.001), defined as prolonged hypotension, ventricular tachycardia/fibrillation requiring defibrillation, or cardiorespiratory arrest requiring assisted ventilation. However, there was a higher rate of minor bleeding in the elective IABP group (15.9% vs. 7.3%; p = 0.02). There was a numerically, but not statistically significantly, lower six-month mortality in the elective IABP group (4.6% vs. 7.4%; p = 0.32). The authors conclude that elective IABP insertion did not reduce the incidence of MACCE following PCI and that these results do not support a strategy of routine IABP placement before PCI in all patients with severe LV dysfunction and extensive CAD.
Commentary:
The use of IABP has been shown to improve hemodynamic status and outcomes in various clinical settings, such as cardiogenic shock from MI. The enhanced diastolic coronary artery perfusion and reduced LV afterload afforded by IABP are attractive properties during high-risk PCI. However, this study shows that prophylactic IABP use in all patients with extensive CAD and LV dysfunction does not improve outcomes. This is in keeping with prior studies during acute MI, which also showed no use for routine IABP use. It is noteworthy, however, that 12% of the no IABP group in this trial required "bail-out" insertion of an IABP during the procedure, predominantly for prolonged hypotension. Rescue IABP use resulted in prolonged hospital stays. Unfortunately, the authors were not able to identify demographic features that would have enabled prediction of these patients in advance.
There may be some role for prophylactic IABP in future if we can recognize subsets of high-risk patients that may benefit. But for now, it seems that IABP use in high-risk PCI should be used for patients who are hypotensive before the procedure or those who become hypotensive during the procedure.
Patients with extensive coronary artery disease (CAD) and left ventricular (LV) dysfunction are at high risk during revascularization.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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