• Myocardial Infarction
• Interventional Techniques & Devices
• Cardiology Clinical Trials

The Intra-Aortic Balloon Pump (IABP) in Cardiogenic Shock II [IABP-SHOCK II; NCT00491036] trial, presented by Holger Thiele, MD, University of Leipzig Heart Center, Leipzig, Germany, failed to demonstrate a significant reduction in 30-day mortality with use of an IABP compared with best available medical therapy (BAT) alone in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock.

IABPs have been used for almost 5 decades in the treatment of cardiogenic shock [Thiele H et al. Eur Heart J 2010]. Although considered a Class I recommendation in patients with AMI complicated by cardiogenic shock in both US and European guidelines [Van de Werf EM et al. Eur Heart J 2008; Wijns F et al. Eur Heart J 2010; Antman W et al. Circulation 2004], there is no evidence for a mortality benefit. IABP-SHOCK II was an investigator-initiated, randomized, prospective, open-label, multicenter trial, designed to compare IABP with BAT in patients presenting with an AMI complicated by cardiogenic shock and for whom early revascularization (using either percutaneous coronary intervention [PCI] or coronary artery bypass graft) was planned. Subjects were assigned to IABP (n=301) or BAT (n=299). The primary efficacy end point was 30-day all-cause mortality. Secondary endpoints included hemodynamic parameters, serum-lactate, Simplified Acute Physiology Score–II (SAPS-II), serial creatinine level and creatinine clearance, and inflammatory reaction (as measured by C-reactive protein). Safety assessments included major bleeding, peripheral ischemic complications, sepsis, and stroke [Thiele H et al. Am Heart J 2012; Thiele H et al. N Engl J Med 2012].

The median age of subjects was 70 years and 77% were men. Almost 50% had undergone resucitation (for 30 or fewer minutes) before randomization and about 80% had multivessel disease. Approximately 95% of subjects in both groups underwent primary PCI. There was a trend toward more frequent use of ventricular assist devices in the BAT group (7.4% of patients vs 3.7% in the IABP group; p=0.053); however, the duration of mechanical ventilation, the number of days in the intensive care unit, the number of subjects receiving renal replacement therapy, and the time to hemodynamic stabilization did not differ.

At 30 days, 119 patients in the IABP group (39.7%) and 123 patients in the control group (41.3%) had died (RR with IABP, 0.96; 95% CI, 0.79 to 1.17; p=0.69). An analysis of prespecified post hoc subgroups showed no benefit for IABP based on sex, age, diabetes, or hypertension status, blood pressure (<80 vs ≥80 mm Hg), ST-segment elevation myocardial infarction (STEMI) versus non–STEMI, or previous history of MI. The groups did not differ significantly with respect to the rates of major bleeding (3.3% vs 4.4%, respectively; p=0.51), peripheral ischemic complications (4.3% vs 3.4%; p=0.53), sepsis (15.7% vs 20.5%; p=0.15), or stroke (0.7% and 1.7%; p=0.28) [Thiele H et al. N Engl J Med 2012].

Concerning the secondary endpoints and process-of-care measures, there was an early trend toward improved SAP-II scores in the IABP group but this did not persist beyond Day 4. There was no benefit with respect to renal function or serum lactate in the IABP group and no difference in C-reactive protein levels.

Prof. Thiele concluded that while IABP support in cardiogenic shock is safe, it does not improve 30-day mortality in patients with cardiogenic shock complicating AMI who underwent early revascularization in the IABP-SHOCK II trial.

• © 2012 MD Conference Express®