Acute Coronary Syndrome: IABP-SHOCK II (The Intraaortic Balloon Pump in Cardiogenic Shock II)

Question 1

IABP-SHOCK II Clinical Question

Answer 1

In patients with acute MI complicated by cardiogenic shock, does an intraaortic balloon pump (IABP) reduce mortality?

Question 2

IABP-SHOCK II Bottom Line

Answer 2

In patients with acute MI complicated by cardiogenic shock, there was no difference in 30-day mortality with IABP placement.

Question 3

IABP-SHOCK II Primary End Point

Answer 3

30-day mortality

Question 4

IABP-SHOCK II inclusion criteria

Answer 4

Acute STEMI or NSTEMI complicated by cardiogenic shock:

• -SBP <90 mmHg for >30 mins or requiring catecholamines to maintain SBP >90 mmHg
• -Clinical signs of pulmonary congestion
• -Impaired end-organ perfusion (i.e. altered mental status, cold, clammy skin and extremities; UOP<30cc/hr; serum lactate >2.0 mmol/L)

Question 5

IABP-SHOCK II criticisms

Answer 5

• LVAD use was not controlled.
• Timing of IABP insertion was not controlled. 86.6% of IABPs went in post-PCI.
• Lower mortality rate (40%) in this trial compared to other registries and RCTs (42-48%) suggests more mild or moderately severe shock cases, precluding generalizability to severe shock.
• Small sample size
• 10% cross-over rate from control group to IABP
• Long-term follow-up results to follow
• High use of catecholamines and relatively low rate of systolic hypotension (many had systolic BP >90 before randomization)

Question 6

What is an intraaortic balloon pump

Answer 6

an inflatable device placed in the aorta that inflates with diastole and deflates with systole