A prospective randomised trial of thrombolysis and counterpulsation to improve cardiogenic shock survival

A prospective randomised trial of thrombolysis and counterpulsation to improve cardiogenic shock survival: preliminary results of the TACTICS trial.

Ohman EM, Nanas J, Stomel R, et al.                                                                                                                      Eur Heart J 2000; 21 (Suppl.):15

Acute myocardial infarction (AMI) complicated by cardiogenic shock accounts for 60% of all deaths following infarction. Early restoration of reperfusion is the single most important variable predicting survival. However, systemic hypotension depresses the effectivness of thrombolytic therapy (TT). We undertook a randomized trial to test the hypothesis that the use of TT and aortic counterpulsation (IABP) could improve 6-month mortality compared with TT alone.
METHODS: Between November 1996 and November 1999 a total of 57 pts with ST-elevation AMI with symptom duration of < 12 hours and hypotension or cardiogenic shock were randomized to TT+IABP versus TT alone at 17 hospitals in Australia, Europe, and USA. Pts with contraindication to IABP, TT, or with planned PTCA for AMI were excluded. Primary endpoint was 6-m onth mortality, with secondary endpoints of 30-day mortality and bleeding events. Analysis was by "intention to treat". Continuous variables are median (25th, 75th) percentile. 30-day follow up is 100%.
RESULTS: 30 pts were randomized to TT+IABP. The IABP was inserted in 27 (90%) pts at a median 30 (20,55) minutes after TT and was in place for 37 (24,68) hours. 27 pts were randomized to TT alone in whom 9 (33%) IABP was inserted due to clinical deterioration at 4 (1,12) hours after TT. Pts assigned to TT+IABP had a trend towards lower 30-day mortality when adjusted for the differences in baseline charcteristics (diabetes, previous MI, MI location, and Killip class; adjusted p=0.17, unadjusted p=0.58).

TT alone TT+IABP p-value
n=27 n=30

age (years) 67 (56,71) 68 (57,74) 0.41
diabetes 11% 31% 0.07
previous MI 19% 37% 0.13
anterior MI 56% 77% 0.09
Killip clas III/IV 44% 60% 0.32
severe bleeding 0 3.3% 0.34
blood transfusion 22% 37% 0.23
30-day mortality 33% 27% 0.17

CONCLUSION: The use of IABP and TT for high-risk AMI pts appears safe with a trend towars improved suvival at 30 days. The primary endpoint at 6 months will be presented.