Impact of thrombolysis, intra-aortic balloon pump counterpulsation, and their combination in cardiogenic shock complicating acute myocardial infarction: A report from the SHOCK Trial Registry

OBJECTIVES We sought to investigate the potential benefit of thrombolytic t herapy (TT) and intra-aortic balloon pump counterpulsation (IABP) on in-hos pital mortality rates of patients enrolled in a prospective, multi-center R egistry of acute myocardial infarction (MI) complicated by cardiogenic shoc k (CS). BACKGROUND Retrospective studies suggest that patients suffering from CS du e to MI have lower in-hospital mortality rates when IABP support is added t o TT. This hypothesis has not heretofore been examined prospectively in a s tudy devoted to CS. METHODS Of 1,190 patients enrolled at 36 participating centers, 884 patient s had CS due to predominant left ventricular (LV) failure. Excluding 26 pat ients with IABP placed prior to shock onset and 2 patients with incomplete data, 856 patients were evaluated regarding TT and IABP utilization. Treatm ents, selected by local physicians, fell into four categories: no TT, no IA BP (33%; n = 285); IABP only (33%; n = 279); TT only (15%; n = 132); and TT and IABP (19%; n = 160). RESULTS Patients in CS treated with TT had a lower in-hospital mortality th an those who did not receive TT (54% vs. 64%, p = 0.005), and those selecte d for IABP had a lower in-hospital mortality than those who did not receive IABP (50% vs. 72%, p < 0.0001). Furthermore, there was a significant diffe rence in in-hospital mortality among the four treatment groups: TT + IABP ( 47%), IABP only (52%), TT only (63%), no TT, no IABP (77%) (p < 0.0001). Pa tients receiving early IABP (less than or equal to 6 h after thrombolytic t herapy, n = 72) had in-hospital mortality similar to those with late IABP ( 53% vs. 41%, n = 64, respectively, p = 0.172). Revascularization rates diff ered among the four groups: no TT, no IABP (18%); IABP only (70%); TT only (20%); TT and IABP (68%, p < 0.0001); this influenced in-hospital mortality significantly (39% with revascularization vs. 78% without revascularizatio n, p < 0.0001). CONCLUSIONS Treatment of patients in cardiogenic shock due to predominant L V failure with TT, IABP and revascularization by PTCA/CABG was associated w ith lower in-hospital mortality rates than standard medical therapy in this Registry. For hospitals without revascularization capability, a strategy o f early TT and IABP followed by immediate transfer for PTCA or CABG may be appropriate. However, selection bias is evident and further investigation i s required. (J Am Coll Cardiol 2000;36:1123-9) (C) 2000 by the American Col lege of Cardiology.