Timing of events in STEMI patients treated with immediate PCI or standard medical therapy: implications on optimisation of timing of treatment from the CARESS-in-AMI trial.

Objectives: Early angioplasty after thrombolysis is now recommended for ST-elevation myocardial infarction, but the current guidelines propose a wide time-window ranging between 3 and 24h after lytic administration. To identify the optimal timing for PCI after thrombolysis, we analyzed frequency and time course of the adverse events in patients randomized in the multicenter CARESS-in-AMI trial.

Methods: 598 high-risk patients with STEMI recruited in the CARESS-in-AMI study, were divided into the Immediate PCI group (IMM, n=298), Rescue PCI group (RES, n=107) and Standard Treatment Arm without rescue PCI (STA, n=193).

Results: RES patients had worse pre-procedural TIMI flow and post-procedural blush grade. At 30 days, there were 23 deaths: 11 (10.3%) in RES, 9 (3%) in IMM and 3 (1.6%) in STA (p<0.001). There were 22 episodes of refractory ischemia or re-infarction: 17 (8.8%) in the STA group, 4 (1.6%) in IMM and 1 (0.9%) in RES (p<0.001). In the RES group 10/11 (90.9%) deaths occurred before day 5. In the STA group, all deaths and the majority of ischemic events occurred after day 3. A reduction of risk of death was observed if PCI after thrombolysis was performed within 3.35 h from initial hospitalization.

Conclusions: The mortality benefit of immediate referral to PCI after pharmacological treatment for STEMI derives from a reduction in the time to reperfusion of patients with failed thrombolysis in need of rescue PCI. In patients with evidence of successful reperfusion, "elective" PCI within 3 days may be sufficient to reduce the recurrent ischemic events.