[Role of direct coronary angioplasty in the course of acute myocardial infarction]

Abstract

The application of coronary angioplasty (PTCA) for early mechanical reperfusion in patients with evolving acute myocardial infarction (AMI) was introduced at the beginning of the '80s. There are 5 distinct approaches to PTCA for AMI mainly based on the timing of the intervention: primary or direct PTCA refers to emergency recanalization (as soon as possible) of the "culprit" vessel by the interventional procedure without the use of thrombolytic agents; immediate or sequential PTCA is the combination of administration of intravenous thrombolytic therapy followed very closely by PTCA; rescue PTCA refers to the use of PTCA as a mechanical approach for reperfusion when thrombolytic therapy has failed (60 to 120 min after such therapy has been initiated); deferred or adjunctive PTCA implies coronary angiography and PTCA delayed by at least several days after thrombolytic therapy and reserved for patients with residual ischemia; elective PTCA refers to a delayed symptom-derived procedure after thrombolytic therapy. Immediate PTCA, in which the procedure urgently follows the thrombolytic therapy has been studied in 3 randomized trials (TAMI 1, ECoS, TIMI 2A). All 3 trials have shown that immediate PTCA does not affect positively, but can worsen, the outcome of thrombolytic therapy since it increases mortality and bleeding complication with no improvement in reocclusion rate. Rescue PTCA was evaluated by several Authors who were able to demonstrate that mechanical reperfusion after failed thrombolytic therapy improves prognosis and reduces in-hospital and long-term mortality in this subgroup of patients with AMI. Deferred or adjunctive and elective PTCA represent therapeutic approaches in patients with residual ischemia following a successful thrombolysis able, when residual or recurrent ischemia are present, to prevent major cardiac events and to improve clinical outcome. The major interest was addressed to the role of primary PTCA in evolving AMI, as alternative therapy to thrombolysis. Randomized trials have been able to demonstrate that primary PTCA could dramatically improve the clinical outcome in AMI complicated by cardiogenic shock. Moreover, this approach can be safely performed in patients with contraindications for thrombolytic therapy with excellent results. Despite other advantages, primary or direct PTCA for evolving AMI is still presenting few points which have to be furtherly evaluated: acute or subacute reocclusion rates, restenosis rates, costs and availability to majority of population. The on-going clinical evaluation of other devices for mechanical reperfusion (transluminal extraction catheter-TEC, directional atherectomy, coronary stents, thermal PTCA, prolonged autoperfusion), in order to improve acute and subacute results, could furtherly expand the use of this approach in AMI-patients.(ABSTRACT TRUNCATED AT 400 WORDS)