Identify those patients who are eligible for direct (primary) percutaneous revascularization.

Direct percutaneous revascularization, performed within 90 minutes of presentation by an experienced center and operator, is the preferred mode of reperfusion. Patients should be evaluated for thrombolytic therapy if the center evaluating the patient cannot perform direct percutaneous revascularization within 90 minutes, or the patient cannot be transferred to a facility with direct percutaneous revascularization capability and an initial presentation to balloon inflation time no greater than 90 minutes.

Since mortality is directly related to operator experience, direct percutaneous revascularization should be performed by adequately, experienced operators at high-volume centers (Canto et al., 2000). This intervention needs to be performed in a timely fashion, with the first balloon inflation within 90 minutes of presentation. Although the ACC/AHA Guidelines (1999) recommend that direct percutaneous revascularization be safely performed at sites with cardiac surgery capability, recent data suggest that primary percutaneous revascularization can be performed by experienced physicians at high volume centers, even if they do not have cardiac surgery backup (Wharton et al., 1999; Brush et al., 1996; Ashmore et al., 1999).

A meta-analysis of trials, comparing direct percutaneous revascularization with thrombolytic agents, suggest that direct percutaneous revascularization is associated with reduced risk of death, reinfarction, or stroke at 30 days (Weaver et al., 1997); however, this analysis can be criticized because it used thrombolytic regimes that are no longer in use. The GUSTO IIb trial (1999) compared primary coronary angioplasty with alteplase and showed an early benefit in the combined end points of death, reinfarction, and disabling stroke, although this benefit was not maintained at 6 months. Long-term follow-up of patients receiving streptokinase, when compared to patients undergoing direct percutaneous coronary angioplasty, showed better five-year clinical outcomes of death and reinfarction in those patients undergoing direct percutaneous transluminal coronary angioplasty (PTCA) (Zijlstra et al., 1999). The use of abciximab, a platelet aggregation inhibitor, with direct percutaneous revascularization using coronary stenting, when compared with alteplase, showed improved myocardial salvage and lower combined end points of death, reinfarction, and stroke at six months (Schomig et al., 2000). In this study, the average door to balloon time was 65 minutes. The Second National Registry of Myocardial Infarction (NRMI-2) found no differences in mortality or reinfarction between direct percutaneous revascularization and thrombolysis in lytic-eligible patients (Tiefenbrunn et al., 1998); however, the median time to administration of thrombolysis was 42 minutes, while the median time to first balloon inflation was 111 minutes. A review of the GUSTO IIb trial showed that 30-day mortality was directly related to the time from enrollment to the first balloon inflation: 1% if <60 minutes, 3.7% if 61 to 75 minutes, 4.0% if 76 to 90 minutes, and 6.4% if >90 minutes (Berger et al., 1999). More recently, analysis of the German Maximal Individual Therapy in Acute Myocardial Infarction Registry (MITRA) and Myocardial Infarction Registry (MIR) showed an improvement in hospital mortality from 1994 to 1998, attributable to the use of primary percutaneous revascularization and not to thrombolysis (Zahn et al., 2000). In 1994, patients treated with direct angioplasty had 13.9% in-hospital mortality, while patients treated with thrombolysis had 10.2% mortality. In 1998, mortality had decreased in the direct angioplasty group to 3.8% (p value for trend of 0.003), while in-hospital mortality remained unchanged in the group treated with thrombolysis, at 12.7% (p value for trend of 0.175). Accordingly, direct percutaneous revascularization is the preferred method of myocardial reperfusion if performed within 90 minutes of presentation by experienced operators at high-volume centers.