Microcatheter-Facilitated Primary Angioplasty in ST-Segment Elevation Myocardial Infarction

Direct stenting is the best method for achieving reperfusion in primary percutaneous coronary intervention (PPCI). We hypothesized that the use of a microcatheter (MC) during PPCI when Thrombolysis in Myocardial Infarction (TIMI) flow ≤ 1 after wire crossing would allow visualization of the downstream artery with an optimal TIMI 3 flow at the end of the procedure.

In this pilot study, PPCI patients with TIMI flow ≤ 1 after wire crossing formed the MC group (n = 60); the MC was positioned in the distal part of the culprit artery and a small amount of contrast was injected through it to determine stent size and length to treat the culprit lesion. The MC group was compared with previous consecutive patients treated using standard PPCI (n = 94; similar characteristics except for the rate of previous percutaneous coronary intervention).

In the MC group, downstream arteries were visualized in 98% of cases and direct stenting was achieved in 72% vs 31% (P < 0.0001). Final TIMI 3 flow was similar in both groups (97%). There was less manual thrombectomy (20% vs 63%; P < 0.001) and bailout glycoprotein IIb/IIIa inhibitor use (6.7% vs 29.8%; P < 0.002). The incidence of major adverse events (death, shock, severe arrhythmia) and left ventricular ejection fraction were similar. The peak cardiac enzymes level was significantly lower in the MC group.

The MC strategy appears feasible and safe. It could allow exploring new strategies on the basis of more systematic direct stenting and prepared reperfusion by injecting drugs through the MC before reperfusion.