Subacute thrombosis after stenting in acute myocardial infarction: four-year experience in a low-volume center

Despite substantial technical and therapeutic improvements, subacute stent thrombosis (SST) remains a feared complication of stenting, especially in acute coronary syndromes. Results of large interventional trials obtained in selected highly skilled centers may underestimate the incidence of SST in the real world of interventional cardiology.

To analyze the incidence of SST after stenting in acute myocardial infarction (AMI) and to identify clinical or procedural parameters associated with its occurrence in a center performing < 40 interventional procedures in AMI per year.

The authors examined their catheterization laboratory database and analyzed a series of 80 consecutive patients treated with stenting for AMI from 1995 to 1998. The incidence of SST among these patients (AMI group) was compared with that observed among 389 elective patients treated during the same period (non-AMI group). Then, results obtained for AMI patients treated during the first half of the study period (1995-1996) were compared with those obtained for patients treated during 1997-1998.

The incidence of SST in AMI group was 6.3%, significantly higher (P < 0.0001) than the 0.5% which occurred in non-AMI group. However, all cases of SST were concentrated during the first half of the experience, whereas no case was reported among the 47 patients treated during 1997-1998 (P = 0.016). Although most clinical and angiographic baseline data for the two study periods were comparable, less bail-out stenting (17 versus 42%; P = 0.024) and higher maximal inflation pressure (15 +/- 4 versus 13 +/- 5; P = 0.031) were found during the latter period.

The authors conclude that SST after stenting in AMI was significantly decreased. Relatively low-volume centers should not be denied the possibility of performing interventional procedures in the clinical setting of AMI, provided that results and complication rates are within pre-defined standards of adequacy.