Long-term outcome following coronary stent embolization or misdeployment. 
Twenty-three patients were identified as having either coronary stent embolization or misdeployment at our center over a 4-year period.  They were matched to an equal number of controls who underwent a stenting procedure but in whom embolization or misdeployment did not occur.  Baseline demographic characteristics were similar between the 2 groups.  The embolization group required higher mean predilation pressure than the control group and more of the embolization group required a predilation pressure >10 atm before attempted stent placement (7 vs 1, p = 0.02).  Total procedure and fluoroscopy time as well as dye volume were dramatically higher in the embolization group compared with the control group.  Lesion angulation >45 degrees was predictive of stent embolization and 6 of 23 (23%) stents embolized during passage through a previously deployed stent.  Sixteen cases of stent embolization and/or misdeployment occurred within the coronary circulation, 8 of which were retrieved, and 7 stents embolized to the central and/or peripheral circulation.  A total of 23 major adverse coronary events occurred in the case group versus 7 events in the control group (p = 0.04) over a mean follow-up of 36 +/- 13 months.  Fifteen of the events (65%) in the case group occurred in those 8 patients in whom the stent remained in the coronary circulation, including 3 bypass surgeries, 2 myocardial infarctions, 5 repeat percutaneous interventions, and 1 death after hospital discharge.  Only 1 patient in whom the stent embolized outside the coronary circulation demonstrated possible evidence for peripheral vascular insufficiency.  Intracoronary stent embolization in which the stent remains misdeployed in the coronary circulation is associated with poor long-term outcomes.  Extracoronary stent embolization is associated with minimal long-term sequelae.