Recurrent Coronary Stent Thromboses and Myocardial Infarctions
- Volume 19 - Issue 11 - November, 2007
- Posted on: 8/1/08
- 0 Comments
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Eight days post-PCI, he presented with an acute inferolateral STEMI, with a CK of 621 U/L and a CK-MB isozyme of 43.7 ng/mL. After failure of initial thrombolytic therapy, he underwent emergent salvage angiography by a different interventionalist. Although the LCX artery demonstrated Thrombolysis in Myocardial Infarction (TIMI)-3 flow, an area of haziness was seen within the previous stent, consistent with residual clot from subacute thrombosis (SAT) (Figure 3). The patient’s left ventricular ejection fraction was now reduced at 40%, with inferolateral akin esis.Balloon angioplasty resulted in a dissection at the distal stent edge. This was repaired with additional deployment of a 2.5 x 8 mm Taxus DES, overlapping the previous distal stent edge, with an excellent final result (Figure 4). Again, the patient had an uncomplicated recovery and was discharged on the third hospital day on his previous medical regimen.
Five days after the second PCI, the patient again underwent unsuccessful thrombolytic therapy for another inferolateral STEMI at an outside facility. The CK level was 120, CK-MB was 15, and TROP-I was 4.01. After transfer to our hospital, emergent salvage catheterization by a third cardiologist revealed LCX stent thrombosis, with total vessel occlusion (Figure 5). After Export catheter (Medtronic, Minneapolis, Minnesota) thrombectomy and subsequent balloon dilatation, a 2.25 x 12 mm MiniVision (Abbott) BMS was deployed, overlapping the previous distal DES edge. The final result revealed no residual stenosis or dissection and excellent TIMI-3 flow (Figure 6). The patient’s clopidogrel dose was increased to 75 mg twice a day. Unfortunately,despite staff recommendations, the patient signed out against medical advice after 2 days.
On day 31 following his third PCI, the patient once again presented with an acute inferolateral STEMI. Repeat emergent coronary angiography revealed a patent LCX stent; however, there was a possible non-flow-limiting linear dissection within the stent lumen (Figure 7). Given the very complicated recent course, no further mechanical interventions were undertaken.The patient emphatically claimed compliance with his twice daily clopidogrel and adult-strength ASA regimen. Hypercoagulable evaluation revealed normal protein C and S levels. After 2 uneventful hospital days, he was discharged on his previous medical regimen. He continues to smoke, despite prescriptions of bupropion and nicotine patches, but has remained infarct-free.
Discussion. DES, like BMS during the balloon angioplasty era, represent a quantum leap in combating coronary restenosis. This dramatic innovation, however, has been recently overshadowed by the specter of thrombosis, especially late angiographic stent thrombosis (LAST), defined as occurring > 30 days. Mechanistically, there is convincing pathological evidence of incomplete or absent neointimal healing, as well as hypersensitivity reactions. As opposed to the gradual process of restenosis, stent thrombosis not infrequently results in acute STEMI or death. However, recurrent DES-SAT (defined as 1 to 30 days), as occurred in our patient, has not been previously reported as a risk.