CASE 14 Extensive Coronary Thrombus

Case presentation

After experiencing a 1-month history of intermittent chest discomfort, a 47-year-old man suddenly developed severe left-sided chest pain while loading a truck. The chest pain continued despite stopping to rest and was associated with nausea, diaphoresis, and light-headedness. He drove himself to a hospital without the capacity to perform primary angioplasty. In the emergency room, he was discovered to have an acute ST-segment elevation inferoposterior myocardial infarction, and the emergency room physician administered sublingual nitroglycerin without relief of pain. The patient was within 1 hour of symptom onset and the treating physician decided to reperfuse with thrombolysis rather than delay reperfusion in order to transfer to a hospital with PCI capability. Therefore, while still in the emergency room, the patient received aspirin, clopidogrel, and tenecteplase, along with enoxaparin (30 mg intravenously and 100 mg subcutaneously). Twenty-five minutes after receiving thrombolysis, the patient noted improvement in chest pain. A repeat electrocardiogram confirmed near complete resolution of ST-segment elevation. Unfortunately, approximately 30 minutes later, his chest pain returned, along with marked ST-segment elevation, hypotension, and bradycardia. At this point, the emergency room physician decided to transfer the patient for rescue intervention, to a hospital 60 minutes away by helicopter.

Upon arrival, the patient continued to report chest pain, and there remained persistent ST-segment elevation present on the electrocardiogram. A review of the patient’s medical history was relevant only for ongoing tobacco abuse and a family history of premature coronary disease. Physical exam was notable for a heart rate of 69 bpm, a blood pressure of 105/63 mmHg, elevated neck veins, and clear lung fields. Initial troponin I was normal and all other laboratory evaluations were within normal limits. He was taken emergently to the cardiac catheterization laboratory.

Cardiac catheterization

The patient arrived in the cardiac catheterization laboratory approximately 2 hours after receiving thrombolysis. As expected, the right coronary artery was completely occluded (Figure 14-1). There was no significant obstructive disease noted in the left coronary arteries. An additional intravenous bolus of enoxaparin was administered, along with a bolus plus infusion of eptifibatide. The operator inserted a guide catheter and easily passed a 0.014 inch floppy-tipped guidewire to the distal artery. A 2.5 mm by 20 mm long compliant balloon inflated at the occlusion site immediately restored TIMI-3 flow, and resulted in resolution of chest pain and ST-segment elevation. However, an extensive filling defect was observed, consistent with a large intracoronary thrombus (Figure 14-2 and Video 14-1). The operator passed a Pronto extraction catheter over the floppy-tipped guidewire to the distal artery and, using a 30 cc syringe, gently aspirated as the catheter was withdrawn to the guide catheter. A large amount of clot was successfully removed and improved the angiographic appearance of the artery with no evidence of distal embolization (Figure 14-3 and Video 14-2). A 4 mm diameter by 28 mm long bare-metal stent postdilated with a 4.5 mm noncompliant balloon successfully treated the residual stenosis (Figures 14-4, 14-5 and Video 14-3). At the completion of the procedure, the patient had no further chest pain and was transferred to the coronary care unit.