M-Guard Stent in Stemi Patients with High Thrombus Burden Lesions: A Prospective, Single Arm Study

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Introduction: Primary PCI is the preferred modality to restore blood perfusion in STEMI patients, but myocardial reperfusion is sometimes lower than optimal. Distal embolization seems to play the leading role. There is rare evidence suggestive of M-Guard stents; a recent innovation which protects against distal embolization may be beneficial in this circumstance. Materials and Methods:This was a prospective single arm study. Patients with acute STEMI admitted at the Cardiac Emergency Unit of Imam Reza Hospital from July 2011 to November  2012 who had a large bulk of thrombus in their angiogram, underwent M-Guard stenting and were followed up for six months for chest pain and secondary revascularization. Results: The 23 patients, aged between 34 and 84; 65.2%, were male and had undergone primary PCI, mechanical thrombus aspiration, and M-Guard stenting. Left Anterior Descending (LAD) (63.9%) and Right Coronary Artery (RCA) (39.1%) were most commonly involved. 78.2%, 13.1%, and 8.9% of patients had primary Thrombolysis in Myocardial Infarction (TIMI) Thrombus grade five, four, and three. Among them, 86.9% achieved TIMI Flow grade three and 13.04% TIMI Flow grade two. The rate of transient "no-reflow" phenomenon was 21%. One patient died after stenting in the setting of cardiogenic shock. There was one case of in-stent restenosis five months after the procedure. Of the other 15 accessible patients, after six months, none experienced a second angioplasty or any ischemic symptoms. Conclusion: Using M-Guard stents in acute STEMI patients having undergone primary PCI with high thrombus burden is probably associated with lower rates of the "no-reflow" phenomenon and improved vessel reperfusion.