Effectiveness of Thrombus Aspiration in Plaque Reduction for Patients With Acute Coronary Syndromes

Periprocedural myocardial infarction (MI) has an independent adverse prognostic relevance. Several trials have documented a reduction in the occurrence of periprocedural MI through various pharmacological strategies, with enhanced inhibition of platelet aggregation or high dose statins. However, real-world registries still document an incidence of periprocedural MI in 30-40% of patients. Currently available intravascular imaging techniques, Intravascular Ultrasound (IVUS) and more recently available Optical Coherence Tomography (OCT) allow a precise evaluation of the coronary plaque and can be extremely useful for monitoring plaque modifications obtained with thrombus aspiration (TA). Plaque burden will be assessed as plaque + media (P+M), commonly measured with IVUS by subtracting lumen (L) to external elastic membrane (EEM) cross sectional area (P+M= EEM-L).

Expecting a mean plaque volume of 160±50 mm3 in a population of patients with ACS undergoing PCI, a sample size of at least 45 patients (52 lesions) with a recent (<15 days, but after 24 hours) STEMI or a non-ST elevation (NSTE)-ACS within 72 hours of symptoms would provide a 90% power to detect a 20% reduction in the plaque volume after TA with an alpha (probability value) of 0.05.

Inclusion criteria

• Age between 18-75 years old.
• Recent(<15 days, >24 hrs)STEMI or NSTE-ACS within 72 hrs of symptoms.
• Presence at least one "culprit" high-grade (>90%)lesion.

Exclusion criteria

• STEMI within 24 hours.
• Cardiogenic shock, decompensated heart failure, LVEF<30%.
• Serum creatinine ≥ 2.5 mg/dl.
• Contraindication to aspirin, heparin, thienopyridines.
• Total occlusion of target vessel.
• Diseased vein graft or a restenosis.