A total of 100 patients with ST-elevation myocardial infarction (STEMI) presenting slow-flow after primary-percutaneous coronary intervention (PPCI) will be randomized to pharmacologic treatment with hyperemic drugs versus flow-mediated hyperemia.
Slow-flow phenomena is observed around 15% of patients undergoing PPCI and has been associated with poor prognosis. Hyperemic drugs, such as nitroprussiate and adenosine, have not yet demonstrated to reduce the infarct size and prognosis in patients with slow flow. Controlled flow-mediated hyperemia using a dedicated catheter for intracoronary saline infusion has been shown to stimulate microcirculatory vasodilatation in stable patients similarly as hyperemic drugs. The aims of the study are to compare the absolute microcirculatory resistance of the infarct-related artery presenting with slow flow after PPCI, as assessed by intracoronary thermo-dilution, treated with standard pharmacologic hyperemia versus flow-mediated hyperemia; and to compare the angiographic TIMI frame count after treatment of slow flow phenomena with the two investigated strategies.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
67
Intracoronary bolus of at least 200 mcg of nitroprussiate or 500 mcg of intracoronary adenosine during 2 minutes. Operators are allowed to combine both drugs.
Intracoronary saline infusion at 20 ml/min via dedicated microcatheter (RayFlow; Hexacath, France) during two minutes.
Hospital Universitari de Bellvitge
L'Hospitalet de Llobregat, Barcelona, Spain
Hospital del Mar
Barcelona, Spain
Hospital Clínic de Barcelona
Barcelona, Spain
Hospital Universitario Puerta del Mar
Cadiz, Spain
Angiographic TIMI frame count
Cine-fluoroscopic recording of the infarct-related artery (IRA) at 30 frames/second and off-line core-laboratory assessment of the number of cineframes needed for dye to reach standardized distal landmarks is the coprimary endpoint. Long TIMI frame counts are indicative of slow coronary flow. Previous studies showed TIMI frame counts of 30 (SD 12) after nitroprussiate in slow flow STEMI patients. The present study is powered to assess 25 percent difference between study groups (80 percent power and 5 percent alfa error).
Time frame: 2 minutes
Minimal microcirculatory resistance (MMR)
MMR is assessed by intracoronary thermodilution with a dedicated pressure wire and microcatheter (RayFlow, Hexacath) during saline infusion at 20 ml/min. MMR is measured offline by the core-laboratory at 20 seconds of the saline infusion in the standard medical treatment group and at 2 minutes and 20 seconds in the experimental group. According to previous studies, MMR was 537 Wood units (SD 289). The present study is powered to assess 30 percent difference between study groups after study intervention (80 percent power and 5 percent alfa error).
Time frame: 2 minutes
Comparison of the MMR in the experimental group during the two-minutes saline infusion
Experimental treatment with saline infusion via microcatheter is performed continuously recording the pressure and temperature values of the culprit artery. Off-line core-laboratory assessment of the MMR will be performed at 20 seconds and at 2 minutes of the saline infusion.
Time frame: 2 minutes
Comparison of the Absolute coronary flow between the study groups.
Absolute coronary flow is performed simultaneously with the MMR. This value shows the coronary blood flow of the culprit artery during maximal hyperemia.
Time frame: 2 minutes
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Hospital La Princesa
Madrid, Spain