Page 79 - Coronary hemodynamics in acute myocardial infarction - Matthijs Bax

Coronary microvascular function and long-term mortality
disease, Thrombolysis In Myocardial Infarction (TIMI) grade 2 or 3 flow at initial angiography before PCI, or unsuccessful PCI defined as TIMI grade 0 or 1 flow or >50% residual stenosis in the infarct-related artery after PCI. The study protocol was approved by the local ethics committee and all patients gave informed consent.
Periprocedural Measurements
Intracoronary blood flow velocity in the infarct-related coronary artery was
measured 5 to 10 minutes after successful PCI using a 0.014-inch Doppler-
sensor equipped guidewire (Volcano Corp., San Diego, CA). CFVR was defined
as the ratio of hyperemic average peak flow velocity (APV) to baseline APV.
Doppler flow velocity was additionally assessed in an angiographic normal
reference coronary artery, defined as a coronary artery with <30% diameter 5 stenosis on visual estimation. Reference vessel measurements were performed
in the left circumflex coronary artery, unless a stenosis of >30% was present, in which case the right coronary artery was used. Hyperemia was induced by an intracoronary bolus of adenosine (20–40 μg). The Doppler flow velocity signal was analyzed offline to evaluate DDT and the presence of SRF in the infarct-related artery. Before and after PCI, coronary angiography suitable for quantitative coronary angiographic analysis was performed for offline analysis of TIMI flow21 and myocardial blush grade.6 Left ventricular function was evaluated by means of echocardiographic 16-segment Wall Motion Score Index (WMSI) performed immediately before primary PCI.8
At 6-month follow-up, echocardiographic evaluation of left ventricular function was repeated, and patients underwent repeat angiography with assessment of intracoronary Doppler flow velocity, the initial results of which have been reported previously.8,20
Long-term Follow-up
Long-term follow-up regarding the occurrence of death was collected by identifying patients in the Dutch national population registry. The cause of death was verified by evaluating hospital records or contacting the general practitioner. Death was considered cardiac unless an unequivocal noncardiac cause could be established.22
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