Page 172 - Coronary hemodynamics in acute myocardial infarction - Matthijs Bax

Chapter 10
70% an FFR less than 0.80 was necessary to enter randomization. Remarkably, FFR was done in less than 1% of the included patients.11, 13
In the DANAMI-3 – PRIMULTI study patients with multivessel disease at the time of PPCI were randomized to either FFR-guided complete revascularization or no further invasive treatment.8 FFR guided revascularization was performed two days after PPCI. Only two third of the patients who on eyeballing of the severity of the non-culprit lesions entered the study, had an FFR below the discrimination value of 0.80. The primary endpoint driven by less revascularizations occurred in favor of the complete revascularization group.
The COMPARE-ACUTE study was an FFR-guided complete revascularization study in STEMI patients with multivessel disease.10 FFR of the non-IRA stenosis at the time of PPCI was mandatory for inclusion of the study. This study showed a reduction of the primary endpoint, again driven by a reduction of subsequent revascularizations in patients in the complete-revascularization group.
The question arises whether FFR measurements can be used to evaluate remote coronary arteries in the context of STEMI. Adequate interrogation of the non- IRA with FFR measurement depends on obtaining maximum hyperemic blood flow velocity as dictated by the definition. Alteration of the blood flow velocity in the non-IRA, basically a reduction of the coronary flow reserve as shown by Uren,14 or more specifically a reduction of hyperemic blood flow as a result of an increased hyperemic microvascular resistance will erroneously increase the FFR value. The consequence might be that a significantly stenosed non-IRA will not be revascularized. It is unclear after what time window following STEMI FFR measurement will result in a veracious outcome on which reliable decisions can be based. The incorrect increase of FFR value might be less pronounced in case of smaller myocardial infarctions due to less disturbed microvascular function, less increased hyperemic resistance, and thus hyperemic blood flow that can approach normal values.
To avoid erroneous decision making based on altered hyperemic blood flow values, iFR measurement could be considered due to the non-hyperemic nature of this measurement. However, the baseline blood flow(velocity) in a non- culprit vessel is changed during STEMI either. Increased baseline flow in the
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