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Physiological Guidance: Effective solution for Reducing Residual Ischemia

By Susan Thomas

Patients undergo stenting guided by intravascular imaging and/or physiology as a standard of care here at St. Francis Hospital—The Heart Center.


However, many hospitals continue to use angiography alone to treat coronary lesions and rely less on physiologic and imaging technology, which have shown to be superior compared to angiography alone. Physiology during stent implementation allows assessment of blood flow to determine if blood flow is impaired, causing chest pain. Studies have shown that many blockages seen on angiogram do not impact blood flow sufficiently to warrant treatment with a stent. On the other hand, mild blockages can impair blood flow. Measuring blood flow before and after stenting is, therefore, essential.

Dr. Allen Jeremias, one of the Principle Investigators for DEFINE PCI study and the Director of Interventional Cardiology Research at the St. Francis Hospital—The Heart Center states that “previous studies measuring blood flow in coronary artery have shown that there is a discrepancy between flow measurements and coronary angiograms”. DEFINE PCI, a multicenter, prospective study with a total of 500 subjects, was conducted to assess: 1) significant impairment of blood flow after what appears to be successful stenting by angiography; 2) abnormal blood flow despite what seems to be successful PCI; 3) relationship between blood flow after stenting to recurrent chest pain and major adverse cardiac events.



Dr. Jeremias revealed the findings of this study during the latest American College of Cardiology Conference, which showed almost 1 in 4 patients leave the hospital with abnormal blood flow despite stenting. In many cases, this was due to lesions not treated and not obvious via angiogram.

For Dr. Jeremias, these findings reveal an “opportunity to optimize results and help more people benefit from PCI”. This transforms the current practices and opens the door for further studies to optimize stent implementation using physiologic assessments.