Читать книгу Interventional Cardiology - Группа авторов - Страница 192

NHPRs can simplify stenosis assessment by removing the absolute need for a vasodilator. This reduces cost, time and patient discomfort from vasodilators [73]. There is additional value in patients cannot be given a vasodilator, such as those with allergy, severe airways disease or with conditions which cannot tolerate hypotension – including aortic stenosis. IFR measurement in aortic stenosis before and after percutaneous valve replacement has shown minimal shifts with the change in after load conditions [79]. This means iFR has utility in making coronary revascularization decisions in patients with concomitant aortic stenosis and coronary artery disease. NHPR studies to date have not routinely included those with left main stem lesions, but observational data in this important cohort demonstrates similar outcomes when patients are deferred or revascularized according to iFR [80].

iFR has also been assessed in non‐culprit vessels during NSTEMI and STEMI [81–83]. Studies have suggested good correlation between acutely measured values and those performed at an interval. Resting coronary flow is somewhat elevated during STEMI meaning that acutely measured iFR values may be artificially elevated and may subsequently become negative during follow‐up [83]. The data suggests a high negative predictive value: those vessels that are negative during the acute admission, are less likely to become positive during interval. More studies are being performed.