Paradigm Shift to Functional Angioplasty

Abstract

Inducible myocardial ischemia during functional testing has crucial prognostic significance in determining whether or not to treat coronary artery stenosis.1–3 In real-world practice, however, fewer than half of all patients are evaluated noninvasively for myocardial ischemia before revascularization therapy.4 Thus, coronary angiograms are still frequently used as a cornerstone of decision making, despite the substantial discrepancy between the angiographic and functional severity of stenosis. Therefore, adjuvant technologies such as fractional flow reserve (FFR) and intravascular ultrasound (IVUS) are considered in daily practice to overcome the limitations of coronary angiography for diagnostic and interventional procedures. The present review evaluates the roles of FFR and IVUS in coronary stenosis and their incorporation into practice in contemporary catheterization laboratories. In contrast to the benefits of percutaneous coronary intervention (PCI) in patients with unstable angina and myocardial infarction, the benefits of PCI in patients with stable angina are less clear.5,6 Nevertheless, recent advances in drug-eluting stents (DES) and adjuvant pharmacological agents may reduce the thresholds for revascularization therapy in the absence of firm evidence of objective ischemia. Thus, consideration is sometimes given to treating stenoses of intermediate degree without consideration of their functional significance.7 In addition, although most surgical recommendations for patients with multivessel coronary artery disease are to bypass all lesions with diameter stenosis of >50% for complete revascularization, the patency rate of vein grafts on vessels with functionally insignificant proximal stenosis has been in question.8 Because revascularization treatment based on ischemia may improve patient outcomes, guidelines have recommended noninvasive functional evaluation before revascularization treatment.3,9 Despite these recommendations, however, noninvasive functional evaluations before revascularization are underutilized in real-world practice. Twenty years ago, Topol et al10 reported that of a total of 2101 patients who underwent coronary angioplasty, only 29% had …