Contemporary Treatment of Small-Vessel Disease

Since the inception of coronary angioplasty, small vessel disease has been a particularly challenging subset to treat with percutaneous interventional therapies. Historically small vessel intervention has been complicated by a higher incidence of significant vessel dissection, acute vessel closure, myocardial infarction and emergent coronary bypass grafting.1,2 Furthermore, these lesions are frequently technically difficult. Their often non-compliant and calcified character, frequent tortuous nature, and predominant distal location impair device delivery and expansion. Along with poorer acute outcomes, these subsets are plagued by high restenosis rates, often necessitating repeat intervention or bypass surgery.3 Despite the challenges and complexities inherent to small-vessel intervention, the problem is common, with 30 to 40% of all interventions involving small coronary arteries.4,5 In this issue of the Journal, Lau and colleagues (see pages 411–416) review the current status of stenting in small-vessel coronary disease.6 They note that the definition of what constitutes a small vessel in the context of coronary interventional therapy has been quite inconsistent. In the literature, small arteries have been defined as vessels less than 2.5 to 3.0 mm in diameter. Intravascular ultrasound (IVUS) has demonstrated that many of these angiographically small vessels are in fact “pseudo-small” as a result of angiographically undetected disease in the reference segment and positive remodeling at the lesion site. The tendency to underestimate arterial size is significantly greater for angiographically small vessels than for larger ones. Moussa and colleagues found that the independent predictors of greater than a 1.0 mm discrepancy between IVUS and angiography included small angiographic vessel size (

1. Schunkert H, Harrell L, Palacios IF. Implications of small reference vessel diameter in patients undergoing percutaneous coronary revascularization. J Am Coll Cardiol 1999;34:40–48. 2. Ellis SG, Vandormael MG, Cowley MJ, et al. Coronary morphologic and clinical determinants of procedural outcome with angioplasty for multivessel coronary disease. Implications for patient selection. Multivessel Angioplasty Prognosis Study Group. Circulation 1990;82:1193–1202. 3. Hirshfield JW, Schwartz JS, Jugo R, et al. Restenosis after coronary angioplasty: a multivariate statistical model to relate lesion and procedure variables to restenosis. J Am Coll Cardiol 1991;18:647–656. 4. Boaurassa MG, Lesperance J, Eastwood C, et al. Clinical, physiologic, anatomic and procedural factors predictive of restenosis after percutaneous transluminal coronary angioplasty. J Am Coll Cardiol 1991;18:368–376. 5. Foley DP, Melkert R, Serruys PW. Influence of coronary vessel size on renarrowing process and late angiographic outcome after successful balloon angioplasty. Circulation 1994;90:1239–1251. 6. Lau KW, Hung JS, Sigwart U. The current status of stent placement in small coronary arteries