Coronary reactivity to nitroglycerin: intravascular ultrasound evidence for the importance of plaque distribution

Cardiology Division of Medicine, National Cardiovascular Center, Osaka, Japan.

OBJECTIVES. This study was designed to assess the extent and timing of vasodilation after intracoronary administration of nitroglycerin using intravascular ultrasound. We also sought to relate the magnitude of nitroglycerin-induced dilation to the distribution of atherosclerotic plaque. BACKGROUND. Although previous angiographic studies have shown that nitroglycerin can dilate both normal and stenotic coronary arteries, it remains uncertain whether atherosclerotic vessels can respond to nitroglycerin to the same extent as normal arteries in the clinical setting. METHODS. We analyzed a total of 48 segments from 48 patients by means of a multielement 3.5F to 5.5F 20-MHz intravascular ultrasound system before and after intracoronary administration of nitroglycerin (250 micrograms). Videotaped images were digitized, and the lumen cross-sectional area was measured with an electronic cursor. In noncircumferential lesions, the perimeters of the normal and diseased portions were measured separately to compare the reactivity to nitroglycerin in each portion. RESULTS. Of 48 sites examined 14 were normal by ultrasound, and 34 revealed atherosclerotic lesions. In the 14 normal segments nitroglycerin produced a large increase in cross-sectional area (31 +/- 16% [mean +/- SD]) within 60 s after injection. In the 34 atherosclerotic segments, nitroglycerin-induced dilation was impaired, and the cross-sectional area increased only 12 +/- 8% (p < 0.01). In 15 of 34 atherosclerotic segments, a noncircumferential lesion was identified, and the cross-sectional area after nitroglycerin increased an average of 17 +/- 6%. In the remaining 19 sites, circumferential disease was present, and the cross-sectional area increased by only 8 +/- 7% (p < 0.05 vs. normal or noncircumferential atherosclerotic segments). In noncircumferential lesions, the increase in the perimeter of the normal portion of the wall was significantly greater (14 +/- 6%) than the increase in the diseased portion (5 +/- 3%, p < 0.05). CONCLUSIONS. These data indicate that vasoreactivity after nitroglycerin administration is reduced in segments with atherosclerosis by ultrasound. We suggest that nitroglycerin-induced vasodilation at the stenotic segments can be produced primarily by expansion of the nondiseased portion of the vessel wall.

This article has been cited by other articles:

				A. S. Jaffe, L. Babuin, and F. S. Apple Biomarkers in Acute Cardiac Disease: The Present and the Future J. Am. Coll. Cardiol., July 4, 2006; 48(1): 1 - 11. [Abstract] [Full Text] [PDF]

				H. Massaeli, J. A. Austria, and G. N. Pierce Lesions in Ryanodine Channels in Smooth Muscle Cells Exposed to Oxidized Low Density Lipoprotein Arterioscler. Thromb. Vasc. Biol., February 1, 2000; 20(2): 328 - 334. [Abstract] [Full Text] [PDF]

				M. Vavuranakis, C. Stefanadis, E. Triandaphyllidi, K. Toutouzas, and P. Toutouzas Coronary artery distensibility in diabetic patients with simultaneous measurements of luminal area and intracoronary pressure: Evidence of impaired reactivity to nitroglycerin J. Am. Coll. Cardiol., October 1, 1999; 34(4): 1075 - 1081. [Abstract] [Full Text] [PDF]

				H. Massaeli, J. A. Austria, and G. N. Pierce Chronic Exposure of Smooth Muscle Cells to Minimally Oxidized LDL Results in Depressed Inositol 1,4,5-Trisphosphate Receptor Density and Ca2+ Transients Circ. Res., September 17, 1999; 85(6): 515 - 523. [Abstract] [Full Text] [PDF]

				T. Akasaka, K. Yoshida, A. Yamamuro, T. Hozumi, T. Takagi, S. Morioka, and J. Yoshikawa Phasic Coronary Flow Characteristics in Patients With Constrictive Pericarditis : Comparison With Restrictive Cardiomyopathy Circulation, September 16, 1997; 96(6): 1874 - 1881. [Abstract] [Full Text]

				H. Berglund, H. Luo, T. Nishioka, M. C. Fishbein, N. L. Eigler, S. W. Tabak, and R. J. Siegel Highly Localized Arterial Remodeling in Patients With Coronary Atherosclerosis : An Intravascular Ultrasound Study Circulation, September 2, 1997; 96(5): 1470 - 1476. [Abstract] [Full Text]

				H. Berglund, H. Luo, T. Nishioka, N. L. Eigler, C.-J. Kim, S. W. Tabak, and R. J. Siegel Preserved Vasodilatory Response to Nitroglycerin in Saphenous Vein Bypass Grafts Circulation, December 1, 1996; 94(11): 2871 - 2876. [Abstract] [Full Text]

				S. Nakatani, M. Yamagishi, J. Tamai, Y. Goto, T. Umeno, A. Kawaguchi, C. Yutani, and K. Miyatake Assessment of Coronary Artery Distensibility by Intravascular Ultrasound : Application of Simultaneous Measurements of Luminal Area and Pressure Circulation, June 15, 1995; 91(12): 2904 - 2910. [Abstract] [Full Text]