Noninvasive quantification of regional myocardial flow reserve in XXXX with @entity453 using @entity1568 -13 @entity3265 positron emission tomography. Determination of extent of altered vascular reactivity.

@entity1 @entity36882 @entity1568 @entity859 @entity66 @entity296 @entity3265 @entity301 @entity731 @entity453 @entity850
OBJECTIVES: The aim of this study was to evaluate @entity1 with @entity453 to 1) determine the relation between flow reserve measured by @entity1568 -13 (N-13) @entity3265 kinetic modeling and @entity850 severity assessed by quantitative angiography, and 2) examine whether flow reserve is impaired in regions supplied by vessels without significant @entity66 . BACKGROUND: With the advent of new therapeutic approaches for @entity301 , an accurate noninvasive approach for absolute quantification of flow and flow reserve is needed to evaluate functional severity and extent of @entity731 . @entity36882 @entity3265 kinetic modeling may permit such evaluation. METHODS: Twenty-seven subjects were classified into three groups: group 1 = 5 young volunteers: group 2 = 7 middle-aged volunteers; and group 3 = 15 @entity1 with @entity453 . Dynamic N-13 @entity3265 positron emission tomographic imaging was performed at rest and during @entity859 infusion. A three-compartment model was fit to regional N-13 @entity3265 kinetic data to determine myocardial flow. Group 3 @entity1 underwent quantitative coronary angiography. RESULTS: The regional blood flow results in @entity1 with @entity301 were classified into four subgroups: no significant detectable disease and mild (50% to 69.9% area @entity850 ), moderate (70% to 94.9% area @entity850 ) or severe (95% to 100% area @entity850 ) @entity301 . Flow reserve was 2.95 +/- 0.65; 2.09 +/- 0.47; 2.02 +/- 0.51; 1.3 +/- 0.32, respectively (p < or = 0.01 except mild vs. moderate). Flow reserve was correlated with percent area @entity850 (r = -0.56) and minimal lumen diameter (r = 0.75). In volunteers (groups 1 and 2), flow reserves were greater than in segments without detectable disease in group 3 @entity1 (4.10 +/- 0.71 and 3.79 +/- 0.42, respectively, vs. 2.88 +/- 0.56, p < or = 0.02). CONCLUSIONS: The functional severity of @entity301 measured by N-13 @entity3265 positron emission tomography varied for a given @entity850 but was significantly related to angiographic severity. Among @entity1 with @entity301 , @entity296 without significant angiographic stenoses displayed reduced flow reserve than did regions in control subjects, indicating that vascular reactivity was more diffusely impaired in group 3 than was suggested by angiography. Noninvasive quantification of myocardial flow reserve using dynamic N-13 @entity3265 positron emission tomography yields important functional data that permit definition of the extent of disease even when disease is not apparent by angiography.
