title: Relation of myocardial perfusion defects and nonsignificant coronary lesions by angiography with insights from intravascular ultrasound and coronary pressure measurements.
abstract: Several studies have demonstrated a correlation between myocardial ischemia and severity of coronary lesions as determined by intravascular ultrasound (IVUS) and fractional flow reserve (FFR) measurements. However, their value for the assessment of mild coronary stenoses that are associated with myocardial perfusion abnormalities has not been well studied. The objective of this study was to prospectively compare the results of myocardial perfusion as determined by exercise/dipyridamole myocardial single-photon emission computed tomography with IVUS and FFR measurements in patients who had angiographically mild coronary stenosis (< 50% diameter stenosis by quantitative coronary angiography). Forty-eight patients who had stable coronary disease (61 +/- 11 years of age; 6 women) were included. All had mild coronary stenosis in the proximal/middle segment of > or = 1 coronary artery and had undergone maximal exercise myocardial technetium-99m tetrofosmin single-photon emission computed tomography within 48 hours before coronary angiography. IVUS measurements included lesion lumen area, external elastic membrane area, lesion plaque burden (calculated as external elastic membrane minus lumen area, divided by external elastic membrane, and multiplied by 100), and lumen area stenosis (calculated as reference lumen area minus lesion lumen area, divided by reference lumen area, multiplied by 100). Fifty-three coronary lesions were studied, with a mean percent diameter stenosis of 34.9 +/- 7.9% on angiography. Myocardial perfusion defects were demonstrated by single-photon emission computed tomography in 11 patients (12 myocardial regions) with no differences in lesion percent diameter stenosis compared with those without perfusion defects. The presence of reversible perfusion defects was associated with a higher lesion plaque burden as evaluated by IVUS (67.4 +/- 8.1% vs 60.2 +/- 9.3%, p = 0.01). FFR values did not differ in the presence or absence of perfusion defects (0.90 +/- 0.06 vs 0.92 +/- 0.07, respectively; p = NS). In conclusion, plaque burden as determined by IVUS may partly explain the presence of myocardial perfusion defects in cases of angiographically nonsignificant coronary lesions. However, the high FFR values associated with these lesions suggest that other mechanisms, such as endothelial/microvascular dysfunction, might also account for perfusion abnormalities in these patients.
authors.affiliation: Department of Cardiology, Hospital Universitari Vall d'Hebron, Barcelona, Spain. josep.rodes@crhl.ulaval.ca
authors.forename: Josep
authors.initials: J
authors.lastname: Rodés-Cabau
authors.forename: Jaume
authors.initials: J
authors.lastname: Candell-Riera
authors.forename: Juan
authors.initials: J
authors.lastname: Angel
authors.forename: Gustavo
authors.initials: G
authors.lastname: de León
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Pereztol
authors.forename: Juan
authors.initials: J
authors.lastname: Castell-Conesa
authors.forename: Adriana
authors.initials: A
authors.lastname: Soto
authors.forename: Inocencio
authors.initials: I
authors.lastname: Anívarro
authors.forename: Santiago
authors.initials: S
authors.lastname: Aguadé
authors.forename: Manuel
authors.initials: M
authors.lastname: Vázquez
authors.forename: Enric
authors.initials: E
authors.lastname: Domingo
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Tardif
authors.forename: Jordi
authors.initials: J
authors.lastname: Soler-Soler
mesh_terms: D001794:Blood Pressure / Q000502:physiology*; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon; D018084:Ultrasonography, Interventional
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin