title: Incremental diagnostic value of ultrasonographic assessment of coronary flow reserve with high-dose dipyridamole in patients with acute coronary syndrome.
abstract: BACKGROUND
  Coronary flow reserve (CFR) assessment by transthoracic Doppler echocardiography has been found to be useful in subjects with suspected coronary artery disease. An important clinical question is whether such technique can be successfully applied in patients admitted to the coronary care unit with an acute coronary syndrome to detect a significant left anterior descending (LAD) disease.
  
  
  METHODS
  One hundred fifty-nine patients with acute coronary syndrome (93 patients with unstable angina, 66 with acute inferior or lateral myocardial infarction) were included in the present analysis. Patients underwent a high-dose dipyridamole stress (0.84 mg/kg) with combined assessment of CFR in the LAD and regional wall motion. Blood flow velocities were recorded in the mid-distal portion of the LAD using a digital ultrasonographic system and CFR was calculated as the ratio of hyperemia-induced peak diastolic velocity to resting peak diastolic flow velocity. All patients underwent coronary angiography and a significant LAD stenosis was classified for lumen narrowing > or = 70%.
  
  
  RESULTS
  Adequate Doppler recordings in the LAD were obtained in 92% of patients. A contrast agent was used in the 39% of examinations. No major adverse reaction occurred in any patient. A receiving operating characteristic curve showed that a CFR value < 1.9 had a sensitivity of 85%, a specificity of 87%, a positive predictive value of 71%, a negative predictive value of 94% and a diagnostic accuracy of 86% for identifying a significant LAD stenosis. The area under the receiving operating characteristic curve computed for CFR was significantly higher than for wall motion score index (p < 0.001). In a stepwise forward, multiple logistic regression analysis, both CFR (OR = 4.8, 95% C.I. 3.7-5.3; p < 0.00001) and the wall motion score index for the LAD territory (OR = 4.2, 95% C.I. 2.6-6.8; p < 0.0001) were independent determinants of LAD stenosis > or = 70%.
  
  
  CONCLUSIONS
  Early assessment of CFR by transthoracic Doppler echocardiography is feasible and safe and provides additional information to identify subjects with acute coronary syndrome and significant LAD stenosis.
authors.affiliation: Division of Cardiology, S. Maria di Loreto Hospital, Naples, Italy. luigi.ascione20@tin.it
authors.forename: Luigi
authors.initials: L
authors.lastname: Ascione
authors.forename: Mario
authors.initials: M
authors.lastname: De Michele
authors.forename: Maria
authors.initials: M
authors.lastname: Accadia
authors.forename: Gianluca
authors.initials: G
authors.lastname: Granata
authors.forename: Cosimo
authors.initials: C
authors.lastname: Sacra
authors.forename: Antonello
authors.initials: A
authors.lastname: D'Andrea
authors.forename: Pasquale
authors.initials: P
authors.lastname: Guarini
authors.forename: Bernardino
authors.initials: B
authors.lastname: Tuccillo
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000209:etiology*; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000150:complications / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology*; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D004176:Dipyridamole