title: Resting coronary flow velocity in the functional evaluation of coronary artery stenosis: study on sequential use of computed tomography angiography and transthoracic Doppler echocardiography.
abstract: OBJECTIVE
  Accelerated flow at the site of flow-limiting stenosis can be detected by transthoracic Doppler echocardiography (TTDE). We studied feasibility and accuracy of sequential coronary computed tomography angiography (CTA) and TTDE in detection of haemodynamically significant coronary artery disease (CAD).
  
  
  RESULTS
  We prospectively enrolled 107 patients with intermediate (30-70%) pre-test likelihood of CAD. All patients underwent CTA using a 64-slice scanner. Using TTDE, the ratio of maximal diastolic flow velocity to pre-stenotic flow velocity (M/P ratio) was measured in the coronary segments with stenosis in CTA. In all patients, the results were compared with invasive coronary angiography, including measurement of fractional flow reserve when appropriate. All analyses were done blinded. TTDE was feasible in 276 of 285 evaluated coronary segments. Significant coronary stenoses were associated with a higher M/P ratio than non-significant stenoses (3.59 ± 1.82 vs. 1.28 ± 0.60, P < 0.001). The optimal M/P ratio for detection of significant stenosis was 2.2 (area under receiver operating characteristic curve 0.92, P < 0.001). Compared with the strategy of CTA alone, sequential CTA and focused TTDE had a better positive predictive value (PPV; 61 vs. 78%) and diagnostic accuracy (93 vs. 96%, P = 0.006) without impairment of the negative predictive value (97 vs. 97%).
  
  
  CONCLUSIONS
  Sequential use of CTA and TTDE is feasible for combined anatomic and functional evaluation of coronary stenoses. Compared with coronary CTA alone, addition of TTDE improved PPV for detection of significant CAD.
authors: Department of Cardiology,  Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku,  Finland.
authors: Esa
authors: E
authors: Joutsiniemi
authors: Antti
authors: A
authors: Saraste
authors: Mikko
authors: M
authors: Pietilä
authors: Heikki
authors: H
authors: Ukkonen
authors: Sami
authors: S
authors: Kajander
authors: Maija
authors: M
authors: Mäki
authors: Juha
authors: J
authors: Koskenvuo
authors: Juhani
authors: J
authors: Airaksinen
authors: Jaakko
authors: J
authors: Hartiala
authors: Markku
authors: M
authors: Saraste
authors: Juhani
authors: J
authors: Knuuti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D004452:Echocardiography; D005240:Feasibility Studies; D005260:Female; D006305:Health Status Indicators; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012146:Rest; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed