title: Assessment of coronary microcirculation in a swine animal model.
abstract: Coronary microvascular dysfunction has important prognostic implications. Several hemodynamic indexes, such as coronary flow reserve (CFR), microvascular resistance, and zero-flow pressure (P(zf)), were used to establish the most reliable index to assess coronary microcirculation. Fifteen swine were instrumented with a flow probe, and a pressure wire was advanced into the distal left anterior descending artery. Adenosine was used to produce maximum hyperemia. Microspheres were used to create microvascular dysfunction. An occluder was used to produce stenosis. Blood flow from the probe (Q(p)), aortic pressure, distal coronary pressure, and right atrium pressure were recorded. Angiographic flow (Q(a)) was calculated using a time-density curve. Flow probe-based CFR and angiographic CFR were calculated using Q(p) and Q(a), respectively. Flow probe-based (NMR(qh)) and angiographic normalized microvascular resistance (NMR(ah)) were determined using Q(p) and Q(a), respectively, during hyperemia. P(zf) was calculated using Q(p) and distal coronary pressure. Two series of receiver operating characteristic curves were generated: normal epicardial artery model (N model) and stenosis model (S model). The areas under the receiver operating characteristic curves for flow probe-based CFR, angiographic CFR, NMR(qh), NMR(ah), and P(zf) were 0.855, 0.836, 0.976, 0.956, and 0.855 in N model and 0.737, 0.700, 0.935, 0.889, and 0.698 in S model. Both NMR(qh) and NMR(ah) were significantly more reliable than CFR and P(zf) in detecting the microvascular deterioration. Compared with CFR and P(zf), NMR provided a more accurate assessment of microcirculation. This improved accuracy was more prevalent when stenosis existed. Moreover, NMR(ah) is potentially a less invasive method for assessing coronary microcirculation.
authors.affiliation: Department of Radiological Sciences, University of California-Irvine, Irvine, California 92697, USA.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Shigeho
authors.initials: S
authors.lastname: Takarada
authors.forename: Sabee
authors.initials: S
authors.lastname: Molloi
mesh_terms: D000241:Adenosine; D000704:Analysis of Variance; D000818:Animals; D001011:Aorta / Q000503:physiopathology; D019540:Area Under Curve; D016280:Atrial Function, Right; D001794:Blood Pressure; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003326:Coronary Circulation; D004195:Disease Models, Animal; D053805:Fractional Flow Reserve, Myocardial; D006439:Hemodynamics; D006940:Hyperemia / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008833:Microcirculation; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D013552:Swine; D013997:Time Factors; D014655:Vascular Resistance; D014665:Vasodilator Agents / Q000627:therapeutic use
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine