Clinical significance of PET-CT coronary flow reserve in diagnosis of non-obstructive coronary artery disease

Abstract Aims Women with evidence of ischaemia but no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD). Although invasively measured coronary flow reserve (CFR) is useful for the diagnosis of CMD, intermediate CFR values are often found of uncertain significance. We investigated myocardial flow reserve and left ventricular (LV) structural and functional remodelling in women with suspected INOCA and intermediate CFR. Methods and results Women’s Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) study participants who had invasively measured intermediate CFR of 2.0≤ CFR ≤3.0 (n = 125) were included for this analysis. LV strain, peak filling rate (PFR) and myocardial perfusion reserve index (MPRI) were obtained by cardiac magnetic resonance imaging. Participants were divided: (i) Group 1 (n = 66) high MPRI ≥ 1.8, and (ii) Group 2 (n = 59) low MPRI < 1.8. The mean age was 54 ± 12 years and CFR was 2.46 ± 0.27. MPRI was significantly different but CFR did not differ between groups. LV relative wall thickness (RWT) trended higher in Group 2 and circumferential peak systolic strain and early diastolic strain rate were lower (P = 0.039 and P = 0.035, respectively), despite a similar LV ejection fraction and LV mass. PFR was higher in Group 1 and LV RWT was negatively related to PFR (r = −0.296, P = 0.001). Conclusions In women with suspected INOCA and intermediate CFR, those with lower MPRI had a trend towards more adverse remodelling and impaired diastolic LV function compared with those with higher MPRI. CFR was similar between the two groups. These findings provide evidence that both coronary microvessel vasomotion and structural and functional myocardial remodelling contribute to CMD.

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Abstract 4234: Prognostic Implication of the Continuous Prognostic Spectrum of Coronary Flow Reserve in Patients with and without Angiographically Obstructive Coronary Artery Disease

Circulation ◽

10.1161/circ.118.suppl_18.s_850 ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Lauro Cortigiani ◽

Fausto Rigo ◽

Sonia Gherardi ◽

Rosa Sicari ◽

Maria Luisa Gianfaldoni ◽

...

Keyword(s):

Coronary Artery Disease ◽

Coronary Artery ◽

Coronary Flow Reserve ◽

Coronary Flow ◽

Prognostic Value ◽

Wall Motion ◽

Obstructive Coronary Artery Disease ◽

Flow Reserve ◽

Stress Echo ◽

Artery Disease

Dual imaging of wall motion and coronary flow reserve (CFR) on left anterior descending (LAD) artery is now the state-of-the art technique for vasodilator stress echo. The additive prognostic value of CFR over regional wall motion has been established, but there is more than a binary (normal-abnormal ) response in CFR, which can be continuously titrated. Objectives. To assess the prognostic value of Doppler echocardiographic derived CFR in patients with and without angiographically obstructive coronary artery disease (CAD). 1244 patients (785 men, age 64±11 yy) with known or suspected CAD underwent dipyridamole (up to 0.84 mg/kg over 6′) stress echo with CFR evaluation of left anterior descending artery by Doppler and coronary angiography. Patients were followed-up for a median of 17 months. Mean CFR in the entire population was 2.25±0.64. During follow-up, there were 227 events (26 deaths, 55 STEMI, and 146 NSTEMI). Patients (n=384) undergoing revascularization were censored. Using the Kaplan-Meier method, the lowest quartile of CFR (<1.80) was associated with a significantly (p<0.0001) worst event rate than other quartiles (Figure ), both considering the group with (83 vs 53%, p<0.0001) and without (53 vs 12%, p<0.0001) obstructive CAD at angiography. CFR is a strong and independent prognostic predictor in patients with known or suspected CAD, but the spectrum of prognostic stratification is expanded if the response is titrated according to a continuous scale rather than artificially dichotomized.

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