Coronary flow velocity reserve by echocardiography: feasibility, reproducibility and agreement with PET in overweight and obese patients with stable and revascularized coronary artery disease.
BACKGROUND
Coronary flow velocity reserve (CFVR) measured by transthoracic Doppler echocardiography of the LAD is used to assess microvascular function but validation studies in clinical settings are lacking. We aimed to assess feasibility, reproducibility and agreement with myocardial flow reserve (MFR) measured by PET in overweight and obese patients.


METHODS
Participants with revascularized coronary artery disease were examined by CFVR. Subgroups were examined by repeated CFVR (reproducibility) or Rubidium-82-PET (agreement). To account for time variation, results were computed for scans performed within a week (1-week) and for all scans regardless of time gap (total) and to account for scar tissue for patients with and without previous myocardial infarction (MI).


RESULTS
Eighty-six patients with median BMI 30.9 (IQR 29.4-32.9) kg × m(-2) and CFVR 2.29 (1.90-2.63) were included. CFVR was feasible in 83 (97 %) using a contrast agent in 14 %. For reproducibility overall (n = 21) limits of agreement (LOA) were (-0.75;0.71), within-subjects coefficient of variation (CV) 11 %, and reliability 0.84. For reproducibility within 1-week (n = 13) LOA were (-0.33;0.25), within-subjects CV 5 %, and reliability 0.97. Agreement with MFR of the LAD territory (n = 35) was without significant bias and overall LOA were (-1.40;1.46). Agreement was best for examinations performed within 1-week of participants without MI of the LAD-territory (n = 12); LOA = (-0.68;0.88).


CONCLUSIONS
CFVR was highly feasible with a good reproducibility on par with other contemporary measures applied in cardiology. Agreement with MFR was acceptable, though discrepancy related to prior MI has to be considered. CFVR of LAD is a valid tool in overweight and obese patients.
Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Building 67, Bispebjerg Bakke 23, DK-2400, Copenhagen NV, Denmark. rasmus.huan.olsen@regionh.dk.
Rasmus Huan
RH
Olsen
Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Building 67, Bispebjerg Bakke 23, DK-2400, Copenhagen NV, Denmark.
Lene Rørholm
LR
Pedersen
Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Building 67, Bispebjerg Bakke 23, DK-2400, Copenhagen NV, Denmark.
Martin
M
Snoer
Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Thomas Emil
TE
Christensen
Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Adam Ali
AA
Ghotbi
Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Philip
P
Hasbak
Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Andreas
A
Kjaer
Department of Internal Medicine and Clinical Research Centre, Amager and Hvidovre Hospitals, University of Copenhagen, Copenhagen, Denmark.
Steen B
SB
Haugaard
Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Building 67, Bispebjerg Bakke 23, DK-2400, Copenhagen NV, Denmark.
Eva
E
Prescott
D000368:Aged; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015150:Echocardiography, Doppler / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization; D050177:Overweight / Q000150:complications*; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results
Coronary artery disease; Coronary flow reserve; Echocardiography; Microvascular function; Obesity; Positron emission tomography