SPECT Myocardial Perfusion Reserve in Patients with Multivessel Coronary Disease: Correlation with Angiographic Findings and Invasive Fractional Flow Reserve Measurements.
Quantification of myocardial perfusion reserve (MPR) is an emerging topic in nuclear cardiology with an expected diagnostic and prognostic incremental value, especially for patients with severe coronary artery disease. The advent of new dedicated solid-state cameras has opened new perspectives for perfusion quantitation in SPECT. We appraised the feasibility of perfusion reserve estimation using a cadmium zinc telluride camera in a cohort of multivessel patients and its pertinence with respect to angiographic data.


METHODS
Twenty-three patients with known multivessel coronary artery disease were prospectively enrolled. Dynamic SPECT acquisitions using (99m)Tc-tetrofosmin at rest and after vasodilator stress were performed using a dedicated cadmium zinc telluride camera. Reconstructed frames were automatically segmented to extract the vascular input function and the myocardial uptake curve. One-compartment kinetic modeling was used to estimate global and regional uptake values, and then myocardial blood flow was derived using the Renkin-Crone equation. Global and regional MPR was assessed using flow difference (stress - rest) and flow ratio (stress/rest). All patients underwent control coronary angiography within 4 wk, which served as the reference for MPR index assessment. Relevant angiographic findings included maximal stenosis and (for a subgroup of 26 vessels) invasive measurement of fractional flow reserve (FFR). A stenosis was considered obstructive if greater than 50% and an FFR abnormal if lower than 0.8.


RESULTS
Global MPR correlated well with number of obstructed vessels (P < 0.001). After multivariate analysis, both regional flow ratio and flow difference were significantly associated with maximal stenosis (P < 0.001) and FFR (P < 0.001). Regional MPR indices were significantly different in obstructed and nonobstructed vessels (P < 0.001) and in vessels with normal and abnormal FFR (P < 0.001). With a cutoff of 2, the sensitivity, specificity, and accuracy of regional flow ratio were, respectively, 80%, 85%, and 81% for the detection of obstructed vessels and 89%, 82%, and 85% for the detection of abnormal FFR.


CONCLUSIONS
Scintigraphic estimations of global and regional MPR in multivessel patients using a cadmium zinc telluride camera appear to correlate well with invasive angiographic findings, including maximal stenosis and FFR measurements.
Nuclear Medicine Department, Lapeyronie University Hospital, Montpellier, France faybenb@hotmail.com.
Fayçal
F
Ben Bouallègue
Department of Cardiology and Cardiovascular Diseases, Arnaud de Villeneuve University Hospital, Montpellier, France; and Montpellier University U1046 INSERM/UMR 9214 CNRS, Montpellier, France.
François
F
Roubille
Department of Cardiology and Cardiovascular Diseases, Arnaud de Villeneuve University Hospital, Montpellier, France; and.
Benoit
B
Lattuca
Department of Cardiology and Cardiovascular Diseases, Arnaud de Villeneuve University Hospital, Montpellier, France; and.
Thien Tri
TT
Cung
Department of Cardiology and Cardiovascular Diseases, Arnaud de Villeneuve University Hospital, Montpellier, France; and.
Jean-Christophe
JC
Macia
Department of Cardiology and Cardiovascular Diseases, Arnaud de Villeneuve University Hospital, Montpellier, France; and.
Richard
R
Gervasoni
Department of Cardiology and Cardiovascular Diseases, Arnaud de Villeneuve University Hospital, Montpellier, France; and.
Florence
F
Leclercq
Nuclear Medicine Department, Lapeyronie University Hospital, Montpellier, France Montpellier University U1046 INSERM/UMR 9214 CNRS, Montpellier, France.
Denis
D
Mariano-Goulart
D000368:Aged; D015331:Cohort Studies; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging; D005080:Exercise Test; D005240:Feasibility Studies; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000295:instrumentation / Q000379:methods*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D010477:Perfusion; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin
CZT camera; dynamic SPECT; fractional flow reserve; multivessel coronary artery disease; myocardial perfusion reserve