Fractional flow reserve and myocardial viability as assessed by SPECT perfusion scintigraphy in patients with prior myocardial infarction.
BACKGROUND
In patients with previous myocardial infarction (MI), assessment of myocardial viability and physiological significance of coronary artery stenoses are essential for appropriate guidance of revascularization. The aim of the study was to evaluate the relation between fractional flow reserve (FFR) and myocardial viability as assessed by gated SPECT MIBI perfusion scintigraphy in patients with previous MI undergoing elective PCI.


METHODS
The study population consisted of 26 patients (mean age 55 ± 7 years; 21 male) with a previous MI and a significant coronary stenosis in a single infarct-related coronary vessel for which PCI was being performed. In all patients, FFR was evaluated before and immediately after PCI. SPECT imaging was done before and 3 ± 1 months after PCI. A region representing the MI was considered viable if MIBI uptake was ≥55% of the normal region. Improvement in perfusion after revascularization was considered achieved if perfusion abnormalities decreased by 5% or more and there was a decrease in segmental score of ≥1 in three segments in PCI-related vascular territory.


RESULTS
Extent of perfusion abnormalities decreased from 32 ± 16% to 27 ± 19% after PCI (P < .001). In patients with myocardial viability in comparison to patients with no viability, there was significant difference in FFR before PCI (.57 ± .14 vs .76 ± .12, P = .002), despite almost the same values of diameter stenosis of infarct-related artery (63 ± 8% vs 64 ± 3%, respectively, P = .572). In addition, FFR prior to PCI was related to improvement in perfusion abnormalities after revascularization (P = .047), as well as with peak activity of creatine-kinase measured during previous MI (r = .56, P = .005).


CONCLUSIONS
Lower values of FFR before angioplasty are associated with myocardial viability and functional improvement as assessed by SPECT perfusion scintigraphy.
Clinic for Cardiology, Department for Diagnostic and Catheterization Laboratories, Clinical Center of Serbia, 8 Koste Todorovica, Belgrade, Serbia. branko2801@eunet.rs
Branko
B
Beleslin
Milan
M
Dobric
Dragana
D
Sobic-Saranovic
Vojislav
V
Giga
Jelena
J
Stepanovic
Ana
A
Djordjevic-Dikic
Milan
M
Nedeljkovic
Sinisa
S
Stojkovic
Vladan
V
Vukcevic
Goran
G
Stankovic
Dejan
D
Orlic
Zorica
Z
Petrasinovic
Smiljana
S
Pavlovic
Vladimir
V
Obradovic
Miodrag
M
Ostojic
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D003326:Coronary Circulation; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D017256:Technetium Tc 99m Sestamibi