Page 74 - ARNM-2-3

Advances in Radiotherapy
& Nuclear Medicine Association between PET-derived flows and angiography

A C

B D

Figure 4. Kaplan–Meier plots depicting survival (all-cause mortality inverse) of patients according to whether they had impairments in MFR of the
coronary territories of the (A) LAD, (B) RCA, (C) LCX, (D) globally < 1.7. Patients with impaired MFR are denoted in blue, while patients with preserved
MFR are denoted in yellow
Abbreviations: LAD: Left descending artery; LCX: Left circumflex artery; MFR: Myocardial flow reserve; RCA: Right coronary artery.
>40% are recognized in the literature as intermediate
and have been associated with variability in hyperemic
MBF and MFR, which is concordant with our data. Small
cohorts have shown a close correlation between MBF
and MFR estimates with quantitative measurements
of stenosis severity on coronary in stenosis >40%. 19,20
Unsurprisingly, our findings suggest a multifactorial
discordance between regional coronary territory MBF and
QCA, likely due to the fact that MBF indices integrate not
only epicardial CAD but also microvascular function.
21
Other pathophysiologic processes that may explain
this discordance include interindividual variability in
hyperemic blood flows and flow reserve, stenosis location
within the vessel (mid, proximal, distal, entrance, and exit
angles), 22,23 concomitant microvascular disease, presence
21
Figure 5. Kaplan-Meier plot depicting survival (all-cause mortality of collaterals, or significant stenoses in other vessels leading
inverse) of patients according to whether they had resting perfusion to coronary steal.
defects spanning >10% (in blue) or ≤10% (in yellow) of left ventricular
myocardial segments Our study also has significant implications for decisions
on downstream testing with coronary angiography. Our
suggesting regional MFR and MBF are overall modest results show that a normal regional coronary territory
indicators of regional obstructive CAD. Second, this study MBF has an excellent negative predictive value for
also demonstrates that regional coronary territory MBF obstructive epicardial CAD ranging from 85 to 95% in all
is only weakly associated with stenoses ≥50% across all three vessels and was similar to the range of 83 – 95% for
three vessels, even when accounting for baseline perfusion global MFR. These findings are in line with other studies
24
defects at rest. In our study, we defined significant stenosis previously published and add to the evidence that the
as ≥50%, as it has also been used in other studies. Lesions addition of regional coronary territory MBF indices to
18
Volume 2 Issue 3 (2024) 6 doi: 10.36922/arnm.3786