Prognostic value of [15O]H2O positron emission tomography-derived global and regional myocardial perfusion

Abstract

Aims To evaluate the prognostic value of global and regional quantitative [15O]H2O positron emission tomography (PET) perfusion. Methods and results In this retrospective study, 648 patients with suspected or known coronary artery disease (CAD) who underwent [15O]H2O PET were followed for the occurrence of death and myocardial infarction (MI). Global and regional hyperaemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) were obtained from [15O]H2O PET. During median follow-up of 6.9 (5.0–7.9) years, 64 (9.9%) patients experienced the composite of death (36–5.6%) and MI (28–4.3%). Impaired global hMBF (<2.65 mL/min/g) and CFR (<2.88) were both significant prognostic factors for death/MI after adjusting for clinical characteristics (both P < 0.001). However, after adjusting for clinical parameters and the combined use of hMBF and CFR, only hMBF remained an independent prognostic factor (P = 0.04). For regional perfusion, both impaired hMBF (<2.10 mL/min/g) and CFR (<2.07) demonstrated prognostic value for events (both P < 0.001). Similarly, after adjusting for clinical characteristics and combined use of hMBF and CFR, only hMBF had independent prognostic value (P = 0.04). The combination of global and regional perfusion did not improve prognostic performance over either global (P = 0.55) or regional perfusion (P = 0.37) alone. Conclusion Global and regional hMBF and CFR were all prognostic factors for death and MI. However, for both global and regional perfusion, hMBF remained the only independent prognostic factor after adjusting for the combined use of hMBF and CFR. Additionally, integrating global and regional perfusion did not increase prognostic performance compared to either regional or global perfusion alone.

PET 18F-flurpridaz quantitative measurements of myocardial blood flow: Added value for diagnosis of coronary artery disease? Of course!

“…The role of MBF and MFR (global or regional) in CAD prognostication was beyond the scope of the present study. However, to the extent that it has demonstrated stress MBF to be a more robust predictor of CAD than MFR particularly at the 50% stenosis level, the results are consistent with outcome data of at least 2 prior studies 6,21 and suggest reasons (e.g., technical, methodological, and population selection) for potential outcome differences with others, which found MFR superior. 7,8,22 The reader should keep in mind in the setting of CAD, outcomes (e.g., CV death or MI) in the vast majority of patients ultimately are indicative of MBF inadequate to meet a given level of myocardial oxygen demand (i.e., ischemia/infarction).…”

“…Unsurprisingly, greater in the human study (± 1.14 mL/min/g) 25 vs the porcine (± 0.75 mL/min/g). 26 Thus, as with the present investigation and others, 12,21 it is becoming increasing clear it is the physiological parameter which matters most. It is very unlikely a level of stress requiring MBF 3.0 mL/min/g (think * 10 to 15 METs 27 ) will be met, without ischemia, by maximal MBF \ 2 mL/min/g ( Figure 8B) simply because rest MBF is 0.50 with stress MBF 1.50 and MFR = 3.0.…”

“…An important PET MBF study with 15 O-water demonstrated this very point. 21 In multi-variable analysis, which held CFR (i.e., MFR) constant, the association of hyperemic MBF (global and regional) with CAD prognosis was found to be a significant (P = 0.04) predictor of MACE (death or myocardial infarction) over follow-up median 6.9 (5.0 to 7.9) years. In contrast, the reverse procedure with the same data set failed to identify MFR as a significant predictor, once the effect of stress MBF was accounted for.…”

Global and segmental absolute stress myocardial blood flow in prediction of cardiac events: [15O] water positron emission tomography study

“…Studies have shown that global MFR provides prognostic information that is independent of the presence of regional myocardial ischemia [15,16,20]. In these studies using [29]. The investigators found that both global and regional sMBF had similar prognostic value in predicting the composite of death and MI, while the combination of global and regional sMBF did not improve the prognostic performance compared to either alone.…”

Coronary computed tomography angiography and [15O]H2O positron emission tomography perfusion imaging for the assessment of coronary artery disease

“…Although CFR has been shown to be of incremental prognostic value it seems justified that for diagnostic purposes stress-only PET protocols suffice, obviating the need for baseline perfusion imaging leading to a reduction of radiation dose and scan acquisition time [21,22]. Furthermore, as recently published, [ 15 O]H2O PET derived hyperaemic MBF predicts adverse patient outcome independently of CFR in patients with suspected CAD [23].…”