Guiding early revascularization using [¹⁵O]H₂O positron emission tomography myocardial perfusion imaging: impact of atrial fibrillation

Myocardial perfusion imaging (MPI) using [¹⁵O]H₂O positron emission tomography (PET) is used to guide the selection of patients with angina for invasive angiography and possible revascularization. Our study evaluated (i) whether atrial fibrillation (AF) reduces global hyperaemic myocardial blood flow (MBF) and (ii) whether [¹⁵O]H₂O PET MPI effectively guides revascularization procedures for patients with ongoing AF.

We prospectively recruited 346 patients with angina and persistent or paroxysmal AF referred for baseline/hyperaemic [¹⁵O]H₂O PET MPI. The primary outcome was revascularization within 3 months of MPI. In the analyses, patients were divided into four groups based on whether they had ongoing AF or sinus rhythm (SR) and whether they had previously documented coronary artery disease (CAD) or not. Thus, four groups were compared: SR-noCAD, AF-noCAD, SR-CAD, and AF-CAD. Hyperaemic MBF was affected by both ongoing AF and prior CAD [MBF (mL/min/g): 2.82 (SR-noCAD) vs. 2.12 (AF-noCAD) vs. 2.22 (SR-CAD) vs. 1.80 (AF-CAD), two-way analysis of variance P < 0.0001]. In multiple linear regression, ongoing AF was independently associated with reduced hyperaemic MBF. Every 0.1 mL/min/g decrease in hyperaemic MBF was associated with a 23% increase in odds of early revascularization. Receiver operating characteristic (ROC) analysis of vessel-specific hyperaemic MBF to predict early revascularization yielded the following areas under the ROC curve: SR-noCAD: 0.95 (P < 0.0001); AF-noCAD: 0.79 (P < 0.0001); SR-CAD: 0.78 (P < 0.0001); and AF-CAD: 0.88 (P < 0.0001).

Ongoing AF is associated with 19–25% reduced global hyperaemic MBF as measured by [¹⁵O]H₂O MPI PET. Regardless, vessel-specific hyperaemic MBF still predicts early revascularization in patients with AF.