Prognostic value of coronary flow capacity derived from [15O]H2O positron emission tomography perfusion imaging

Abstract Background Coronary flow capacity (CFC) is a cross-modality framework integrating hyperemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) to quantify the physiological impact of coronary atherosclerotic disease on vasodilator capacity. Purpose This study explores the prognostic value of CFC derived from [15O]H2O positron emission tomography (PET) perfusion imaging in addition to traditional perfusion metrics. Methods Quantitative perfusion measurements were obtained from 1300 patients with suspected or known coronary artery disease who underwent [15O]H2O PET imaging. Patients were classified as having myocardial steal, severely reduced CFC, moderately reduced CFC, minimally reduced CFC or normal flow using previously defined perfusion thresholds. The endpoint was a composite of death and non-fatal myocardial infarction (MI). Results The composite endpoint occurred in 153 (12%) patients during a median follow-up of 5.5 (interquartile range 3.7–7.8) years. Myocardial steal (HR 10.65, 95% CI 4.45–25.49, p<0.001), severely reduced CFC (HR 3.77, 95% CI 1.88–7.58, p<0.001), moderately reduced CFC (HR 2.03, 95% CI 1.25–3.29, p=0.004) and minimally reduced CFC (HR 1.72, 95% CI 1.05–2.81, p=0.030) were independently associated with worse outcome after adjusting for clinical risk factors. Similarly, increased resting MBF (HR 3.19, 95% CI 1.74–5.83, p<0.001), decreased hMBF (HR 0.72, 95% CI 0.57–0.90, p=0.004) and decreased CFR (HR 0.59, 95% CI 0.47–0.73, p<0.001) were significant prognostic factors for events. In a combined perfusion model, only resting MBF (p=0.018) and CFC (overall p=0.012) demonstrated independent prognostic value. Conclusions [15O]H2O PET-derived resting MBF, hMBF, CFR and CFC were prognostic factors for death and non-fatal MI. Notably, in a combined model including all perfusion metrics, only resting MBF and CFC were independently associated with adverse outcome. Funding Acknowledgement Type of funding sources: None.