Prognostic implications of myocardial perfusion imaging by 82-rubidium positron emission tomography in male and female patients with angina and no perfusion defects

Myocardial perfusion imaging with 82-rubidium positron emission tomography (⁸²Rb-PET) is increasingly used to assess stable coronary artery disease (CAD). We aimed to evaluate the prognostic value of ⁸²Rb-PET-derived parameters in patients with symptoms suggestive of CAD but no significant reversible or irreversible perfusion defects.

Among 3726 consecutive patients suspected of stable CAD who underwent ⁸²Rb-PET between January 2018 and August 2020, 2175 had no regional perfusion defects. Among these patients, we studied the association of ⁸²Rb-PET-derived parameters with a composite endpoint of all-cause mortality, hospitalization for unstable angina pectoris, acute myocardial infarction, heart failure, or ischaemic stroke. During a median follow up of 1.7 years (interquartile range 1.1–2.5 years), there were 148 endpoints. Myocardial blood flow (MBF) reserve (MFR), MBF during stress, left ventricular ejection fraction (LVEF), LVEF-reserve, heart rate reserve, and Ca score were associated with adverse outcomes. In multivariable Cox model adjusted for patient and ⁸²Rb-PET characteristics, MFR < 2 (hazard ratio (HR) 1.75, 95% confidence interval (CI) 1.24–2.48), LVEF (HR 1.38 per 10% decrease, 95% CI 1.24–1.54), and LVEF-reserve (HR 1.19 per 5% decrease, 95% CI 1.07–1.31) were significant predictors of endpoints. Results were consistent in subgroups defined by gender, history of ischaemic heart disease, low LVEF, and atrial fibrillation.

MFR, LVEF, and LVEF-reserve derived from ⁸²Rb-PET provide prognostic information on cardiovascular outcomes in patients with no perfusion defects. This may aid in identifying patients at risk and might provide an opportunity for preventive interventions.