Diffuse Perfusion Impairment Versus Global Myocardial Flow Reserve and Focal Perfusion Impairments in Patients Undergoing 82 Rb-PET Imaging

Le résumé fourni par la source

BACKGROUND: Although global myocardial flow reserve (MFR) is a powerful prognostic factor, it may overlook segmental abnormalities and does not differentiate focal from diffuse perfusion impairments. Therefore, we sought to assess whether integrated MFR provides incremental prognostic value beyond global MFR. METHODS: Consecutive patients undergoing positron emission tomography myocardial perfusion imaging between 2019 and 2025 were included. For each patient, global MFR and the proportion of the myocardium with diffuse and focal integrated MFR impairment were quantified. The primary outcome was the total burden of death, myocardial infarction, and heart failure hospitalization. Multivariable Andersen-Gill Cox models with robust variance estimators were used to estimate hazard ratios (HRs). Restricted cubic splines were used to account for potential nonlinearity. RESULTS: Over a median follow-up of 550 days (interquartile range, 203–1017 days), 1511 primary outcome events occurred in 8500 patients. In a multivariable model adjusted for both parameters, diffusely impaired integrated MFR (HR per interquartile range, 2.02 [95% CI, 1.33–3.05]), but not global MFR (HR per interquartile range, 1.10 [95% CI, 0.82–1.47]), was associated with poorer outcomes. Diffuse perfusion impairment was more strongly associated with the primary outcome (HR per interquartile range, 2.20 [95% CI, 1.72–2.82]) than focal impairment (HR, 1.25 [95% CI, 1.07–1.46]). Diffusely impaired integrated MFR was more prognostic in patients with a preserved left ventricular ejection fraction ( P for interaction <0.001). At ejection fractions of 40%, 50%, 60%, and 70%, the HRs per interquartile range for greater diffuse impairment were 1.43, 1.97, 2.49, and 3.02, respectively. CONCLUSIONS: Diffuse impairments in myocardial perfusion are associated with poorer outcomes compared with focal impairments and are more informative than global MFR. Diffuse impairments may be more prognostic in patients with a preserved ejection fraction.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.