Ejection Fraction And Ventricular Volumes On Rubidium Positron Emission Tomography: Prospective Validation Against Cardiovascular Magnetic Resonance.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is the non-invasive gold standard for non-invasively determining left ventricular volumes (LVV) and ejection fraction (EF). We aimed to assess the accuracy of LVV and LVEF measured by Positron Emission Tomography (PET) as compared to CMR.

METHODS: Patients who underwent both PET and CMR within 1 year were identified from prospective institutional registries. Analysis was performed to evaluate the agreement between the raw and body-surface-area-normalized left ventricular volume (LVV) and ejection fraction (EF) derived from PET vs. those derived from CMR.

RESULTS: The study population consisted of 669 patients (mean age 62 ± 13 years, 65% male). The median (IQR) duration between CMR and PET imaging was 36 (7-118) days. The median (IQR) EF values were 52% (38-63%) on CMR and 53% (37-65%) on PET (mean difference 0.53% ± 9.1, p=0.129) with a strong correlation (Spearman rho=0.84, P <0.001; Intraclass Correlation Coefficient 0.84, 95% CI 0.82 - 0.86, P<0.001; Lin's Concordance Correlation Coefficient was 0.844, 95% CI 0.822 to 0.865). Results were similar with LVV, normalized LVV/EF, and in subgroups of patients with reduced EF, coronary artery disease scar, LV hypertrophy as well as patients with defibrillators. However, PET tended to underestimate LVV compared to CMR.

CONCLUSION: Our analysis showed a strong correlation of EF and LVV by PET against a reference standard of CMR, while PET significantly underestimated LVV, but not EF, compared to CMR.