Rb-82 PET/CT left ventricular mass-to-volume ratios

• Published in: The International Journal of Cardiovascular Imaging Vol. 33; no. 8; pp. 1263 - 1270
• Main Authors: Tosh, Andrew Van, Reichek, Nathaniel, Cooke, C. David, Palestro, Christopher J., Nichols, Kenneth J.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2017; Springer Nature B.V
• Subjects: Accuracy; Aged; Aged, 80 and over; Blood flow; Body size; Cardiac Imaging; Cardiology; Coronary Artery Disease - complications; Coronary Artery Disease - diagnostic imaging; Coronary Artery Disease - physiopathology; Coronary Circulation; Data processing; Female; Heart; Heart diseases; Humans; Imaging; Magnetic Resonance Imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Myocardial Perfusion Imaging - methods; Original Paper; Patients; Population studies; Positron emission; Positron Emission Tomography Computed Tomography - methods; Predictive Value of Tests; Prognosis; Radiology; Radiopharmaceuticals - administration & dosage; Reproducibility of Results; Retinoblastoma protein; Retrospective Studies; Risk; Risk Assessment; Risk Factors; Rubidium Radioisotopes - administration & dosage; Stresses; Stroke Volume; Tomography; Ventricle; Ventricular Function, Left; Rubidium isotopes; Myocardial perfusion imaging: PET; Quantification; PET/CT; Left ventricular function
• ISSN: 1569-5794; 1875-8312; 1573-0743; 1875-8312
• DOI: 10.1007/s10554-017-1087-1

Left ventricular (LV) mass:volume ratios indexed to body size (Mi/Vi) provide risk stratification for cardiac events. We sought to determine whether Rb-82 PET mass and volume indices are similar to MRI normal values for low likelihood subjects, and whether abnormal indices are related to abnormal myocardial blood flow (MBF). Data were analyzed retrospectively for 194 patients referred for rest/stress Rb-82 PET. LV EF, volume and mass values were calculated and mass:volume ratios were indexed to patients’ height and weight. MBF was computed from the first pass dynamic component of PET data. 53 patients at low likelihood of CAD had PET Mi/Vi = 1.35 ± 0.27, consistent with the MRI literature range of 1.0–1.5. Compared to patients with normal indexed volume (Vi), patients with abnormally high Vi had lower rest MBF (0.56 ± 0.24 vs 0.93 ± 0.57 ml/g/min, p = 0.0001), and lower stress MBF (0.97 ± 0.52 vs. 1.83 ± 0.96 ml/g/min, p < 0.0001). Stress EF < 50% predicted abnormal Vi with 90% accuracy. Patients with Mi/Vi < 1.0 had abnormally low rest EF (45 ± 16% vs. 60 ± 15%, p < 0.0001) and low rest MBF (0.58 ± 0.25 vs. 0.96 ± 0.59 ml/g/min, p < 0.0001). In our study population, abnormal LV volume and mass correlated with lower rest and stress MBF and EF, suggesting that the pathophysiologic explanation of these patients’ increased risk is more extensive obstructive CAD.