Abstract 532: Relationships of Pericardial and Thoracic Fat Burden to Subsequent Adverse Cardiac Events in Asymptomatic Patients Undergoing Noncontrast CT for Coronary Calcium Scoring
Background: Pericardial fat volume (PFV) and thoracic fat volume (TFV) can be routinely measured from noncontrast CT (NCT) performed for calculating coronary calcium score (CCS) and may predict major adverse cardiovascular event (MACE) risk.
Methods: From a registry of 2751 asymptomatic patients without known CAD and 4-year follow-up after NCT for MACE (cardiac death, myocardial infarction, stroke, late revascularization), we compared 58 patients who experienced MACE (“EVENTS”) to 174 event-free controls (1:3 EVENT-to-control ratio) matched by sex and a propensity score to account for age, traditional risk factors, and CCS. On NCT, TFV was automatically calculated by applying our previously-described fat-segmenting algorithm. PFV was calculated by manually placing 5–7 pericardium-defining points to create the pericardial contour, within which all fat voxels were automatically identified. Relationships of PFV and TFV to MACE were evaluated using conditional multivariable logistic regression.
Results: EVENTS had higher mean PFV (101.8 ± 49.2 cm3 vs. 84.9 ± 37.7 cm3, p = 0.007) and mean TFV (204.7 ± 90.3 cm3 vs. 177 ± 80.3 cm3, p = 0.029) and higher frequencies of PFV > 125 cm3 (33% vs. 14%, p = 0.002) and TFV > 250 cm3 (31% vs. 17%, p = 0.025). Each doubling of PFV and TFV were significantly associated with MACE (OR 1.91, 95%CI 1.14 –3.19 for PFV; OR 1.83, 95%CI 1.08 –3.09 for TFV) after adjusting for traditional risk factors and CCS. These associations remained significant after adjusting for Framingham Risk Score, CCS, and BMI (OR 1.74, 95%CI 1.03–2.95 for PFV; OR 1.78, 95%CI 1.01–3.14 for TFV, see Table⇓). PFV and TFV were highly correlated to each other (r2 = 0.74), and each showed weak correlations to waist, waist-to-height ratio, and BMI (r2 ranged from 0.12 to 0.28).
Conclusion: Patients who experience MACE exhibit greater PFV and TFV on pre-MACE NCT than matched event-free controls, suggesting that PFV and TFV has added value in predicting adverse cardiovascular outcomes.