title: Pericardial fat burden on ECG-gated noncontrast CT in asymptomatic patients who subsequently experience adverse cardiovascular events.
abstract: OBJECTIVE
  We aimed to evaluate whether pericardial fat has value in predicting the risk of future adverse cardiovascular outcomes.
  
  
  BACKGROUND
  Pericardial fat volume (PFV) and thoracic fat volume (TFV) can be routinely measured from noncontrast computed tomography (NCT) performed for calculating coronary calcium score (CCS) and may predict major adverse cardiac event (MACE) risk.
  
  
  METHODS
  From a registry of 2,751 asymptomatic patients without known cardiac artery disease and 4-year follow-up for MACE (cardiac death, myocardial infarction, stroke, late revascularization) after NCT, we compared 58 patients with MACE with 174 same-sex, event-free control subjects matched by a propensity score to account for age, risk factors, and CCS. The TFV was automatically calculated, and PFV was calculated with manual assistance in defining the pericardial contour, within which fat voxels were automatically identified. Independent relationships of PFV and TFV to MACE were evaluated using conditional multivariable logistic regression.
  
  
  RESULTS
  Patients experiencing MACE had higher mean PFV (101.8 +/- 49.2 cm(3) vs. 84.9 +/- 37.7 cm(3), p = 0.007) and TFV (204.7 +/- 90.3 cm(3) vs. 177 +/- 80.3 cm(3), p = 0.029) and higher frequencies of PFV >125 cm(3) (33% vs. 14%, p = 0.002) and TFV >250 cm(3) (31% vs. 17%, p = 0.025). After adjustment for Framingham risk score (FRS), CCS, and body mass index, PFV and TFV were significantly associated with MACE (odds ratio [OR]: 1.74, 95% confidence interval [CI]: 1.03 to 2.95 for each doubling of PFV; OR: 1.78, 95% CI: 1.01 to 3.14 for TFV). The area under the curve from receiver-operator characteristic analyses showed a trend of improved MACE prediction when PFV was added to FRS and CCS (0.73 vs. 0.68, p = 0.058). Addition of PFV, but not TFV, to FRS and CCS improved estimated specificity (0.72 vs. 0.66, p = 0.008) and overall accuracy (0.70 vs. 0.65, p = 0.009) in predicting MACE.
  
  
  CONCLUSIONS
  Asymptomatic patients who experience MACE exhibit greater PFV on pre-MACE NCT when they are compared with event-free control subjects with similar cardiovascular risk profiles. Our preliminary findings suggest that PFV may help improve prediction of MACE.
authors.affiliation: Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Victor Y
authors.initials: VY
authors.lastname: Cheng
authors.forename: Damini
authors.initials: D
authors.lastname: Dey
authors.forename: Balaji
authors.initials: B
authors.lastname: Tamarappoo
authors.forename: Ryo
authors.initials: R
authors.lastname: Nakazato
authors.forename: Heidi
authors.initials: H
authors.lastname: Gransar
authors.forename: Romalisa
authors.initials: R
authors.lastname: Miranda-Peats
authors.forename: Amit
authors.initials: A
authors.lastname: Ramesh
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Wong
authors.forename: Leslee J
authors.initials: LJ
authors.lastname: Shaw
authors.forename: Piotr J
authors.initials: PJ
authors.lastname: Slomka
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000368:Aged; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000401:mortality; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010496:Pericardium / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011379:Prognosis; D057216:Propensity Score; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed
references.citation: Circulation. 1998 May 12;97(18):1837-47
references.pmid: 9603539
references.citation: Arterioscler Thromb Vasc Biol. 2009 May;29(5):781-6
references.pmid: 19229071
references.citation: JAMA. 2004 May 5;291(17):2092-9
references.pmid: 15126437
references.citation: Am J Clin Nutr. 2008 Sep;88(3):645-50
references.pmid: 18779279
references.citation: Stat Med. 1998 Oct 15;17(19):2265-81
references.pmid: 9802183
references.citation: N Engl J Med. 2008 Mar 27;358(13):1336-45
references.pmid: 18367736
references.citation: Circulation. 2007 May 1;115(17):2340-3
references.pmid: 17470708
references.citation: Circulation. 2007 Sep 11;116(11):1234-41
references.pmid: 17709633
references.citation: Am J Physiol. 1986 Jun;250(6 Pt 1):E736-45
references.pmid: 3717334
references.citation: Obesity (Silver Spring). 2008 Aug;16(8):1914-9
references.pmid: 18535554
references.citation: Invest Radiol. 2005 Feb;40(2):97-101
references.pmid: 15654254
references.citation: JAMA. 2007 Jan 17;297(3):278-85
references.pmid: 17227979
references.citation: Am J Cardiol. 2008 Sep 15;102(6):767-71
references.pmid: 18774004
references.citation: J Am Coll Cardiol. 2009 Jan 20;53(3):244-53
references.pmid: 19147041
references.citation: Atherosclerosis. 2010 Mar;209(1):136-41
references.pmid: 19748623
references.citation: Eur Heart J. 2009 Apr;30(7):850-6
references.pmid: 19136488
references.citation: Radiology. 1999 Apr;211(1):283-6
references.pmid: 10189485
references.citation: Invest Radiol. 2008 Feb;43(2):145-53
references.pmid: 18197067
references.citation: Circulation. 2007 Oct 30;116(18):2029-35
references.pmid: 17923573
references.citation: Am J Clin Nutr. 1988 Dec;48(6):1351-61
references.pmid: 3202084
references.citation: J Am Coll Cardiol. 1990 Mar 15;15(4):827-32
references.pmid: 2407762
references.citation: Circulation. 2008 Feb 5;117(5):605-13
references.pmid: 18212276
references.citation: Circulation. 2007 Jul 3;116(1):39-48
references.pmid: 17576866
references.citation: Atherosclerosis. 2001 Jul;157(1):203-9
references.pmid: 11427222
references.citation: N Engl J Med. 2003 Feb 27;348(9):781-90
references.pmid: 12606732
references.citation: Circulation. 2003 Nov 18;108(20):2460-6
references.pmid: 14581396
references.citation: Circulation. 2008 Jan 1;117(1):16-23
references.pmid: 18071069