Abstract 14401: Coronary Calcium Quantification in Patients With Normal Cardiac PET/CT Imaging Identifies Patients With Residual High Risk of MACE at One Year
Introduction: Cardiac PET/CT is a coronary imaging modality with increased accuracy over SPECT and can be used to quantify coronary artery calcification (CAC). Whether obtaining a separate CAC score during the performance of a clinically indicated cardiac PET/CT can further stratify future cardiovascular risk among patients with normal perfusion imaging remains unknown.
Methods: From March 2013 to April 2015, a total of 658 (age = 67±10 years, males = 54%, diabetes = 29%, smoker = 37%) patients at Intermountain Medical Center undergoing clinically indicated regadenoson 82Rb PET/CT imaging and concurrent CAC quantification, found to have normal coronary perfusion, were analyzed. Patients were stratified according to CAC severity [none/mild = 0-10 (n=33); moderate = 11-299 (n=309); severe = 300-1000 (n=190); very severe >1000 (n=126)] and followed clinically for one year for the first occurrence of a major adverse cardiovascular event (defined as death, myocardial infarction or stroke). Statistical tests were performed to see if a trend amongst the CAC categories exists.
Results: Overall, 31(4.7%) patients experienced a MACE event during the first year of clinical follow-up. When stratified according to CAC severity (see Figure), no MACE occurred among patients with mild CAC and a clear trend (p=0.058) towards an increasing risk of MACE with increasing CAC severity was identified.
Conclusion: In this study of patients undergoing clinically indicated cardiac PET/CT, despite normal coronary perfusion, nearly 5% of patients still experienced an adverse cardiovascular event within one year. In this group, the risk of an event strongly correlated with the severity of CAC. While normal perfusion may signify lack of ischemia at index assessment, quantifying CAC identifies patients at risk of CVD events within 12 months of the index scan. Future study should assess if earlier aggressive medical therapy reduces MACE events in those identified as high risk.
Author Disclosures: V.T. Le: None. R.O. McCubrey: None. K.R. Jensen: None. H. Raasch: None. S. Mason: None. S. Knight: None. K.G. Meredith: None. D.L. Lappé: None. D. Bruno: None. J.L. Anderson: None. K.U. Knowlton: None. J.B. Muhlestein: None.
- © 2016 by American Heart Association, Inc.