Author + information
- Received July 20, 2015
- Revision received February 19, 2016
- Accepted March 24, 2016
- Published online December 1, 2016.
- Nina B. Radford, MDa,
- Laura F. DeFina, MDb,
- Carolyn E. Barlow, PhDb,
- Susan G. Lakoski, MDc,
- David Leonard, PhDb,
- Andre R.M. Paixao, MDd,
- Amit Khera, MD, MSce and
- Benjamin D. Levine, MDe,f,∗ ()
- aCooper Clinic, Dallas, Texas
- bCooper Institute, Dallas, Texas
- cUniversity of Texas MD Anderson Cancer Center, Houston, Texas
- dDivision of Cardiology, Department of Medicine, Emory University, Atlanta, Georgia
- eDivision of Cardiology, Department of Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- fInstitute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, and University of Texas Southwestern Medical Center, Dallas, Texas
- ↵∗Reprint requests and correspondence:
Dr. Benjamin D. Levine, Institute for Exercise and Environmental Medicine, 7232 Greenville Avenue, Suite 435, Dallas, Texas 75231.
Objectives The authors sought to determine the relative contributions of baseline coronary artery calcification (CAC), follow-up CAC, and CAC progression on incident cardiovascular disease (CVD).
Background Repeat CAC scanning has been proposed as a method to track progression of total atherosclerotic burden. However, whether CAC progression is a useful predictor of future CVD events remains unclear.
Methods This was a prospective observational study of 5,933 participants free of CVD who underwent 2 examinations, including CAC scores, and subsequent CVD event assessment. CAC progression was calculated using the square root method. The primary outcome was total CVD events (CVD death, nonfatal myocardial infarction, nonfatal atherosclerotic stroke, coronary artery bypass surgery, percutaneous coronary intervention). Secondary outcomes included hard CVD events, total coronary heart disease (CHD) events, and hard CHD events.
Results CAC was detected at baseline in 2,870 individuals (48%). The average time between scans was 3.5 ± 2.0 years. After their second scan, 161 individuals experienced a total CVD event during a mean follow-up of 7.3 years. CAC progression was significantly associated with total CVD events (hazard ratio: 1.14, 95% confidence interval: 1.01 to 1.30 per interquartile range; p = 0.042) in the model including baseline CAC, but the contribution of CAC progression was small relative to baseline CAC (chi-square 4.16 vs. 65.92). Furthermore, CAC progression was not associated with total CVD events in the model including follow-up CAC instead of baseline CAC (hazard ratio: 1.05, 95% confidence interval: 0.92 to 1.21; p = 0.475). A model that included follow-up CAC alone performed as well as the model that included baseline CAC and CAC progression.
Conclusions Although CAC progression was independently, but modestly, associated with CVD outcomes, this relationship was no longer significant when including follow-up CAC in the model. These findings imply that if serial CAC scanning is performed, the latest scan should be used for risk assessment, and in this context, CAC progression provides no additional prognostic information.
This study was supported by the National Space Biomedical Research Institute through NASA NCC 9-58. The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received July 20, 2015.
- Revision received February 19, 2016.
- Accepted March 24, 2016.
- American College of Cardiology Foundation