Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

251 computed tomographic coronary artery calcium

SHAPE Society

  • Login to see the comments

  • Be the first to like this

251 computed tomographic coronary artery calcium

  1. 1. CRP + Calcium Score; More Powerful Together Provided by: M. Leila Rasouli, M.D. Division of Cardiology, Harbor UCLA Medical Center Editorial Slides VP Watch – October 30, 2002 - Volume 2, Issue 43
  2. 2. Computed Tomographic Coronary Artery Calcium (CAC) • A manifestation of subclinical atherosclerosis • A Recent meta-analysis reported a pooled 4-fold relative risk (RR) for CAC as a predictor of myocardial infarction (MI) or coronary death.1
  3. 3. High-sensitivity C-Reactive Protein (CRP) • A measure of chronic inflammation • Serum levels of CRP in highest tertile predict future coronary events in asymptomatic men2 and postmenopausal women.3,4 • Elevated CRP levels impart an approximately 2-fold risk of coronary events after adjustment for demographic and risk factors.
  4. 4. South Bay Heart Watch (SBHW) • As reported in VP Watch of this week, a prospective cohort study designed to appraise the value of coronary calcium and both traditional & non-tradidtional risk factors for cardiovascular outcomes in asymptomatic adults • Objective of investigation: To evaluate prospectively the combined use of CT coronary calcium scores & high-sensitivity CRP in predicting cardiovascular events in SBHW cohort of nondiabetics
  5. 5. Methods • SBHW cohort: n=1461. Asymptomatic participants ≥ 45 yo with multiple cardiac risk factors • Study inclusion criteria: SBHW cohort who were nondiabetic5 and CRP ≤10 mg/L • Exclusion criteria: Participants with ECG/clinical evidence of infarction, revascularization, or typical angina
  6. 6. Methods • Enrollment: between December 1990 –December 1992 • Final N= 967 • Baseline and follow-up risk factor screening, CT for CAC, and CRP measurement conducted • Follow-up: 6.4 ± 1.3 years
  7. 7. Methods • Study end points: 1)nonfatal MI or coronary death, 2 )any cardiovascular event (MI, coronary death, coronary revascularization, or stroke) • Statistical Analysis: t-test, Cox regression analyses, all analyses conducted at .05 significance level and used SAS software
  8. 8. Results • 50 participants experienced MI/coronary death endpoint • Participants with MI/coronary death had higher systolic BP and lower HDL cholesterol • 104 participants experienced any cardiovascular event (CV) • Participants with any CV event were older, less likely to smoke, took ASA, had higher BP and BMI, and lower HDL
  9. 9. Results • Median calcium score was 5 times greater in participants who had an event than in those who did not (p<0.0001) • Significantly larger CRP values for those who experienced end points (p=0.002)
  10. 10. Results • Calcium score was a statistically significant predictor of both end points (p<0.005) • CRP was a marginally significant predictor of MI/coronary death (p=0.09) & statistically significant predictor of any CV event (p=0.03)
  11. 11. Results • Risk group analysis defined by tertiles for CAC (<3.7, 3.7-142.1, >142.1) and the 75th percentile for CRP (>4.05 mg/L) indicated increasing risk with increasing CAC and CRP
  12. 12. Results • RR for medium-calcium/low CRP risk group to high-calcium/high CRP risk group ranged from 1.8-6.1 for MI/coronary death (p=0.003) • For any CV event: RR ranged from 2.8-7.5 (p<0.001)
  13. 13. 6.1 4.3 1.7 4.9 1.8 1 0 2 4 6 8 High Medium Low Low High Relative risks of nonfatal MI or coronary death associated with high (> 75th percentile = 4.05 mg/L) and low (<4.05 mg/L) levels of CRP and high (> 142.1), medium (3.7 to 142.1) and low (< 3.7) tertiles of calcium scores.
  14. 14. 7.5 3.4 1.64.4 2.8 1 0 2 4 6 8 High Medium Low Low High Relative risks of nonfatal MI, coronary death, PTCA, CABG, or stroke associated with high (> 75th percentile = 4.05 mg/L) and low (<4.05 mg/L) levels of CRP and high (> 142.1, medium (3.7 to 142.1) and low (< 3.7) tertiles of calcium scores.
  15. 15. Discussion • Risk-adjusted analysis revealed CAC and CRP are associated with ischemic cardiovascular events in previously asymptomatic nondiabetic adults • Lack of interaction in nondiabetics between CRP levels and CAC along with the complementary predictive power of the 2 tests suggests that they assess different aspects/mechanisms that result in CV events
  16. 16. Limitations • Participants homogeneous (older men) • Statistical analyses could not control for all possible relevant confounders (ie physical activity) • CRP levels in the study were greater than those derived from a meta-analysis based on 14 population-based studies.4
  17. 17. Conclusion • Combined use of calcium scores and CRP improves risk stratification in non-diabetic patients. • Use of combined testing with CT and CRP appears to complementary.
  18. 18. Question • What is the exact role of both calcification and CRP in the development of atherosclerosis and cardiovascular events? – Only markers of disease? – CRP is a marker but calcification is a risk factor? – Calcification is a marker but CRP is a risk factor? – Both are risk factors?
  19. 19. References 1) O’Malley PG, Taylor AJ, Jackson JL, et al. Prognostic value of coronary electron-beam computed tomography for coronary heart disease events in asymptomatic populations. Am J Cardiol. 2000;85:945-948. 2) Koenig W, Sund M, Frohlich M, et al. C-reactive protein, a sensitive marker of inflammation, predicts future risk of coronary heart disease in initially healthy middle-aged men:results from the MONICA. Circulation 1999;99:237-242. 3) Ridker PM, Hennekens CH, Buring JE, et al. C-reactive protein and other markers of inflammation in the prediction of cardiovascular disease in women. N Engl J Med. 2000;342:836-843. 4) Danesh J, Whincup P, Walker M, et al. Low grade inflammation and coronary heart disease: prospective study and updated meta-analyses. BMJ. 2000;321:199-204. 5) Le T, Wong N, Detrano R, et al. The relationship between clinical coronary events and coronary artery calcium as detected by electron beam computed tomography in diabetes. Diabetologia 1999;42:A231.