Coronary Calcium and the Prediction of Coronary Heart Disease Kiang Liu Overview • Why Should We Study Subclinical Cardiovascular Disease (CVD)? • Coronary Calcium and the Prediction of Coronary Events • MESA Findings on Ethnic Differences of Coronary Calcium and on Coronary Calcium and the Prediction of Coronary Events • Improvement of Using CAC to Identify People at High Risk for Coronary Events • Conclusions Why Should We Study Subclinical CVD? Crude Death Rates for Selected Causes, U.S., 1950-2006 From NHLBI Chartbook, 2009 Leading Causes of Death U.S., 2006 Cause of Death Number Total 2,426,264 1 Heart Disease * 631,636 2 Cancer 559,888 3 Cerebrovascular Disease (stroke) 137,119 4 COPD and allied conditions ** 124,583 5 Accidents 121,599 6 Diabetes 72,449 7 Alzheimer’s disease 72,432 8 Influenza and pneumonia 56,326 9 Nephritis 45,344 Septicemia 34,234 10 All other causes of death * Includes 425,425 deaths from coronary heart disease ** Chronic lower respiratory diseases. From NHLBI Chartbook, 2009 570,654 Total Cholesterol Distribution CHD vs Non-CHD Population Framingham Heart Study—26-Year Follow-up No CHD 35% of CHD occurs in people with TC<200 mg/dL CHD 150 200 250 Total Cholesterol (mg/dL) Adapted from Castelli WP. Atherosclerosis. 1996;124(suppl):S1-S9. 300 Percentage of MRFIT Men with 1+, 2+, or 3+ Risk Factors by age group 19-year follow-up for CHD mortality RISK FACTOR STATUS CHD Death All Other CHD Death All Other Number 1,112 67,572 12,689 237,767 1+ RISK FACTORS 98.6% (97.9-99.3) 89.8% (89.6-90.0) 98.8% (98.6-99.0) 93.6% (93.5-93.7) 2+ RISK FACTORS 85.8% (83.7-87.9) 57.8% (57.4-58.2) 86.1% (85.5-86.7) 65.6% (65.4-65.8) 3+ RISK FACTORS 46.9% (44.0-49.8) 17.0% (16.7-17.3) 38.9% (38.1-39.7) 18.4% (18.2-18.6) AGES 35-39 AGES 40-57 Adapted from Greenland et al. JAMA. 2003; 290: 891-7. Subclinical Cardiovascular Disease (CVD) Subclinical disease: No manifest disease, but pathogenic changes have occurred Identify people at high risk if subclinical CVD can be detected non-invasively before it produces clinical signs and symptoms Measures of Subclinical CVD Examples: • Coronary Calcium Score • Carotid IMT • Flow Mediated Vasodilation • Ankle Brachial Index • Cardiac MRI measures • Biomarkers Coronary Calcium and the Prediction of Coronary Events EBT Coronary Calcium Screen No Coronary Artery Calcium Extensive Coronary Artery Calcium Graph showing square-root sum of coronary calcium areas (mm) by electron-beam computed tomography vs. square-root sum of atherosclerotic plaque areas (mm) for each of the individual coronary arteries studied (n=38) Rumberger, J. A. et al. Circulation. 1995;92:2157-62 Studies on Coronary Calcium as a Predictor of Coronary Events Size Average Follow-up (Months) Detrano et al. JACC 1996 4221 (55 11 yrs) Arad et al. Circulation 1996 11732 (55 11 yrs) Study Arad et al. JACC 1998 Abstract Risk Ratio 30 MI + cardiac deaths Q4 vs. Q1 RR=10 19 MI, CABG, PTCA, cardiac death Calcium score >160 vs. 160 OR = 35.4 43 OR=23 32 MI + cardiac death revasc Log calcium score5 OR=1.24(NS) OR=2.87 3672 (52 yrs) 36-72 Angina, MI, angiography, CABG, PTCA Calcium score ≥ 50 vs. 0 OR = 6.87 11964 (66 8 yrs) 44 MI, cardiac death, revasc No significant improvement of ROC curve area6 Secci et al. Circulation 1997 3263 (66 8 yrs) Agatston et al. Circulation 1996 Detrano et al. Circulation 1999 1 Events Patients underwent angiography Asymptomatic subjects 3 High-risk subjects 4 High-risk asymptomatic subjects 5 Adjusting for age and CVD risk factors 6 No significant improvement of ROC curve area in addition to CVD Risk model 2 Association Between CAC Score Categories and Hard Events in Men CAC Score Relative Risk 95% CI Range 0.0 1.0† Referent Quartile 1 1.0-3.8 1.76 0.39-7.88 Quartile 2 4.0-30.5 2.84 0.73-11.11 Quartile 3 31-169 5.61† 1.57-20.06 Quartile 4 170-7,000 7.24† 2.01-26.15 The multivariable Cox proportional-hazards regression analysis was performed with adjustment for age and other CAD risk factors. †0.001<P<0.01 Kondos, et al. Circulation. 2003;107:2571-6. Multivariable Association Between CAC and Cardiac Events (Hazard Ratio) Men Hard events 3.86* (1.17-12.70) Women 1.53 (0.23-10.09) Soft events 26.8† (3.72-193.11) 3.08* (1.11-8.58) All events 10.46† (3.85-28.40) 2.57* (1.06-6.23) *0.01 < P < 0.05 †0.001 < P < 0.01 Kondos, et al. Circulation. 2003;107:2571-6. MESA Findings on Coronary Calcium and the Prediction of Coronary Events Multi-Ethnic Study of Atherosclerosis MESA • An NHLBI-sponsored multi-center study investigating prevalence, correlates, and progression of subclinical CVD (i.e., disease detected noninvasively before it produces clinical signs and symptoms) in a population-based sample of 6,814 men and women aged 45-84. • 6 U.S. field centers recruited healthy men and women (~50% each sex) from 4 racial/ethnic groups (42% white, 13% Chinese, 24% African-American, and 21% Hispanic). Multi-Ethnic Study of Atherosclerosis MESA Objectives To determine characteristics related to progression of subclinical to clinical CVD. To determine characteristics related to progression of subclinical CVD. To assess ethnic, age, and gender differences in subclinical disease prevalence and risk of progression to clinical cardiovascular disease Collaborating Centers in MESA • Univ of Washington • Univ of MN • U of Vermont • New Engl Med Cntr • Northwestern Univ •Columbia •Johns Hopkins • UCLA (2) • Wake Forest Cohort Characteristics - Men White African A (n=1218) (n=815) Hispanic (n=700) Chinese (n=379) P Value† Age, yrs 63.3 62.8 61.7*** 63.1 .009 % <HS 3.8 12.4*** 42.1*** 16.7*** < .0001 BMI 27.9 28.8*** 28.7*** 24.0*** < .0001 Waist, cm 100.8 100.7 100.8 87.7*** < .0001 % current smoker 11.3 19.5*** 15.7** 9.9 < .0001 % former smoker 48.8 42.8** 45.3 36.9*** .0003 Alcohol, dk/wk 6.8 4.4*** 5.2*** 2.8*** < .0001 Age adjusted; *p< 0.05; **p<0.01; ***p<0.001 compared to White; †P values for overall group comparisons Cohort Characteristics - Men, continued P Value§ White African A Hispanic Chinese SBP, mmHg 123.6 130.1*** 126.2** 123.5 <.0001 DBP, mmHg 73.7 77.1*** 74.8* 74.8 <.0001 LDL-C, mg/dl 117.3 113.5** 118.9 116.7 .006 HDL-C, mg/dl 45.3 46.8** 42.8*** 45.9 <.0001 TG, mg/dL 127.9 105.9*** 153.4*** 136.2* <.0001 Glucose mg/dl 101.2 108.9*** 113.4*** 109.0*** <.0001 % Hypertension† 36.8 57.1*** 38.6 34.6 <.0001 % Diabetes 8.1 20.4*** 20.6*** 14.1*** <.0001 % Chol Rx 18.4 15.0* 13.2** 13.6* .008 Age adjusted;*p< 0.05; **p<0.01; ***p<0.001 compared to White; †BP >140/90 or reported to be on antihypertensive medication; ‡Fasting glucose >126 mg/dl or on hypoglycemic medication;§P values for overall group comparisons Cohort Characteristics - Women White African A (n=1313) (n=1019) Hispanic (n=750) Chinese (n=404) P Value† Age, yrs 63.0 62.6 62.1 62.8 .26 % <HS 5.5 11.7*** 48.1*** 31.3*** < .0001 BMI 27.5 31.3*** 30.0*** 23.9*** < .0001 Waist, cm 94.9 101.6*** 100.5*** 86.4*** < .0001 % current smoker 11.7 15.9** 9.8 1.3*** < .0001 % former smoker 39.9 31.9*** 21.3*** 2.2*** < .0001 Alcohol, dk/wk 3.4 1.9*** 1.2*** 0.8*** < .0001 Age adjusted; *p< 0.05; **p<0.01; ***p<0.001 compared to White; †P values for overall group comparisons Cohort Characteristics - Women, continued White African A Hispanic Chinese P Value§ SBP, mmHg 122.4 132.9*** 128.3*** 125.1* <.0001 DBP, mmHg 66.9 72.5*** 68.4** 69.2*** <.0001 LDL-C, mg/dl 117.1 118.7 119.8 113.9 .01 HDL-C, mg/dl 59.0 57.0** 52.7*** 53.3*** <.0001 TG, mg/dl 126.8 99.2*** 143.1*** 137.0** <.0001 Glucose mg/dl 94.8 105.2*** 107.9*** 102.5*** <.0001 % Hypertension† 36.4 61.1*** 46.5*** 40.3 <.0001 % Diabetes 4.9 17.1*** 17.4*** 13.3*** <.0001 % Chol Rx 16.2 18.4 15.5 15.5 .26 Age adjusted;*p< 0.05; **p<0.01; ***p<0.001 compared to White; †BP >140/90 or reported to be on antihypertensive medication; ‡Fasting glucose >126 mg/dl or on hypoglycemic medication;§P values for overall group comparisons Age-Adjusted Prevalence of Coronary Calcium (CAC) > 20 100 80 60 40 55 *** *** *** 43 44 38 31 *** *** 30 25 22 20 0 Men Women *p< 0.05, **p<0.01, ***p<0.001 compared to White. White African American Hispanic Chinese Unadjusted Kaplan–Meier Cumulative-Event Curves for Major Incident CHD by CAC Score, MESA Rates for major coronary events (myocardial infarction and death from coronary heart disease) Differences among all curves are statistically significant (P<0.001). Detrano, et al. N Engl J Med. 2008;358:13. Unadjusted Kaplan–Meier Cumulative-Event Curves for Any Incident CHD by CAC Score, MESA Rates for any coronary event Differences among all curves are statistically significant (P<0.001). Detrano, et al. N Engl J Med. 2008;358:13. Risk Factor Adjusted Risk of Incident CHD by CAC Score, MESA Major Coronary Event† Coronary-Artery Calcium Score No./No. at Risk Hazard Ratio (95% CI) 0 8/3409 1.00 1-100 25/1728 3.89 (1.72-8.79) 101-300 24/752 >300 32/833 Log2 (CAC+1) § †Major §Each Any Coronary Event P Value No./No. at Risk Hazard Ratio (95% CI) 15/3409 1.00 <0.001 39/1728 3.61 (1.96-6.65) <0.001 7.08 (3.05-16.47) <0.001 41/752 7.73 (4.13-14.47) <0.001 6.84 (2.93-15.99) <0.001 67/833 9.67 (5.20-17.98) <0.001 1.20 (1.12-1.29) <0.001 1.26 (1.19-1.33) <0.001 coronary events are myocardial infarction and death from coronary heart disease unit increase in log2 (CAC+1) represents a doubling of the coronary-artery calcium score Detrano, et al. N Engl J Med. 2008;358:13. P Value Risk of Incident CHD Associated with CAC Score in Four Racial or Ethnic Groups* Major Coronary Event† Racial or Ethnic Group Any Coronary Event No. Hazard Ratio (95% CI)§ P Value No. Hazard Ratio (95% CI) P Value White 41 1.17 (1.06-1.30) <0.005 74 1.22 (1.13-1.32) <0.001 Chinese 6 1.25 (0.95-1.63) 0.11 14 1.36 (1.12-1.66) <0.005 Black 18 1.35 (1.16-1.57) <0.001 38 1.39 (1.25-1.56) <0.001 Hispanic 24 1.15 (1.02-1.29) <0.025 36 1.18 (1.07-1.30) <0.001 *CAC denotes coronary-artery calcium score and CI confidence interval †Major coronary events are myocardial infarction and death from coronary heart disease §Hazard ratios were calculated with the use of Cox regression for coronary heart disease (major event and any event) for baseline levels of log2 (CAC+1) after adjustment for risk factors and interactions between racial or ethnic group and coronary calcium score and between racial or ethnic group and diabetes (the only significant interaction). Hazard ratios are calculated on the basis of a doubling of CAC+1 Detrano, et al. N Engl J Med. 2008;358:13. Area under the Curve (AUC), Risk Factors vs. Risk Factors plus CAC Score to Predict Incident CHD by Race or Ethnicity*, MESA Study Major Coronary Event† Racial or Ethnic Group Any Coronary Event AUC for Risk Factors Alone AUC for Risk Factors plus Coronary Artery Calcium Score P Value AUC for Risk Factors Alone AUC for Risk Factors plus Coronary Artery Calcium Score P Value White 0.76 0.79 0.10 0.75 0.79 0.02 Chinese 0.83 0.88 0.05 0.74 0.85 <0.001 Black 0.79 0.87 0.04 0.81 0.87 0.005 Hispanic 0.84 0.86 0.11 0.80 0.84 0.10 Total 0.79 0.83 0.006 0.77 0.82 <0.001 *Separate models are fitted for each racial or ethnic group. AUC denotes area under the receiver-operating characteristic curve. P values are for the comparison between AUC without and AUC with the coronary-artery calcium score. †Major coronary events are myocardial infarction and death from coronary heart disease Detrano, et al. N Engl J Med. 2008;358:13. Hazard Ratios (HRs) for an Incident CVD, CHD, or Stroke Event in Relation to a 1-SD Increment of Maximal Carotid IMT or CAC Score (MESA 2000-04) Measure* CVD (n = 222) Age-, race-, and sex-adjusted z Score max IMT In(CAC score + 1) Multivariable-Adjustedb z Score max IMT In(CAC score + 1) CHD (n = 159) Age-, race-, and sex-adjusted z Score max IMT In(CAC score + 1) Multivariable-Adjustedb z Score max IMT In(CAC score + 1) Stroke (n = 59) Age-, race-, and sex-adjusted z Score max IMT In(CAC score + 1) Multivariable-Adjustedb z Score max IMT In(CAC score + 1) HR Per 1-SD Increment Z Statistic (95% CI) P Value 1.3 (1.1-1.4) 2.1 (1.8-2.5) 4.1 8.6 <.001 <.001 1.2 (1.0-1.3) 1.9 (1.6-2.2) 2.7 7.5 .007 <.001 1.2 (1.0-1.4) 2.5 (2.1-3.1) 2.5 8.8 .01 <.001 1.1 (1.0-1.3) 2.3 (1.9-2.8) 1.5 7.9 .12 <.001 1.4 (1.2-1.8) 1.1 (0.8-1.5) 3.5 0.8 .001 .41 1.3 (1.1-1.7) 1.1 (0.8-1.4) 2.5 0.4 .01 .71 Folsom, et al. Arch Intern Med. 2008;168:12. Abbreviations: CAC, coronary artery calcium; CHD, coronary heart disease; CVD, cardiovascular disease; IMT, intimamedia thickness; max, maximum; MESA, Multi-Ethnic Study of Atherosclerosis *Coronary artery calcium score and IMT were in the same model bAdjusted as described in the “Methods” section Hazard Ratios (HR) for Incident CVD, CHD, or Stroke Event in Relation to Quartiles of Maximal Carotid IMT or CAC Score (MESA 2000-04) HR (95% Cl) Measure* CVD (n = 222) Age-, race-, and sex-adjusted z Score max IMT CAC Score Multivariable-Adjustedb z Score max IMT CAC Score CHD (n = 159) Age-, race-, and sex-adjusted z Score max IMT CAC Score Multivariable-Adjustedb z Score max IMT CAC score Stroke (n = 59) Age-, race-, and sex-adjusted z Score max IMT CAC Score Multivariable-Adjustedb z Score max IMT CAC score <50th Percentile X2 P Value Statistic Quartile 3 Quartile 4 1 [Reference] 1 [Reference] 1.4 (0.9-2.0) 2.6 (1.6-4.1) 2.2 (1.5-3.2) 5.3 (3.4-8.2) 20.1 58.4 <.001 <.001 1 [Reference] 1 [Reference] 1.3 (0.9-2.0) 2.3 (1.5-3.7) 1.7 (1.2-2.5) 4.4 (2.8-6.8) 8.7 44.7 .01 <.001 1 [Reference] 1 [Reference] 1.5 (1.0-2.4) 4.1 (2.2-2.7) 2.1 (1.4-3.3) 10.3 (5.6-18.9) 11.5 63.8 <.01 <.001 1 [Reference] 1 [Reference] 1.5 (0.9-2.3) 3.5 (1.9-6.6) 1.7 (1.1-2.7) 8.2 (4.5-15.1) 5.4 51.5 .07 <.001 1 [Reference] 1 [Reference] 0.9 (0.4-2.0) 1.4 (0.8-2.7) 2.4 (1.2-4.7) 1.2 (0.6-2.4) 9.9 0.7 <.01 .70 1 [Reference] 1 [Reference] 0.9 (0.4-2.0) 1.3 (0.6-2.6) 1.8 (0.9-3.6) 1.0 (0.5-2.1) 4.7 0.6 .10 .73 Folsom, et al. Arch Intern Med. 2008;168:12. Abbreviations: CAC, coronary artery calcium; CHD, coronary heart disease; CVD, cardiovascular disease; IMT, intima-media thickness; max, maximum; MESA, Multi-Ethnic Study of Atherosclerosis *Coronary artery calcium score and IMT were in the same model bAdjusted as described in the “Methods” section Prevalence of High CAC Score in People with Different Risk Factor Status, MESA % of CAC ≥ 100 50 40 30 20 10 0 0 1 Men % 100 ≤ CAC< 300 % 300 ≤ CAC 2 3+ 0 1 Number of Risk Factors 2 3+ Women Risk Factors: LDL ≥ 130 mg/dl or Rx; BP 140/90 mmHg or Rx; fasting glucose ≥ 126 mg/dl or Rx; current smoker Improvement of Using CAC to Identify People at High Risk for Coronary Events Current Paradigm for Risk Estimation and Treatment: ATP-III “Intensity of prevention efforts should match the absolute risk of the patient” Estimate 10-year risk (FRS) <10% 10-20% >20% or DM Further testing Lifestyle modification Lifestyle and drug therapy Calculation of the NRI Proportion of events and nonevents correctly reclassified Events reclassified higher – events reclassified lower Total number of events PLUS Nonevents reclassified lower – nonevents reclassified higher Total number of nonevents Pencina et al. Statist. Med. 2008;27:157-72 Participants not reclassified 5-Year Risk from Model with CAC 5-Year Risk from Model without CAC 0% to <3%, n=3,746 Events, n Proportion with events 3% to 10%, n=1847 Events, n Proportion with events >10%, n=285 Events, n Proportion with events 0% to <3% 3% to 10% >10% 3,310 34 0.9 843 52 5.4 183 28 14.4 Participants reclassified to higher risk 5-Year Risk from Model with CAC 5-Year Risk from Model without CAC 0% to <3%, n=3,746 Events, n Proportion with events 3% to 10%, n=1847 Events, n Proportion with events >10%, n=285 Events, n Proportion with events 0% to <3% 3% to 10% >10% 430 22 4.8 6 1 20.0 292 48 14.8 Participants reclassified to lower risk 5-Year Risk from Model with CAC 5-Year Risk from Model without CAC 0% to <3%, n=3,746 Events, n Proportion with events 0% to <3% 3% to 10%, n=1847 Events, n Proportion with events 712 15 1.9 >10%, n=285 Events, n Proportion with events 32 2 6.2 3% to 10% 70 7 8.9 >10% Calculation of NRI NRI for events: 0.23 PLUS = 0.25 (95% CI 0.16-0.34 NRI for non-events: 0.02 P<0.001) Reclassification among intermediate risk participants • Among 1847 intermediate risk participants, 39% were reclassified to low risk and 16% were reclassified to high risk – NRI = 0.55 (95% CI 0.41-0.69, P<0.001) – NRI = 0.29 for events and 0.26 for nonevents • 115 events occurred among intermediate risk participants; 48 were among people reclassified to high risk and 15 were among those reclassified to low risk CAC Prevalence, Amount and ‘Number Needed to Screen’ Compared with Framingham Risk Score Categories CAC Score Group Framingham Risk Score Categories (n = 5660) 5.10-2.5% 2.6-5% 7.6-10% 10.1-15% 7.5% (1730) (1045) (779) (617) (442) Median CAC 28.6 39.7 62.5 71.5 111.6 score > 0 (7.4, (11.9, (15.9, (19.3, (27.7, (IQR) 91.6) 140.6) 211.2) 257) 284.1) CAC > 0: n, (%) N = 2626 NNS (CAC > 0) 386 (22.3) 4.5 CAC ≥ 100: n, (%) 89 N = 1163 (5.1) NNS (CAC ≥ 100) 19.4 411 (39.3) 2.5 198 (44.8) 2.2 449 (57.6) 1.7 394 (63.9) 1.6 132 (12.6) 7.9 81 (18.3) 5.5 193 (24.8) 4.0 205 (33.2) 3.0 15.1-20% > 20% (793) (254) 134.6 (33.5, 427.6) 198.6 (56.5, 483.7) 579 (73) 209 (82.3) 1.4 1.2 324 (40.9) 2.5 139 (54.7) p value < 0.01 < 0.01 1.8 CAC ≥ 300: n, (%) 29 102 191 46 (4.4) 33 (7.5) 96 (15.6) 77 (30.3) < 0.01 N = 574 (1.7) (13.1) (24.1) NNS (CAC ≥ 300) 59.7 22.7 13.4 7.6 6.4 4.2 3.3 IQR: Interquartile Range CAC (25th percentile, 75th percentile) NNS: Number needed to screen to identify one individual with CAC value above a specified CAC cutoff point, within each specified FRS stratum Okwuosa TM, et al. Distribution of Coronary Artery Calcium Scores by Framingham 10-Year Risk Strata in the MultiEthnic Study of Atherosclerosis (MESA): Potential Implications for Coronary Risk Assessment. J Am Coll Cardiol 2011. Conclusions Coronary calcium score is strongly associated with incident coronary heart disease and provides additional predictive information beyond that provided by standard risk factors in four major racial and ethnic groups in the U.S.A. However the CT scan to detect coronary calcium produces radiation exposure that is equivalent to one year’s exposure from natural sources. Coronary calcium scores may be used to screen asymptomatic patients who have multiple CVD risk factors or whose Framingham Risk Scores are in the intermediate range. Age-Adjusted CHD Mortality Rate per 10,000 Person Years by SBP, Cholesterol, and Smoking MRFIT Screenee Study 70 60 50 Smokers 40 Non-Smokers 30 20 10 0 2+ 4 1 1 4 1 -1 13 4 2 2 13 12 5 1 8-1 <118 1 Neaton JD, Wentworth D. Arch Intern Med. 1992;152:56 SBP (mmHg) 2+ 14 -14 1 3 1 4 2 1 13 12 5- 8-12 118 < 11 <1 82 24 5+ 20 3-2 2 0 Cholesterol (ml/dl) Additional Findings Lumbar Bone Density and ABI, CAC, and AAC Baseline CAC and coronary artery stenoses during follow-up ECG abnormalities and CAC and carotid IMT Incidence and progression of aortic valve calcium; relationship between aortic valve calcium and severity of CAC Arterial age as a function of CAC Incident CHD and CVD by CAC Score in Low Risk1 Women Based on FRS, MESA No. of Events/ Total No. (%) Unadjusted HR P Value Adjusted HR ‡ 0 1-99 100-299 ≥300 6/1814 (0.3) 8/589 (1.4) 3/176 (1.7) 7/105 (6.7) 1 [Reference] 4.2 (1.5-12.0) 5.7 (1.4-22.9) 22.3 (7.5-66.5) .008 .01 <.001 1 [Reference] 2.4 (0.8-7.3) 1.5 (0.3-8.3) 8.3 (2.3-30.0) .12 .63 .001 0 1-99 100-299 ≥300 10/1814 (0.6) 11/589 (1.9) 4/176 (2.3) 9/105 (8.6) 1 [Reference] 3.4 (1.5-8.1) 4.5 (1.4-14.3) 17.3 (7.0-42.5) .005 .01 <.001 1 [Reference] 2.0 (0.8-4.9) 1.4 (0.4-5.6) 6.0 (2.1-17.2) .13 .62 .001 CAC Score P Value CHD CVD 1Low Risk: FRS<10% for age, ethnicity, body mass index, low-density lipoprotein cholesterol level, hypertension, smoking, family history of CHD, estrogen use and statin use ‡Adjusted Lakoski, et al. Arch Intern Med. 2007;167:22. Results • Final cohort of 5878 participants • 209 CHD events, overall event rate 3.5% – 122 major events (96 MI, 14 death from CHD, 12 resuscitated cardiac arrest) – 87 angina events (73 followed by revascularization, 14 not followed by revascularization) • AUROC using traditional risk factors was 0.76, increased to 0.81 with the addition of CAC (P<0.001) • Both models well calibrated – HL χ2 statistic model 1: 6.72, P=0.46; model 2: 9.15 P=0.24 Polonsky et al JAMA 2010