1. *Imperial College London
Peter S. Sever*, Neil R Poulter, Choon L Chang,
Aroon Hingorani, Simon McG Thom, Alun D Hughes,
Paul Welsh, Naveed Sattar,
on behalf of the ASCOT Investigators
*Imperial College London .
Evaluation of C-reactive protein, prior to and on-treatment, as a predictor of benefit from atorvastatin:
Nested case control study from ASCOT

2. ASCOT CRP Analysis Background
Lowering C-reactive protein (CRP) by statins has been shown to independently predict cardiovascular (CV) outcomes
The ASCOT database was used to explore the relationship between circulating CRP prior to, and on-treatment, with statins and their association with CV events

3. ASCOT Study Design
Placebo
Atenolol ± bendrofluazide
Amlodipine ± perindopril
Atorvastatin 10 mg
19342 hypertensive patients randomized to antihypertensive treatment
10305 patients eligible and randomized in lipid-lowering arm
TC ≤ 6.5 mmol/L (250 mg/dL)
ASCOT-BPLA
stopped after 5.5 yrs
ASCOT-LLA
stopped after 3.3 yrs
Investigator-led, multinational randomised controlled trial
conducted in hypertensive patients, yrs, with no prior history
of CHD, but with 3 additional cardiovascular risk factors (male sex,
> 55 yrs, smoking etc )

4. Nested Case-control Trial Profile
ASCOT – Subjects in the UK & Ireland
(n = 9098)
On-treatment Analysis Population (ASCOT-LLA)
LDL-C: 156 cases & 498 controls
CRP: 166 cases & 522 controls
LDL-C & CRP: 155 cases & 488 controls
14 cases & 37 controls were excluded because event occurred before blood samples were obtained.
66 cases & 252 controls did not have both baseline and on- treatment CRP & LDL-C or with missing values in covariates
White European (n = 8217)
6549 subjects met entry criteria as potential cases/controls
235 cases & 777 controls participating in ASCOT-LLA
485 cases matched with controls (ASCOT-BPLA case- control population)
Baseline CRP Analysis Population (ASCOT-BPLA) 452 cases & 1269 controls
490 cases & 5750 controls with valid lab data
No controls available for 5 cases
33 cases & 98 controls with missing values in covariates

5. Study Subjects & Blood Samples
485 cases (355 CHD & 130 stroke) matched with 1367 controls
Up to 3 controls from the same risk-set were matched to each case by age±1 year, sex and study entry time±90 days.
Fasting serum HDL-C, triglycerides and total cholesterol
Routinely measured at study visits
CRP at baseline and 6 months
Measured at the same time using stored serum samples
By a high sensitivity method (Dade-Behring, the lower limit of sensitivity was 0.1 mg/L)

6. Statistical Methods
t-test or Χ2 test for baseline characteristics comparison between cases and controls
Odd ratio obtained from a conditional logistic regression model for the association between CRP and the risk of CV events (CHD or stroke)
Loge CRP (baseline) as a continuous variable
Categorizing CRP into tertiles with the lowest as reference
Conditional logistic regression model
Model 1: unadjusted
Model 2 (Framingham CV risk factors + randomised treatment )
Model 3 (extended CV risk factors): as in Model 2 plus
Body mass index (BMI) ,Loge transformed fasting glucose, Family history of coronary heart disease (FHCHD) ,Creatinine and Educational attainment

7. Baseline Characteristics
Variable
Cases
(n = 485)
Controls
(n = 1367)
P value
Male (%)
409 (84.3)
1159 (84.8)
0.81
Age, years
64.80 (7.83)
64.65 (7.66)
0.71
Current Smokers (%)
127 (26.2)
297 (21.7)
0.04
Diabetes (%)
150 (30.9)
356 (26.0)
0.038
SBP, mmHg
(17.81)
(17.48)
0.002
DBP, mmHg
92.95 (10.37)
92.13 (9.83)
0.12
Total cholesterol, mmol/L
5.99 (1.07)
5.92 (1.07)
0.21
LDL- C, mmol/L
3.92 (0.97)
3.79 (0.96)
0.02
HDL-C, mmol/L
1.26 (0.33)
1.30 (0.34)
Loge triglyceride, mmol/L
0.52 (0.46)
0.50 (0.49)
0.44
Loge CRP, mg/L
1.13 (0.98)
0.95 (0.98)
0.0006
Loge glucose, mmol/L
1.82 (0.31)
1.78 (0.28)
0.03
Creatinine, mmol/L
(19.31)
99.23 (16.57)
0.0008
Amlodipine (%)
227 (46.8)
694 (50.8)
0.13
Atorvastatin* (%)
101 (43.0)
407(52.4)
0.01
Values are mean (SD) or n (%)
Missing: LDL-C:121, triglycerides: 79, fasting glucose: 84, CRP: 4, creatinine: 45
*235 cases and 777 controls participated in ASCOT-LLA

8. Baseline CRP and Risk of CV Events (CHD or Stroke)
Cases
Control OR
P value
Trend
Per 1 SD increase in loge CRP
452
1269
1.21
0.0004
Tertile 1 CRP: <1.74 mg/L
131
448
1 (ref)
0.005
Model 1
Tertile 2 CRP: mg/L
153
417
1.26
0.08
Tertile 3 CRP: >4.09 mg/L
168
404
1.45
Unadjusted
Per 1 SD increase in loge CRP
452
1269
1.16
0.009
Tertile 1 CRP: <1.74 mg/L
131
448
1 (ref)
0.057
Model 2*
Tertile 2 CRP: mg/L
153
417
0.29
Tertile 3 CRP: >4.09 mg/L
168
404
1.30
0.06
Per 1 SD increase in loge CRP
452
1269
1.19
0.006
Tertile 1 CRP: <1.74 mg/L
131
448
1 (ref)
0.05
Model 3
Tertile 2 CRP: mg/L
153
417
1.25
0.14
Tertile 3 CRP: >4.09 mg/L
168
404
1.35
Adjusted as for in Model 2 plus BMI, loge-glucose, family history of CHD, creatinine and educational attainment
Odd ratio (95% CI)
*Model 2: Adjusted for current smoking status, diabetes mellitus, randomized BP treatment (atenolol/amlodipine), randomized atorvastatin/placebo/not in LLA, left ventricular hypertrophy, baseline SBP, total cholesterol and HDL-C

9. Modified Framingham Model (Model 2)
Predictive Ability of Baseline CRP in CVD Prediction Beyond Classical Risk Factors - 1
Modified Framingham Model (Model 2)
Full Model
(Model 3)
Performance Measure
Without CRP
With CRP
Discrimination
Area under ROC (95% CI)
0.592
(0.562, 0.621)
0.600
(0.571, 0.630)
0.620
(0.591, 0.650)
0.627
(0.598, 0.656)
P-value
0.20
0.18
Calibration
Hosmer-Lemeshow, χ² ,deciles
5.94
10.88
2.83
2.97
0.65
0.21
0.94
Adjusted for age, sex, smoking status, diabetic mellitus, baseline SBP, total cholesterol, HDL-C, randomized BP treatment, randomized statin/placebo/not in LLA and LVH
Full model: as for reduced model plus loge glucose, family history of CHD, educational attainment, creatinine and BMI

10. Predictive Ability of Baseline CRP in CVD Prediction Beyond Classical Risk Factors - 2
Net Reclassification Improvement (NRI) for model including CRP over model without CRP
Of 485 cases the Framingham model with CRP improved risk classification in 54 but worsened classification in 39
In 1367 controls CRP improved classification in 116 and worsened classification in 131
In Model 2, NRI=0.021 (p=0.32)
In Model 3, NRI=0.03 (p=0.17)
Estimation of Integrated Discrimination Improvement (IDI)
When CRP was included
In Model 2, IDI increased 0.38% (P=0.015)
In Model 3, the increase in IDI was 0.49% (P=0.013)
It suggests that the addition of CRP to the model with established risk factors very modestly improved the discriminatory property of the model for risk prediction.

11. Effect of Atorvastatin on CVD events by Tertile of Baseline CRP
Odd Ratios (95% CI) by Tertile of Baseline CRP
Low
Middle
High
Interaction*
CVD
0.60
(0.33, 1.10)
0.77
(0.41, 1.46)
0.94
(0.51, 1.78)
P=0.54
Adjusted for current smoking status, diabetes mellitus, randomized BP treatment (atenolol/amlodipine), randomized atorvastatin/placebo/not in ASCOT-LLA. Left ventricular hypertrophy, baseline SBP, total cholesterol, HDL-C, BMI, loge-glucose, family history of CHD, creatinine and educational attainment and baseline LDL-C.
* Interaction between statin treatment and tertile baseline CRP

12. Effects of Atorvastatin on LDL-C and CRP (median and interquartile range)
40.3% reduction
27.4% reduction
3.55
2.52
2.12
1.83
On-treatment change in CRP was independent of baseline classical risk factors, baseline CRP and change in LDL-C (P=0.02)
In ASCOT-LLA, in those assigned atorvastatin, age-adjusted Spearman’s correlation between percentage change in CRP and percentage change in LDL-C was modest (r=0.19 P=0.0006)

13. Baseline Profiles by 6 Month Median CRP
Variable
On-treatment
CRP ≥1.83mg/L
(n = 195)
CRP <1.83mg/L
(n = 193)
P value
Male (%)
171 (87.7)
175 (90.7)
0.34
Age (Years)
64.69 (7.67)
65.44 (6.86)
0.31
Current Smokers (%)
53 (27.2)
31 (16.1)
0.008
Alcohol (%): Never
45 (23.1)
35 (18.1)
<=14/21 units/week
109 (55.9)
125 (64.8)
>14/21 units/week
41 (21.0)
33 (17.1)
0.20
SBP (mmHg)
(16.95)
(19.04)
0.27
DBP (mmHg)
91.70 (9.17)
92.47 (9.52)
0.42
BMI (Kg/m2)
29.76 (4.43)
27.95 (4.07)
<0.0001
Total Cholesterol (mmol/L)
5.53 (0.71)
5.51 (0.75)
0.83
LDL-C (mmol/L)
3.53 (0.66)
3.50 (0.71)
0.69
HDL-C (mmol/L)
1.23 (0.30)
1.30 (0.36)
0.04
Loge Triglyceride (mmol/L)
0.46 (0.44)
0.35 (0.47)
0.03
Loge glucose (mmol/L)
1.77 (0.31)
1.78 (0.25)
0.73
Loge CRP (mg/L)
1.41 (0.91)
0.49 (0.89)
Creatinine (mmol/L)
(19.43)
99.99 (14.62)
0.47
Diabetes (%)
61 (31.3)
41 (21.2)
0.02
Family history CHD (%)
87 (44.6)
61 (31.6)
Amlodipine (%)
31 (15.9)
23 (11.9)
0.26
Values are mean (SD) or n (%)
Missing: fasting glucose: 24; creatinine: 12; LDL-C: 27; triglyceride: 22

14. On-treatment LDL-C (6 Month in Trial) and Risk of CV Events (CHD or Stroke)
Cases
Control OR
P value
Placebo 89
232
1 (ref)
Atorvastatin
LDL-C ≥2.1 mmol/L 44
126
0.97
0.87
Model 1
LDL-C <2.1 mmol/L 23
140
0.45
0.001
LDL-C <2.1 vs. ≥2.1 mmol/L
0.40
0.002
Unadjusted
Placebo 89
232
1 (ref)
Atorvastatin
LDL-C ≥2.1 mmol/L 44
126
1.09
0.71
Model 2
LDL-C <2.1 mmol/L 23
140
0.45
0.003
LDL-C <2.1 vs. ≥2.1 mmol/L
0.41
Adjusted for baseline LDL-C
and loge baseline CRP
Placebo 89
232
1 (ref)
Atorvastatin
LDL-C ≥2.1 mmol/L 44
126
1.10
0.68
Model 3*
LDL-C <2.1 mmol/L 23
140
0.45
0.003
LDL-C <2.1 vs. ≥2.1 mmol/L
0.41
0.004
Odd ratio (95% CI)
*Model 3: Current smoking status, diabetes mellitus, randomized BP treatment (atenolol/amlodipine), left ventricular hypertrophy, baseline SBP, HDL-C, BMI, loge-glucose, family history of CHD, creatinine, educational attainment, baseline LDL-C or total cholesterol and loge baseline CRP

15. On-treatment CRP (6 Month in Trial) and Risk of CV Events (CHD or Stroke)
Cases
Control OR
P value
Placebo 93
245
1 (ref)
Atorvastatin
CRP ≥1.83 mg/L 41
137
0.86
0.47
Model 1
CRP <1.83 mg/L 32
140
0.61
0.03
CRP <1.83 vs. ≥1.83 mg/L
0.70
0.17
Unadjusted
Placebo 93
245
1 (ref)
Atorvastatin
CRP ≥1.83 mg/L 41
137
0.83
0.39
Model 2
CRP <1.83 mg/L 32
140
0.71
0.14
CRP <1.83 vs. ≥1.83 mg/L
0.86
0.56
Adjusted for baseline LDL-C and loge baseline CRP
Placebo 93
245
1 (ref)
Atorvastatin
CRP ≥1.83 mg/L 41
137
0.82
0.38
Model 3*
CRP <1.83 mg/L 32
140
0.70
0.15
CRP <1.83 vs. ≥1.83 mg/L
0.86
0.60
Odd ratio (95% CI)
*Model 3: Current smoking status, diabetes mellitus, randomized BP treatment (atenolol/amlodipine), left ventricular hypertrophy, baseline SBP, HDL-C, BMI, loge-glucose, family history of CHD, creatinine, educational attainment, baseline LDL-C or total cholesterol and loge baseline CRP

16. Risk of CV Events (CHD or Stroke) by On-treatment (6 Month in Trial) LDL-C and CRP*
Cases
Control OR
P value
Placebo 88
230
1 (ref)
LDL-C ≥2.1 & CRP ≥1.83 27 65
1.28
0.40
LDL-C ≥2.1 & CRP <1.83 17 55
0.99
0.98
ASCOT Medians
LDL-C <2.1 & CRP ≥1.83 11 62
0.43
0.02
LDL-C <2.1 & CRP <1.83 12 76
0.49
0.05
Placebo 88
230
1 (ref)
LDL-C ≥1.8 & CRP ≥2 30 81
1.05
0.85
LDL-C ≥1.8 & CRP <2 27 94
0.93
0.80
JUPITER Cut-offs
LDL-C <1.8 & CRP ≥2 3 36
0.21
0.01
LDL-C <1.8 & CRP <2 7 47
0.42
0.06
Placebo 88
230
1 (ref)
LDL-C ≥1.8 & CRP ≥1 46
126
1.08
0.75
LDL-C ≥1.8 & CRP <1 11 49
0.76
0.48
JUPITER Cut-offs
LDL-C <1.8 & CRP ≥1 5 53
0.23
0.003
LDL-C <1.8 & CRP <1 30
0.53
*LDL-C in mmol/L and CRP in mg/L
Odd ratio (95% CI)
Adjusted for current smoking status, diabetes mellitus, randomised BP treatment (atenolol/amlodipine), , left ventricular hypertrophy, baseline SBP, total cholesterol, HDL-cholesterol, BMI, loge-glucose, family history of CHD, creatinine, educational attainment, and baseline LDL or total cholesterol and loge baseline CRP

17. Summary
Baseline LDL-C and loge transformed CRP were correlated and predicted CV events respectively
Inclusion of baseline CRP into a modified Framingham risk model in the whole cohort very modestly improved risk prediction
Baseline CRP was not an indicator of the magnitude of the effect of atorvastatin on CV outcome of those assigned atorvastatin
At 6 months, atorvastatin reduced median LDL-C by 40.3% and median CRP by 27.4%
In those randomized to atorvastatin
Lower on-treatment LDL-C at 6 months was associated with a highly significant reduction in subsequent CV events
By contrast, lower CRP at 6 months was not associated with CV events
Consequently, addition of on-treatment CRP to on-treatment LDL-C did not improve prediction of statin efficacy

18. Conclusion
In ASCOT-LLA, neither baseline nor on-treatment CRP provide useful information about the efficacy of statin treatment to reduce CV events beyond LDL-C reduction
The results do not support current proposals to measure CRP in the clinical setting either to assign statins to individuals on the basis of an elevated CRP alone, or to monitor CRP levels as an indicator of the efficacy of statin treatment