1. Landmark clinical trials with pravastatin WOS CARE LIPID

2. WOS : NEJM 1995; 333 : 1301-1307 CARE : NEJM 1996; 335 : 1001-1009 LIPID : NEJM 1998; 339: 1349-1357 4S : Lancet 1994; 344 : 1383-1389 TexCAPS: JAMA 1998; 279: 1615-1622 Major HMG Trials CARE n=4,159 TC 5.4 mmol/l LIPID n=9,014 TC 5.6 mmol/l WOS n=6,595 TC 7.0 mmol/l 4S n=4,444 TC 6.8 mmol/l With CHD + high cholesterol With CHD + normal cholesterol Without CHD + high cholesterol TexCAPS n=6,605 TC 5.7 mmol/l Without CHD + low HDL 22.6 15.9/13.2 7.9 2.8 Placebo MI rate per 100 subjects per 5 years

3. Pravastatin Therapy in Post-MI Patients with Average Cholesterol CARE: Study Design 4159 men and women post-MI Total Cholesterol <6.2 mmol/l (mean 5.4 mmol/l) Pravastatin 40 mg, follow-up 5.0 years 83% aspirin, 40% beta-blockers, 54% PTCA/CABG at baseline Prespecified end points: –Nonfatal MI and CHD death –CHD death –Revascularizations –Stroke

4. Sacks et al: N Engl J Med 1996;335:1001–1009 –24%* –20% –27%* Stroke –10 –20 –30 –40 0 *P < 0.05 vs placebo Pravastatin Therapy in Post-MI Patients with Average Cholesterol CARE: Results Summary % Risk reduction CHD death or nonfatal MI CHD death CABG/PTCA –31%*

5. 0 1 2 3 4 5 012345 Time (yr) Placebo Pravastatin –32% P=0.03 CARE: Pravastatin Reduces Risk of Stroke % with event Plehn et al: Circulation 1999;99:216–223 128 strokes in total 83% of patients on antiplatelet therapy

6. LIPID: Pravastatin Reduces Risk of Stroke Time (yr) 0 2 4 6 The LIPID Study Group: N Engl J Med 1998;339:1349–1357 % with event 0123456 –19% P=0.048 Placebo Pravastatin 419 strokes in total 83% of patients on antiplatelet therapy

7. Fatal coronary heart disease 11 Nonfatal MI 26 CABG 25 PTCA 37 38 Stroke/TIA 13 Sacks et al. NEJM. 1996;335:1001-1009 Size of the Benefit with Pravastatin Events Prevented in CARE Event Events prevented per 1,000 patients treated for 5 years Other cardiovascular events All cardiovascular events 150

8. Pravastatin Therapy in Patients with MI or Unstable Angina and Average Cholesterol LIPID: Study Design 9014 men and women with MI or unstable angina Total Cholesterol 4-7 mmol/l (mean 5.6 mmol/l) Pravastatin 40 mg, follow-up 6.1 years 83% aspirin, 47% beta-blockers, 41% PTCA/CABG at baseline Prespecified end points: –CHD mortality –Revascularizations –Total mortality –Stroke

9. The LIPID Study Group: N Engl J Med 1998;339:1349–1357 –19% –20% –22% –24% –35 –30 –25 –20 –15 –10 –5 0 CHD mortality Total mortality Stroke All risk reductions are P < 0.05 vs placebo Pravastatin Therapy in Patients With MI or Unstable Angina and Average Cholesterol LIPID: Results Summary PTCA/CABG % Risk reduction

10. Deaths30 Nonfatal MI28 CABG23 PTCA20 Unstable Angina Episodes82 Nonfatal Stroke9 The LIPID Study Group. N Engl J Med 1998;339:1349-1357 Size of the Benefit with Pravastatin Events Prevented in LIPID Event Events prevented per 1,000 patients treated over 6 years

11. Pravastatin Therapy in a Population at Risk for CHD WOS: Study Design 6595 men without history of CHD Total Cholesterol  6.5 mmol/l (mean 7.0 mmol/l) Pravastatin 40 mg, follow-up 4.9 years 3% aspirin, 7% beta-blockers, 0% PTCA/CABG at baseline Prespecified end points: –Nonfatal MI and CHD death –CHD mortality –Total mortality –Revascularizations

12. Shepherd et al: N Engl J Med 1995;333:1301–1307 –31% –33% –37% –22% –10 –20 –30 –40 0 All risk reductions are P  0.05 vs placebo Pravastatin Therapy in a Population at Risk for CHD WOS: Results Summary % Risk reduction Nonfatal MI / CHD death CHD mortality Total mortality CABG/ PTCA

13. Deaths9 Nonfatal MI20 PTCA/CABG8 Coronary Angiograms14 Shepherd et al: N Engl J Med 1995;333:1301–1307 Size of the Benefit with Pravastatin Events Prevented in WOS Event Events prevented per 1,000 patients treated over 5 years

14. Shepherd et al: N Engl J Med 1995;333:1301–1307; The LIPID Study Group: N Engl J Med 1998;339:1349–1357; Sacks et al: N Engl J Med 1996;335:1001–1009 Clinical Benefit of Pravastatin Evidence of Protection –31% In post-MI patients with average cholesterol Stroke –31% In patients with high cholesterol –24% In post-MI patients with average cholesterol –10 –20 –30 –40 0 % Risk reduction –22% In patients with MI or unstable angina –27% In post-MI patients with average cholesterol First MI Recurrent MI Total mortality PTCA/ CABG CAREWOSCARELIPIDCARE All risk reductions are P < 0.05 vs placebo

15. Lewis et al: J Am Coll Cardiol 1998;32:140–146; Lewis et al: Ann Intern Med 1998; 129:681-689 Goldberg et al: Circulation 1998;98:2513–2519 The LIPID Study Group: N Engl J Med 1998;339:1349–1357 –50 –40 –30 –20 –10 0 –29% † –25%* –32%* –46%* Women Elderly (  65 yr) Unstable angina patients * CHD death, nonfatal MI, CABG, or PTCA † CHD death and nonfatal MI –24% † Mixed hyper- lipidemia CARE LIPIDCARELIPID % Risk reduction Diabetics Clinical Benefit of Pravastatin Broad Range of Patients All risk reductions are P < 0.05 vs placebo

16. * No long-term clinical trials published Weight of Clinical Evidence 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000 No. patients in clinical event trials PravastatinSimvastatinLovastatinAtorvastatin, cerivastatin, and fluvastatin * LIPID 9014 WOS 6595 CARE 4159 4S 4444 TexCAPS 6605

17. Analysis of Coronary Heart Disease Event Reduction and Cholesterol Reduction with Pravastatin Observations from Landmark Clinical Trials

18. Martin et al: Lancet 1986;2:933–936 MRFIT Age-Adjusted CHD Death Rate and Serum Cholesterol in 361,662 US Men Serum cholesterol (mmol/l) 6-yr CHD death rate per 1,000 men 18 16 14 12 10 8 6 4 2 0 4567

19. Pravastatin Event Reduction Analysis To determine the relationship between reduction in CHD events and change in LDL-C with pravastatin To evaluate whether LDL-C reduction alone adequately explains the observed reduction in CHD events Overall Objectives

20. Influence of Pravastatin and Plasma Lipids on Clinical Events in the West of Scotland Coronary Prevention Study (WOS) West of Scotland Coronary Prevention Study Group Circulation, 1998;97:1440-1445

21. WOS Results Summary Shepherd et al: N Engl J Med. 1995;333:1301-1307 % Risk Reduction -31 -32 -37 -32 -22 -40 -30 -20 -10 0 NFMI CABG/PTCA Total mortality NFMI or CHD Death CV mortality Are these impressive results seen in WOS entirely explained by the change in LDL-C ? All risk reductions are P  0.05 vs placebo

22. Pravastatin Event Reduction Analysis Components of the WOS Analysis Quintile Analysis –Objective: To examine the relationship between reduction in CHD events and reduction in LDL-C levels Overlap Analysis Framingham Analysis

23. Quintile Analysis  Methods 1. Rank all pravastatin subjects on the basis of percent change in LDL-C 2. Divide group into quintiles of equal subject numbers (n  500/quintile) 3. Derive Kaplan-Meier risk of cardiac event for each quintile 1 2 345 Quintile

24. Baseline LDL-C On-treatment LDL-C 4.4 Yr CHD Event Rate (%) Mean % LDL-C Reduction 4.9 5.0 5.1 4.94.33.73.43.0 Circulation, 1998; 97:1440-1445 Quintile Analysis – Results 0 2.5 5.0 7.5 10.0 0%12%24%31%39% n  500/quintile

25. Quintile Analysis – Results LDL-C lowering was an important contributor to CHD event reduction with pravastatin in WOS Maximum risk reduction (~45%) occurred in pravastatin-treated subjects whether the LDL-C was decreased by 25% or by 40% or more

26. Pravastatin Event Reduction Analysis Components of the WOS Analysis Quintile Analysis Overlap Analysis –Objective: To determine whether subjects on placebo or pravastatin therapy who had similar LDL-C levels had similar CHD risk Framingham Analysis

27. On-treatment LDL-C (mmol/l) Overlap Analysis: Methods 2 4 6 8 10 12 14 0 Pravastatin Placebo Percentage of patients 6 5 432 Adapted from WOS Group: Circulation 1998;97:1440–1445 Overlap (3.6 - 4.6 mmol/l)

28. 9.6% 6.3% 0 2 4 6 8 10 12 Placebo Mean LDL-C, 4.38 mmol/l Pravastatin Mean LDL-C, 4.10 mmol/l 36% lower risk (P=0.014)* *Adjusted for risk factors 4.4-yr event rates (%) WOS Group: Circulation 1998;97:1440–1445 Overlap Analysis – Results Pravastatin subjects with similar LDL-C levels had lower risk LDL-C range, 3.6–4.6 mmol/l (n=2191)

29. Overlap Analysis – Results Pravastatin subjects had a 36% lower event rate compared to placebo subjects with similar LDL-C levels (P=0.014) Analysis of different LDL-C ranges of overlap supported the same conclusion

30. Pravastatin Event Reduction Analysis Components of the WOS Analysis Quintile Analysis Overlap Analysis Framingham Analysis –Objective: To compare on-treatment event rates for WOS to the event rates predicted by the Framingham model

31. Framingham Analysis – Results Predicted vs Actual CHD Event Rate in WOS Circulation, 1998; 97:1440-1445 0 2 4 6 8 10 1214 Quintiles of Predicted Framingham Risk P = 0.5812345 Observed Predicted P = 0.02612345 Observed Predicted Event Rate (%) 0 2 4 6 8 10 1214 Placebo Group Pravastatin Group

32. WOS Group: Circulation 1998;97:1440–1445 *Based on lipid changes achieved by pravastatin † Nonfatal MI, CHD death, CABG, PTCA % Risk reduction † Predicted*Actual –40 –30 –20 –10 0 –24% –35% Framingham Analysis – Results Risk reduction with pravastatin was greater than predicted P = 0.026

33. Framingham Analysis – Results When event rates in WOS were compared to those predicted by Framingham, subjects on pravastatin therapy had greater risk reduction than predicted from lipid changes Circulation, 1998; 97:1440-1445

34. Relationship Between Plasma LDL Concentrations During Treatment with Pravastatin and Recurrent Coronary Events in the CARE Trial Frank M. Sacks, Lemuel A. Moye, Barry R. Davis, Thomas G. Cole, Jean L. Rouleau, David Nash, Marc A. Pfeffer, Eugene Braunwald for the CARE Investigators Circulation, 1998;97:1446-1452

35. CARE Results Summary Risk Reduction with Pravastatin Therapy Sacks et al: N Engl J Med 1996;335. % Risk Reduction CHD Death or Nonfatal MI * -24 CHD Death -20 Fatal MI -37 Nonfatal MI * -23 CABG * -26 PTCA * -23 Unstable Angina -13 Stroke * -31 -10 -20 -30 -40 0 * p < 0.05 vs. placebo

36. *CHD death, nonfatal MI, CABG / PTCA Pravastatin Treatment Analysis – Results Pravastatin Treatment Group CARE Circulation, 1998;97:1446-1452 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Follow-up LDL-C (mmol/l) Relative Risk of an Event* ( ) 2 2.5 3 3.5 Decile # Median follow-up LDL-C % LDL-C decrease 1 1.8 43 2 2.0 38 3 2.2 35 4 2.3 33 5 2.4 31 6 2.5 30 7 2.7 26 8 2.8 25 9 3.0 21 10 3.5 9

37. Pravastatin Treatment Analysis– Results CARE: CHD Events and Achieved LDL-C The relationship between follow-up LDL-C levels and coronary events was not linear Maximal benefit was observed when LDL-C was lowered to the range of 1.8 - 3.2 mmol/l 90% of subjects in the pravastatin group achieved this maximal benefit

38. Pravastatin Event Reduction Analysis Consistent Results from Two Independent trials, WOS and CARE: The relationship between CHD risk and LDL-C concentration was found to be nonlinear The absolute or the percent LDL-C reduction did not predict the event rate Maximum risk reduction (~45%) occurred in pravastatin subjects whether the LDL-C was decreased by 25% or by 40% or more

39. Pravastatin Event Reduction Analysis Implications Epidemiology does not fully explain the results of treatment Extreme LDL-C reductions may not be necessary with pravastatin treatment Additional mechanisms beyond LDL-C lowering may account for some of the benefit with pravastatin LDL-C changes alone do not explain the full benefit of pravastatin therapy

40. Additional Mechanisms for Coronary Event Reduction Plaque stabilisation Reduced thrombus formation Anti-inflammatory effects

41. Atherosclerosis Involves More Than Just Lipids Thrombus Fibrous Cap Lipid Core

42. Thin Fibrous Cap Inflammatory Cells Few SMCs Unstable plaque Eroded Endothelium Activated Macrophages Thick Fibrous Cap Lack of Inflammatory Cells Foam Cells Intact Endothelium More SMCs Stable plaque Adapted from Libby: Circulation. 1995;91:2844-2850. Atherosclerosis Involves More Than Just Lipids

43. Most MIs Arise From Smaller Stenoses 68% 18% 14% 0 10 30 50 70 <50%50%–70%>70% % Stenosis MI patients (%) Falk et al: Circulation 1995;92:657–671

44. Rosenson et al: JAMA 1998;279:1643–1650 Atherosclerosis Involves More Than Just Lipids: Effects of Statins Common to all statins –Lipid modification –Lipoprotein oxidation –Endothelial function Differences among statins –Effect on smooth muscle cells –Effect on inflammation? –Effect on platelet thrombus formation?

45. Effects of Pravastatin Effects on lipids Additional mechanisms Pravastatin 40 mg*: TC-25%, LDL -34% TG-24%, HDL+12% Effects on atherosclerosis Reduction cardiovascular morbidity/mortality (including MI and stroke) No inhibition SMCs Reduced thrombus formation Anti-inflammatory effects * Jones: Clin Cardiol 1991;14:146-151

46. Crisby et al: The Lancet Conference. The Challenge of Stroke, October 1998. Parameter Lipid Content Oxidized LDL Macrophages # T-cells # Cell Death Smooth Muscle Cells # * Carotid endarterectomy samples following 3 months pravastatin therapy P value <0.05 <0.001 <0.05 Effect of Pravastatin (n=11) vs. Control (n=13) Effects of Pravastatin On Plaque Composition in Humans* ApoB, ICAM-1, VCAM-1 and NF-KB didn’t differ between the 2 graphs =NS

47. Smooth Muscle Cells Foster Plaque Stability Smooth Muscle Cells: Strengthen the fibrous cap Regulate synthesis of interstitial collagen Are involved in the healing process after plaque rupture Lafont A., Libby P.: J Am Coll Cardiol 1998;32:283-285

48. 37.6 Drug concentration required to inhibit 25% of human smooth muscle cell proliferation in vitro 40 0 1 2 3 4 CerivastatinFluvastatinLovastatinSimvastatin Atorvastatin 1.0 0.2 0.4 0.02 0.8 IC 25 (µmol/L) Adapted from Negre-Aminou et al: Biochim Biophys Acta 1997;1345:259–268 Pravastatin Effects of Statins on Smooth Muscle Cells

49. Adapted from Lacoste et al: Circulation 1995;92:3172–3177 *P < 0.05 vs baseline Platelet thrombus formation (µm 2 /mm) Hypercholesterolemic patients (n=16) BaselineAfter Pravastatin Pravastatin Reduces Platelet Thrombus Formation 0 1 2 3 4 5 2.0* 4.8

50. Lacoste et al: J Am Coll Cardiol 1996 ;27:413A Includes ASA 325 mg/d *P < 0.05 vs baseline † P < 0.05 vs simvastatin Platelet thrombus formation (µm 2 /mm) 2.0 1.0* † 2.1 2.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Pravastatin Simvastatin BaselineTreatmentBaselineTreatment Reduced Thrombus Formation With Pravastatin but not with Simvastatin (n=16)

51. Ridker et al: Circulation. 1998;98:839-844. Effects of Statins on Inflammation Inflammation is associated with initiation and progression of atherosclerosis Markers of inflammation have been shown to predict risk of vascular events Preventive agents may have differential effects on inflammation

52. 0 1 2 3 Relative risk of an event Inflammation AbsentInflammation Present ( CRP and SAA) P trend = 0.005 Ridker et al: Circulation 1998;98:839–844 P = 0.007 CARE: Pravastatin Reduces Risk Posed by Inflammation PravastatinPlaceboPravastatinPlacebo

53. Ridker et al: Circulation. 1998;98:839-844. Inflammation, Pravastatin and Events Conclusion Evidence of inflammation after MI is associated with increased risk of recurrent coronary events The effect of inflammation on coronary risk may be lowered by pravastatin therapy “... the efficacy of pravastatin may result in part from anti-inflammatory as well as lipid-lowering properties... ”

54. The Complexity of Atherosclerosis: Beyond Cholesterol Lowering Conclusions Apart from lipid modification, other mechanisms may play a role in the net benefits of statin therapy Statins may differ in their effect on: –Smooth muscle cells –Platelet thrombus formation –Inflammation –Others

55. “Since the nonlipid properties of statins differ despite comparable LDL cholesterol level lowering, the net clinical efficacy of these agents requires validation by randomised clinical trials.” Rosenson: JAMA 1998; 279 : 1643-1650