Inflammation, Thrombosis, Inflammation, Thrombosis, Infection, and CARDIOVASCULAR Infection, and CARDIOVASCULAR DISEASE DISEASE Nathan D Wong, PhD, FACC Nathan D Wong, PhD, FACC Professor and Director Professor and Director Heart Disease Prevention Program Heart Disease Prevention Program University of California, Irvine University of California, Irvine
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Inflammation, Thrombosis, Infection, and CARDIOVASCULAR DISEASE Nathan D Wong, PhD, FACC Professor and Director Heart Disease Prevention Program University.
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coronary events and provide additional coronary events and provide additional
predictive information beyond predictive information beyond
traditional risk factors?traditional risk factors?
Evaluating Novel Risk Factors for Evaluating Novel Risk Factors for CADCAD
Consistency of Consistency of prospective dataprospective data
Strength of associationStrength of association
Independence of Independence of associationassociation
Improve predictive Improve predictive valuevalue
Standardized measureStandardized measure
Low variability
High reproducibility
Biologic plausibility
Low cost
Modifiable
Biomarkers for Venous and Arterial Biomarkers for Venous and Arterial ThrombosisThrombosis
++++++––hs-CRP / SAA / IL-6 / TNFhs-CRP / SAA / IL-6 / TNF
++––Lp(a)Lp(a)
++++––Platelet functionPlatelet function
++++––PAI-1: agPAI-1: ag
++++++––tPA: agtPA: ag
++++––vWF: agvWF: ag
++––Factor VIIFactor VII
++++++––FibrinogenFibrinogen
ArterialArterialVenousVenousParameterParameter
Biomarkers for Venous and Arterial Biomarkers for Venous and Arterial Thrombosis Thrombosis (cont’d)(cont’d)
++++++++D-dimerD-dimer
++++++++HomocysteineHomocysteine
––++Protein SProtein S
––++Protein CProtein C
––++++Anti-thrombin IIIAnti-thrombin III
––++++Factor VIIIFactor VIII
––++ProthrombinProthrombin
––++++Prothrombin mutationProthrombin mutation
––++++++Factor V LeidenFactor V Leiden
ArterialArterialVenousVenousParameterParameter
Thrombosis and Cardiovascular RiskThrombosis and Cardiovascular Risk
Thrombus formation is a crucial factor in the Thrombus formation is a crucial factor in the precipitation of unstable angina or myocardial precipitation of unstable angina or myocardial infarction, as well as occlusion during or following infarction, as well as occlusion during or following angioplasty.angioplasty.
Often preceded by platelet aggregation and Often preceded by platelet aggregation and activation of the coagulation system.activation of the coagulation system.
A thrombus may develop at sites of only mild to A thrombus may develop at sites of only mild to moderate coronary stenosis. The majority of moderate coronary stenosis. The majority of coronary events occur where there is less than coronary events occur where there is less than 70% stenosis.70% stenosis.
Occlusive coronary thrombosis plays a role in over Occlusive coronary thrombosis plays a role in over 80% of myocardial infarctions and about 95% of 80% of myocardial infarctions and about 95% of sudden death victims.sudden death victims.
Fibrinogen and AtherosclerosisFibrinogen and Atherosclerosis
Promotes atherosclerosisPromotes atherosclerosis Essential component of platelet aggregationEssential component of platelet aggregation Relates to fibrin deposited and the size of the Relates to fibrin deposited and the size of the
clotclot Increases plasma viscosityIncreases plasma viscosity May also have a proinflammatory roleMay also have a proinflammatory role Measurement of fibrinogen, incl. Test Measurement of fibrinogen, incl. Test
variability, remains difficult. variability, remains difficult. No known therapies to selectively lower No known therapies to selectively lower
fibrinogen levels in order to test efficacy in fibrinogen levels in order to test efficacy in CHD risk reduction via clinical trials.CHD risk reduction via clinical trials.
Fibrinogen and CHD Risk: Fibrinogen and CHD Risk: Epidemiologic StudiesEpidemiologic Studies
Recent meta-analysis of 18 studies involving 4018 Recent meta-analysis of 18 studies involving 4018 CHD cases showed a relative risk of CHD of 1.8 CHD cases showed a relative risk of CHD of 1.8 (95% CI 1.6-2.0) comparing the highest vs lowest (95% CI 1.6-2.0) comparing the highest vs lowest tertile of fibrinogen levels (mean .35 vs. .25 g/dL)tertile of fibrinogen levels (mean .35 vs. .25 g/dL)
ARIC study in 14,477 adults aged 45-64 showed ARIC study in 14,477 adults aged 45-64 showed relative risks of 1.8 in men and 1.5 in women, relative risks of 1.8 in men and 1.5 in women, attenuated to 1.5 and 1.2 after risk factor attenuated to 1.5 and 1.2 after risk factor adjustment.adjustment.
Scottish Heart Health Study of 5095 men and 4860 Scottish Heart Health Study of 5095 men and 4860 women showed fibrinogen to be an independent women showed fibrinogen to be an independent risk factor for new events--RRs 2.2-3.4 for coronary risk factor for new events--RRs 2.2-3.4 for coronary death and all-cause mortality.death and all-cause mortality.
Fibrinogen and CHD Risk FactorsFibrinogen and CHD Risk Factors
Fibrinogen levels increase with age and body Fibrinogen levels increase with age and body mass index, and higher cholesterol levelsmass index, and higher cholesterol levels
Smoking can reversibly elevated fibrinogen Smoking can reversibly elevated fibrinogen levels, and cessation of smoking can lower levels, and cessation of smoking can lower fibrinogen.fibrinogen.
Those who exercise, eat vegetarian diets, and Those who exercise, eat vegetarian diets, and consume alcohol have lower levels. Exercise consume alcohol have lower levels. Exercise may also lower fibrinogen and plasma viscosity.may also lower fibrinogen and plasma viscosity.
Studies also show statin-fibrate combinations Studies also show statin-fibrate combinations (simvastatin-ciprofibrate) and estrogen therapy (simvastatin-ciprofibrate) and estrogen therapy to lower fibrinogen.to lower fibrinogen.
Other Thrombotic Factors and CHDOther Thrombotic Factors and CHD
Mixed reports of coagulation factor VIIc in Mixed reports of coagulation factor VIIc in cardiovascular disease. PROCAM study cardiovascular disease. PROCAM study showed no association with CHD events, CHS showed no association with CHD events, CHS also showed no relation to subclinical CVD.also showed no relation to subclinical CVD.
Endogenous tissue-type plasminogen activator Endogenous tissue-type plasminogen activator (tPA) shown in some studies to relate to (tPA) shown in some studies to relate to increased cardiovascular risk--Physician’s increased cardiovascular risk--Physician’s Health Study showed RR for MI 2.8, stroke 3.5 Health Study showed RR for MI 2.8, stroke 3.5 in those in 5th vs. 1st quintile of tPA.in those in 5th vs. 1st quintile of tPA.
Plasminogen activitor inhibitor type 1 (PAI-1) Plasminogen activitor inhibitor type 1 (PAI-1) shown associated with increased shown associated with increased cardiovascular risk, esp in diabetic patients.cardiovascular risk, esp in diabetic patients.
Aspirin and Cardiovascular Risk: Aspirin and Cardiovascular Risk: Clinical Trial Evidence for Primary Clinical Trial Evidence for Primary
PreventionPrevention US Physician’s Health Study- 22,071 male physicians - US Physician’s Health Study- 22,071 male physicians -
44% reduction in MI risk, 13% nonsignificant increase in 44% reduction in MI risk, 13% nonsignificant increase in risk of strokerisk of stroke
British Doctor’s Study of 5139 male physicians showed British Doctor’s Study of 5139 male physicians showed nonsignificant 3% reduction in MI risk,13% nonsignificant 3% reduction in MI risk,13% nonsignificant increase in strokenonsignificant increase in stroke
Hypertension Optimal Treatment (HOT) study among Hypertension Optimal Treatment (HOT) study among 18,790 pts w/htn showed 15% reduction in CVD events, 18,790 pts w/htn showed 15% reduction in CVD events, 36% reduction in MI36% reduction in MI
Women’s Health Study (n=39,876 women aged 45+) Women’s Health Study (n=39,876 women aged 45+) randomized to 100 mg asprin/day vs placebo, 10 years randomized to 100 mg asprin/day vs placebo, 10 years follow-up – results recently released and asprin follow-up – results recently released and asprin preventive only for stroke (17% reduction overall, preventive only for stroke (17% reduction overall, p=0.04; 24% ischemic stroke, p<.001); nonfatal MI p=0.04; 24% ischemic stroke, p<.001); nonfatal MI RR=1.02, CVD death 0.95, ns) (NEJM 2005; 352: 1366-RR=1.02, CVD death 0.95, ns) (NEJM 2005; 352: 1366-8).8).
Aspirin and Cardiovascular Risk: Aspirin and Cardiovascular Risk: Clinical Trial Evidence for Secondary Clinical Trial Evidence for Secondary
PreventionPrevention
Antiplatelet Trialists Collaboration of 54,000 Antiplatelet Trialists Collaboration of 54,000 patients with cardiovascular disease (10 trials patients with cardiovascular disease (10 trials post-MI) showed 31% reduction in MI, 42% post-MI) showed 31% reduction in MI, 42% reduction in stroke, 13% reduction in total reduction in stroke, 13% reduction in total vascular mortalityvascular mortality
International Study of Infarct Survival of International Study of Infarct Survival of 17,187 pts w/evolving MI showed 49% 17,187 pts w/evolving MI showed 49% reduction in reinfarction, 26% reduction in reduction in reinfarction, 26% reduction in nonfatal stroke, and 23% reduction in total nonfatal stroke, and 23% reduction in total vascular mortalityvascular mortality
Aspirin (75-162 mg daily) for intermediate risk men Aspirin (75-162 mg daily) for intermediate risk men with a 10 year risk of CHD with a 10 year risk of CHD >>10%.10%.
Aspirin (75-162 mg daily) for intermediate risk Aspirin (75-162 mg daily) for intermediate risk women with a 10 year risk of CHD women with a 10 year risk of CHD >>10%.10%.
Aspirin for low risk women with a 10 year risk of Aspirin for low risk women with a 10 year risk of CHD<10%.CHD<10%.
Aspirin (75-325 mg daily) for those with known CHD.Aspirin (75-325 mg daily) for those with known CHD.
CRP is an acute-phase protein produced by the liver CRP is an acute-phase protein produced by the liver in response to cytokine production (IL-6, IL-1, tumor in response to cytokine production (IL-6, IL-1, tumor necrosis factor) during tissue injury, inflammation, necrosis factor) during tissue injury, inflammation, or infection.or infection.
Standard CRPStandard CRP tests determine levels which are tests determine levels which are increased up to 1,000-fold in response to infection increased up to 1,000-fold in response to infection or tissue destruction, but cannot adequately assess or tissue destruction, but cannot adequately assess the normal rangethe normal range
High-sensitivity CRPHigh-sensitivity CRP (hs-CRP) assays (i.e. Dade (hs-CRP) assays (i.e. Dade Behring) detect levels of CRP within the normal Behring) detect levels of CRP within the normal range, levels proven to predict future cardiovascular range, levels proven to predict future cardiovascular events.events.
hs-CRP Adds to Predictive Value of TC:HDL hs-CRP Adds to Predictive Value of TC:HDL Ratio in Determining Risk of First MIRatio in Determining Risk of First MI
0.0
1.0
2.0
3.0
4.0
5.0
High Medium Low Low
Medium
High
Total Cholesterol:HDL RatioTotal Cholesterol:HDL Ratio
Ridker et al, Circulation. 1998;97:2007–2011.
hs-CRP
hs-CRP
Rel
ativ
e R
isk
Rel
ativ
e R
isk
Risk Factors for Future Cardiovascular Risk Factors for Future Cardiovascular Events: WHSEvents: WHS
0 1.0 2.0 4.0 6.0
Lipoprotein(a)
Homocysteine
IL-6
TC
LDLC
sICAM-1
SAA
Apo B
TC: HDLC
hs-CRP
hs-CRP + TC: HDLC
Relative Risk of Future Cardiovascular Events
Ridker et al, N Engl J Med. 2000;342:836-43
Is there clinical evidence that Is there clinical evidence that
inflammation can be modified by inflammation can be modified by
preventive therapies?preventive therapies?
0
5
10
15
20
25
Elevated CRP Levels in Obesity: Elevated CRP Levels in Obesity: NHANES 1988-1994NHANES 1988-1994
Visser M et al. JAMA 1999;282:2131-2135.
Normal
Perc
en
t w
ith C
RP
0.2
2
mg/d
L
Overweight Obese
Effects of Weight Loss on CRPEffects of Weight Loss on CRPConcentrations in Obese Healthy Concentrations in Obese Healthy
WomenWomen 83 women (mean BMI 33.8, range 28.2-43.8 kg/m2) placed
on very low fat, energy-restricted diet (6.0 MJ, 15% fat) for 12 weeks
Baseline CRP positively associated with BMI (r=0.281, p=0.01)
CRP reduced by 26% (p<0.001)
Average weight loss 7.9 kg, associated with change in CRP
Change in CRP correlated with change in TC (r=0.240, p=0.03) but not changes in LDL-C, HDL-C, or glucose
At 12 weeks, CRP concentration highly correlated with TG (r=0.287, p=0.009), but not with other lipids or glucose
Heilbronn LK et al. Arterioscler Thromb Vasc Biol 2001;21:968-970.
Effect of HRT on hs-CRP: Effect of HRT on hs-CRP: the PEPI the PEPI StudyStudy
3.0
2.0
1.0hs-
CR
P (
mg/d
L)
Months
0 12 36
Cushman M et al. Circulation 1999;100:717-722.1999 Lippincott Williams & Wilkins.
CEE + MPA cyclicCEE + MPA continuousCEE + MP
CEE
Placebo
Long-Term Effect of Statin Therapy on Long-Term Effect of Statin Therapy on hs-CRP: Placebo and Pravastatin Groupshs-CRP: Placebo and Pravastatin Groups
PravastatinPravastatin
PlaceboPlacebo
Me
dia
n h
s-C
RP
Me
dia
n h
s-C
RP
Co
nc
en
tra
tio
nC
on
ce
ntr
ati
on
(mg
/dL
)(m
g/d
L) -21.6%-21.6%
((PP=0.004)=0.004)
0.18
0.19
0.20
0.21
0.22
0.23
0.24
0.25
Baseline 5 Years
Ridker et al, Circulation. 1999;100:230-235.
hs-
CR
P (
mg/L
)Effect of Statin Therapy on hs-CRP Levels Effect of Statin Therapy on hs-CRP Levels
at 6 Weeksat 6 Weeks
Jialal I et al. Circulation 2001;103:1933-1935.2001 Lippincott Williams & Wilkins.
6
5
4
3
2
1
0 Baseline
* * *
Prava(40 mg/d)
Simva(20 mg/d)
Atorva(10 mg/d)
*p<0.025 vs. Baseline
Effect of Bezafibrate with and without Effect of Bezafibrate with and without Fluvastatin on Plasma Fibrinogen, PAI-1, and Fluvastatin on Plasma Fibrinogen, PAI-1, and
CRP in Patients with CAD and Mixed CRP in Patients with CAD and Mixed HyperlipidemiaHyperlipidemia
Beza 400 mg/d
Beza 400 mg/d+ fluva 20 mg/d
Beza 400 mg/d+ fluva 40 mg/d
Cortellaro M et al. Thromb Haemost 2000;83:549-553.
-20-15-10
-505
1015
Chan
ge a
t 24
weeks
, %
n: 81
Fibrinogen PAI-1 CRP
80 74
70 72 63 83 80 75
P<0.05 vs. baseline**
*
No History of CADMen > 55, Women >
65 LDL-C <130 mg/dL
hs-CRP >2 mg/L
Rosuvastatin (N =7500)
Placebo (N =7500)
MIStroke
Unstable Angina
CVD DeathCABG/PTCA
4 weekRun-in
JUPITERJUPITERRandomized Trial of Rosuvastatin in the Primary Randomized Trial of Rosuvastatin in the Primary
Prevention of Cardiovascular Events Among Prevention of Cardiovascular Events Among Individuals with Low Levels of LDL-CIndividuals with Low Levels of LDL-C
and Elevated Levels of hs-CRPand Elevated Levels of hs-CRP
hs-CRPLipids
hs-CRP LFTs
UA
hs-CRPLFTsUA
LipidsHbA1C
Screening
Visit 1
Randomization
Visit
SafetyVisit
Bi-Annual Follow-Up
Visits
End of Study Visit
hs-CRP LFTsHbA1C
Screening
Visit 2
N Engl J Med. 2002;347:1157-1165
0 2 4 6 8
Years of Follow-Up
0.9
60
.97
0.9
80
.99
1.0
0
Quintiles of LDL
0 2 4 6 8
Years of Follow-Up
0.9
60
.97
0.9
80
.99
1.0
0
CV
D E
ven
t-F
ree
Su
rviv
al P
rob
abili
ty
Quintiles of CRP
Ridker et al, N Engl J Med. 2002;347:1157-1165.
5
4
3
2
1
5
4
3
2
1
Event-Free Survival According to Baseline Quintiles Event-Free Survival According to Baseline Quintiles of of
C-Reactive Protein and LDL CholesterolC-Reactive Protein and LDL Cholesterol
1.00
0.99
0.98
0.97
0.96
0.000 2 4 6 8
Years of Follow-up
Low CRP-low LDL
Low CRP-high LDL
High CRP-low LDL
High CRP-high LDL
CV Event-Free Survival Using Combined CV Event-Free Survival Using Combined hs-CRP and LDL-C Measurementshs-CRP and LDL-C Measurements
Ridker et al, N Engl J Med. 2002;347:1157-1165.
Pro
bab
ility
of
Eve
nt-
free
Su
rviv
al
Median LDL 124 mg/dlMedian CRP 1.5mg/l
hs-CRP Adds Prognostic Information at all Levels of hs-CRP Adds Prognostic Information at all Levels of LDL-C and at all Levels of the Framingham Risk ScoreLDL-C and at all Levels of the Framingham Risk Score
0-1
25
20
15
10
5
0
Rel
ativ
e ri
sk
Mu
ltiv
aria
ble
rel
ativ
e ri
sk2-4 5-9 10-20 130-160<130 >160
Framingham estimate of 10-year risk (%) LDL cholesterol (mg/dL)
C-Reactive Protein (mg/L)C-Reactive Protein (mg/L)
1
0
2
3
<1.0 1.0-3.0 >3.0
Ridker et al, N Engl J Med. 2002;347:1557.
<1.0 1.0-3.0 >3.0
What is the role of hs-CRP withWhat is the role of hs-CRP withregard to diabetes and theregard to diabetes and the
metabolic syndrome?metabolic syndrome?
Circulation. 2003;107:391-397.
0 1 2 3 4 50
2
4
6
8
C-r
ea
cti
ve
pro
tein
(m
g/L
)
Number of Components of the Metabolic Syndrome
Ridker et al, Circulation 2003;107:391-7
Plasma hs-CRP Levels According to Plasma hs-CRP Levels According to Severity of the Metabolic SyndromeSeverity of the Metabolic Syndrome
0 2 4 6 8
Years of Follow-Up
0.95
0.96
0.97
0.98
0.99
1.00C
VD
Ev
ent-
Fre
eS
urv
iva
l Pro
ba
bili
ty
CRP <1 mg/L
CRP 1-3 mg/L
CRP >3 mg/L
Event Free Survival According to hs-CRP Levels: Analysis Event Free Survival According to hs-CRP Levels: Analysis Limited to Participants Limited to Participants withwith Metabolic Syndrome at BaselineMetabolic Syndrome at Baseline
Ridker et al, Circulation 2003;107:391-7
AHA / CDC Scientific StatementAHA / CDC Scientific StatementMarkers of Inflammation and Cardiovascular Disease:Markers of Inflammation and Cardiovascular Disease:
Applications to Clinical and Public Health PracticeApplications to Clinical and Public Health Practice
Circulation January 28, 2003Circulation January 28, 2003
“Measurement of hs-CRP is an independent marker of risk“Measurement of hs-CRP is an independent marker of riskand may be used at the discretion of the physician as partand may be used at the discretion of the physician as part
of global coronary risk assessment in adults without knownof global coronary risk assessment in adults without knowncardiovascular disease. Weight of evidence favors use cardiovascular disease. Weight of evidence favors use particularly among those judged at intermediate risk byparticularly among those judged at intermediate risk by
global risk assessment”.global risk assessment”.
1 mg/L 3 mg/L 10 mg/L
LowRisk
ModerateRisk
HighRisk
Acute Phase ResponseIgnore Value, Repeat Test in 3
weeks
>100 mg/L
Ridker PM. Circulation 2003;107:363-9
Clinical Application of hs-CRP forClinical Application of hs-CRP forCardiovascular Risk Prediction Cardiovascular Risk Prediction
Inflammatory and Infections Agents in CHDInflammatory and Infections Agents in CHD
Belgian epidemiologic study included 446 of Belgian epidemiologic study included 446 of 16307 male workers aged 35-39 who had 16307 male workers aged 35-39 who had evidence of CHD vs. 892 controls.evidence of CHD vs. 892 controls.
CRP, but none of the infectious agents (H. CRP, but none of the infectious agents (H. pylori, C. pneumoniae, CMV, and EBV) were pylori, C. pneumoniae, CMV, and EBV) were associated with CHD, even after adjustment associated with CHD, even after adjustment for other risk factors.for other risk factors.
De Backer et al. Atherosclerosis 2002; 160: 457-63.
Infection and CHD - is there a Infection and CHD - is there a connection?connection?
Local or systemic infections resulting from Local or systemic infections resulting from gram negative bacteria such as Chlamydia gram negative bacteria such as Chlamydia pneumoniae and Helicobacter pylori, including pneumoniae and Helicobacter pylori, including cytomegalovirus (CMV) have been implicated cytomegalovirus (CMV) have been implicated in atheroscelosisin atheroscelosis
While several case control studies have shown While several case control studies have shown increased titers of C.pneumoniae and H. Pylori increased titers of C.pneumoniae and H. Pylori in those with vs. without CHD, convincing in those with vs. without CHD, convincing evidence from prospective studies is lacking.evidence from prospective studies is lacking.
Prospective Studies of CHD and Prospective Studies of CHD and Infectious PathogensInfectious Pathogens
Physician’s Health Study (nested case-control) Physician’s Health Study (nested case-control) shows RR 1.1 (0.8-1.5) for C. Pneumoniae, shows RR 1.1 (0.8-1.5) for C. Pneumoniae, 0.94 (0.7-1.2) for cytomegalovirus, and 0.72 0.94 (0.7-1.2) for cytomegalovirus, and 0.72 (0.6-0.9) for Herpes simplex virus.(0.6-0.9) for Herpes simplex virus.
H. pylori also shows mixed results. Whincup H. pylori also shows mixed results. Whincup showed a nonsignificant 1.3 OR when adjusted showed a nonsignificant 1.3 OR when adjusted for other risk factors, the large ARIC study for other risk factors, the large ARIC study showed no relation, and the Caerphilly showed no relation, and the Caerphilly Prospective study showed RR=1.05 in 1796 Prospective study showed RR=1.05 in 1796 men followed 14 years.men followed 14 years.
Other Studies of Infectious AgentsOther Studies of Infectious Agents
In South Asian persons with CHD vs. controls, C. pneumoniae In South Asian persons with CHD vs. controls, C. pneumoniae specific IgG antibody was seropositive in similar proportions; risk specific IgG antibody was seropositive in similar proportions; risk factors appeared to mediate any relations (Mendis et al. Int J factors appeared to mediate any relations (Mendis et al. Int J Cardiol 2001; 79: 191-6).Cardiol 2001; 79: 191-6).
Cross-sectional survey of 704 individuals of C. pneumoniae and Cross-sectional survey of 704 individuals of C. pneumoniae and CMV with risk factors did nto show significant associations CMV with risk factors did nto show significant associations (Danesh et al., J Cardiovasc Risk 1999; 6: 387-90).(Danesh et al., J Cardiovasc Risk 1999; 6: 387-90).
Meta-analysis of 24 articles involving H. pylori infection and CHD Meta-analysis of 24 articles involving H. pylori infection and CHD showed a pooled odds ratio of 1.55 (95% CI: 1.38-1.74) (p<0.001), showed a pooled odds ratio of 1.55 (95% CI: 1.38-1.74) (p<0.001), suggested a weak relation, but high hetrogeneity between studies suggested a weak relation, but high hetrogeneity between studies precludes clear demonostration (Pellicano et al., Eur J Epidemiol precludes clear demonostration (Pellicano et al., Eur J Epidemiol 1999; 15: 611-9).1999; 15: 611-9).
ARIC Study failed to show clear relation between IgG antibodies ARIC Study failed to show clear relation between IgG antibodies for C. pneumoniae and incident CHD occurring over average 3.3 for C. pneumoniae and incident CHD occurring over average 3.3 years. (Nieto et al. Am J Epidemiol 1999; 150: 149-56).years. (Nieto et al. Am J Epidemiol 1999; 150: 149-56).
Clinical Trial Evidence for Antibiotic Clinical Trial Evidence for Antibiotic Treatment and Prevention of CVDTreatment and Prevention of CVD
ACADEMIC Study of 302 patients with CHD seropositive to ACADEMIC Study of 302 patients with CHD seropositive to C. Pneumoniae randomized to azithromycin 500 mg/wk or C. Pneumoniae randomized to azithromycin 500 mg/wk or placebo for 3 months showed no significant treatment placebo for 3 months showed no significant treatment difference (HR=0.89, p=0.74) for recurrent events difference (HR=0.89, p=0.74) for recurrent events (Muhlestein et al., Circulation 2000; 102: 1755-60).(Muhlestein et al., Circulation 2000; 102: 1755-60).
AZACS Multicenter study of 1439 pts with unstable angina AZACS Multicenter study of 1439 pts with unstable angina randomized to 250 mg azithromycin/day for up to 6 randomized to 250 mg azithromycin/day for up to 6 months showed no significant benefit for death, recurrent months showed no significant benefit for death, recurrent MI, or recurrent ischemia (Cercek et al., Lancet 2003; 361: MI, or recurrent ischemia (Cercek et al., Lancet 2003; 361: 809-13).809-13).
WIZARD trial of 7,747 pts post-MI randomized to 12 week WIZARD trial of 7,747 pts post-MI randomized to 12 week of therapy with azithromycin or placebo showed no of therapy with azithromycin or placebo showed no significant reduction in reinfarction, revascularization, significant reduction in reinfarction, revascularization, hospitalization for angina, or death (O’Connor et al., JAMA hospitalization for angina, or death (O’Connor et al., JAMA 2003; 290: 1459-66).2003; 290: 1459-66).
Infectious Agents and the FutureInfectious Agents and the Future
Individuals with greater infectious burdens may Individuals with greater infectious burdens may be at greater risk, because they are older, have be at greater risk, because they are older, have poorer health habits, less access to care.poorer health habits, less access to care.
Observed associations often may be due to Observed associations often may be due to selection biases or confounding from age and selection biases or confounding from age and other factorsother factors
Prospective clinical trials under way examining Prospective clinical trials under way examining role of certain antibiotics such as azithromycin role of certain antibiotics such as azithromycin on reduction of recurrent events in CHD on reduction of recurrent events in CHD patients.patients.
Until these data are available, no role for Until these data are available, no role for measurement or treatment of infectious burden.measurement or treatment of infectious burden.