Enhanced inflammatory response in patients with preinfarction unstable angina

Indications for angiography subsequent to coronary artery bypass grafting

BACKGROUND

Postoperative myocardial infarction is a rare, but potentially severe complication after coronary artery bypass grafting (CABG). Early markers for coronary bypass graft failure or native vessel occlusion are required, because immediate intervention could prevent major myocardial damage.

METHODS

One thousand patients with coronary artery disease consecutively underwent CABG. Postoperative coronary angiography was performed in 40 patients with suspected myocardial ischemia. Creatine kinase (CK), CK-MB, leukocyte count, C-reactive protein (CRP), lactate dehydrogenase (LDH), and glutamate-oxalacetate transaminase (GOT) were assessed at 0, 6, 12, 24, 48, and 72 hours after CABG as well as 12-lead standard electrocardiography (ECG).

RESULTS

Postoperative angiography of 40 patients with suspected myocardial infarction revealed graft failure or occluded native vessels in 13 (32.5%) individuals. Patients with graft or vessel occlusion presented elevated (P < .005) leukocyte counts (17,215 +/- 6632 vs 10,773 +/- 3902 G/L) immediately after CABG. CK-MB concentrations differed ( P < .05) at 6 hours after CABG (54 +/- 48 vs 30 +/- 18 U/L). CK, CRP, LDH, and GOT did not show any differences between both groups. Frequency of ECG ST-segment elevation was increased (P < .05) in ischemic patients (69.2% vs 29.6%).

CONCLUSIONS

Common signs of myocardial ischemia usually allow to diagnose unstable angina or myocardial infarction under native conditions. In contrast, these criteria frequently fail after CABG. Combined diagnostic criteria of elevated leukocytes (>14,000 G/L, at hour 0) and either ST elevation or CK-MB concentrations >35 U/L (at hour 6) at least seem to be very useful in detecting myocardial infarction after bypass grafting. In parallel, CK-MB elevation (>70 U/L, at hour 6) alone seems to predict ischemia. Both criteria should indicate angiography and potential revascularization. If these conditions were not fulfilled, the risk of perioperative myocardial infarction appears to be moderate.

Acute myocardial infarction in young patients: nutritional status and biochemical factors

PURPOSE

The aim of this study was to establish whether nutritional status and biochemical factors, C-reactive protein (CRP), serum amyloid A (SAA) protein, serum iron (Fe) and fibrinogen at admission were different in patients with acute myocardial infarction (AMI) at a young age (<40 years) vs. those with AMI at an older age (>60 years). We also investigated whether during the stay in the hospital, the increase in acute-phase reactants was different in young vs. older subjects, and if dyslipidemic aspects were different between the two groups.

METHODS

The study population consisted of 40 patients, all males with a mean age of 36.7+/-1.16 years, admitted to our facility with AMI. The control group included 40 patients, all males, mean age of 66.3+/-4.24 years, with AMI. CRP, SAA, Fe and fibrinogen were determined at admission to the hospital and daily for 7 days in the two groups of patients.

RESULTS

In young patients the median value of the highest levels were 6.2 mg/l (range 0.7-27.30) for CRP, 13.22 mg/l (range 0.7-130) for SAA, 420 mg/dl (range 76-840) for fibrinogen and 49.1 gamma/ml (range 14-102) for Fe levels. In the older patients, the median value of the highest levels were 5.9 mg/l (range 0.6-28.30) for CRP, 12.12 mg/l (range 0.9-280) for SAA, 480 mg/dl (range 60-780) for fibrinogen and 47.1 gamma/ml (range 12-94) for Fe levels.

CONCLUSIONS

In the present study, acute-phase reactants were quantitatively similar in young and old patients. On the contrary, nutritional status, homocysteine, LDL and triglycerides are significantly higher in young patients than in old patients.

An acute inflammatory reaction induced by myocardial damage is superimposed on a chronic inflammation in unstable coronary artery disease

BACKGROUND

Inflammation plays an important role in unstable coronary artery disease (CAD). We assessed the kinetics of inflammatory markers from symptom onset in patients with unstable CAD and their relation to myocardial damage.

METHODS

Serial measurements of inflammatory mediators were performed in consecutive patients with unstable CAD enrolled at selected sites in the FRISC II (n = 558) and the GUSTO IV (n = 404) trials. The time from symptom onset was calculated for every serum sample (total 4400 samples).

RESULTS

Median levels of interleukin 6 and C-reactive protein reached their peaks at 36 to 42 hours and at 48 to 54 hours, respectively, from symptom onset and returned to early postsymptom levels within 6 weeks. The early increase occurred almost exclusively in patients with baseline troponin T elevation (>0.01 microg/L). In contrast, median levels of fibrinogen increased continuously up to 120 hours after symptom onset, independently of myocardial damage. At 6 months, fibrinogen levels were still higher than in the early phase after symptom onset. The median levels of interleukin 6, C-reactive protein, and fibrinogen were still higher at 6 months than in healthy controls matched for age and sex to a population with unstable CAD.

CONCLUSIONS

An early acute inflammatory reaction induced by myocardial damage seems to be superimposed on a chronic inflammatory condition, both of which might influence long-term outcome in unstable CAD.

Relationship between adrenomedullin and left-ventricular systolic function and mortality in acute myocardial infarction

The purpose of this study was to investigate the relationship between plasma adrenomedullin concentration levels and left-ventricular systolic function in patients with acute myocardial infarction (AMI), and to assess whether these findings can be used to predict clinical outcomes, including mortality. One hundred twenty-four consecutive first AMI attack subjects were successfully reperfused with primary percutaneous coronary intervention therapy. Plasma adrenomedullin concentrations were evaluated at 24 hours from onset. Left ventriculograms of all patients taken in the acute (soon after reperfusion therapy) and subacute (21 +/-9 days after onset) phases were used to evaluate left-ventricular ejection fraction (LVEF), and the difference in LVEF (delta-LVEF) between the two stages calculated. There were significantly more patients with cardiogenic shock in the H-Adm group (above the median value of plasma adrenomedullin concentrations > or =3.5 Fmol/mL) than in the L-Adm (< 3.5 Fmol/mL) group (p<0.0001). There was significantly higher mortality in the H-Adm group (p<0.01). Multivariate analysis identified plasma adrenomedullin concentrations alone as an independent predictor of mortality (p<0.05). There were no significant differences in acute-stage LVEF between the groups. LVEF in the subacute stage was, however, significantly lower in the H-Adm group than in the L-Adm group (52 +/-12% vs 59 +/-11%, p<0.05). Also, delta-LVEF was significantly lower in the H-Adm group than in the L-Adm group (1.9 +/-9.7% vs 6.3 +/-10.3%, p<0.01). Plasma adrenomedullin concentrations in the early phase of AMI correlate closely with the severity of heart failure, and may offer important prognostic information about the risk of mortality. Our data suggest that plasma adrenomedullin concentrations may be an independent predictor of the deterioration of left-ventricular systolic function.

Inflammatory markers at the site of ruptured plaque in acute myocardial infarction: locally increased interleukin-6 and serum amyloid A but decreased C-reactive protein

BACKGROUND

Acute myocardial infarction (AMI) is associated with inflammation. However, it remains unclear whether it originates from the ruptured plaque or represents a systemic process.

METHODS AND RESULTS

In 42 patients with AMI, a balloon-based embolization protection device and aspiration catheter (PercuSurge) were used during acute coronary interventions. Samples from the site of the ruptured plaque were taken under distal balloon occlusion. Systemic samples were taken from the aorta. Sera, plaques, and thrombi were analyzed for inflammatory markers and lipoproteins. Systemic levels of C-reactive protein (CRP), interleukin-6 (IL-6), and serum amyloid A (SAA) in the aorta amounted to 3.0 mg/L, 5.0 ng/L, and 22.1 mg/L, respectively (interquartile ranges [IQRs], 1.1 to 7.4 mg/L, 5.0 to 6.5 ng/L, and 13.9 to 27.0 mg/L, respectively). In blood surrounding ruptured plaques, local levels of IL-6 (8.9 ng/L; IQR, 5.0 to 16.9 ng/L) and SAA (24.3 mg/L; IQR, 16.3 to 44.0 mg/L) were significantly higher, whereas CRP levels (2.5 mg/L; IQR, 0.9 to 7.7 mg/L) were decreased compared with the aorta (all P<0.0001). The coronary levels of IL-6 determined in vivo showed biological activity in vitro. Harvested thrombus contained CD68-positive monocytes expressing IL-6 and showed extracellularly and intracellularly positive staining for SAA, whereas CRP was found exclusively in the cytoplasm of phagocyting white blood cells.

CONCLUSIONS

Coronary levels of IL-6 and SAA at the site of plaque rupture were increased relative to the systemic circulation, indicating local production of biologically active inflammatory mediators. In contrast, CRP was locally decreased, at least in part by uptake by the phagocyting cells, suggesting a systemic origin of the protein.

Persistent systemic inflammation in unstable angina is largely unrelated to the atherothrombotic burden

OBJECTIVES

The aim of this study was to assess the relationship between systemic inflammation, atherosclerosis, and thrombosis in two distinct clinical models of atherothrombosis.

BACKGROUND

Persistent unstable angina (UA) is commonly associated with coronary thrombosis and persistent systemic inflammation.

METHODS

We assessed circulating markers of activation of the thrombotic and fibrinolytic cascades and systemic soluble and cellular markers of inflammation on admission in 40 patients with persisting UA (Braunwald class IIIB; group 1) and 30 patients with Leriche-Fontaine stage IIB-III peripheral artery disease awaiting revascularization (group 2).

RESULTS

The extent of atherosclerosis (p < 0.01) and activation of the coagulation system were greater in group 2, which had higher thrombin-antithrombin III complexes and D-dimer levels (2.7 and 24.4 microg/l, respectively), than in group 1 (2.0 microg/l and 12.9 microg/l, p = 0.02 and p = 0.0001, respectively). In contrast, C-reactive protein and interleukin-6 levels were higher in group 1 (7.6 pg/ml and 7.8 pg/ml, respectively) than in group 2 (4.5 pg/ml and 3.0 pg/ml, p < 0.01 and p = 0.03, respectively). Moreover, neutrophil activation was only found in group 1 (neutrophil myeloperoxidase content -4.0 arbitrary units vs. +3.4 arbitrary units in group 2, p < 0.0001). These differences persisted during the initial three days of hospitalization.

CONCLUSIONS

Such a large, consistent discrepancy between atherothrombotic burden and systemic inflammation suggests that atherothrombosis, by itself, is an unlikely cause of persisting, recurring UA. An understanding of the primary inflammatory mechanisms of persistent and recurrent coronary instability could open the way to novel therapeutic strategies.

Clinical progression of incidental, asymptomatic lesions discovered during culprit vessel coronary intervention

BACKGROUND

With the reduction in restenosis rates by drug-eluting stents, there is new controversy concerning the optimal management of incidental, nontarget lesions identified during percutaneous coronary intervention (PCI). Such lesions have been treated conservatively because of risk of restenosis but now are being considered for PCI to prevent plaque instability. However, the impact of incidental stenoses on future cardiac events remains unknown.

METHODS AND RESULTS

We performed a retrospective cohort study to determine the rate and features of clinical plaque progression using the National Heart, Lung, and Blood Institute Dynamic Registry of consecutive patients undergoing PCI at multiple centers in 1997 to 1998 and 1999. Of 3747 PCI patients, 216 (5.8%) required additional nontarget lesion PCI for clinical plaque progression at 1 year. Fifty-nine percent presented with new unstable angina, and 9.3% presented with nonfatal myocardial infarction. Patients with multivessel coronary artery disease during original PCI were more likely to require nontarget lesion PCI during follow-up (adjusted odds ratio, 1.72 [95% CI, 1.18 to 2.52] for 2 vessels; adjusted odds ratio, 3.37 [95% CI, 2.32 to 4.89] for 3 vessels). Angiographic review showed that the majority (86.9%) of lesions requiring subsequent PCI were < or =60% in severity during original PCI, with the mean lesion stenosis 41.8+/-20.8% at the time of the initial PCI and 83.9+/-13.9% during the recurrent event.

CONCLUSIONS

Approximately 6% of PCI patients will have clinical plaque progression requiring nontarget lesion PCI by 1 year. Greater coronary artery disease burden confers a significantly higher risk for clinical plaque progression.

Plasma N-terminal pro-B-type natriuretic peptide for prediction of death or nonfatal myocardial infarction following percutaneous coronary intervention

B-type natriuretic peptide (BNP) and the N-terminus of pro-BNP (NT-pro-BNP) have prognostic value in patients with heart failure and patients with acute coronary syndromes. Little is known about the prognostic value of baseline NT-pro-BNP alone or in combination with C-reactive protein (CRP) for clinical outcome after percutaneous coronary intervention (PCI). Within a single center registry of contemporaneous PCI, we investigated the prognostic value of baseline plasma NT-pro-BNP and CRP concentrations for the prediction of death or nonfatal myocardial infarction (MI) during 12 to 14 months of follow-up. Among 1,172 consecutive patients, the occurrence of death or MI increased significantly with baseline NT-pro-BNP before PCI (first quartile 0 of 294, second quartile 6 of 291 [2.1%], third quartile 4 of 294 [1.4%], fourth quartile 22 of 293 [7.5%)]; p <0.0001). NT-pro-BNP in the top quartile significantly predicted death (odds ratio [OR] 13.37, 95% confidence interval [CI] 4.50 to 40.38, p <0.0001) and was associated with nonfatal MI (OR 2.53, 95% CI 0.77 to 8.34, p = 0.22) An abnormal CRP was significantly associated with death (OR 3.47, 95% CI 1.26 to 9.54, p = 0.019). Stepwise multivariate logistic regression analysis identified age >65 years and NT-pro-BNP as independent significant predictors of death/MI (age OR 3.18, 95% CI 1.32 to 7.67, p = 0.01; NT-pro-BNP OR 4.57, 95% CI 2.07 to 10.10, p = 0.0001). Baseline NT-pro-BNP before PCI provides important, independent prognostic information for the occurrence of death or nonfatal MI during long-term follow-up.

Medical lipid-regulating therapy: current evidence, ongoing trials and future developments

Coronary heart disease (CHD) is a major cause of morbidity and mortality worldwide. Elevated low density lipoprotein-cholesterol (LDL-C) and reduced high density lipoprotein-cholesterol (HDL-C) levels are well recognised CHD risk factors, with recent evidence supporting the benefits of intensive LDL-C reduction on CHD risk. Such observations suggest that the most recent National Cholesterol Education Program Adult Treatment Panel III guidelines, with LDL-C targets of 2.6 mmol/L, may result in under-treatment of a significant number of patients and form the basis for the proposed new joint European Societies treatment targets of 2 and 4 mmol/L, respectively, for LDL and total cholesterol. HMG-CoA reductase inhibitors (statins) reduce LDL-C by inhibiting the rate-limiting step in cholesterol biosynthesis and reduced CHD event rates in primary and secondary prevention trials. The magnitude of this effect is not fully accounted for by LDL-C reduction alone and may relate to effects on other lipid parameters such as HDL-C and apolipoproteins B and A-I, as well as additional anti-inflammatory effects. With increasing focus on the benefits of intensive cholesterol reduction new, more efficacious statins are being developed. Rosuvastatin is a potent, hydrophilic enantiomeric statin producing reductions in LDL-C of up to 55%, with about 80% of patients reaching European LDL-C treatment targets at the 10 mg/day dosage. The Heart Protection Study (HPS) demonstrated that LDL-C reduction to levels as low as 1.7 mmol/L was associated with significant clinical benefit in a wide range of high-risk individuals, including patients with type 2 diabetes mellitus, or peripheral and cerebrovascular disease, irrespective of baseline cholesterol levels, with no apparent lower threshold for LDL-C with respect to risk. Various large endpoint trials, including Treating to New Targets (TNT) and Study of Effectiveness of Additional reductions in Cholesterol and Homocysteine (SEARCH) will attempt to further address the issue of optimal LDL-C reduction. At low LDL-C levels, HDL-C becomes an increasingly important risk factor and is the primary lipid abnormality in over half of CHD patients, with the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study set to assess the effect of raising HDL-C on cardiovascular events in patients with low HDL-C and LDL-C levels below 3 mmol/L. A variety of agents are being developed, which affect both LDL-C and HDL-C metabolism, including inhibitors of acyl-coenzyme A-cholesterol acyl transferase, microsomal transfer protein and cholesterol ester transfer protein, as well as specific receptor agonists. Ezetimibe is a selective cholesterol absorption inhibitor, which produces reductions in LDL-C of up to 25 and 60% reduction in chylomicron cholesterol content with a 10 mg/day dosage. A 1 mmol/L reduction in LDL-C results in a 25% reduction in cardiovascular risk, independent of baseline LDL-C levels. Growing evidence supports the concept that lower is better for LDL-C and that increasing HDL-C represents an important therapeutic target. Furthermore, there is growing appreciation of the role of inflammation in atherogenesis. Consequently, increasing numbers of people should receive lipid-regulating therapy with the development of newer agents offering potential mechanisms of optimising lipid profiles and thus risk reduction. In addition, the pleiotropic anti-inflammatory effects of lipid lowering therapy may provide further risk reduction.

Relationship between minor myocardial damage and inflammatory acute-phase reaction in acute coronary syndromes

BACKGROUND

In severe acute coronary syndromes (ACS) elevation of markers of inflammation and acute phase reaction (APR) like C-reactive protein (CRP) as well as a release of troponin have been reported. Using a high sensitivity troponin T (TnT) test we investigated whether an APR occurs in ACS only in the presence of ischemic myocardial damage.

METHODS

In 85 patients with ACS C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen, thrombin antithrombin III complexes (TAT) and kallikrein were determined vs. high sensitive TnT (> or =0.02 ng/ml) initially and 2 d later vs. 45 patients with stable angina pectoris and 42 controls.

RESULTS

In stable angina pectoris, markers of inflammation and coagulation were slightly elevated (p < 0.05). Initially in ACS elevations of CRP to 1.2 +/- 0.3 mg/dl, SAA to 4.8 +/- 2.6 mg/dl and fibrinogen to 448 +/- 21 mg/dl (all p < 0.01 vs. controls) were found followed by a significant APR (p < 0.01). In the subgroup of TnT positive ACS patients, an APR with increased CRP (4.1 +/- 1.3 mg/dl), SAA (20.4 +/- 8.3 mg/dl), and fibrinogen (641 +/- 45 mg/dl) was detectable (all p < 0.05 vs. TnT negative patients). In contrast, patients without TnT release showed APR markers comparable to patients with stable angina pectoris.

CONCLUSION

Our findings demonstrate an association between myocardial injury in ACS and acute phase reaction as evidenced by several molecular markers. A highly sensitive TnT-test identified myocardial injury in about all patients with APR while a standard TnT cut-off (0.1 ng/ml) missed 32% of these patients. Thus, the APR in patients with ACS is strongly associated with at least minor ischemic myocardial damage and prior findings of an APR independent from myocardial injury are probably based on less sensitive troponin tests.

Multiple complex stenoses, high neutrophil count and C-reactive protein levels in patients with chronic stable angina

Inflammation plays an important role in atherosclerosis and the genesis of acute coronary syndromes, i.e., atheromatous plaque disruption. Neutrophil count and C-reactive protein (CRP) levels are markers of ongoing inflammation and predictors of cardiovascular risk. We sought to assess whether these inflammatory markers are associated with the presence of multiple complex stenoses in patients with chronic stable angina.

METHODS AND RESULTS

We assessed 150 patients with chronic stable angina, 121 with significant coronary artery stenosis (> or =50% diameter reduction) and 29 without. CRP levels and neutrophil count were assessed at study entry. Stenoses were classified as "complex" (irregular or scalloped borders, ulceration or filling defects) or "smooth" (absence of complex features). Eighty-eight percent of the complex lesions were of type C according to AHA/ACC classification whereas the rest were type B. Patients with > or =3 complex lesions were considered to have multiple complex stenoses. Extent of coronary artery disease was assessed using a validated score. Baseline neutrophil count (4.39 x 10(9) L (-1) +/- 28 versus 3.82 x 10(9) L (-1) +/- 0.77; P = 0.004) and CRP levels (2.15 mg/L (4.6-1) versus 0.39 mg/L (0.69-0.23); P < 0.0001) were higher in patients with significant stenoses compared to patients without. No association was found between disease extent and CRP levels or neutrophil count. Neutrophil count, however (but not CRP) correlated with stenosis complexity (r = 0.28; P = 0.002 ) and was also an independent predictor of the presence of multiple complex stenoses (OR: 4.05; CI 95% (1.9-10.4); P = 0.038).

CONCLUSIONS

CRP levels and neutrophil count are higher in angina patients with coronary stenoses compared to those without. Neutrophil count, but not CRP levels, correlates with angiographic stenosis complexity.

Is the Beneficial Effect of Preinfarction Angina Related to an Immune Response?

Immune-mediated mechanisms are thought to play a key role in the development of coronary artery disease and its thrombotic complications. Preinfarction angina has been suggested to improve left ventricular function and short-term outcomes. The purpose of the present study was to investigate the relation between the immune response and in-hospital clinical course in preinfarction angina. We prospectively evaluated 93 patients. Forty-three patients exhibited preinfarction angina within 24 hours before the onset of acute myocardial infarction (AMI) (preinfarction angina group) and 50 patients were free from preinfarction angina (sudden onset group). The incidence of complications (heart failure, recurrent angina, arrhythmia and coronary interventions) and in-hospital mortality were assessed in the two study groups. We detected some immune markers, including white blood cells, C-reactive protein, immunoglobulins, and complement. White blood cells and CRP were significantly lower in the preinfarction angina group than in the sudden onset group (P < 0.001, P < 0.005, respectively). Conversely, IgE and C(4) were significantly higher in the preinfarction angina group than in the sudden onset group (P < 0.001, P < 0.001, respectively). The incidences of heart failure and severe arrhythmias were lower in the preinfarction group than in the sudden onset group (P < 0.005, P < 0.05 respectively). The beneficial effect of preinfarction angina may be associated with an immune-inflammatory response modified by a brief ischemic episode.

Human CRP gene polymorphism influences CRP levels: implications for the prediction and pathogenesis of coronary heart disease

OBJECTIVE

C-reactive protein (CRP) concentrations are predictive of cardiovascular disease, and levels are heritable, in part. We identified novel polymorphisms in the CRP gene and assessed their influence on CRP level.

METHODS AND RESULTS

CRP was measured in 250 male army recruits before and after strenuous exercise and perioperatively in 193 coronary artery bypass graft (CABG) patients. Two novel polymorphisms were identified in the CRP gene, -717G>A in the promoter and +1444C>T in the 3'UTR. Among army recruits, CRP was higher in +1444TT homozygotes than +1444 C-allele carriers at baseline (1.04+/-0.38 versus 0.55+/-0.06, P=0.014) and at all time points after exercise (2.35+/-0.68 versus 1.07+/-0.12, 2.11+/-0.53 versus 0.88+/-0.09, and 1.77+/-0.44 versus 0.71+/-0.09, P=0.034, P=0.007, and P=0.013, at 2, 48, and 96 hours after exercise, respectively). In the CABG patients, mean CRP (mg/L) rose from 1.97+/-0.36 at baseline to 167.2+/-5.0 72 hours postoperatively. Genotype did not influence CRP at baseline; however, peak post-CABG CRP levels were higher in +1444TT homozygotes compared with +1444C-allele carriers (198+/-17 versus 164+/-5, P=0.03).

CONCLUSIONS

The CRP gene +1444C>T variant influences basal and stimulated CRP level. These findings have implications both for the prediction and pathogenesis of coronary heart disease.

C-Reactive protein on admission and the success of thrombolytic therapy with streptokinase: is there any relation?

BACKGROUND

Recent evidence has demonstrated that inflammation plays a major role in the initiation and progression of atheroma plaques. C-reactive protein (CRP) is shown to have prognostic significance in acute coronary syndromes. We investigated the influence of CRP levels before thrombolytic therapy on infarct-related artery (IRA) patency and the degree of residual stenosis.

METHODS

45 consecutive patients with a first attack of acute myocardial infarction (MI) who underwent streptokinase therapy and subsequently coronary angiography were enrolled into the study. Patients were divided into 2 groups according to the level of CRP on admission.

RESULTS

Serum CRP levels were > or =0.5 mg/dL in 26 patients (Group-I) and <0.5 mg/dL in 19 patients (Group-II). The patency of IRA (TIMI-2 and 3) evaluated at 90th minute after the initiation of thrombolytic therapy was similar between the two groups (62% vs. 68%, p>0.05). However, the presence of TIMI-3 flow was significantly lower and TIMI-2 flow was higher in Group-I as compared to Group-II (12% vs. 53%, p=0.003 and 50% vs. 16%, p=0.018 respectively). Additionally, among patients with patent IRA, the degree of residual stenosis was significantly higher in Group-I (80 +/- 14% vs. 68 +/- 15%, p=0.032).

CONCLUSION

High serum CRP levels on admission in patients within 6 hours after the start of acute ST-segment elevation MI are associated with lower TIMI flow grades and higher residual stenosis of IRA after intravenous streptokinase. Our observations imply that patients with higher CRP levels on admission require closer follow-up during and after acute MI.

High-dose atorvastatin enhances the decline in inflammatory markers in patients with acute coronary syndromes in the MIRACL study

BACKGROUND

Inflammation promotes acute coronary syndromes and ensuing clinical complications. Although statins reduce inflammatory markers in asymptomatic adults or in patients with stable angina, the effect of statins on the markedly heightened inflammation in patients with acute coronary syndromes is unknown.

METHODS AND RESULTS

We measured C-reactive protein (CRP), serum amyloid A (SAA), and interleukin 6 (IL-6) in 2402 subjects enrolled the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study. Subjects with unstable angina or non-Q-wave myocardial infarction were randomized to atorvastatin 80 mg/d or placebo within 24 to 96 hours of hospital admission and treated for 16 weeks. The effect of treatment on inflammatory markers was assessed by ANCOVA after adjustment for presenting syndrome, country, and initial level of marker. All 3 markers were markedly elevated at randomization and declined over the 16 weeks in both treatment groups. Compared with placebo, atorvastatin significantly reduced CRP, -83% (95% CI, -84%, -81%) versus -74% (95% CI, -75%, -71%) (P<0.0001) and SAA, -80% (95% CI, -82%, -78%) versus -77% (-79%, -75%) (P=0.0006) but not IL-6, -55% (95% CI, -57%, -53%) versus -53% (95% CI, -55%, -51%) (P=0.3). Reductions in CRP and SAA were observed in patients with unstable angina and non-Q-wave myocardial infarction, with initial LDL cholesterol <3.2 or > or =3.2 mmol/L (125 mg/dL), age > or =65 or <65 years, and in men and women. By 16 weeks, CRP was 34% lower with atorvastatin than with placebo.

CONCLUSIONS

High-dose atorvastatin potentiated the decline in inflammation in patients with acute coronary syndromes. This supports the value of early statin therapy in these patients.

Inflammatory and thrombotic mechanisms in coronary atherosclerosis

Many molecular and cellular mechanisms link inflammation and haemostatic mechanisms. Inflammation, and perhaps chronic infection, may play important roles in the initiation and progression of atherosclerosis. Atherosclerotic lesions are heavily infiltrated by cellular components associated with inflammation (macrophages and T lymphocytes), and acute plaque rupture is also associated with inflammatory components. Several markers of systemic inflammation may predict future cardiovascular events in apparently healthy subjects as well as in patients with chronic and acute syndromes. There may thus be therapeutic potential in modifying the atherosclerotic, vasomotor, and thrombotic components of ischaemic heart disease.

Preoperative white blood cell count and mortality and morbidity after coronary artery bypass grafting

BACKGROUND

Arteriosclerosis is increasingly viewed as an inflammatory disease. The purpose of these analyses was to examine the preoperative white blood cell (WBC) count, a generalized marker of inflammation, and to assess its association with in-hospital mortality and other adverse outcomes after coronary artery bypass grafting.

METHODS

Information was collected prospectively on 11,270 consecutive patients who had isolated coronary artery bypass grafting in northern New England from 1996 through 2000. Patients were divided into five categories based on their preoperative WBC count. Crude and adjusted in-hospital mortality rates and adverse event rates were calculated using logistic regression.

RESULTS

Increasing WBC count across its entire range was associated with a linear increase in the mortality rate. This finding was highly significant (p [trend] < 0.001) and persisted after adjustment for patient and disease characteristics. Patients with preoperative WBC of at least 12.0 x 10(9)/L had an adjusted mortality rate 2.8 times higher than those with a WBC less than 6.0 x 10(9)/L (4.8% versus 1.7%). An increasing preoperative WBC count was also significantly associated with increasing rates of perioperative strokes and the need for an intraaortic balloon pump but was not associated with mediastinitis.

CONCLUSIONS

The preoperative WBC count across its entire observed range is a statistically significant independent predictor of in-hospital death and other adverse outcomes after coronary artery bypass grafting. Although the cause of the association between increased WBC count and increased morbidity and mortality is unknown, the preoperative WBC count, which is objectively measured, inexpensive, and always available, can serve as a useful marker to help predict risk before coronary artery bypass grafting.

C-reactive protein and coronary events following percutaneous coronary angioplasty

PURPOSE

We investigated the associations between baseline C-reactive protein levels in patients undergoing percutaneous coronary angioplasty and death, nonfatal myocardial infarction, and repeat revascularization during 14 months of follow-up.

METHODS

In a single-center, prospective, cohort study, plasma levels of C-reactive protein were measured in 1458 consecutive patients undergoing elective or urgent coronary angioplasty. Patients were followed at 12 to 14 months for the occurrence of death, nonfatal myocardial infarction, and repeat revascularization.

RESULTS

The incidence of death or myocardial infarction was 6.1% (44/716) in patients with an increased C-reactive protein level (>3 mg/L) and 1.5% (11/742) in patients with a normal level (relative risk [RR] = 4.4; 95% confidence interval [CI]: 2.2 to 8.5; P <0.0001). In a multivariate logistic regression model, an increased C-reactive protein level was an independent predictor of death or nonfatal myocardial infarction (RR = 3.6; 95% CI: 1.8 to 7.2; P =0.0001). The incidence of repeat revascularization was similar in patients with or without an increased C-reactive protein level (23% [168/716] vs. 22% [163/742], P = 0.54). Statin therapy at the time of the procedure was associated with a lower mean (+/- SD) C-reactive protein level (5.8 +/- 9.7 mg/L vs. 7.2 +/- 12.1 mg/L, P =0.02), but was not associated with the risk of death, nonfatal myocardial infarction, and repeat revascularization during follow-up.

CONCLUSION

An increased C-reactive protein level is an independent prognostic indicator for the occurrence of death or nonfatal myocardial infarction following coronary angioplasty, but is not associated with the need for repeat revascularization.

Preanalytic and analytic sources of variations in C-reactive protein measurement: implications for cardiovascular disease risk assessment

BACKGROUND

C-reactive protein (CRP) is a widely recognized indicator of inflammation and is known to play an important role in atherogenesis. Recent prospective studies have demonstrated that increased CRP concentrations within the reference interval are a strong predictor of myocardial infarction, stroke, sudden cardiac death, and peripheral vascular disease in apparently healthy adults. On the basis of available evidence, the American Heart Association and the CDC have issued guidelines for the utility of CRP in the primary prevention of coronary heart disease and in patients with stable coronary disease or acute coronary syndromes. Nevertheless, there remains considerable work to optimize the utility of this marker for risk assessment.

ISSUES

Most traditional CRP tests designed to monitor acute and chronic inflammation have inadequate sensitivity for risk stratification of coronary disease. Thus, manufacturers have had to develop tests with higher sensitivity. Because an individual's CRP concentration will be interpreted according to fixed cut-points, issues related to the preanalytic and analytic components of CRP measurement must be considered and standardized where possible to avoid potential misclassification of cardiovascular risk.

CONCLUSIONS

Efforts to define performance criteria for high-sensitivity CRP applications coupled with growing awareness of the physiologic aspects of CRP most likely will lead to refinements in standardization, improved performance in quality-assessment schemes, and enhanced risk prediction.

Clinical evaluation of coronary lesion characteristics in acute myocardial infarction

Coronary lesion instability at the onset of acute myocardial infarction (AMI) was evaluated. The mechanism of AMI has been considered to be coronary lesion instability with occlusive thrombus, although more than one half of AMI occurs in clinically stable patients. A total of 313 AMI patients treated by primary percutaneous transluminal coronary angioplasty with provisional stenting (rate, 41%) were studied. They were divided into 2 groups: group 1A (n = 211), without unstable angina before AMI onset, and group 1B (n = 102), with unstable angina before onset. Moreover, angina patients treated similarly were studied: group 2A (n = 180), with stable angina, and group 2B (n = 204), with unstable angina. Coronary lesion instability at AMI onset was also predicted by C-reactive protein (CRP) levels within 6 hours after onset, before they were affected by myocardial damage. The incidence of repeated AMI and/or target vessel revascularization was 1.9% in group 1A, 7.8% in 1B (p=0.035), 1.7% in 2A, and 5.9% in 2B (p=0.043). Event-free survival curves were consistent with each other in groups 1A and 2A and in groups 1B and 2B. CRP levels on admission were 2.0 +/- 1.7 mg/L in group 1A, 3.3 +/- 4.8 mg/L in group 1B (p<0.001), 2.1 +/- 1.7 mg/L in group 2A, and 3.4 +/- 4.7 mg/L in group 2B (p<0.001). Thus coronary lesion characteristics at AMI onset appeared to be similar in groups 1A and 2A and in groups 1B and 2B. A substantial number of patients have stable culprit lesions at the onset of AMI.

Update on C-reactive protein as a risk marker in cardiovascular disease

Atherosclerosis is characterized by a nonspecific local inflammatory process, which is accompanied by a systemic response. A number of prospective studies have convincingly demonstrated a strong and independent association between even slightly elevated concentrations of systemic markers of inflammation, like C-reactive protein (CRP), and cardiovascular events in initially healthy subjects and in patients with manifest atherosclerosis. Increased concentrations of CRP were also associated with recurrent instability after discharge, and with early and late complications after percutaneous interventions, bypass operation, and in patients with end-stage renal disease. Recent data have strengthened the role for CRP testing in primary prevention, and potentially new indications like glucose disorders have emerged. In addition, new experimental data suggest that CRP may not only be a risk marker, but may be directly involved in the pathogenesis of atherothrombosis. Testing the "inflammation hypothesis" now represents an important goal for clinical research of atherosclerosis.

Atorvastatin affects C-reactive protein levels in patients with coronary artery disease

BACKGROUND

Elevated levels of C-reactive protein (CRP) are considered to be one of the indicators of poor prognosis in coronary artery disease (CAD). The aim of this study was to evaluate anti-inflammatory effects of atorvastatin in patients with CAD by measuring serum CRP levels.

METHODS

After measuring the baseline levels of CRP and lipid fractions, the patients were divided into two groups. In Group A (n = 46), atorvastatin (20 mg/day) was administered in addition to classic antianginal treatment (beta-blocker, nitrate and aspirin). In Group B (n = 32), the usual antianginal treatment was continued. Following 4 weeks of treatment the same measurements were repeated.

RESULTS

In Group A, CRP decreased from 20.3 mg/dl (95% CI, 9-31.8) to 10.8 mg/dl (95% CI, 2.7-18.9) (p < 0.001). In Group B, CRP decreased from 17 mg/dl (95% CI, 13.1-21) to 12.8 mg/dl (95% CI, 9.7-15.9) (p < 0.01). The decrease in group A was more than in group B (p = 0.003).

CONCLUSIONS

In patients with CAD, atorvastatin exerted an anti-inflammatory effect represented by decreasing CRP levels. This effect was independent of the change in low density lipoprotein cholesterol (LDL-C) or high density lipoprotein cholesterol (HDL-C) levels.

Nitric oxide, atherosclerosis and the clinical relevance of endothelial dysfunction

The endothelium plays a key role in vascular homeostasis through the release of a variety of autocrine and paracrine substances, the best characterized being nitric oxide. A healthy endothelium acts to prevent atherosclerosis development and its complications through a complex and favorable effect on vasomotion, platelet and leukocyte adhesion and plaque stabilization. The assessment of endothelial function in humans has generally involved the description of vasomotor responses, but more widely includes physiological, biochemical and genetic markers that characterize the interaction of the endothelium with platelets, leukocytes and the coagulation system. Stable markers of inflammation such as high sensitivity C-reactive protein are indirect and potentially useful measures of endothelial function for example. Attenuation of the effect of nitric oxide accounts for the majority of what is described as endothelial dysfunction. This occurs in response to atherosclerosis or its risk factors. Much remains to be learned about the molecular and genetic pathophysiological mechanisms of endothelial cell abnormalities. However, pharmacological intervention with a growing list of medications can favorably modify endothelial function, paralleling beneficial effects on cardiovascular morbidity and mortality. In addition, several small studies have provided tantalizing evidence that measures of endothelial health might provide prognostic information about an individual patient's risk of subsequent events. As such, the sum of this evidence makes the clinical assessment of endothelial function an attractive surrogate marker of atherosclerosis disease activity. The review will focus on the role of nitric oxide in atherosclerosis and the clinical relevance of these findings.

Widespread coronary inflammation in unstable angina

BACKGROUND

Inflammation within vulnerable coronary plaques may cause unstable angina by promoting rupture and erosion. In unstable angina, activated leukocytes may be found in peripheral and coronary-sinus blood, but it is unclear whether they are selectively activated in the vascular bed of the culprit stenosis.

METHODS

We measured the content neutrophil myeloperoxidase content in the cardiac and femoral circulations in five groups of patients: two groups with unstable angina and stenosis in either the left anterior descending coronary artery (24 patients) or the right coronary artery (9 patients); 13 with chronic stable angina; 13 with variant angina and recurrent ischemia; and 6 controls. Blood samples were taken from the aorta, the femoral vein, and the great cardiac vein, which selectively drains blood from the left but not the right coronary artery.

RESULTS

The neutrophil myeloperoxidase content of aortic blood was similar in both groups of patients with unstable angina (-3.9 and -5.5, with negative values representing depletion of the enzyme due to neutrophil activation) and significantly lower than in the other three groups (P<0.05). Independently of the site of the stenosis, the neutrophil myeloperoxidase content in blood from the great cardiac vein was significantly decreased in both groups of patients with unstable angina (-6.4 in those with a left coronary lesion and -6.6 in those with a right coronary lesion), but not in patients with stable angina and multiple stenoses, patients with variant angina and recurrent ischemia, or controls. There was also a significant transcoronary reduction in myeloperoxidase content in both groups with unstable angina.

CONCLUSIONS

The widespread activation of neutrophils across the coronary vascular bed in patients with unstable angina, regardless of the location of the culprit stenosis, challenges the concept of a single vulnerable plaque in unstable coronary syndromes.

Hormonal regulation of interleukin-6 production in human adipocytes

OBJECTIVE

To elucidate the hormonal regulation of interleukin-6 (IL-6) production by human adipose tissue and its relation to leptin.

DESIGN

In vitro study. Human adipocytes were incubated with dexamethasone (with or without RU486), norepinephrine and epinephrine (with or without propranolol), or insulin.

MEASUREMENTS

IL-6 and leptin secretion by human adipocytes.

RESULTS

A gradual increase in IL-6 secretion by adipocytes during differentiation was observed. A positive correlation was found between basal IL-6 release and both glycerol 3-phosphate dehydrogenase activity--a marker of adipocyte differentiation-and leptin release. Dexamethasone decreased IL-6 secretion and increased leptin secretion in a dose-dependent manner. Both catecholamines increased IL-6 and leptin secretion. The effects of dexamethasone and catecholamines on IL-6 and leptin were abrogated by RU486 and propranolol, respectively. Incubation with insulin resulted in a dose-dependent stimulation of IL-6 and leptin secretion.

CONCLUSIONS

IL-6 is produced by human adipocytes and is a potential marker of adipocyte differentiation. Furthermore it is a hormonally regulated cytokine, suppressed by glucocorticoids, and stimulated by catecholamines and insulin in physiological concentrations.

Acute myocardial infarction 2000 recognition

Acute myocardial infarction occurs in two forms: unheralded attacks and those preceded by unstable angina. As the leading cause of death in the US, accounting for over 95 billion dollar annual cost, acute myocardial infarction requires up-to-date recognition and management.

Impact of angiotensin converting enzyme inhibition on post-coronary artery bypass interleukin 6 release

BACKGROUND

Angiotensin 1 converting enzyme (ACE) inhibitors reduce morbidity and mortality after coronary artery bypass graft surgery (CABG). This benefit may result from an anti-inflammatory action.

OBJECTIVE

To examine the effect of ACE inhibition on interleukin 6 (IL-6) concentrations after CABG.

PATIENTS AND METHODS

161 patients undergoing elective first time CABG were recruited, of whom 41 (25%) were receiving ACE inhibitor treatment; 21 patients with confounding postoperative complications were excluded. After these exclusions there were 33 patients (24%) on ACE inhibitor treatment. Plasma IL-6 was measured preoperatively and again six hours after CABG.

RESULTS

Baseline IL-6 concentrations (geometric mean (SEM)) were non-significantly lower among the patients receiving ACE inhibitors (3.7 (0.1) v 4.3 (0.1) pg/ml, p = 0.12). Overall, post-CABG IL-6 concentrations increased significantly (mean rise 177 (12) pg/ml, p < 0.0005). This response was blunted among ACE inhibitor treated patients. Median increases in IL-6 concentrations were 117 v 193 pg/ml, for treated v non-treated patients, respectively (Kruskal-Wallis, p = 0.02), with peak postoperative IL-6 concentrations lower among the subjects receiving ACE inhibitors than in untreated subjects (142 (19) v 196 (13) pg/ml, p = 0.02). The effect of ACE inhibitors remained significant after multivariate analysis (p = 0.018).

CONCLUSIONS

ACE inhibitor treatment is associated with a reduction in IL-6 response to CABG. The data suggest that this class of drug may have a direct anti-inflammatory effect, which could explain some of its clinical benefit.

C-reactive protein and cardiovascular disease: a review of risk prediction and interventions

BACKGROUND

Coronary vascular disease (CVD) has a high prevalence in the United States, yet 40-50% of those with that diagnosis have normal or mildly increased cholesterol levels. Increased C-reactive protein (CRP) has been associated with CVD, in those presenting after an acute coronary event, and also in apparently healthy individuals.

METHODS

We reviewed the literature on this association, and on the relationship between CRP and traditional CVD risk factors including smoking, hypertension, cholesterol and obesity. Also examined is the effect of various medications used in patients with CVD on CRP concentrations.

RESULTS

CRP correlates with risk of CVD in patients who have a history of acute coronary disease, stable angina, and in those who have never been diagnosed with CVD. CRP imparts risk that is independent of hyperlipidemia.

CONCLUSION

Once commercially available CRP assays are shown to be reliable, CRP may help predict short- and long-term cardiovascular outcomes and may have a role in CVD screening analogous to that of lipid. In the future CRP may modify treatment and preventive therapies.

Risk of myocardial infarction and angina in patients with severe peripheral vascular disease: predictive role of C-reactive protein

BACKGROUND

Patients undergoing revascularization procedures for peripheral vascular disease (PVD) have a greatly increased risk for coronary artery disease (CAD) that is predicted only partly by clinical data and cardiovascular risk factors. We investigated whether the prognostic assessment in PVD patients could be improved by preoperative measurements of C-reactive protein (CRP).

METHODS AND RESULTS

We assessed clinical and risk factors profiles, Eagle clinical scores, and preoperative CRP serum levels in 51 patients with PVD at Fontaine-Leriche stages II to IV without severe rest ventricular dysfunction or ischemia. During 24 months of follow-up, 17 patients (34%) had fatal (11) or nonfatal (6) myocardial infarction (MI). With univariate logistic regression analysis, only previous history of CAD, Eagle score, and CRP were independently related to MI. At multivariate logistic regression analysis, only CRP values in the upper tertile (<9 mg/L) were significantly associated with MI (P<0.05) and identified 65% of cases.

CONCLUSIONS

The high incidence of MI in patients with PVD severe enough to require revascularization is strongly predicted by preprocedural measurements of serum CRP, independent of previous CAD, Eagle score index, and traditional cardiovascular risk factors. These patients may benefit from therapy modulating the inflammatory response.

Increased circulating monocyte activation in patients with unstable coronary syndromes

OBJECTIVES

The primary objective of this research was to assess the activation level of circulating monocytes in patients with unstable angina.

BACKGROUND

Markers of systemic inflammatory responses are increased in patients with unstable coronary syndromes, but the activation state and invasive capacity of circulating monocytes have not been directly assessed.

METHODS

Peripheral blood mononuclear cell (MC) activation in blood samples isolated from patients with stable and unstable coronary artery disease was measured in two studies. In study 1, a modified Boyden chamber assay was used to assess spontaneous cellular migration rates. In study 2, optical analysis of MC membrane fluidity was correlated with soluble CD14 (sCD14), a cellular activation marker.

RESULTS

Increased rates of spontaneous monocyte migration (p < 0.01) were detected in patients with unstable angina (UA) (Canadian Cardiovascular Society [CCS] angina class IV) on comparison to patients with acute myocardial infarction (MI), stable angina (CCS angina classes I to III) or normal donors. No significant increase in lymphocyte migration was detected in any patient category. Baseline MC membrane fluidity measurements and sCD14 levels in patients with CCS class IV angina were significantly increased on comparison with MCs from normal volunteers (p < 0.001). A concomitant reduction in the MC response to activation was detected (p < 0.05).

CONCLUSIONS

Using two complementary assays, activated monocytes with increased invasive capacity were detected in the circulation of patients with unstable angina. This is the first demonstration of increased monocyte invasive potential in unstable patients, raising the issue that systemic inflammation may both reflect and potentially drive plaque instability.

Acute-phase proteins and Chlamydia pneumoniae infection: which one is more important in acute coronary syndrome?

Elevated levels of acute-phase proteins, a systemic marker for inflammation, predict coronary events; Chlamydia pneumoniae (C. pneumoniae) infection is associated with coronary atherosclerosis. The present study investigated whether inflammation or infection is involved in the pathogenesis of acute coronary syndrome (ACS) and which one has the more important role. The study group comprised 49 patients with angiographically diagnosed ACS, 48 cases of chronic coronary heart disease (CCHD), and 44 subjects with a normal coronary profile. The levels of serum C-reactive protein (CRP), fibrinogen and anti-C. pneumoniae IgG antibody were measured. The IgG antibody against C. pneumoniae was higher in the ACS and CCHD groups compared with the control group after adjusting for age and gender. The levels of CRP and fibrinogen were significantly increased in patients with ACS compared with controls and CCHD patients. Multiple stepwise logistic regression analysis revealed that C. pneumoniae IgG antibody is an independent risk factor for both ACS and CCHD (odds ratio 2.3 and 2.1, respectively), but the CRP level is a risk factor only for ACS (odds ratio 6.9). The inflammatory response, as indicated by acute-phase proteins, especially CRP, rather than C. pneumoniae infection, may contribute more to the clinical course of ACS.

Differences in inflammatory activity at the onset of acute myocardial infarction according to the clinical presentation of preinfarction angina

It is unknown whether the pathogenetic mechanisms underlying acute myocardial infarction (AMI) differ according to the clinical presentation of preinfarction angina, so the present study measured plasma levels of C-reactive protein (CRP) in 280 patients with AMI in whom serum creatine kinase levels were normal on admission and increased subsequently. Patients were classified into 3 groups according to the type of preinfarction angina: no angina (n=95), stable angina (n=48), and unstable angina (n= 137). Patients with unstable angina were subdivided according to the Braunwald classification: class IB (n=39), class IIB (n=22), and class RIB (n=76). There were no differences among the 5 groups in baseline characteristics. CRP on admission was significantly higher and the level of physical activity at symptom onset was significantly lower in the Braunwald class RIB group than in the other groups, but no differences were observed among the other groups. Patients with preinfarction Braunwald class IIB unstable angina had higher CRP levels on admission and symptom onset at a lower level of physical activity. In such patients, the pathogenetic mechanisms may differ from those in other subsets of patients with AMI and active inflammation may play a more important role in AMI onset.

Pre-infarction angina elicits greater myocardial viability on reperfusion after myocardial infarction: a dobutamine stress echocardiographic study

OBJECTIVES

We sought to evaluate myocardial viability (inotropic reserve) after myocardial infarction (MI) and its relationship with the presence of unstable pre-infarction angina (PIA).

BACKGROUND

Several studies have suggested that PIA can limit infarct size, but it is not known whether PIA can elicit myocardial viability after an acute MI, with left ventricular function improvement.

METHODS

Before discharge from the hospital, 91 patients with a reperfused MI (either fibrinolysis or primary coronary angioplasty) had low-dose dobutamine echocardiography performed to assess the myocardial inotropic reserve of the infarct-related area.

RESULTS

Twenty-nine patients (31.9%) had PIA in the 24-h period before the onset of MI. Nine patients were treated with primary coronary angioplasty: five (8.1%) in the group with PIA and four (13.8%) in the group without PIA. There were no other significant differences in the baseline characteristics of the patients. There were more viable segments in patients with PIA (44.9% vs. 30.7%, p = 0.007), and the number of patients with significant viability was higher in the PIA group (73.9% vs. 46.3%, p = 0.026). This occurred despite a similar number of segments with segmental wall abnormalities at baseline in both groups (46.1% vs. 46.9%, p = NS).

CONCLUSIONS

The presence of previous unstable PIA induces greater myocardial viability of the infarct-related area upon reperfusion and, as such, could have considerable therapeutic and clinical implications.

Enhanced response of blood monocytes to in vitro lipopolysaccharide-challenge in patients with recurrent unstable angina

BACKGROUND

C-reactive protein (CRP) plasma levels have been associated with short- and long-term occurrence of coronary events. We investigated whether circulating inflammatory cell responsiveness to low-grade stimuli could contribute to the reported association between CRP and coronary events.

METHODS AND RESULTS

We studied 32 patients with unstable angina who were followed for 24 months and were free of symptoms for 6 months (group 1): 19 patients had persistently high CRP levels (>0.3 mg/dL) (group 1A); 13 patients had normal CRP levels (group 1B). During the follow-up, 12 (63%) group 1A but no group 1B patients developed an infarction or recurrence of unstable angina (P<0.001). Eighteen patients with chronic stable angina (group 2) and 18 healthy subjects (group 3) were studied as controls. Interleukin (IL)-6 production (median, range) by peripheral blood mononuclear cells after 4 hours of in vitro stimulation with 1 ng/mL lipopolysaccharide (LPS) was significantly higher in group 1A (4526 pg/mL, 3042 to 10 583 pg/mL) than in group 1B (1752 pg/mL, 75 to 3981 pg/mL), group 2 (707 pg/mL, 41 to 3275 pg/mL), and group 3 (488 pg/mL, 92 to 3503 pg/mL) (all P<0.001). No significant differences were observed among the other groups. IL-6 production after LPS-challenge was correlated with baseline CRP levels (r=0.42, P=0.005).

CONCLUSIONS

Mononuclear cells of patients with recurrent phases of instability exhibit an enhanced production of IL-6 in response to low-dose of LPS, correlated with baseline CRP levels, 6 months after the last acute event. This persisting enhanced acute-phase responsiveness may help explain the association between CRP and acute coronary events.

C-Reactive Protein Concentrations and Angiographic Characteristics of Coronary Lesions

Background: C-Reactive protein (CRP) is a strong predictor of clinical outcome in coronary artery disease (CAD), and inflammation has been implicated in the process. We aimed to evaluate whether CRP concentrations measured with a new, automated particle-enhanced immunoturbidimetric method for high-sensitivity CRP may be related to specific high-risk angiographic features of coronary lesions.

Methods: In a cross-sectional study, we examined 103 consecutive patients undergoing cardiac catheterization for suspected CAD. We assessed the association of preprocedural CRP concentrations with clinical presentation (unstable angina) and angiographic features of coronary lesions.

Results: Twenty patients had unstable angina. Independent predictors of unstable angina included increased CRP [odds ratio (OR), 2.93 per 10-fold increase in CRP; 95% confidence interval (CI), 1.28–6.69; P = 0.01] and the presence of macroscopic thrombus (OR, 7.08; 95% CI, 1.33–37.8; P = 0.02). Thirty-two culprit lesions had macroscopic thrombus or eccentric/irregular discrete morphology without total occlusion. Increased CRP was the strongest predictor of such features (OR, 2.04 per 10-fold increase in CRP; 95% CI, 1.03–4.04; P = 0.04), and the effect was independent of the presence of unstable angina.

Conclusions: Among patients with suspected CAD undergoing coronary angiography, increased CRP is strongly associated with unstable angina and with specific high-risk features of the culprit coronary lesions.

Therapeutic relevance of altered cytokine expression

Cytokines and their receptors have numerous physiological functions. Altered concentrations of these mediators are associated with various afflictions. For example, over-expression of cytokines has been associated with altered drug concentrations and activity. Greater concentrations of cardiovascular drugs have been observed in humans and laboratory animals with various types of inflammatory disorders compared to healthy controls. Interestingly, the observed higher concentrations of drugs such as propranolol and verapamil have not been associated with increased effects. Indeed, reduced response to these cardiovascular drugs is observed, suggestive of cytokine-mediated downregulation of receptors. Increased cytokine concentrations have also been associated with decreased response to drugs used in treatment of other disorders such as AIDS, asthma and psychiatric diseases. This reduced response to drug in the presence of altered cytokine concentrations is especially relevant to the elderly population which has a greater incidence of multiple diseases and elevated concentrations of various cytokines compared to younger individuals. Furthermore, inflammatory conditions and their accompanied increased over-expression of cytokines are suggested to be the main determinants of therapeutic failure in myocardial infarction and angina. Therefore, altered cytokine concentrations may influence therapeutic outcomes of pharmacotherapy and result in treatment failure.

Role of cytokines in the pathogenesis of restenosis after percutaneous transluminal coronary angioplasty

BACKGROUND

Inflammatory cytokines play an important role in mediating inflammatory/proliferative responses including atherosclerosis. However, their role in the pathogenesis of restenosis after percutaneous transluminal coronary angioplasty (PTCA) remains to be clarified.

OBJECTIVE

To determine plasma levels of inflammatory cytokines as well as cytokine-generation capacities of monocytes before PTCA and after the follow-up period.

METHODS

Plasma levels of cytokines in 34 consecutive patients before and 3-6 months after PTCA were measured by enzyme-linked immunosorbent assay. We measured the plasma levels of macrophage-colony-stimulating factor (MCSF) and transforming growth factor-beta. Cytokine-generation capacities of monocytes were also measured by a whole-blood induction method with lipopolysaccharide. The levels of cytokines measured for assessment of the capacities included those of interleukin-1alpha, interleukin-1beta, interleukin-6, granulocyte-colony-stimulating factor, tumor necrosis factor-alpha and interferon-gamma.

RESULTS

Plasma levels of MCSF in patients without restenosis (n = 20) decreased significantly (from 1460+/-138 microg/ml before PTCA to 1039+/-125 microg/ml after the follow-up period, P < 0.01), whereas those in patients with restenosis (n = 14) increased significantly (from 1107+/-105 microg/ml before PTCA to 1039+/-125 microg/ml after the follow-up period, P < 0.05). We noted a positive correlation between the increase in plasma levels of MCSF and the extent of loss of lumen by restenosis. Cytokine-generation capacities of monocytes for interleukin-1alpha and interleukin-1beta of patients with restenosis significantly increased but those of patients without restenosis did not. Furthermore, plasma levels of C-reactive protein decreased significantly only in patients without restenosis after the follow-up period.

CONCLUSIONS

These results suggest that inflammatory changes mediated by cytokines may be involved in the pathogenesis of restenosis after PTCA.

On the wide spectrum of abnormalities in the coronary arteries of Whipple's disease

BACKGROUND

There is growing interest in the role of microbes in the pathogenesis of coronary atherosclerosis but most of the evidence has been seroepidemiologic. It would be useful to know more about the cytology and histology of coronary lesions containing clearly depicted microbes.

OBJECTIVE

To define carefully the assorted abnormalities apparent in the coronary arteries of individuals dying with Whipple's disease.

METHODS

Myocardial tissue from 12 cases of Whipple's disease was studied by light microscopy. Slides were stained routinely (in sequence) with either the periodic-acid-Schiff (PAS) or Goldner-trichrome method and some with Gomori methenimine silver. Cardiac slides with PAS-positive bacilli were compared to lesions in jejunal lamina propria.

RESULTS

There were abundant sites of coronary arterial damage associated with presence of Whipple bacilli, more in the tunica media than in intima and adventitia. Bacilli in the arterial lesions were identical to those in lamina propria. Medial lesions were often associated with a fibroproliferative 'atheroma'. Both intracellular and extracellular bacilli were found. Most lesions were devoid of inflammation, but some sites exhibited either florid arteritis or dense scarring. Arteries that were scarred or inflamed exhibited only a few bacilli. There was an apparent affinity of bacilli for the nuclei in medial smooth muscle cells and in nearby ventricular myocytes. Apoptosis (TUNEL-positive) was present in medial smooth muscle cells, endothelial cells, and ventricular myocytes.

CONCLUSIONS

There is a wide spectrum of coronary abnormalities in Whipple's disease. It would be useful to know how often the Whipple bacillus is a part of the total pathogen burden in coronary disease.

Low-density lipoprotein apheresis in the treatment of atherosclerosis and other potential uses

This review concerns the clinical impact of low-density lipoprotein (LDL) apheresis for patients with refractory hypercholesterolemia. We examine and provide examples of investigations that have demonstrated the clinical benefits of LDL apheresis. In addition to benefits derived from the stabilization or regression of arterial lesions, we highlight other possible mechanisms related to clinical improvement. We also discuss the potential advantages of lipid apheresis for the treatment of patient populations other than those characterized by severe hypercholesterolemia and premature coronary heart disease.

Cardiovascular disease, interleukin-6, and risk of mortality in older women: the women's health and aging study

BACKGROUND

Systemic chronic inflammation has been found to be related to all-cause mortality risk in older persons. We investigated whether specific chronic conditions, particularly cardiovascular disease (CVD), affect the association between high interleukin (IL)-6 level and mortality in a sample of disabled older women.

METHODS AND RESULTS

IL-6 serum level was measured at baseline in 620 women >/=65 years old. The presence and severity of medical conditions was ascertained by standard criteria that used multiple sources of information. The sample was surveyed over the 3-year follow-up. After adjustment for potential confounders, compared with those in the lowest tertile, women in the highest IL-6 tertile were at higher risk of all-cause mortality. The presence of CVD, however, strongly affected the risk of mortality associated with high IL-6. Among women with prevalent CVD, those with high IL-6 levels had >4-fold risk of death (RR 4.6; 95% CI 2.0 to 10.5) compared with women in the lowest tertile, whereas the relative risk associated with high IL-6 among those without CVD was much lower and not significant (RR 1.8; 95% CI 0.7 to 4.2). Adjustment for all chronic diseases and disease severity measures, including ankle-brachial index, forced expiratory volume, and exercise tolerance, did not change the results.

CONCLUSIONS

IL-6 level is helpful in identifying a subgroup of older CVD patients with high risk of death over a period of 3 years. Systemic inflammation, as measured by IL-6, may be related to the clinical evolution of older patients with CVD.

Relationship between myocardial damage and C-reactive protein levels immediately after onset of acute myocardial infarction

The present study investigated the relationship between myocardial damage and C-reactive protein (CRP) levels, with no increase in creatine kinase (CK) activity, immediately after the onset of acute myocardial infarction (AMI) in 85 patients with their first reperfused anterior AMI without CK elevation on admission and no ischemic events during hospitalization. Patients were classified into those with low levels (<0.3 mg/dl) of CRP (Group L; n=67) and those with high levels (> or =0.3 mg/dl) of CRP (Group H; n=18). Group H had a higher proportion of patients with a history of preinfarction angina (89 vs 55%, p<0.01), especially unstable angina. SigmaST in leads V1-6 on admission ECG was lower in Group H than in Group L (14+/-7 vs 21+/-13 mm, p<0.05). Predischarge left ventriculography showed that the left ventricular global ejection fraction (55+/-11 vs 48+/-10%, p<0.01) and SD/chord at the left anterior descending artery lesion (-1.7+/-0.9 vs -2.3+/-0.9, p<0.01) were better in Group H. Multivariate analysis demonstrated that both CRP on admission (p=0.011) and preinfarction angina (p=0.002) were independently associated with better regional wall motion (SD/chord >-2.0) before discharge. These results suggest that the clinical situation of elevated CRP immediately after onset is associated with less myocardial damage and better left ventricular function in reperfused anterior AMI.

Amyloid precursors and amyloidosis in inflammatory arthritis

Recent data demonstrating the multifunctional role of serum amyloid A (SAA) in the pathogenesis of amyloidosis have yielded important insights into this potentially fatal consequence of chronic inflammation. SAA has been shown to participate in chemotaxis, cellular adhesion, cytokine production, and metalloproteinase secretion and is thus integrally involved in the disease process. In addition to its production by the liver as part of the acute phase response, SAA is also expressed by several pathologic tissues such atherosclerotic plaques, rheumatoid synovitis and in the brains of patients with Alzheimer disease. Its constitutive production in normal tissue suggests a role for SAA in host defense and tissue turnover. Many pathways are involved in the regulation of SAA, and as more becomes known about these, potential therapeutic targets may be identified. However, the prevention of secondary amyloidosis is best achieved by early and adequate treatment of patients with chronic inflammatory disorders. Suppression of the acute phase response and normalization of SAA levels are likely to significantly impact on the incidence of amyloidosis in inflammatory arthritis.