Elevated plasma lipoprotein(a) is associated with coronary artery disease in patients with chronic stable angina pectoris

Relationship Between Lipoprotein(a) and Angiographic Severity of Femoropopliteal Lesions

AIM

High levels of lipoprotein(a) [Lp(a)] are a risk factor for peripheral artery disease (PAD). However, the relationship between Lp(a) levels and the severity of femoropopliteal lesions in patients with PAD has not been systematically studied. This study aimed to assess the impact of Lp(a) levels on angiographic severity of femoropopliteal lesions in patients with PAD.

METHODS

We retrospectively analyzed a single-center database including 108 patients who underwent endovascular therapy for de novo femoropopliteal lesions and measured the Lp(a) levels before therapy between June 2016 and September 2019. Patients were divided into low Lp(a) [Lp(a) ＜30 mg/dL; 77 patients] and high Lp(a) [Lp(a) ≥ 30 mg/dL; 31 patients] groups. Trans-Atlantic Inter-Society Consensus (TASC) II classification, calcification [referring to the peripheral arterial calcium scoring system (PACSS) classification], and lesion length were compared between the groups.

RESULTS

The prevalence of TASC II class D (13% vs 38%, P＜0.01) and severe calcification (PACSS 4) (6% vs 23%, P=0.02) was significantly higher and the lesion length longer (123±88 mm vs 175±102 mm, P＜0.01) in the high Lp(a) group than in the low Lp(a) group. In multivariate analysis, Lp(a) ≥ 30 was an independent predictor for the prevalence of TASC II class D (HR=3.67, 95% CI 1.27-10.6, P=0.02) and PACSS 4 (HR=4.97, 95% CI 1.27-19.4, P=0.02).

CONCLUSION

The prevalence of TASC II class D and severe calcification of femoropopliteal lesions was higher in patients with high Lp(a) than those with low Lp(a).

Elevated Lipoprotein A in South Asians and the Associated Risk of Cardiovascular Disease: A Systematic Review

BACKGROUND

South Asians have a premature risk of cardiovascular disease and increased lipoprotein A which enhances their risk.

METHODS

This systematic review evaluates the role of elevated lipoprotein A in cardiovascular disease risk for South Asians. It discusses the pathophysiology, clinical studies, and treatment of elevated lipoprotein A using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method.

RESULTS

A total of 72 articles was incorporated which consisted of clinical studies, case-control and cohort studies, meta-analysis, reviews, and editorials. Cardiovascular disease and myocardial infarction occurs prematurely in South Asians, which is further enhanced with an elevated lipoprotein A.

CONCLUSIONS

South Asians with an elevated lipoprotein A have an increased risk of coronary artery disease so they should have early enactment of lifestyle modification and aggressive medical management.

Lipoprotein(a) Is Associated with the Presence and Severity of New-Onset Coronary Artery Disease in Postmenopausal Women

Background: Lipid disorder was one of the major risk factors for coronary artery disease (CAD), especially in postmenopausal women, whose lipid profile significantly changed during the transition period to menopause. The aim of the present study was to examine whether plasma lipoprotein(a) [Lp(a)] was a biomarker for predicting the presence and severity of CAD in postmenopausal women. Methods: A total of 783 postmenopausal women who had their first angina-like chest pain were enrolled and classified into two groups according to the results of coronary angiography: CAD group (n = 309) and age-matched non-CAD group (n = 309). Patients with CAD were further divided into the three groups based on Gensini score (GS). The relationships of plasma Lp(a) levels to the presence and severity of CAD were evaluated, and the predictive value of Lp(a) for CAD was also examined. Results: CAD group had higher Lp(a) levels when compared to non-CAD ones (p < 0.001). The multivariate logistic regression analysis suggested that Lp(a) was an independent predictor for the presence of CAD (p < 0.001). Plasma levels of Lp(a) were significantly related to GS (p < 0.001). In addition, plasma Lp(a) level was significantly elevated according to the tertiles of GS (p = 0.001) and was independently associated with high GS (p < 0.001). In receiver-operating characteristic analysis for predicting the presence of CAD in postmenopausal women, Lp(a) was found to have the area under the curve of 0.703, with an optimal cutoff value of 255.69 mg/L. Conclusions: Lp(a) is an independent risk factor for predicting the presence and the severity of new-onset CAD in postmenopausal women, suggesting that Lp(a) may be a lipid target for prevention and treatment in such patients.

Lipoprotein(a) and apolipoprotein(a) isoform size: Associations with angiographic extent and severity of coronary artery disease, and carotid artery plaque

BACKGROUND AND AIMS

Lipoprotein(a) [Lp(a)] is an emerging genetic risk factor for cardiovascular disease (CVD). We examined whether plasma Lp(a) concentration and apolipoprotein(a) [apo(a)] isoform size are associated with extent and severity of coronary artery disease (CAD), and the presence of carotid artery plaque.

METHODS

We included in our study male participants (n = 263) from a cohort with angiographically defined premature CAD (Carotid Ultrasound in Patients with Ischemic Heart Disease). The angiographic extent and severity of CAD were determined by the modified Gensini and Coronary Artery Stenosis≥20% (CAGE) scores. Carotid artery plaque was assessed by bilateral carotid B-mode ultrasound. Apo(a) isoform size was determined by LPA Kringle IV-2 copy number (KIV-2 CN).

RESULTS

Lp(a) concentration, but not KIV-2 CN, was positively associated with the Gensini score. The association remained significant following adjustment for conventional CVD risk factors (all p < 0.05). Lp(a) concentration and elevated Lp(a) [≥50 mg/dL] were positively associated with the CAGE≥20 score, independent of conventional CVD risk factors. KIV-2 C N Q1 (lowest KIV-2 CN quartile) was associated with CAGE≥20 score and KIV-2 CN, with the CAGE≥20 score in those without diabetes. In multivariate models that included phenotypic familial hypercholesterolemia or low-density lipoprotein cholesterol, Lp(a) concentration, but not KIV-2 CN, was independently associated with the Gensini and CAGE≥20 scores. No significant associations between Lp(a) concentration and KIV-2 CN with carotid artery plaque were observed.

CONCLUSIONS

Lp(a) concentration, but not apo(a) isoform size, is independently associated with angiographic extent and severity of CAD. Neither Lp(a) nor apo(a) isoform size is associated with carotid artery plaque.

Low-density lipoprotein 4: a novel predictor of coronary artery disease severity

BACKGROUND

Hyperlipidemia is a well established risk factor for coronary artery disease (CAD). Severe CAD has been observed in patients with normal levels of total and low-density lipoprotein (LDL) cholesterol. Small dense LDL particle subtypes (LDL₃ and LDL₄) have been observed to be more oxidizable and atherogenic. We aimed to identify the role of cholesterol particle subtypes in predicting CAD severity.

METHODS

Blood samples were obtained immediately before cardiac catheterization in 179 consecutive patients with suspected CAD. Detailed lipid profiling was performed using a VAP cholesterol test. CAD severity was categorized angiographically as no/minor CAD (<20% luminal diameter stenosis [LDS]), moderate CAD (20% to 74% LDS) and severe CAD (>75% LDS of any major coronary vessel).

RESULTS

Patients with severe CAD had significantly higher LDL₄ and triglycerides, and lower total HDL, HDL₂, HDL₃, LDL₂ and LDL₃ compared to patients with no/minor CAD (p < .05 for all). Multivariate analysis showed high LDL₄ as an independent predictive of severe CAD. ROC analysis showed an area under the curve of 0.62 (p < .0001) with a cut-point of >16.9 mg/dL to predict severe CAD with a sensitivity of 53% and specificity of 79%.

CONCLUSION

Elevated LDL₄ levels are associated with severe CAD. Further large-scale investigations are required to evaluate the utility of LDL₄ in predicting CAD severity.

Impact of Lipoprotein(a) on Long-term Outcomes in Patients With Diabetes Mellitus Who Underwent Percutaneous Coronary Intervention

Patients with diabetes mellitus (DM) are at twofold to fourfold higher cardiovascular risk than those without DM. Serum levels of lipoprotein(a) (Lp(a)) can be risk factors for adverse events. However, the clinical implications of Lp(a) in patients with DM who underwent percutaneous coronary intervention (PCI) is unknown. The aim of the study was to determine the role of Lp(a) in patients with DM who underwent PCI. A total of 3,508 patients were treated by PCI from 1997 to 2011 at our institution. Among them, we analyzed consecutive 1,546 patients with DM. Eligible 1,136 patients were divided into 2 groups (high Lp(a) [n = 575] and low Lp(a) [n = 561]) by the median of Lp(a) levels. The number of chronic kidney disease, multivessel disease, and the level of LDL-C were higher in the group with high Lp(a) than with low Lp(a). The median follow-up period was 4.7 years. Event rate of all-cause death was same between the 2 groups (p = 0.37). However, cumulative incidence of cardiac death and acute coronary syndrome was significantly higher in the high Lp(a) than in the low Lp(a) group (p = 0.03). Multivariable analysis selected a high Lp(a) level as an independent predictor of cardiac death and acute coronary syndrome (hazard ratio 1.20; 95% confidence interval 1.00 to 1.42; p = 0.04). In conclusion, a high Lp(a) value could be associated with advanced cardiac events after PCI for patients with DM.

Lipoprotein(a) and lipid profiles of patients awaiting coronary artery bypass graft; a cross sectional study

Background

Lipoprotein(a) (Lp(a)) excess is an independent risk factor of coronary artery disease (CAD) and have shown wide ethnic variations. Further, lipid parameters used in the assessment and management of risk factors for CAD may not reflect accurately the disease or severity if the patients are on pharmacological interventions when compared to Lp(a). Lp(a) levels of Sri Lankan CAD patients awaiting coronary artery bypass graft are not documented.

Methods

A cross sectional study was carried out with patients (n = 102) awaiting coronary artery bypass graft at a tertiary healthcare institution in Sri Lanka. Lp(a) was determined by immunoturbidimetric method (Konelab 20XT) and information on risk factors collected using a standardized questionnaire. The severity of CAD was determined by Gensini score. Lipid parameters and pharmacological treatment data were obtained from the Medical Records. Data were analysed using independent sample t-test, Pearson and Spearman tests respectively.

Results

Total cholesterol (TC), LDL cholesterol (LDLc) and HDL cholesterol (HDLc) of the total study sample (average ± SD) were, 150 ± 36 mg/dL, 92 ± 36 mg/dL and 34 ± 9 mg/dL respectively with no significant difference irrespective of being on pharmacological treatment or not. All lipid parameters were significantly high (p < 0.05) in females. The average Lp(a) was 50 ± 38 (SD) mg/dL with no significant difference in males or females independent of being on treatment (50 ± 39 mg/dL) or not (49 ± 39 mg/dL) and above the cut off value (30 mg/dL).

Conclusions

Despite pharmacological interventions 27 % of the study population had high LDLc and majority low HDLc. Mean Lp(a) was in excess irrespective of risk factors or being on treatment or not and is confirmed as an independent, potential marker for assessing the susceptibility for CAD especially in those with other intermediate risk factors but considered non-hyperlipidemic by conventional methods.

Lipoprotein (a) is related to coronary atherosclerotic burden and a vulnerable plaque phenotype in angiographically obstructive coronary artery disease

BACKGROUND

Lipoprotein Lp(a) has been shown to be an independent risk factor for coronary artery disease (CAD). However, its association with CAD burden in patients with ACS is largely unknown, as well as the association of Lp(a) with lipid rich plaques prone to rupture.

AIM

We aim at assessing CAD burden by coronary angiography and plaque features including thin cap fibroatheroma (TCFA) by optical coherence tomography (OCT) in consecutive patients presenting with acute coronary syndrome (ACS) and obstructive CAD along with serum Lp(a) levels.

METHODS

This study comprises an angiographic and an OCT cohort. A total of 500 ACS patients (370 men, average age 66 ± 11) were enrolled for the angiographic cohort and 51 ACS patients (29 males, average age 65 ± 11) were enrolled for the OCT cohort. Angiographic CAD severity was assessed by Sullivan score and by Bogaty score including stenosis score and extent index. OCT plaque features were evaluated at the site of the minimal lumen area and along the culprit segment.

RESULTS

In the angiographic cohort, at multivariate analysis, Lp(a) was a weak independent predictor of Sullivan score (p < 0.0001), stenosis score (p < 0.0001) and extent index (p < 0.0001). In the OCT cohort, patients with higher Lp(a) levels (≥ 30 md/dl) compared to patients with lower Lp(a) levels (<30 md/dl) exhibited a higher prevalence of lipidic plaque at the site of the culprit stenosis (67% vs. 27%; P = 0.02), a wider lipid arc (135 ± 114 vs 59 ± 111; P = 0.03) and a higher prevalence of TCFA (38% vs. 10%; P = 0.04).

CONCLUSIONS

Among patients with ACS, raised Lp(a) levels are associated with an increased atherosclerotic burden and it identifies a subset of patients with features of high risk coronary atherosclerosis.

[Lipoprotein(a): influence on cardiovascular manifestation]

The clinical relevance of lipoprotein(a) (Lp(a)) as a cardiovascular risk factor is currently underestimated. The aim of our study was to assess the influence of increased Lp(a) values on the development and severity of coronary artery disease (CAD).In our retrospective analysis of 31,274 patients, who were hospitalized for the first time, we compared patients with isolated increased Lp(a) (> 110 mg/dl) and normal Lp(a) (< 30 mg/dl), with increased Lp(a) concentrations (30-60 mg/dl, 61-90 mg/dl, 91-110 mg/dl), and in a third analysis with additionally increased LDL cholesterol and HbA1c values.Patients with high Lp(a) levels showed a significantly higher incidence of advanced CAD with a three-vessel disease being present in 50.2 vs. 25.1 %. Patients with high Lp(a) levels had a significantly more frequent history of myocardial infarction (34.6 vs. 16.6 %, p < 0.001), surgical myocardial revascularization (40.8 vs. 20.8 %, p < 0.001) and percutaneous coronary intervention (55.3 vs. 33.6 %, p < 0.001). In addition, there was a marked difference in gender to the disadvantage of male patients regarding development and severity of CAD. CAD risk (Odds ratio) was increased 5.5-fold in patients with Lp(a) ≥ 110 mg/dl. Additionally elevated LDL and HbA1c levels were not associated with increased manifestation and severity of CAD.High Lp(a) concentration leads to an increased manifestation and severity of coronary artery disease. Additional risk factors do not aggravate manifestation of CAD.

Plasma lipoprotein(a) predicts major cardiovascular events in patients with chronic kidney disease who undergo percutaneous coronary intervention

BACKGROUND

Chronic kidney disease (CKD) is associated with increased risk for cardiovascular disease. The predictive power of traditional risk factors for cardiovascular disease is diminished in patients with CKD. The serum level of lipoprotein(a) [Lp(a)] can be a risk factor for adverse events, but the clinical implications of Lp(a) in patients with CKD who have been treated by percutaneous coronary intervention (PCI) remain uncertain. We aimed to determine the role of Lp(a) on long-term outcomes in patients with CKD after PCI.

METHODS

We analyzed data from 904 patients with CKD among 3508 patients who underwent a first PCI between 1997 and 2011 at our institution. We divided patients into 2 groups [high (n=454) or low (n=450)] according to median levels of Lp(a). The primary outcome was a composite of all-cause death and acute coronary syndrome (ACS).

RESULTS

The baseline characteristics of the groups were similar and the median follow-up period was 4.7 years. Cumulative event-free survival was significantly worse for the group with high, than low Lp(a) (P=0.01). Multivariable analysis indicated a high Lp(a) level as an independent predictor of primary outcomes (hazard ratio, 1.35; 95% CI, 1.01-1.82; P=0.04).

CONCLUSIONS

A high Lp(a) value is associated with a poor prognosis after PCI for patients with CKD.

Lipoprotein (a) Levels in Relation to Severity of Coronary Artery Disease in North Indian Patients

BACKGROUND

Lipoprotein (a) [Lp (a)] is an established risk marker of coronary artery disease which is independent from other risk factors.

OBJECTIVE

The aim was to address the association between Lp (a) and CAD risk in North Indians. To evaluate whether high levels of lipoprotein (a) [Lp (a)] is a predictor of risk and is related to the severity of CAD.

MATERIALS AND METHODS

This was a cross-sectional study done on 360 patients presenting with chest pain. Coronary angiography revealed CAD in 270 patients and 90 patients without CAD. Lipoprotein (a) level, lipid profile, fasting blood glucose, anthropometric and clinical parameters were analyzed.

RESULTS

Lipoprotein (a) 21.0 mg/dL is associated with the presence of coronary lesions (P = 0.0001). A highly significant difference in Lp (a) levels was observed between normal coronaries vs. single-vessel disease, double-and triple-vessel disease ( P < 0.0001). Body mass index (BMI) was significantly raised in CAD group compared to normal coronary.

CONCLUSION

Multivariate analysis found that Lp (a) was considered an independent predictor for severity of CAD and Lp (a) levels 21.0 mg/dL are associated with severe patterns of coronary atherosclerosis.

Lipoprotein(a) in cardiovascular diseases

Lipoprotein(a) (Lp(a)) is an LDL-like molecule consisting of an apolipoprotein B-100 (apo(B-100)) particle attached by a disulphide bridge to apo(a). Many observations have pointed out that Lp(a) levels may be a risk factor for cardiovascular diseases. Lp(a) inhibits the activation of transforming growth factor (TGF) and contributes to the growth of arterial atherosclerotic lesions by promoting the proliferation of vascular smooth muscle cells and the migration of smooth muscle cells to endothelial cells. Moreover Lp(a) inhibits plasminogen binding to the surfaces of endothelial cells and decreases the activity of fibrin-dependent tissue-type plasminogen activator. Lp(a) may act as a proinflammatory mediator that augments the lesion formation in atherosclerotic plaques. Elevated serum Lp(a) is an independent predictor of coronary artery disease and myocardial infarction. Furthermore, Lp(a) levels should be a marker of restenosis after percutaneous transluminal coronary angioplasty, saphenous vein bypass graft atherosclerosis, and accelerated coronary atherosclerosis of cardiac transplantation. Finally, the possibility that Lp(a) may be a risk factor for ischemic stroke has been assessed in several studies. Recent findings suggest that Lp(a)-lowering therapy might be beneficial in patients with high Lp(a) levels. A future therapeutic approach could include apheresis in high-risk patients in order to reduce major coronary events.

Interactions of lipoprotein(a) with diabetes mellitus, apolipoprotein B and cholesterol enhance the prognostic values for coronary artery disease

BACKGROUND

Synergistic interactions between elevated serum lipoprotein(a) [Lp(a)] and other unfavorable risk factors have been proposed to cause very high risk for coronary artery disease (CAD). The aim of this study was to examine the potential interactions between Lp(a) and other risk factors.

METHODS

The profiles of serum (apo)(lipo)proteins, markers of inflammation, indicators of hemoconcentration as well as classical risk factors were determined in 264 clinically stable angiographically documented subjects. Correlation, linear and logistic regression and stratification analyses were performed.

RESULTS

The frequency and severity of CAD and the prevalence of diabetes mellitus were significantly higher in the 3rd relative to 1st tertile of Lp(a). Subjects with Lp(a) levels in the upper tertile had significantly higher levels of serum glucose, total cholesterol and low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (apoB), calcium, phosphate and their ion product. Bivariate correlation analysis indicated that serum Lp(a) was associated positively with the occurrence and severity of CAD, diabetes mellitus and the levels of serum glucose, cholesterol, LDL-C, apoB, calcium, phosphate and inversely to physical inactivity. In linear regression analysis, LDL-C (or apoB), diabetes, physical inactivity and phosphate were the major independent determinants of Lp(a) values. In multiple logistic regression analysis, after adjusting for major risk factors, Lp(a) showed a significant and independent association with the prevalence of CAD. By constructing dummy combined variables, elevated Lp(a) accompanied with diabetes or high levels of serum glucose, apoB and cholesterol exhibited an amplified high risk for CAD.

CONCLUSIONS

The results indicate that serum Lp(a) does interact multiplicatively with diabetes, apoB and cholesterol. The simultaneous assessment of Lp(a) and interactive risk factors enhances the discriminating value for CAD.

Relation between lipoprotein(a) and fibrinogen and serial intravascular ultrasound plaque progression in left main coronary arteries

OBJECTIVES

Patients with elevated lipoprotein(a) [Lp(a)] and fibrinogen levels have an increased risk of coronary heart disease and adverse cardiovascular events. There is evidence that coronary plaque progression is linked to a higher risk for future cardiovascular events.

BACKGROUND

There are no data demonstrating a relation between Lp(a), fibrinogen, and directly measured coronary plaque progression over time.

METHODS

We performed a retrospective analysis of serial intravascular ultrasound (IVUS) studies of 60 left main stems (18 +/- 9 months apart) to evaluate plaque progression in relation to Lp(a) and fibrinogen levels and association with adverse cardiovascular events.

RESULTS

There was a positive correlation between Lp(a) (r = 0.58; p < 0.0001), fibrinogen (r = 0.48; p < 0.0001), and changes in plaque-plus-media area. Patients with plaque progression (n = 41) had higher Lp(a) (30 +/- 26 mg/dl vs. 14 +/- 9 mg/dl; p < 0.0012) and fibrinogen (295 +/- 88 mg/dl vs. 240 +/- 72 mg/dl; p = 0.019) levels than patients with plaque regression (n = 19). Multivariate linear regression analysis showed Log Lp(a) (regression coefficient = 9.45; p = 0.0008) but not fibrinogen to be independently associated with plaque progression. A total of 19 patients suffered from adverse cardiovascular events; they had higher Lp(a) (44 +/- 30 mg/dl vs. 16 +/- 12 mg/dl; p < 0.0001) and fibrinogen (342 +/- 73 mg/dl vs. 248 +/- 76 mg/dl; p < 0.0001) levels. Multivariate logistic regression analysis showed Log Lp(a) (odds ratio 10.20, 95% confidence interval 2.36 to 44.13; p = 0.0019) and fibrinogen (odds ratio 1.01, 95% confidence interval 1.00 to 1.03; p = 0.018) were independently associated with adverse cardiovascular events.

CONCLUSIONS

Serial IVUS showed a positive correlation between Lp(a) and fibrinogen levels and plaque progression. Lp(a), but not fibrinogen, remains independently associated with plaque progression. In addition, the present data suggest a considerable incremental value of Lp(a) in predicting cardiovascular risk.

Predictors of coronary artery disease in the Lebanese population

BACKGROUND

Coronary artery disease (CAD) is one of the major causes of morbidity and mortality in the world. The disease is determined by many risk factors such as age, gender, diabetes, dyslipidemia, smoking, as well as elevated serum levels of lipoprotein (a) (Lp(a)), homocysteine, C-reactive protein (CRP) and uric acid. In this study, we evaluated the association of biologic and metabolic parameters with CAD in a group of Lebanese patients.

METHODS

Three hundred patients were recruited for the study. Biologic and blood metabolic parameters were measured. Patients were then divided into 3 groups according to their catheterization result: 0% stenosis (controls), <50% stenosis and >or=50% stenosis.

RESULTS

Hyperlipidemias, CRP, homocysteine and uric acid levels in CAD patients were not different from those of the controls. However, age, elevated fasting blood glucose (FBG) and elevated serum Lp(a) levels were found to be strong independent predictors of CAD in our study population. Association with CAD was also shown for gender, hypertension, diabetes and family history of CAD.

CONCLUSION

We report the importance of serum Lp(a) levels and FBG in the prediction and prevention of CAD in our population.

Independent predictors of the severity of angiographic coronary atherosclerosis: the lack of association between impaired glucose tolerance and stenosis severity

Independent predictors of the severity of coronary atherosclerosis are ill defined. We sought to determine the predictors and examine the association of impaired glucose tolerance with stenosis severity. Four hundred thirty-seven patients were studied who underwent coronary angiography for suspected coronary artery disease. Serum concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDLc), lipoprotein(a) [Lp(a)] and apolipoproteins (Apo A-I and Apo B) were measured and low-density lipoprotein cholesterol (LDLc) concentration was calculated. Except the patients treated for diabetes mellitus (DM), patients were classified into three groups such as normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and DM by glucose tolerance test. Coronary atherosclerosis index (CAI) representing the severity of coronary atherosclerosis was determined by summation of the stenosis score of all lesions on coronary angiograms. Results indicated that age, total amount of cigarettes smoked, Apo B/Apo A-I, and LDLc/HDLc correlated with CAI, whereas HDLc and Apo A-I concentrations inversely correlated with CAI. TC, TG, Lp(a), LDLc, Apo B concentrations and body mass index did not correlate with CAI. One- and two-hour plasma glucose concentrations and the area of plasma glucose concentration under the curve at the glucose tolerance test did not correlate with CAI, revealing that post-challenge glycemia is not associated with stenosis severity. CAI in IGT patients was significantly lower than that in DM patients but did not differ from that in NGT patients, indicating that IGT does not affect the stenosis severity. Multivariate analysis showed that age, male gender, Apo B/Apo A-I, DM, systemic hypertension, and total amount of cigarettes smoked were independent predictors of CAI.

Association Between Plasma Lipoprotein(a) Concentration and Restenosis After Stent Implantation

BACKGROUND

The plasma concentration of lipoprotein (a) [Lp(a)] is associated with atherosclerotic and thrombotic vascular diseases. The aim of the present study was to evaluate the association between plasma Lp(a) concentration and in-stent restenosis.

METHODS AND RESULTS

One hundred and 9 patients with successful elective coronary stent implantation underwent follow-up angiography at 24+/-6 weeks. Restenosis after stent implantation occurred in 38 patients. Univariate analysis showed that the reference diameter of the lesion was smaller in the restenosis group (2.93+/-0.29 mm) than in the no-restenosis group (3.21+/-0.43 mm) (p < 0.05). The lesion was longer in the restenosis group (14.2+/-5.3 mm) than in the no-restenosis group (11.6+/-4.9 mm) (p < 0.05). Plasma Lp(a) concentrations in the restenosis group (30.5+/-23.9 mg/dl) were higher than in the no-restenosis group (16.9+/-11.1 mg/dl) (p < 0.01). Other lipid concentrations were similar in both groups. Among the plasma Lp(a) concentrations, the rate of restenosis (71.4%) in the high Lp(a) group (> 40 mg/dl) (n = 14) was greater compared with the other groups: 33.3% in the intermediate Lp(a) group (10-40 mg/dl) (n = 54), and 24.4% in the low Lp(a) group (< 10 mg/dl) (n = 41) (p < 0.01). The late loss (0.57+/-0.53 mm) in the low Lp(a) group was significantly less than the other groups: 0.88+/-0.47 mm in the intermediate Lp(a) group, and 1.08+/-0.56 mm in the high Lp(a) group (p < 0.05). In a multivariate regression model, plasma Lp(a) concentration remained significant as an independent predictor of restenosis in patients undergoing stent implantation (p = 0.020 odds ratio (OR) 1.37 95%conficence interval (CI) 1.050-1.793), although the reference diameter (p = 0.025 OR 0.23 95%CI 0.061-0.830) and lesion length (p = 0.021 OR 1.12 95%CI 1.017-1.232) were related to stent restenosis.

CONCLUSIONS

Plasma Lp(a) concentration is an independent predictor of stent restenosis.

Lack of association between lipoprotein(a) and coronary artery calcification in the Genetic Epidemiology Network of Arteriopathy (GENOA) study

OBJECTIVE

To investigate the relationship between lipoprotein(a) [Lp(a)] levels and the extent of coronary atherosclerosis in a cohort that consisted predominantly of hypertensive patients.

PATIENTS AND METHODS

Patients were ascertained through sibships that contained at least 2 individuals with essential hypertension diagnosed before the age of 60 years. The 10-year coronary heart disease (CHD) risk was estimated on the basis of the Framingham risk equation. Serum Lp(a) was measured by an immunoturbidimetric assay. Coronary artery calcification (CAC) was measured noninvasively by electron beam computed tomography and CAC score calculated using the Agatston score.

RESULTS

Patients included 765 non-Hispanic, white individuals (59% women) participating in the Genetic Epidemiology Network of Arteriopathy study. The mean +/- SD age of the patients was 62 +/- 8 years, and 77% had hypertension. The prevalence of detectable CAC was 87% in men and 60% in women. The CAC scores did not differ significantly across quintiles of Lp(a) levels in either men or women. In a multiple regression model that included conventional risk factors, Lp(a) levels were not related to CAC quantity in either sex. No significant interactions were noted between Lp(a) levels and the conventional risk factors in the prediction of CAC quantity. When stratified on the basis of the 10-year CHD risk, 26.5% of the patients were low risk (< 6%), 60.5% were intermediate risk (6%-20%), and 12.9% were high risk (> 20%). Lipoprotein(a) was not associated with CAC quantity within subgroups based on 10-year CHD risk.

CONCLUSION

In this cohort enriched with hypertensive patients, the estimated 10-year CHD risk did not appear to modify the lack of an association between Lp(a) levels and CAC.

Plasma lipoprotein Lp(a), markers of haemostasis and inflammation, and risk and severity of coronary heart disease

BACKGROUND

Elevated plasma (Lp(a)) levels may represent an independent risk factor for atherothrombotic complications but the relation between Lp(a) levels and the extent of coronary artery disease (CHD) has been discussed controversially. Little is known about potential atherothrombogenic mechanisms of Lp(a).

DESIGN

Case-control study.

METHODS

We assessed the relationship between plasma Lp(a) and angiographically defined CHD, evaluating the severity of coronary atherosclerosis by three different scores. A total of 312 patients with stable angina aged 40-68 years with at least one coronary stenosis > 50% were studied. A group of 479 voluntary blood donors matched for age and sex served as controls. A complete lipid profile and a large number of markers of coagulation, fibrinolysis and inflammation were measured.

RESULTS

Plasma levels of Lp(a) were significantly higher in patients (14.8 mg/dl; 5.4-47.1 mg/dl; median/interquartile range) than in controls (9.7 mg/dl; 3.5-25.3) (P<0.0001). In a logistic regression model, the fully adjusted Odds Ratio for CHD was 3.3 (95% confidence interval (CI) 1.8-5.6, P<0.0001) for patients in the upper quartile of the Lp(a) distribution compared to the bottom quartile. There was no appreciable association between Lp(a) and apolipoproteins, markers of haemostasis, fibrinolysis and inflammation and the severity of CHD.

CONCLUSIONS

These results indicate that elevated plasma Lp(a) levels may be an independent risk factor for CHD but unrelated to the severity and extension of CHD. Furthermore, there is no good evidence that the presumed link between Lp(a) and CHD is mediated by increased levels of markers of inflammation, or interference with markers of fibrinolysis or coagulation.

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.

Electrophoretic measurement of lipoprotein(a) cholesterol in plasma with and without ultracentrifugation: comparison with an immunoturbidimetric lipoprotein(a) method

OBJECTIVES

Elevated plasma lipoprotein(a) [Lp(a)] is a significant risk factor for vascular disease. Standardization of Lp(a) mass measurement is complicated by the heterogeneity of apolipoprotein(a) [apo(a)]. We investigated whether Lp(a) cholesterol measurement, which is not influenced by apo(a) size, is a viable alternative to measuring Lp(a) mass.

DESIGN AND METHODS

Plasma Lp(a) cholesterol was measured electrophoretically, with and without ultracentrifugation, and results were compared to each other and to immunoturbidimetrically measured Lp(a) mass in 470 subjects.

RESULTS

Ultracentrifuged and whole plasma Lp(a) cholesterol levels demonstrated high correlation (R = 0.964). All samples with detectable (>/=2.0 mg/dl) Lp(a) cholesterol had Lp(a) mass >30 mg/dl (the clinically relevant cutpoint), while 59 samples with Lp(a) mass >30 mg/dl did not have detectable Lp(a) cholesterol.

CONCLUSIONS

Lp(a) cholesterol can be measured in whole plasma without interference from VLDL lipoproteins. The relative clinical merits of measuring Lp(a) cholesterol vs. Lp(a) mass or both in combination deserves investigation.

Pregnancy-Associated Plasma Protein A and Its Endogenous Inhibitor, the Proform of Eosinophil Major Basic Protein (proMBP), Are Related to Complex Stenosis Morphology in Patients With Stable Angina Pectoris

Background— The metalloproteinase pregnancy-associated plasma protein-A (PAPP-A) has been implicated in coronary plaque disruption. Its endogenous inhibitor, the proform of eosinophil major basic protein (proMBP), may also play a role in this process. Atheromatous plaque disruption often presents as complex angiographic lesions. We sought to assess whether PAPP-A, proMBP, and PAPP-A/ProMBP ratio are markers of angiographic plaque complexity in patients with chronic stable angina.

Methods and Results— We studied 396 stable angina patients (age 63±10 years, 230 men) of whom 289 had angiographically documented coronary artery disease (≥75% stenosis). All coronary stenoses ≥30% diameter reduction (n =531 in 322 patients) were assessed and classified as complex (n =228) or smooth (n =303) by previously validated criteria. PAPP-A, proMBP, and C-reactive protein (hs-CRP) serum levels were measured by ELISA. Patients with complex coronary stenoses had a significantly ( P <0.001) higher PAPP-A/proMBP ratio (3.1±1.2 versus 2.7±0.8×10 −3 ) and PAPP-A levels (5.9±1.6 versus 5.1±1.4 mIU/L) than those without. On univariate analysis, male gender ( P <0.001), age ( P <0.001), previous history of myocardial infarction ( P =0.013), reduced ejection fraction ( P <0.001), severe coronary artery disease ( P <0.001), aspirin treatment ( P <0.001), PAPP-A levels ( P <0.001), and PAPP-A/proMBP ratio ( P <0.001) were correlated with the number of complex stenoses. Multiple regression analysis showed that male gender, age, severe coronary artery disease, and PAPP-A/proMBP ratio were independent predictors of the number of angiographically complex stenoses.

Conclusions— In patients with stable angina, PAPP-A and PAPP-A/proMBP ratio are associated with angiographic plaque complexity.

The pre-existence of an acute coronary event predicts differences in biological parameters and clinical evolution among patients with longstanding stable angina

BACKGROUND

To date, patients displaying stable angina with or without a previous acute coronary event have been grouped together and are offered nowadays, similar clinical approach. However, from clinical experience, increasing doubt exists whether they behave clinically in the same way. In the current study, we investigated whether differences might exist in the clinical, angiographic and biological parameters between these two distinct clinical presentations.

METHODS

The cardiovascular risk factor profile, clinical evolution, angiographic data, white blood cell (WBC) count and plasma concentrations of lipids and fibrinogen were compared between two groups of patients with longstanding stable angina. The first group consisted of 160 subjects who had undergone myocardial infarction (MI) as the first manifestation of coronary artery disease (CAD) and had no further coronary event. The second group was composed of 226 subjects who had effort-induced angina but never experienced an acute coronary event. The mean period between the first CAD manifestation and entry into the study was 7+/-6 years for MI group and 7+/-4 years for patients with uneventful angina.

RESULTS

MI patients displayed 8% higher WBC count (P=0.038), 20% higher fibrinogen (P=0.001), 12% lower HDL cholesterol (P=0.02), 8% lower apoA1 (P=0.005) and 46% higher lipoprotein (a) (P=0.005) than patients who presented an uneventful clinical course. Upon multivariate logistic regression analysis, fibrinogen (OR=1.14; 95% CI=1.08-1.28; P=0.033), lipoprotein (a) (OR=1.19; 95% CI=1.05-1.34; P=0.0036) and HDL cholesterol levels (OR=0.97; 95% CI=0.94-0.99; P=0.0095) remained independently associated with the pre-existence of MI. Patients with prior MI evolved more frequently towards clinically refractory angina (P=0.04). In addition, fibrinogen levels were independently associated with evolution to clinically refractory angina (OR=1.03; 95% CI=1.005-1.550; P=0.0448).

CONCLUSIONS

Stable CAD patients with a prior MI differ from those who display an uneventful effort-induced angina in their biological profile and their evolution towards clinically refractory angina.

Predictors of adverse long-term outcome in acute myocardial infarction patients undergoing primary percutaneous transluminal coronary angioplasty: with special reference to the admission concentration of lipoprotein (a)

The predictive values for long-term outcome in 127 consecutive patients with acute myocardial infarction (AMI) after successful primary percutaneous transluminal coronary angioplasty (PTCA) were prospectively investigated in the present study. The primary endpoint was a composite of cardiac death, nonfatal AMI, and recurrent angina. Follow-up angiography was performed in 120 patients to assess restenosis. The primary endpoint occurred in 21 patients during a follow-up period of 35+/-24 months. These patients had a higher lipoprotein(a) [Lp(a)] concentration (p=0.0105) and more prevalence of multivessel disease (p=0.0028) than the other patients. The subjects were divided into 2 groups at the 75th percentile Lp(a) value: group A had an Lp(a) concentration >or=47 mg/dl and group B <47 mg/dl. Kaplan-Meier analysis showed a lower cardiac event-free survival rate in group A (p=0.0007) and in patients with multivessel disease (p=0.001). In Cox proportional hazards regression analysis, an Lp(a) level >or=47 mg/dl (relative risk[RR] 5.5, 95% confidence interval [CI] 2.0-15.0, p=0.0007) and multivessel disease (RR 5.3, 95% CI 2.0-13.7, p=0.0006) were independent predictors of the primary endpoint. An elevated Lp(a) concentration on admission and multivessel disease are significant predictors for long-term adverse outcome in AMI patients treated by primary PTCA.

The association of lower testosterone level with coronary artery disease in postmenopausal women

OBJECTIVE

Testosterone (T) is assumed to be a risk factor for coronary artery disease (CAD). However, recent studies have demonstrated a beneficial effect of T on myocardial ischaemia in men with CAD. To assess the potential role of T in CAD in postmenopausal women we investigated the association between T level and CAD and relationship between T and other CAD metabolic risk factors.

RESULTS

Within the 12-month study period, 108 consecutive, postmenopausal women (age 62+/-7 years) referred for diagnostic coronary angiography were prospectively included in the study. In all patients serum level of T, sex hormone-binding globulin (SHBG), total cholesterol (T-chol), LDL-chol, HDL-chol, triglycerides (TG), apolipoproteins A(1) and B (apo A(1), apo B), lipoprotein a [Lp(a)], and C reactive protein were measured. Testosterone free index (TFI) was calculated as Tx100/SHBG. CAD was documented in 51 (47%) patients (CAD+). Women with CAD had decreased T level and lower TFI (T: 0.99+/-0.4 vs. 1.41+/-0.7 nmol/l, P=0.005; TFI: 3.2+/-1.4 vs. 4.2+/-2.2, P=0.04, CAD+ vs. CAD-, respectively). No difference in SHBG was found between the two groups. In 16 women (six CAD+, 10 CAD-) who were on hormonal replacement therapy (HRT+) we observed significantly elevated T level and TFI (T: 1.62+/-0.5 vs. 1.15+/-0.7 nmol/l; TFI: 5.0+/-2.2 vs. 3.5+/-1.8, HRT+ vs. HRT-, respectively, P<0.05). When these women were excluded from the analysis, T level remained decreased in CAD+ group (0.96+/-0.4 vs. 1.22+/-0.5 nmol/l, CAD+ vs. CAD- respectively, P<0.02). CAD+ group had an unfavourable profile of metabolic CAD risk factors as evidenced by elevated T-chol, LDL-chol, Lp(a), apoB, and decreased apoA(1) (P<0.05 vs. CAD- in all comparisons). Neither T nor TFI correlated with CAD metabolic risk factors (r<0.2, P>0.1 for all correlations), apart from an inverse correlation between T and Lp(a) (r=-0.24, P=0.04).

CONCLUSION

In postmenopausal women decreased T level is associated with CAD independently of the other CAD metabolic risk factors. Hormonal replacement therapy tends to increase T level which may further support the beneficial role of HRT in postmenopausal women.

Serum lipids, lipoprotein(a) level, and apolipoprotein(a) isoforms as prognostic markers in patients with coronary heart disease

OBJECTIVE

Our objective was to study prognostic factors for death in patients with coronary heart disease (CHD), focusing on serum lipids and lipoproteins.

DESIGN AND SUBJECTS

The study subjects were 964 patients with angina pectoris who underwent coronary angiography between 1985 and 1987. Follow-up, including survival and cause of death, was carried out in April 1998.

RESULTS

A total of 363 patients died. Increasing age, diabetes and low levels of HDL cholesterol and of apolipoprotein (apo) AI were associated with increased risk of total mortality and cardiac mortality. In men, low levels of LDL cholesterol and of apoB were associated with increased risk of death, but not of cardiac death only; high levels of lipoprotein(a) [Lp(a)] were not associated with increased risk. In women, however, there was a trend towards increased risk with increasing Lp(a) levels (P = 0.054); the smallest isoform of apo(a) was associated with a twofold increase in risk. In women, but not in men, risk decreased with increasing molecular weight of the apo(a) isoforms.

CONCLUSIONS

Amongst lipoprotein variables, low levels of HDL cholesterol and of apoAI and the presence of low-molecular weight isoforms of apo(a) are associated with increased risk of death in patients with CHD. Apo(a) isoforms and Lp(a) levels seem to be more important as risk factors amongst women. Low LDL cholesterol and apoB levels were associated with increased risk, but only in men. These findings demonstrate the importance of a gender-specific analysis of risk factors for CHD.

[Inflammation and infection in stable coronary disease and acute coronary syndrome]

OBJECTIVE

To study whether inflammation and infection are related to coronary artery disease.

DESIGN

Sixty patients (44 males, mean age 62 +/- 13 years) with acute coronary syndrome and 40 with stable coronary artery disease (31 males, age 64 +/- 10 years) and a control group of 40 individuals (34 males, 53 +/- 5 years) were analyzed. IgG against Chlamydia pneumoniae, Cytomegalovirus and Helicobacter pylori plus C-reactive protein were assessed in all serum samples. In addition, IgM against C. pneumoniae and Cytomegalovirus on admission and C-reactive protein one month later were measured in acute patients.

RESULTS

No IgM seropositivity was observed. A high prevalence of IgG seropositivity with no significant differences among the groups was found: C. pneumoniae: acute group 44 (73%), stable group 29 (73%) and control group 25 (63%); Cytomegalovirus: 55 (92%), 37 (92%) and 38 (95%), respectively; and H. pylori, 43 (72%), 32 (80%) and 34 (85%) respectively. There was a high rate of positive C-reactive protein in the acute group: 48 (80%) vs 10 (25%) the stable group and 0% the control group (p < 0.001). C-reactive protein levels were higher in Q-wave infarction than in unstable angina/ non-Q-wave infarction (median 22.65 vs 7.69, p < 0.001). One month later, C-reactive protein levels decreased (median 22.65 vs 3.38, p < 0.001), but were still positive in 40%.

CONCLUSIONS

These data suggest that inflammation is detected by the commonly used methods in clinic practice in acute coronary syndromes and to a lesser extent in stable coronary artery disease. It seems that different mechanisms other than infection account for this inflammatory response, at least this being so when infection is assessed by serology. Serology does not appear to be an adequate method to determine the possible relationship among coronary syndromes, infection and inflammation.

Lipoprotein(a) changes during natural menstrual cycle and ovarian stimulation with recombinant and highly purified urinary FSH

This prospective, randomized, controlled study compared the effects of recombinant human FSH (r-hFSH) and highly purified urinary FSH (u-hFSH HP) on lipoprotein(a) [Lp(a)] concentrations in women undergoing ovarian stimulation. Fifty infertile women were randomly allocated into two equally sized treatment groups (n = 25 per group). Thirty normal ovulation women were recruited as controls. The infertile women received u-hFSH or r-hFSH 150 IU/day starting on cycle day 2. From cycle day 6 the dose was adjusted according to ovarian response. Human chorionic gonadotrophin 10,000 IU was administered once there was at least one follicle > or =18 mm in diameter. The luteal phase was supported with progesterone 50 mg/day for at least 15 days. Repeated measurements of Lp(a) concentrations were performed during both stimulated and natural cycles. A significant increase in luteal phase Lp(a) concentrations was detected in the stimulated cycles, whereas no significant changes in serum Lp(a) concentrations were observed during natural cycles. There were no significant differences between the urinary and recombinant FSH effects on serum Lp(a). The luteal Lp(a) increase was transitory because after 1 month Lp(a) concentrations returned to baseline values if pregnancy failed to occur; in pregnant women persistent increased Lp(a) concentrations were found at the 8th week. The percentage changes in serum Lp(a) were positively correlated with the luteal progesterone increase (r = 0.40, P < 0.05), but not with follicular or luteal oestradiol increase. The women with low baseline Lp(a) (< or =5 mg/dl) had a greater increase of the Lp(a) concentrations at midluteal phase than women with baseline Lp(a) >5 mg/dl. In conclusion, the recombinant or urinary hFSH administration does not directly influence Lp(a) concentrations. The luteal Lp(a) increase in stimulated cycles is not related to gonadotrophin treatment per se, but appears to be related to the high luteal progesterone concentrations, physiologically or pharmacologically determined. Our results also suggest that the sensitivity to the progesterone changes could be related to apolipoprotein(a) phenotype.

Risk factors that discriminate 'high- risk' from 'low-risk' Japanese patients with coronary artery disease

Although various risk factors have been implicated in the progression of coronary artery disease (CAD), coronary risk factors specifically related to the long-term prognosis for high-risk CAD have not been determined. The study enrolled 311 consecutive Japanese patients with CAD who underwent diagnostic coronary arteriography and divided them into 2 groups: (i) 135 high-risk patients with either impaired left ventricular function (ejection fraction <50%) or multivessel disease and (ii) 176 low-risk patients with normal left ventricular function and 0- or 1-vessel disease. The prevalence of risk factors including age, gender, smoking, hypertension, diabetes mellitus (DM), obesity and lipid variables were compared between the 2 groups. The prevalence of DM, a serum high-density lipoprotein (HDL)-cholesterol level below 35 mg/dl and a serum lipoprotein (Lp) (a) level above 25 mg/dl was significantly higher in the high-risk group as compared with the low-risk group. Multiple logistic regression analysis demonstrated that DM (odds ratio (OR): 1.72, 95% confidence intervals (CI): 1.02-2.92, p<0.05), a low HDL-cholesterol level (OR: 2.49, 95% CI: 1.49-4.17, p<0.001) and a high Lp(a) level (OR: 1.68, 95% CI: 1.02-2.76, p<0.05) were all independent risk factors for high-risk CAD. However, if the patients with 0-vessel disease were excluded from the low-risk group, a low HDL-cholesterol level was found to be the only independent predictor for high-risk CAD (OR: 2.07, 95% CI: 1.15-3.70, p<0.05). Among both men and smokers in this population, a higher Lp(a) level was found to be a significant predictor for high-risk CAD. A low serum level of HDL-cholesterol, a high serum level of Lp(a) and DM were significant predictors of high-risk in patients with CAD. Among patients with a significant coronary stenosis or left ventricular dysfunction, a low serum level of HDL-cholesterol was the only significant predictor for high-risk CAD.

Hyperinsulinemia, lipoprotein (a), and Chlamydia pneumoniae antibodies--are they risk factors or serologic predictors for progression of coronary artery disease?

The authors studied 134 patients with unstable angina pectoris symptoms and 32 subjects without coronary artery disease (CAD) for the presence of classical risk factors such as hypercholesterolemia, smoking, and family history of CAD. In addition they analyzed plasma insulin levels, lipoprotein (a) (Lp [a]) levels, and antibody titers against Chlamydia pneumoniae. All patients had a heart catheterization. Patients with diabetes mellitus were excluded from the study. Fasting insulin, low-density lipoprotein (LDL) cholesterol and Chlamydia pneumoniae immunoglobulin G (IgG) and IgA antibody titers did not show any difference in CAD from healthy control subjects, whereas Lp(a) was increased and high-density lipoprotein (HDL) decreased in CAD patients. These data indicate that lipoprotein (a), low HDL cholesterol, and smoking, but neither hyperinsulinemia nor elevated Chlamydia pneumoniae titers, are risk factors or predictors for CAD.

[Lipoprotein (a) as a predictor of severity of coronary artery stenosis documented by angiography in male coronary patients under 50 years old]

OBJECTIVE

To determine the relationship between lipoprotein (a) seric levels with the age of coronary artery disease debut and the severity of coronary lesions in a group of male patients less than 50 years old.

PATIENTS AND METHODS

We studied a group of 230 male patients, younger than 50 who were consecutively admitted to the hospital because of an ischemic coronary event. During hospitalization, the lipoprotein (a) in plasma was measured in all patients. They were distributed in two groups according to age at time of coronary disease clinical presentation with a cut off age of 40. A group of 142 patients underwent a cardiac catheterism and coronariography due to clinical or electrical unstability.

RESULTS

The lipoprotein (a) levels were related with the number of diseased vessels. In this way lipoprotein (a) levels were 12 mg/dl (1.5-75) in those patients showing a normal coronariography; 27 mg/dl (2. 5-96) in those with one vessel disease; 34 mg/dl (7-90) in those with two vessels affected and 63 mg/dl (2-116) in the case of three-vessel disease, with statistical significance of p = 0.003. No significant differences in lipoprotein (a) levels were found when the age of coronary artery disease presentation was taken into account. In this way lipoprotein (a) levels were 31 mg/dl (2-97) in patients younger than 40 years of age, in comparison to 33 mg/dl (2-94) in those older than 40.

CONCLUSIONS

In our community male patients with a diagnosis of coronary artery disease and less than 50 years old showed a relationship between lipoprotein (a) levels and the severity and number of coronary vessel diseases. However, an association between lipoprotein (a) levels with the age of coronary disease presentation was not evident.

Lipoprotein(a) is a risk factor for occurrence of acute myocardial infarction in patients with coronary vasospasm

OBJECTIVES

The purpose of this study is to determine whether lipoprotein(a) (Lp[a]) is an independent risk factor for coronary spasm and occurrence of acute myocardial infarction (AMI) in patients with coronary spasm.

BACKGROUND

Although elevated serum Lp(a) levels are known to be associated with coronary atherosclerosis and AMI, the association between the elevated level of this lipoprotein and coronary spasm remains to be elucidated.

METHODS

Serum Lp(a) levels were measured using a latex immunoassay in 77 patients with coronary spasm but without a significant (>75%) fixed coronary stenosis, including 16 with prior myocardial infarction (MI), in 177 patients with a fixed stenosis but without rest angina, including 114 with prior MI and in 81 control subjects without coronary artery disease.

RESULTS

The serum Lp(a) level in patients with coronary spasm (median; 17 mg/dl) was higher (p < 0.01) than in control subjects (12 mg/dl) but lower (p < 0.01) than in patients with a fixed stenosis (23 mg/dl). The incidence of subjects with higher (>25 mg/dl) serum Lp(a) levels was higher in patients with a fixed stenosis (46%, p < 0.01) but not in patients with coronary spasm (27%), compared with control subjects (21%). Among the patients with coronary spasm, the incidence of higher Lp(a) levels was higher in patients with than in those without a history of prior MI (56% vs. 21%, p < 0.05). The patients with higher Lp(a) levels had a higher incidence of prior MI than those without (41% vs. 13%, p < 0.05). The multivariate analysis confirmed that higher serum Lp(a) level is an independent determinant for prior MI in these patients (odds ratio, 4.19; 95%, confidence interval, 1.03 to 17.00).

CONCLUSIONS

Elevated serum level of Lp(a) was found to be associated with a history of prior MI in patients with coronary spasm, suggesting that Lp(a) may play an important role in the genesis of thrombotic coronary occlusion and the occurrence of AMI subsequent to coronary spasm.

Serum neopterin and complex stenosis morphology in patients with unstable angina

OBJECTIVES

We sought to assess the relation between serum neopterin concentration and complex coronary artery stenosis in patients with unstable angina.

BACKGROUND

Monocyte activation is associated with acute atheromatous plaque disruption and acute coronary syndromes. Angiographically demonstrated complex coronary stenosis is often an expression of plaque disruption. Increased serum concentration of neopterin, a pterydine derivative secreted by macrophages after stimulation by interferon-gamma, has been observed in patients with acute coronary syndromes as compared with control subjects and patients with stable angina pectoris.

METHODS

We studied 50 patients with unstable angina (32 men) who underwent coronary angiography after hospital admission. All coronary stenoses with > or =30% diameter reduction were assessed and classified as "complex" (irregular or scalloped borders, ulceration or filling defects suggesting thrombi) or "smooth" (absence of complex features). Serum neopterin levels were assessed within 24 h of hospital admission using a commercially available immunoassay (enzyme-linked immunosorbent assay kit, IBL, Hamburg, Germany).

RESULTS

Thirty-nine patients were classified in Braunwald class IIIb, four in class IIb and seven in class Ib. The number of complex lesions per patient was 2.6+/-1.8 (mean +/- SD). The mean neopterin concentration was 7.76+/-3.62 nmol/liter. A significant correlation was observed between neopterin serum concentration and the presence of complex coronary stenoses (r = 0.35, p = 0.015). Multiple regression analysis showed that serum neopterin (p < 0.0001) was independently associated with the number of complex lesions. Other variables associated with complex lesions were the number of vessels with > or =75% stenosis (p < 0.0001), plasma creatinine (p = 0.003), triglycerides (p = 0.014) and a history of unstable angina (p = 0.032).

CONCLUSIONS

Serum neopterin concentration is associated with the presence of angiographically demonstrated complex lesions in patients with unstable angina and may represent a marker of coronary disease activity.

Lack of association of lipoprotein(a) levels with coronary calcium deposits in asymptomatic postmenopausal women

OBJECTIVES

This study sought to determine the relationship of lipoprotein(a) (Lp(a)) and other cardiac risk factors to coronary atherosclerosis as measured by calcification of coronary arteries in asymptomatic postmenopausal women.

BACKGROUND

Lipoprotein(a) is considered a risk factor for coronary heart disease. Coronary calcium deposition is believed to be a useful noninvasive marker of coronary atherosclerosis in women. However, to our knowledge, there are no reports of the relationship of Lp(a) to coronary calcium in postmenopausal women.

METHODS

In 178 asymptomatic postmenopausal women (64 +/- 8 years), we measured Lp(a) and other cardiac risk factors: age, hypertension, diabetes, low-density lipoprotein cholesterol, smoking status, body mass index, physical activity level and duration of hormone replacement therapy. Electron-beam computed tomography was done to measure coronary calcium (calcium score). We analyzed the relationship between calcium score and cardiac risk factors using multivariate analysis.

RESULTS

Although calcium score correlated with traditional risk factors of age, diabetes, hypertension and smoking, it did not correlate with Lp(a) in the asymptomatic postmenopausal women. Similar multivariate analyses were done in the subjects age >60 years and in the subjects with significant coronary calcium deposit (calcium score > or =50). These analyses also have failed to show an association of levels of Lp(a) with coronary calcium deposits.

CONCLUSIONS

We conclude that in asymptomatic postmenopausal women, Lp(a) levels do not correlate with coronary atherosclerosis as measured by coronary calcium deposits.

Lipoprotein(a) is a potential coronary risk factor

Lipoprotein(a) (Lp(a)) is recognized as a new coronary risk factor, but few studies have quantitatively assessed the relationship of serum Lp(a) levels with other coronary risk factors in many patients undergoing coronary cineangiography. Seventeen coronary risk factors were quantified (i.e., age, gender, hypertension, impaired glucose tolerance, cerebrovascular accident, hyperuricemia, smoking, family history of ischemic heart disease (IHD), history of hyperlipidemia, Lp(a), total cholesterol, high density lipoprotein (HDL)-cholesterol, triglyceride, low density lipoprotein-cholesterol, apolipoproteins(apo)A-I,B, E) to determine their relationship with the numbers of involved coronary vessels using multiple regression test in 1,006 patients who underwent coronary cineangiogram (280 non-IHD patients: 144 men, 136 women; 726 IHD patients: 460 men, 266 women; age 16-84 years, mean 60.5+/-0.3). Multiple regression test indicated R = 0.506 and items that showed high beta weight and significant p level were age, Lp(a), impaired glucose tolerance, total cholesterol, cerebrovascular accidents, HDL-cholesterol, smoking, gender, family history of IHD, and apo-A-I (0.221, p<0.001; 0.174, p<0.001; 0.616, p<0.001; 0.138, p<0.001; 0.122, p<0.001; -0.12, p<0.001; 0.092, p<0.01; 0.091, p<0.01; 0.067, p<0.05; -0.065, p<0.05; respectively). It was concluded that Lp(a) is an independent, potential, and modifiable coronary risk factor, and that reduction of serum Lp(a) is important in the clinical management of patients with IHD.

[Ischemic cardiopathy: inflammation markers and the cardiovascular risk]

In recent years it has been established that inflammation is a key mechanism in the pathogenesis of atherosclerosis and in coronary artery disease progression. Inflammation is a host response to a wide variety of tissue injuries. A persistent or continually repeated insult will lead to chronic inflammation which may result in tissue destruction and/or loss of normal organ function. Atherosclerosis and other pathologies involving inflammation are associated with increased levels of cytokines, which in turn raise acute-phase proteins levels in blood (acute inflammation markers, i.e. fibrinogen and C-reactive protein). It has been shown recently that concentrations of these proteins are higher in individuals at increased risk of developing cardiac events in the years to come. This is true both in apparently healthy men and women and in ischaemic heart disease patients. CRP is currently the inflammatory marker which appears to have captured the investigators' attention around the globe. In this report we review the current data on the relationship between atherosclerosis and inflammation, with special attention to cytokines and acute phase reactants. The use of acute phase reactants as prognostic risk markers in ischaemic heart disease is also discussed.

International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Standardization Project for the Measurement of Lipoprotein(a). Phase 2: selection and properties of a proposed secondary reference material for lipoprotein(a)

The International Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Standardization of Lipoprotein(a) Assays has initiated a project to select a secondary reference material for lipoprotein(a) that can standardize the measurement of this lipoprotein. Most of the analytical problems with lipoprotein(a) assays are due to apolipoprotein(a) kringle 4 type 2 reactive antibodies and values being expressed in mg/l mass units rather than as nmol/l of apolipoprotein(a) particles. In Phase 2, four manufactured materials were compared for analytical performance, commutability properties and method harmonization in 27 lipoprotein(a) test systems. Results of precision and linearity testing were comparable for all materials whereas testing for the harmonization effect resulted in an among-assay coefficient of variation for corrected lipoprotein(a) values of between 11% and 22%. The material that gave maximum harmonization achieved a variation of < 8% for 18 immunonephelometric and immunoturbidimetric assay systems. It can be hypothesized that this residual variation in part takes into account the inaccuracy of lipoprotein(a) measurement due to apolipoprotein(a) size polymorphism. On the basis of acceptable analytical performance, maximal harmonization effect and documented stability, a lyophilized material has been selected as the common calibrator for lipoprotein(a) to be used in a value transfer procedure by diagnostic companies.

A randomised comparison of the effects of oral versus transdermal 17beta-oestradiol, each combined with sequential oral norethisterone acetate, on serum lipoprotein levels

OBJECTIVE

To investigate the effects of oral versus transdermal 17beta-oestradiol, given in both cases with sequential addition of oral norethisterone acetate, on serum lipid and lipoprotein levels in postmenopausal women.

DESIGN

Open, randomised, parallel groups study.

SETTING

University Clinical Research Group.

POPULATION

Sixty-four postmenopausal women with climacteric complaints who were otherwise healthy were screened. Of these, 58 fulfilled the entry criteria.

METHODS

Fifty-eight postmenopausal women were randomised to receive either oral 17beta-oestradiol/oestriol (Trisequens) or transdermal 17beta-oestradiol (Estrapak) together with cyclical addition of norethisterone acetate for 48 weeks.

MAIN OUTCOME MEASURES

Serum levels of total cholesterol, triglycerides, high density lipoproteins (HDL), low density lipoproteins (LDL), very low density lipoproteins (VLDL), apolipoproteins, and lipoprotein(a) at baseline, and after 46 weeks (oestrogen-alone phase), and 48 weeks (oestrogen-progestogen phase) of treatment.

RESULTS

Oral oestradiol therapy did not affect serum total cholesterol levels during the oestrogen-alone phase, but during the combined phase there was a 5% fall (P < 0.05) due to a 7% decrease in LDL cholesterol levels (P < 0.01). Oral therapy also increased serum triglyceride levels by 9.4% during the oestrogen-alone phase (P < 0.05). During the combined phase of transdermal therapy, there was a 19% fall in serum triglyceride levels (P < 0.05) and a 6% fall in HDL levels (P < 0.05). Oral oestradiol reduced lipoprotein(a) levels by 31% during the oestrogen-alone phase and by 37% with norethisterone acetate addition (P < 0.05). Transdermal therapy had no significant effect on lipoprotein(a).

CONCLUSIONS

Other than a minor fall in HDL3 in women receiving transdermal 17beta-oestradiol, coadministration of oral progestogen in general improved, rather than worsened, this serum lipoprotein profile.

Increased expression of the CD11b/CD18 antigen on the surface of peripheral white blood cells in patients with ischemic heart disease: further evidence for smoldering inflammation in patients with atherosclerosis

BACKGROUND

This study examined the availability of the CD11b/CD18 and CD62L antigens on the surface of peripheral blood leukocytes in patients with ischemic heart disease.

METHODS AND RESULTS

The study population included 45 patients with angiographically documented ischemic heart disease admitted to our department of internal medicine and the cardiology department during 1 month (December 1997). Sixty-six healthy members of the hospital medical staff served as control subjects. Another 39 post-trauma patients who were admitted to the emergency room were also evaluated. Patients with ischemic heart disease had significantly (P <.002) higher concentrations of CD11b/CD18 antigen on the surface of their polymorphonuclear leukocytes and monocytes (mean fluorescence intensity of 203 +/- 81 and 261 +/- 75, respectively) compared with the control group (mean fluorescence intensity 158 +/- 68 and 211 +/- 74, respectively) and to the group of patients with acute stress (mean fluorescence intensity of 146 +/- 70 and 200 +/- 22, respectively).

CONCLUSIONS

The presence of increased concentration of CD11b/CD18 suggests that circulating leukocytes are activated in patients with ischemic heart disease. This activation probably reflects the presence of an inflammatory response involving the atherosclerotic lesion and is not merely a result of acute stress.