Plasma lipoprotein(a) is not a predictor for restenosis after elective high-pressure coronary stenting

Impact of high lipoprotein(a) levels on in-stent restenosis and long-term clinical outcomes of angina pectoris patients undergoing percutaneous coronary intervention with drug-eluting stents in Asian population

Lipoprotein(a) (Lp(a)) is known to be associated with cardiovascular complications and atherothrombotic properties in general populations. However, it has not been examined whether Lp(a) levels are able to predict adverse cardiovascular outcomes in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES). A total of 595 consecutive patients with angina pectoris who underwent elective PCI with DES were enrolled from 2004 to 2010. The patients were divided into two groups according to the levels of Lp(a): Lp(a) < 50 mg/dL (n = 485 patients), and Lp(a) ≥ 50 mg/dL (n = 111 patients). The 6-9-month angiographic outcomes and 3-year cumulative major clinical outcomes were compared between the two groups. Binary restenosis occurred in 26 of 133 lesions (19.8%) in the high Lp(a) group and 43 of 550 lesions (7.9%) in the low Lp(a) group (P = 0.001). In multivariate analysis, the reference vessel diameter, low density lipoprotein cholesterol, total lesion length, and Lp(a) ≥ 50 mg/dL were predictors of binary restenosis. In the Cox proportional hazards regression analysis, Lp(a) > 50 mg/dL was significantly associated with the 3-year adverse clinical outcomes including any myocardial infarction, revascularization (target lesion revascularization (TLR) and target vessel revascularization (TVR)), TLR-major adverse cardiac events (MACEs), TVR-MACE, and All-MACEs. In our study, high Lp(a) level ≥ 50 mg/dL in angina pectoris patients undergoing elective PCI with DES was significantly associated with binary restenosis and 3-year adverse clinical outcomes in an Asian population.

Lipoprotein(a), interleukin-10, C-reactive protein, and 8-year outcome after percutaneous coronary intervention

BACKGROUND

This prospective study investigated the association between preprocedural biomarker levels and incident major adverse cardiac events (MACE) in complex patients undergoing percutaneous coronary intervention (PCI) with sirolimus-eluting stenting.

HYPOTHESIS

Lipoprotein(a) (Lp[a]), interleukin-10 (IL-10), and high-sensitivity C-reactive protein (CRP) have long-term prognostic value in patients undergoing PCI.

METHODS

Between April 2002 and February 2003, 161 patients were included in the study. Blood was drawn before the procedure, and biomarkers were measured. Patients were followed-up for MACE (death, nonfatal myocardial infarction, and repeat revascularization). Cox proportional hazard models were used to determine risk of MACE for tertiles of biomarkers. Both 1-year and long-term follow-up (median, 6 years; maximum, 8 years) were evaluated.

RESULTS

Mean age was 59 years, and 68% were men. During long-term follow-up, 72 MACE occurred (overall crude cumulative incidence: 45% [95% confidence interval (CI): 37%-52%]). Lp(a) was associated with a higher 1-year risk of MACE, with an adjusted hazard ratio (HR) of 3.1 (95% CI: 1.1-8.6) for the highest vs the lowest tertile. This association weakened and lost significance with long-term follow-up. IL-10 showed a tendency toward an association with MACE. The 1-year HR was 2.1 (95% CI: 0.92-5.0). Long-term follow-up rendered a similar result. The association of CRP with MACE did not reach statistical significance at 1-year follow-up. However, CRP was associated with long-term risk of MACE, with an HR of 1.9 (95% CI: 1.0-3.5).

CONCLUSIONS

In this prospective study, preprocedural Lp(a) level was associated with short-term prognosis after PCI. The preprocedural CRP level was associated with long-term prognosis after PCI.

High Lipoprotein(a) Levels are Associated With Long-Term Adverse Outcomes in Acute Myocardial Infarction Patients in High Killip Classes

Background and Objectives

An elevated concentration of lipoprotein(a) {Lp(a)} is associated with an increased prevalence and increased severity of coronary artery disease. However, the relationship between Lp(a) levels and outcomes after acute myocardial infarction (AMI) is unclear.

Subjects and Methods

Between October 2005 and June 2007, we measured serum Lp(a) levels in 832 consecutive AMI patients (age, 62.8±12.4 years, 600 men) on admission. They were divided into tertiles according to their serum Lp(a) levels {Tertile 1 (n=276), Lp(a)<13.8 mg/dL; Tertile 2 (n=279), Lp(a)=13.8-30.6 mg/dL; Tertile 3 (n=277), Lp(a)>30.6 mg/dL}.

Results

There were no differences in baseline clinical characteristics among Tertiles 1, 2, and 3, except for proportions of Killip class III-IV patients (5.8% vs. 10.0% vs. 18.8%, respectively, p<0.001). There were significant differences in left ventricular ejection fractions (57.3±11.4% vs. 55.9±12.3% vs. 53.1±13.1%, p<0.001). Among the laboratory findings, there were significant differences in total cholesterol (173.3±37.2 vs. 183.5±38.9 vs. 185.3±43.8 mg/dL, p=0.001), low density lipoprotein-cholesterol (111.3±34.3 vs. 122.9±34.7 vs. 123.3±39.4 mg/dL, p<0.001), apolipoprotein B (92.8±25.4 vs. 100.8±26.0 vs. 101.9±28.8 mg/dL, p<0.001), and amino-terminal pro-brain natriuretic peptide levels (1805.2±4343.3 vs. 2607.9±5216.3 vs. 3981.5±7689.7 pg/mL, p<0.001). After adjusting for multiple variables in the high Killip class (III-IV) subgroup, the risk estimate for major adverse cardiovascular events (MACE) at 1-year follow-up was significantly higher in Tertile 3 than in Tertiles 1 or 2 (hazard ratio 6.723, 95% confidence interval 1.037-43.593, p=0.046).

Conclusion

In patients in high Killip classes, high serum levels of Lp(a) were significantly associated with long-term adverse outcomes after AMI.

Serum lipoprotein(a) level and clinical coronary stenosis progression in patients with myocardial infarction: re-revascularization rate is high in patients with high-Lp(a)

BACKGROUND

High serum lipoprotein(a) (Lp(a)) levels are associated with coronary artery disease.

METHODS AND RESULTS

The serum Lp(a) levels of 130 patients with acute myocardial infarction (AMI) who underwent direct percutaneous coronary intervention were investigated. On the basis of Lp(a) level at 1 month after the onset of AMI, the patients were classified into 2 groups (high-Lp(a) (> or =30 mg/dl) and low-Lp(a) (< 30 mg/dl)) for evaluation of the clinical coronary stenosis progression (CCSP) rate. CCSP is defined as either target lesion revascularization (TLR) or new lesion revascularization (NLR). The CCSP rate was significantly higher in the high-Lp(a) group than in the low-Lp(a) group (65.8% vs 29.3%, p<0.01). In patients who had coronary stents in the acute phase (n=79), the CCSP and NLR rates were significantly higher in the high-Lp(a) group than in the low-Lp(a) group (45.0% vs 20.3%, p<0.05; 35.0% vs 6.8%, p<0.01), but there was no significant difference in TLR rate between the 2 groups (10.0% vs 13.6%, p=0.858).

CONCLUSIONS

High serum Lp(a) level is a significant risk factor for CCSP, but does not influence restenosis after stenting.

Relationship of a comprehensive panel of plasma oxidized low-density lipoprotein markers to angiographic restenosis in patients undergoing percutaneous coronary intervention for stable angina

BACKGROUND

This study was performed to assess the relationship between oxidized low-density lipoprotein (OxLDL) and restenosis. OxLDL induces up-regulation of inflammatory genes and cytokines and recruits monocytes to the vessel wall. Elevated levels of monocytes post-percutaneous coronary intervention (PCI) are associated with in-stent restenosis.

METHODS AND RESULTS

One hundred forty-one patients with stable angina pectoris had serial blood samples drawn before PCI (68% balloon only, 32% stent), immediately post-PCI and at 6 and 24 hours, 3 days, 1 week, and 1, 3, and 6 months. Plasma levels of OxLDL-E06, a measure of oxidized phospholipid (OxPL) content on apoB-100 detected by antibody E06 (OxPL/apoB), autoantibodies to malondialdehyde-LDL and copper-oxidized LDL, and apoB-immune complexes were measured in all samples. Quantitative and qualitative coronary angiography was performed with 94% angiographic follow-up. Restenosis was defined as >50% diameter stenosis (%DS). The overall angiographic restenosis rate was 32% (39% in balloon group, 16% in stent group). OxPL/apoB levels rose significantly and OxLDL autoantibody titers decreased immediately post-PCI in patients both with and without restenosis, but there were no significant differences among groups. There was also no relationship of any OxLDL marker to lesion length, %DS, or minimal lumen diameter. No differences were noted in stent versus balloon-treated patients.

CONCLUSIONS

Serial measurement of a comprehensive panel of circulating OxLDL markers after uncomplicated PCI for stable angina does not predict restenosis.

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.

Lipoprotein(a), apolipoprotein(a) polymorphism and restenosis after intracoronary stent placement in Type 2 diabetic patients

The relationship between lipoprotein(a) [Lp(a)] and restenosis after intracoronary stent implantation has never been analysed in diabetic patients. The aim of the present prospective study was to evaluate whether Lp(a) levels and apolipoprotein(a) [apo(a)] phenotypes are predictors of restenosis after elective stent implantation in Type 2 diabetic patients with de novo lesions of coronary arteries. We recruited 102 Type 2 diabetic patients with a new lesion successfully treated with elective placement of one or two Palmaz-Schatz stents. Follow-up angiography was scheduled at 6 months or earlier if clinically indicated. Seven patients were lost to the follow up. Among 95 patients enrolled, restenosis was present in 37 (38.9%) and absent in 58 (61.1%). The restenosis group showed Lp(a) levels higher than the nonrestenosis group (25.1+/-14.4 vs. 21.3+/-14.6 mg/dl), but the difference was not significant. The restenosis group had a percentage of subjects with at least one apo(a) isoform of low molecular weight (MW) significantly greater than the nonrestenosis group (75.7% vs. 55.1%; P<.05). A multiple logistic regression analysis showed that presence of multivessel disease (risk relative [RR]: 5.83; 95% confidence interval [CI]: 1.21-28.15; P<.05) was the only predictor of restenosis after stent placement in diabetic patients. Lp(a) and apo(a) polymorphisms did not enter the model as predictive variables. Our study shows that the presence of multivessel disease is a predictor of restenosis after intracoronary stent implantation in diabetic patients. On the contrary, Lp(a) and apo(a) polymorphisms do not appear to be reliable markers of restenosis in patients with Type 2 diabetes mellitus.

Restenosis after intracoronary stent placement: can apolipoprotein(a) polymorphism play a role?

BACKGROUND

The relationship between lipoprotein(a) and restenosis after intracoronary stent implantation has been analysed by two specific studies, but the role of apoliprotein(a) polymorphism was not considered. The aim of the present prospective study was to evaluate whether lipoprotein(a) levels and apolipoprotein(a) phenotypes are predictors of restenosis after elective stent implantation in patients with de novo lesions of coronary arteries.

METHODS

We recruited 182 patients with a new lesion successfully treated with elective placement of one or two Palmaz-Schatz stents. Follow-up angiography was scheduled at 6 months or earlier if clinically indicated. Nine patients were lost to the follow up. Among 173 patients enrolled, restenosis was present in 52 (30.0%) and absent in 121 (70.0%).

RESULTS

Lipoprotein(a) levels were higher in the restenosis than in the nonrestenosis group (29.5+/-17.2 versus 27.4+/-20.2 mg/dl), even if the difference did not attain statistical significance (P=0.067). The restenosis group had a percentage of subjects with at least one apolipoprotein(a) isoform of low molecular weight significantly greater than the nonrestenosis group (82.7 versus 66.9%; P=0.035). A multiple logistic regression analysis showed that multiple stenting (RR: 4.01; CI 95%: 1.65-13.91; P=0.004), presence of diabetes (RR: 3.96; CI 95%: 1.67-9.37; P=0.002) and presence of multivessel disease (RR: 2.71; CI 95%: 1.19-6.16; P=0.017) were predictors of restenosis after stent placement. Lipoprotein(a) and apolipoprotein(a) polymorphism did not enter the model as predictive variables.

CONCLUSIONS

Our study confirms that multiple stenting, diabetes and multivessel disease are powerful predictors of restenosis after intracoronary stent implantation. On the contrary, lipoprotein(a) and apolipoprotein(a) polymorphism do not appear to be reliable markers of restenosis in patients with stent implantation.

The impact of plasma levels of C-reactive protein, lipoprotein (a) and homocysteine on the long-term prognosis after successful coronary stenting: The Global Evaluation of New Events and Restenosis After Stent Implantation Study

OBJECTIVES

The objective of this study was to evaluate the association of high plasma levels of either C-reactive protein (CRP), lipoprotein (a) (Lp[a]) or total homocysteine (tHCY) with the long-term prognosis after successful coronary stenting (CS).

BACKGROUND

High plasma levels of either CRP, Lp(a) or tHCY may have an impact in coronary artery disease. However, long-term prospective data after coronary stenting (CS) are limited.

METHODS

Four-hundred and eighty-three consecutive patients with either stable or unstable coronary syndromes were followed for up to three years after successful CS. The composite of cardiac death, myocardial infarction or rehospitalization for rest unstable angina, whichever occurred first, was the prespecified primary end point. Moreover, the one-year incidence of clinical recurrence of symptoms, in-stent restenosis (ISR) and progression of atherosclerosis to a significant lesion (PTSL) were additionally evaluated. PTSL was defined as an increase by at least 25% in the luminal diameter stenosis of a known nonsignificant lesion (<or=50% luminal diameter stenosis) that was located in a nonintervened vessel at restudy, resulting in an angiographically significant lesion (>or=70% luminal diameter stenosis).

RESULTS

By the end of the follow-up, high plasma levels of either CRP or Lp(a) but not tHCY were independently associated with the primary end point. In particular, CRP >or=0.68 mg/dl (p < 0.001) or Lp(a) >or=25 mg/dl (p = 0.003) conferred a significantly increased risk. By 1 year, a CRP >or=0.68 mg/dl conferred a significantly increased risk for clinical recurrence of symptoms (p < 0.001) or PTSL (p < 0.001). None of the studied biochemical markers was related to ISR.

CONCLUSIONS

High plasma levels of either CRP or Lp(a) but not tHCY may be associated with a higher incidence of late adverse events after successful CS. PTSL in vessels not previously intervened upon may play a significant role in the underlying pathophysiology as opposed to ISR.

Association of lipoprotein(a) concentration and apo(a) isoform size with restenosis after percutaneous transluminal coronary angioplasty

Lp(a) is a unique class of lipoprotein particles that exhibits a considerable size heterogeneity resulting from the size polymorphism of apo(a), its unique protein component. An elevated level of Lp(a) in plasma has been proposed to be a risk factor for premature development of coronary artery disease. To evaluate the relationship between Lp(a) concentration and apo(a) isoform size with restenosis after percutaneous transluminal coronary angioplasty, Lp(a) levels and apo(a) phenotypes were determined in 204 patients who underwent a successful coronary angioplasty procedure and stent implantation. The patients were followed with clinical examinations and exercise tests at 1, 3, and 6 months, and a control coronary angiography was performed after 6 months to evaluate restenosis. Lp(a) levels were determined with an ELISA that is insensitive to the size heterogeneity of Lp(a), and the apo(a) isoforms were determined by a high-resolution agarose gel electrophoresis method followed by immunoblotting with a specific monoclonal antibody. Of the 146 patients who underwent angiographic evaluation, 57 (39%) had restenosis, whereas 89 (61%) did not. Lp(a) levels and the distribution of the expressed apo(a) phenotypes were compared in these two groups of patients. Although the mean and median Lp(a) levels were higher in the restenosed group, the difference was not statistically significant. However, a significant difference in Lp(a) values was found in women (P=0.043), even though, because of the small number of women in the study (n=35), no sound conclusions can be reached on the predictive role of Lp(a) in restenosis. There also was no difference in the distribution of apo(a) phenotypes between the two groups. Because of their wide distribution, Lp(a) values and apo(a) isoforms do not seem to be a useful indicator of risk of restenosis after percutaneous transluminal coronary angioplasty in our study cohort.

Predictors of restenosis after coronary angioplasty. A study on demographic and metabolic variables

OBJECTIVE

The major concern about percutaneous transluminal coronary angioplasty (PTCA) is the high incidence of restenosis.

METHODS

Demographic, clinical and biochemical data were recorded 2 weeks prior to PTCA in 388 patients fulfilling the criteria for initial stenosis, successful PTCA, and angiographic follow-up after 6 months. Restenosis was evaluated by quantitative coronary angiography.

RESULTS

Variables predictive of restenosis in univariate analysis were diabetes mellitus, male gender, and the levels of high density lipoprotein (HDL) cholesterol, apolipoprotein A1 (Apo A1) and thio-barbituric acid-reactive substances (TBARS). In trend analysis through quartiles TBARS and fasting glucose levels were significantly associated with restenosis (p = 0.016 and 0.044, respectively), whereas the negative predictivity of Apo A1 and HDL-cholesterol were of borderline significance. In multivariate analysis male gender and diabetes mellitus showed predictivity of significance, and a negative predictivity was also apparent for HDL-cholesterol.

CONCLUSION

We conclude that diabetes mellitus, male gender, and low HDL-cholesterol are predictors of restenosis 6 months after PTCA. In addition, TBARS may be a marker for the development of restenosis after PTCA.

Lipoprotein (a) and anticardiolipin antibodies are risk factors for clinically relevant restenosis after elective balloon percutaneous transluminal coronary angioplasty

Recent reports have shown the importance of new risk factors for cardiovascular disease. We investigated the relationship between Lp(a), fibrinolytic parameters and anticardiolipin antibodies (aCL) and the occurrence of clinical recurrence owing to restenosis after elective balloon percutaneous transluminal coronary angioplasty (PTCA) without stenting. In 167 patients, undergoing PTCA, Lp(a) plasma levels, aCL, euglobulin lysis time (ELT), plasminogen activator inhibitor-1 (PAI-1) activity and tissue-type plasminogen activator (t-PA) plasma levels were evaluated before the procedure. During follow-up 29 patients underwent clinical recurrence due to restenosis. Lp(a) levels were significantly higher in patients with restenosis in comparison to those without (P<0.05); an earlier restenosis was observed in patients with Lp(a) values >450 mg/L. Kaplan-Meier survival estimate showed an earlier occurrence of restenosis in patients with base-line Lp(a)>300 mg/l associated with aCL positivity. High Lp(a) plasma levels play a role in the occurrence of clinical recurrence due to restenosis after elective balloon PTCA without stenting; the association with aCL accelerates the development of restenosis.

Homocysteine, lipoprotein(a), and restenosis after percutaneous transluminal coronary angioplasty: a prospective study

BACKGROUND

Restenosis complicates 30% to 40% of angioplasty procedures and may be unrelated to traditional coronary risk factors. Homocysteine, lipoprotein(a), and methylenetetrahydrofolate reductase (MTHFR 677T) (a genetic determinant of plasma homocysteine concentrations) are novel risk factors for coronary artery disease. Their roles in restenosis are unclear, and the potential synergism between homocysteine and lipoprotein(a) has not previously been studied. The objective of this study was to determine the relations among homocysteine, lipoprotein (a), MTHFR 677T, and restenosis after percutaneous transluminal coronary angioplasty.

METHODS

This prospective study enrolled patients with successful elective percutaneous transluminal coronary angioplasty or stenting of a single, de novo, native coronary lesion. Fasting blood was drawn the morning of the procedure for homocysteine, lipoprotein(a), and MTHFR 677T. Follow-up angiography was performed 6 months after the procedure or earlier if clinically indicated. All cineangiograms were analyzed quantitatively.

RESULTS

A total of 144 (92%) of 156 eligible patients underwent follow-up coronary angiography. The overall angiographic restenosis rate (residual stenosis >50%) was 31%. Mean homocysteine concentration was 10.1 +/- 3.7 micromol/L. Plasma homocysteine concentrations were not significantly different in patients with or without angiographic restenosis (9.6 +/- 3.3 vs 10.3 +/- 3.8 micromol/L; P =.31). Mean lipoprotein(a) concentration was 21.2 +/- 20.1 mg/dL. Plasma lipoprotein(a) concentrations were not significantly different in patients with or without restenosis (21.9 +/- 21.8 vs 20.9 +/- 19.5 mg/dL). Homozygosity for MTHFR 677T was present in 6.5% and was not associated with increased restenosis. No interaction between homocysteine and lipoprotein(a) was detected.

CONCLUSIONS

Homocysteine, lipoprotein(a), and MTHFR 677T are not associated with restenosis after percutaneous transluminal coronary angioplasty.

Lipoprotein(a): intrigues and insights

Lipoprotein(a) is an atherogenic, cholesterol ester-rich lipoprotein of unknown physiological function. The unusual species distribution of lipoprotein(a) and the extreme polymorphic nature of its distinguishing apolipoprotein component, apolipoprotein(a), have provided unique challenges for the investigation of its biochemistry, genetics, metabolism and atherogenicity. Some fundamental questions regarding this enigmatic lipoprotein have escaped elucidation, as will be highlighted in this review.

Lipoprotein(a), homocysteine, and remnantlike particles: emerging risk factors

Although lipoprotein(a) [Lp(a)] was first described more than 35 years ago, adequate prospective data have only recently supported Lp(a) as an independent risk factor for coronary heart disease (CHD). In vitro studies suggest that Lp(a) contributes to atherogenesis directly by cholesterol uptake and indirectly by the inhibition of fibrinolysis. In patients with CHD or a significant risk for CHD, Lp(a) should be measured and treated with either niacin or estrogen if the patient has Lp(a) cholesterol levels of more than 10 mg/dL or an Lp(a) mass of more than 30 mg/dL. In addition, homocysteine and remnantlike lipoprotein cholesterol are strongly supported by prospective or population-based prevalence data as independent risk factors for CHD. Homocysteine levels of more than 14 mumol/L should be treated with vitamin supplements of folate, B6, and B12. Remnantlike lipoprotein cholesterol is the product of a novel immunoassay that separates the partially hydrolyzed triglyceride-rich remnant particles. The association of these particles with CHD risk in women may explain the small independent CHD risk that triglycerides have in women in the Framingham Heart Study. A clear therapeutic intervention has not been documented but may include diet, fibric acid derivatives, or hydroxymethylglutamyl coenzyme A reductase inhibitors.