Relationship among pregnancy associated plasma protein-A levels, clinical characteristics, and coronary artery disease extent in patients with chronic stable angina pectoris

The Regulatory Variant -108C/T in the Promoter of Paraoxonase 1 (PON1) Gene has a More Important Role in Regulating PON1 Activity Compared to rs3735590 in 3'-UTR in Patients with Coronary Artery Disease

Background

This study aimed to assess the serum activity of paraoxonase 1 (PON1) in patients with coronary artery disease (CAD) based on two genetic variants including the -108C/T variant in the promoter region and the rs3735590 variant in the binding site of miR-616 at the 3'-UTR of the PON1 gene.

Materials and Methods

A total of 140 subjects who exhibited clinical symptoms of CAD underwent diagnostic coronary angiography. The patients with CAD were further categorized into two groups: single-vessel disease (SVD) and multi-vessel disease (MVD). The study variants were genotyped using the restriction fragment length polymorphism (RFLP) technique after polymerase chain reaction amplification.

Results

After adjusting for age, gender, body mass index, metformin, and statin usage, a significant association was observed between the -108C/T variant and PON1 activity (P < 0.001). In the sub-groups of both SVD and MVD, individuals with the TC+CC genotypes exhibited significantly higher PON1 activity compared to TT homozygotes (P = 0.001 for SVD and P = 0.01 for MVD). As for the rs3735590 variant, individuals with the A allele (GA+AA genotypes) had higher PON1 activity compared to those with the GG genotype in both the SVD and MVD groups, although the results did not reach statistical significance.

Conclusions

Our study findings indicate a significant decrease in PON1 activity among patients with obstructive CAD. Notably, our results suggest that the -108C/T variant exerts a greater influence on PON1 activity compared to the rs3735590 variant. These findings highlight the crucial role of the -108C/T variant in modulating PON1 activity within the context of atherosclerosis.

Heritability and circulating concentrations of pregnancy-associated plasma protein-A and stanniocalcin-2 in elderly monozygotic and dizygotic twins

Introduction

Pregnancy-associated plasma protein-A (PAPP-A) is an IGF-activating enzyme suggested to influence aging-related diseases. However, knowledge on serum PAPP-A concentration and regulation in elderly subjects is limited. Therefore, we measured serum PAPP-A in elderly same-sex monozygotic (MZ) and dizygotic (DZ) twins, as this allowed us to describe the age-relationship of PAPP-A, and to test the hypothesis that serum PAPP-A concentrations are genetically determined. As PAPP-A is functionally related to stanniocalcin-2 (STC2), an endogenous PAPP-A inhibitor, we included measurements on STC2 as well as IGF-I and IGF-II.

Methods

The twin cohort contained 596 subjects (250 MZ twins, 346 DZ twins), whereof 33% were males. The age ranged from 73.2 to 94.3 (mean 78.8) years. Serum was analyzed for PAPP-A, STC2, IGF-I, and IGF-II by commercial immunoassays.

Results

In the twin cohort, PAPP-A increased with age (r=0.19; P<0.05), whereas IGF-I decreased (r=-0.12; P<0.05). Neither STC2 nor IGF-II showed any age relationship. When analyzed according to sex, PAPP-A correlated positively with age in males (r=0.18; P<0.05) and females (r=0.25; P<0.01), whereas IGF-I correlated inversely in females only (r=-0.15; P<0.01). Males had higher levels of PAPP-A (29%), STC2 (18%) and IGF-I (19%), whereas serum IGF-II was 28% higher in females (all P<0.001). For all four proteins, within-pair correlations were significantly higher for MZ twins than for DZ twins, and they demonstrated substantial and significant heritability, which after adjustment for age and sex averaged 59% for PAPP-A, 66% for STC2, 58% for IGF-I, and 52% for IGF-II.

Discussion

This twin study confirms our hypothesis that the heritability of PAPP-A serum concentrations is substantial, and the same is true for STC2. As regards the age relationship, PAPP-A increases with age, whereas STC2 remains unchanged, thereby supporting the idea that the ability of STC2 to inhibit PAPP-A enzymatic activity decreases with increasing age.

Improved risk assessment of coronary artery disease by substituting paraoxonase 1 activity for HDL-C: Novel cardiometabolic biomarkers based on HDL functionality

BACKGROUND AND AIMS

Developing laboratory assays to evaluate HDL functions and improve cardiovascular disease (CVD) risk assessment has recently emerged as a challenge. The present study was conducted to help predict the risk of coronary artery disease (CAD) by investigating new cardiometabolic risk factors based on substituting paraoxonase 1 (PON1) as a critical enzyme in the functionality of HDL for that of HDL-C.

METHODS AND RESULTS

The present study recruited 274 subjects undergoing diagnostic coronary angiography, 92 without significant CAD (non-CAD), and 182 with a severe CAD. The diagnostic accuracy of the new biomarkers in non-CAD versus multi-vessel disease was obtained in descending order of AUC as 0.72 (P < 0.001) for log (TG/PON1), 0.70 (P < 0.001) for nonHDL-C/PON1, and 0.67 (P < 0.001) for LDL-C/PON1. After performing a multivariate adjustment for age, gender, BMI, statin therapy, and diabetes mellitus, the increased odds of CAD remained significant for the new cardiometabolic ratios as independent variables [adjusted OR = 1.47 (1.15-1.88), p = 0.002 for LDL-C/PON1; adjusted OR = 2.15 (1.41-3.5), p = 0.009 for nonHDL-C/PON1; adjusted OR = 5.03 (2.14-13.02), p = 0.004 for log (TG/PON1)]. CAD was diagnosed with an optimal discriminating cutoff of 1.84 for LDL-C/PON1, 2.8 for nonHDL-C/PON1, and 0.48 for log (TG/PON1).

CONCLUSIONS

To improve CAD's risk assessment, the PON1 activity was proposed as an alternative to HDL-C in the commonly used atherogenic lipid ratios. Substituting the PON1 activity for the HDL-C concentration can provide an index of the HDL activity. The present study sought to exploit the lipoprotein-related risk factors of CAD from a more effective perspective.

Pregnancy Associated Plasma Protein-A as a Cardiovascular Risk Marker in Patients with Stable Coronary Heart Disease During 10 Years Follow-Up-A CLARICOR Trial Sub-Study

Elevated pregnancy-associated plasma protein A (PAPP-A) is associated with mortality in acute coronary syndromes. Few studies have assessed PAPP-A in stable coronary artery disease (CAD) and results are conflicting. We assessed the 10-year prognostic relevance of PAPP-A levels in stable CAD. The CLARICOR trial was a randomized controlled clinical trial including outpatients with stable CAD, randomized to clarithromycin versus placebo. The placebo group constituted our discovery cohort (n = 1.996) and the clarithromycin group the replication cohort (n = 1.975). The composite primary outcome was first occurrence of cardiovascular event or death. In the discovery cohort, incidence rates (IR) for the composite outcome were higher in those with elevated PAPP-A (IR 12.72, 95% Confidence Interval (CI) 11.0-14.7 events/100 years) compared to lower PAPP-A (IR 8.78, 8.25-9.34), with comparable results in the replication cohort. Elevated PAPP-A was associated with increased risk of the composite outcome in both cohorts (discovery Hazard Ratio (HR) 1.45, 95% CI 1.24-1.70; replication HR 1.29, 95% CI 1.10-1.52). In models adjusted for established risk factors, these trends were attenuated. Elevated PAPP-A was associated with higher all-cause mortality in both cohorts. We conclude that elevated PAPP-A levels are associated with increased long-term mortality in stable CAD, but do not improve long-term prediction of death or cardiovascular events when added to established predictors.

Pregnancy-associated plasma protein A as a predictor of all-cause mortality and cardiovascular events in patients with chronic kidney disease: a meta-analysis of prospective studies

INTRODUCTION

The aim of the study was to assess the association of elevated serum pregnancy associated plasma protein A (PAPP-A) and the risk of all-cause mortality, cardiovascular events and mortality due to infection in patients with chronic kidney disease (CKD).

MATERIAL AND METHODS

We systematically searched the Medline database up to March 2017. A random effects model was used to pool the relative risks (RRs) and their 95% confidence intervals (CIs). Sensitivity analysis and subgroup analysis were performed to explore the potential sources of heterogeneity.

RESULTS

Six studies involving 2034 subjects were included. The pooled RRs for the risk of all-cause mortality and cardiovascular events were 1.50 (95% CI: 1.17-1.92), 1.26 (95% CI: 0.95-1.69), respectively. Sensitivity analysis by excluding each individual study showed no influence on the main results. Subgroup analysis showed that age, male proportion, follow-up term, and assay methods were not modifiable factors.

CONCLUSIONS

Our study suggests that elevated serum PAPP-A is associated with the risk of all-cause mortality in patients with CKD.

IGFBP-4 and PAPP-A in normal physiology and disease

Insulin-like growth factor (IGF) binding protein-4 (IGFBP-4) is a modulator of the IGF system, exerting both inhibitory and stimulatory effects on IGF-induced cellular growth. IGFBP-4 is the principal substrate for the enzyme pregnancy-associated plasma protein-A (PAPP-A). Through IGF-dependent cleavage of IGFBP-4 in the vicinity of the IGF receptor, PAPP-A is able to increase IGF bioavailability and stimulate IGF-mediated growth. Recently, the stanniocalcins (STCs) were identified as novel inhibitors of PAPP-A proteolytic activity, hereby adding additional members to the seemingly endless list of proteins belonging to the IGF family. Our understanding of these proteins has advanced throughout recent years, and there is evidence to suggest that the role of IGFBP-4 and PAPP-A in defining the relationship between total IGF and IGF bioactivity can be linked to a number of pathological conditions. This review provides an overview of the experimental and clinical findings on the IGFBP-4/PAPP-A/STC axis as a regulator of IGF activity and examines the conundrum surrounding extrapolation of circulating concentrations to tissue action of these proteins. The primary focus will be on the biological significance of IGFBP-4 and PAPP-A in normal physiology and in pathophysiology with emphasis on metabolic disorders, cardiovascular diseases, and cancer. Finally, the review assesses current new trajectories of IGFBP-4 and PAPP-A research.

Preeclampsia biomarkers: An assessment of maternal cardiometabolic health

Preeclampsia is a serious pregnancy condition defined as new-onset hypertension and proteinuria, commonly characterized as either early, 'placental', or late onset, 'maternal', using a cut-off of 34 weeks gestation. However, it may be more useful to differentiate between the vascular remodelling and placental invasion vs. inflammation and metabolic pathophysiology that underlie these forms of preeclampsia. Due to rising rates of obesity, the late-onset, maternal form is increasingly occurring earlier in pregnancy. Predictive tests for preeclampsia typically include biophysical markers such as maternal body mass index and mean arterial pressure, indicating the importance of cardiovascular and metabolic health in its pathophysiology. In contrast, the placental, inflammatory, endothelial and/or metabolic biomarkers used in these tests are generally thought to indicate an abnormal response to placentation and predict the disease. However, many of these non-placental biomarkers are known to predict impaired metabolic health in non-pregnant subjects with obesity (metabolically unhealthy obesity) and coronary artery disease or stroke in people at risk for cardiovascular events. Similarities between the performance of these markers in the prediction of cardiovascular and metabolic health outside of pregnancy suggests that they may be more indicative of maternal health than predictive for preeclampsia. This paper reviews the biophysical and biochemical markers in preeclampsia prediction and compares their performance to tests assessing metabolic health and risk of cardiovascular disease, particularly in the obese population.

Prognostic value of the Stanniocalcin-2/PAPP-A/IGFBP-4 axis in ST-segment elevation myocardial infarction

Objective

The aim of the present study was to evaluate the prognostic value of the Stanniocalcin-2/PAPP-A/IGFBP-4 axis in patients with ST-segment elevation myocardial infarction (STEMI).

Methods

Observational cohort study performed in 1085 consecutive STEMI patients treated with early reperfusion between February 2011 and August 2014. Stanniocalcin-2, PAPP-A, and IGFBP-4 were measured using state-of-the art immunoassays. The primary outcome was the composite endpoint of all-cause mortality and readmission due to heart failure (HF).

Results

Median follow-up was 3.3 years (IQR 1.0–3.7), during which 176 patients (16.2%) presented a composite endpoint. Multivariable cox regression analysis revealed that Stanniocalcin-2 (HR 2.06; 95% CI 1.13–3.75; p = 0.018), IGFBP-4 (HR 1.73; 95% CI 1.14–2.64; p = 0.010), Killip–Kimball class III–IV (HR 1.40; 95% CI 1.13–1.74; p = 0.002), NT-ProBNP (HR 1.21; 95% CI 1.07–1.37; p = 0.002), age (HR 1.06; 95% CI 1.04–1.08; p < 0.001) and left ventricular ejection fraction (HR 0.97; 95% CI 0.95–0.98; p < 0.001) were independent predictors of the composite endpoint. A model containing Stanniocalcin-2 and IGFBP-4 on top of clinical variables significantly improved C-index discrimination (p = 0.036). Stanniocalcin-2 was also identified as independent predictor of all-cause mortality (HR 2.23; 95% CI 1.16–4.29; p = 0.017) and readmission due to HF (HR 3.42; 95% CI 1.22–9.60; p = 0.020).

Conclusions

In STEMI patients, Stanniocalcin-2 and IGFBP-4 emerged as independent predictors of all-cause death and readmission due to HF. The Stanniocalcin-2/PAPP-A/IGFBP-4 axis exhibits a significant role in STEMI risk stratification.

Insulin-Like Growth Factor Binding Protein 4 Fragments Provide Incremental Prognostic Information on Cardiovascular Events in Patients With ST-Segment Elevation Myocardial Infarction

BACKGROUND

Fragments of insulin-like growth factor binding protein 4 (IGFBP-4) are potential new biomarkers for cardiac risk assessment. The fragments are generated on specific cleavage by pregnancy-associated plasma protein-A, which exerts proatherogenic activity. This study investigated the prognostic value of IGFBP-4 fragments in patients with ST-segment elevation myocardial infarction.

METHODS AND RESULTS

We prospectively included 656 patients with ST-segment elevation myocardial infarction treated with percutaneous coronary intervention from September 2006 to December 2008. Blood samples were drawn before percutaneous coronary intervention, and levels of intact IGFBP-4 and N-terminal and C-terminal IGFBP-4 fragments were measured by specific assays. End points were 5-year all-cause and cardiovascular mortality and the combined end point of major adverse cardiac events. Prognostic potential was evaluated on top of a clinical model in terms of discrimination, calibration, and reclassification analysis. During follow-up, 166 patients experienced a major adverse cardiac event and 136 patients died, of whom 69 died from cardiovascular causes. Both IGFBP-4 fragments were associated with all end points (P<0.001). After multivariable adjustments, both N-terminal and C-terminal IGFBP-4 fragment levels remained associated with all end points, including cardiovascular mortality with hazard ratios per doubling in protein concentration of 2.54 (95% CI 1.59-4.07; P<0.001) and 2.07 (95% CI 1.41-3.04; P<0.001), respectively. Incorporation of IGFBP-4 fragments into a clinical model with 15 risk factors improved C-statistics and model calibration and provided incremental prognostic contribution, as assessed by net reclassification improvement and integrated discrimination improvement.

CONCLUSIONS

IGFBP-4 fragments are associated with increased risk of all-cause mortality, cardiovascular mortality, and major adverse cardiac events in patients with ST-segment elevation myocardial infarction.

Pregnancy-associated plasma protein-A (PAPP-A) as a possible biomarker in patients with coronary artery disease

BACKGROUND

Cardiovascular disease is the leading cause of death in the Western world, and a major cause of this disease is atherosclerosis. Research has demonstrated that pregnancy-associated plasma protein A (PAPP-A) plays a role in cardiovascular disease, as evidenced by the association between PAPP-A and severity of heart damage.

AIM

The aim of this work was to investigate the correlation between PAPP-A concentrations in coronary and peripheral blood and certain clinicopathological factors and antioxidant enzyme activities in patients diagnosed with coronary artery disease.

METHODS

For 65 patients, arterial blood was obtained by puncturing the femoral or radial artery, and coronary blood was obtained via percutaneous coronary intervention. PAPP-A, catalase (CAT), superoxide dismutase-1 (SOD-1), and superoxide dismutase-2 (SOD-2) levels were measured using spectrometric methods.

RESULTS

Coronary PAPP-A levels were slightly higher than peripheral PAPP-A levels (81.25 ± 2.34 and 62 ± 3 ng/mL, respectively, P < 0.0001); these levels were correlated with each other (r = 0.6629, P < 0.001) but not with clinicopathological factors (P > 0.05). Coronary PAPP-A levels were significantly elevated among patients at risk for cardiovascular disease (P < 0.05). Antioxidant enzyme activities were significantly higher in coronary samples than in peripheral samples from subjects with ischemic cardiopathy secondary to atherosclerosis (P < 0.001). Neither coronary nor peripheral PAPP-A levels were correlated with antioxidant enzyme activities in patients with cardiopathy secondary to atherosclerosis (P > 0.05).

CONCLUSIONS

PAPP-A levels could be used as biomarkers to identify patients at risk of coronary artery disease.

Pregnancy-associated plasma protein-A and the vulnerable plaque

For more than a decade, pregnancy-associated plasma protein-A (PAPP-A) has been examined for its relation to acute coronary syndrome (ACS) and the vulnerable plaque. This review summarizes the current knowledge of plasma PAPP-A in relation to nonpregnant individuals focusing on patients with ACS, discusses its use as a possible biomarker for diagnosis and prognosis in ACS, briefly describes the challenges in different assay technologies and describes the effect of heparin administration on PAPP-A concentrations in plasma.

Association of E-selectin gene polymorphism and serum PAPP-A with carotid atherosclerosis in end-stage renal disease

BACKGROUND

Atherosclerotic vascular disease represents a significant cause of morbidity and mortality in patients with end-stage renal disease (ESRD). The endothelium plays a crucial role in vascular inflammation. E-selectin is exclusively expressed on activated endothelial cells and is upregulated following an inflammatory response and oxidative stress, while serum pregnancy-associated plasma protein-A (PAPP-A) concentrations are related to the presence and stability of carotid atherosclerotic plaques.

OBJECTIVE

The aim of this study was to investigate whether there is an association between SELE rs5355C>T gene polymorphism, serum PAPP-A level and the presence of carotid atherosclerosis in ESRD patients.

SUBJECTS AND METHODS

Seventy subjects were recruited into this study; 40 ESRD patients [age (mean ± SD) 43.42 ± 13.94 years] and 30 age- and gender-matched healthy individuals assigned to the control group. Polymerase chain reaction-restriction fragment length polymorphism was performed for the analysis of SELE rs5355C>T gene polymorphism, while serum PAPP-A concentrations were measured using electro-chemiluminescence immunoassay. Routine laboratory tests were measured on an automated chemistry analyzer. Carotid ultrasonographic studies were performed by a bilateral high-resolution B-mode ultrasound.

RESULTS

There was no significant relationship between the SELE rs5355C>T gene polymorphism and ESRD incidence. Serum PAPP-A levels were significantly higher in ESRD patients compared with controls [median (interquartile range) 5.8 (5.1-11.6) and 5.1 (4.1-6.7), respectively; p = 0.005]. Serum PAPP-A correlated positively with urea, creatinine, systolic and diastolic blood pressure (DBP). Serum PAPP-A showed a statistically significant increase in SELE rs5355TT versus CC in both patients and controls. There was no association on comparing right intima-media thickness (IMT), left IMT, right cross-sectional area (CSA) and left CSA with the CC, CT and TT genotypes of SELE rs5355C>T. No correlation between serum PAPP-A with each of the above-mentioned carotid doppler findings was observed. There was a statistically significant increase in DBP in TT genotype carriers when compared with CC genotype carriers (p = 0.009). Serum PAPP-A levels were higher in hypertensive ESRD patients when compared with normotensive ESRD patients. There was a statistically significant decrease in high-density lipoprotein cholesterol (HDL-C) in TT genotype carriers when compared with CT genotype carriers in the whole study group (p = 0.003). Serum PAPP-A correlated negatively with HDL-C.

CONCLUSION

The lack of a direct association between SELE rs5355C>T gene polymorphism, serum PAPP-A level and IMT suggests that their hypothesized association with carotid atherosclerosis might reflect an indirect mechanism of SELE rs5355C>T gene polymorphism and serum PAPP-A with cardiovascular risk factors such as blood pressure and HDL-C rather than a direct effect on the vasculature.

Lipocalin-type prostaglandin D synthase is not a biomarker of atherosclerotic manifestations

OBJECTIVE

Over the last decades Lipocalin-type prostaglandin D synthase (L-PGDS), Osteoprotegerin (OPG), Osteopontin (OPN) and Pregnancy associated plasma protein A (PAPP-A) have been reported to be associated with coronary artery disease, and L-PGDS has been proposed as a potential new diagnostic tool in the setting of stable coronary artery disease. We set out to investigate if measurement of concentrations of these biomarkers could be used to differentiate between four groups of individuals with different atherosclerotic manifestations.

METHODS

A total of 120 individuals from four equal gender- and age-matched groups were studied: (i) no previous cardiovascular disease (CVD) and no coronary calcifications [CAC-negative group], (ii) no previous CVD but evidence of severe coronary calcifications [CAC-positive group], (iii) acute coronary syndrome [ACS-group], and (iv) clinical stable patients with CVD, who were referred for cardiovascular surgery [CVD-group]. Concentrations of L-PGDS, OPG, OPN and PAPP-A were analyzed and compared between the four groups.

RESULTS

We did not find any significant differences in L-PGDS concentrations between the four groups (p = 0.32). OPG concentrations differed significantly (p = 0.003), with the highest concentration observed in ACS patients. Considering OPN (p = 0.12) and PAPP-A (p = 0.53) their concentrations between groups did not differ significantly.

CONCLUSION

The main message from this study is the observation that L-PGDS based on a single blood test appears to be less valuable than previously proposed in identification of patients with coronary artery disease. However, ACS patients have higher OPG concentrations than patients with different manifestations of stable atherosclerosis. Neither OPN nor PAPP-A concentrations differed between groups.

Elevated PAPP-A sets alarm bells ringing in patients with cardiac chest pain

Novel biochemical markers may improve the estimation of overall risk in subjects at a high risk of adverse cardiac events. Measurement of some of these markers, including pregnancy-associated plasma protein A (PAPP-A), brings significant prognostic information independent of traditional risk factors. PAPP-A has been recently identified as a marker of plaque destabilization with growing interest in cardiovascular research. Our group has recently demonstrated that higher levels of serum PAPP-A were independently associated with an increased short-term risk of cardiovascular events in a large sample of 2568 consecutive patients presenting with cardiac chest pain. PAPP-A levels above 34.6 mIU/l in cardiac chest-pain patients sets alarm bells ringing as a warning for higher risk of short-term cardiovascular adverse events, including stent thrombosis, myocardial infarction, ischemic stroke or cardiovascular-related death within 90 days, the combined primary end point of this study. Cardiac chest pain patients with PAPP-A levels above 34.6 mIU/l may suffer from adverse cardiovascular events five times more frequently within 90 days than those with lower PAPP-A levels (hazard ratio: 5.28; 95% CI: 3.81-7.31). However, current data do not support the diagnostic role of PAPP-A for acute coronary syndrome in comparison to the gold standard biomarker troponin. Additionally, PAPP-A is known to interact with heparin, which may diminish its potential utility in every day clinical life. Future multicenter and large-volume studies are warranted to validate the use of PAPP-A in routine clinical practice.

Association of pregnancy-associated plasma protein-A gene polymorphism with ischemic stroke in northern Chinese Han population

OBJECTIVES

The pregnancy-associated plasma protein-A (PAPP-A), belonging to the metalloproteinase superfamily, plays an important role in destabilization of atherosclerotic plaques. The aim of this study is to evaluate whether PAPP-A gene polymorphism is associated with the risk of ischemic stroke (IS) in northern Chinese Han populations.

METHODS

A total of 368 patients with IS and 374 aged-matched healthy controls in a Chinese Han population were included in the case-control study. The single-nucleotide polymorphism (SNP) IVS6+95 (rs13290387) in the PAPP-A gene was analyzed by the polymerase chain reaction-ligation detection reaction (PCR-LDR) method.

RESULTS

Compared with the GG+CG genotype, the frequencies of the CC genotype of IVS6+95 (rs13290387) in the patients with IS were significantly higher than those in the controls (P  =  0·026). After adjusting the confounding risk factors of IS (age, gender, smoking, alcohol drinking, hypertension, diabetes mellitus, and hyperlipidemia) by the multivariate logistic analysis, this significant correlation still remained (P  =  0·010).

DISCUSSION

The CC genotype of IVS6+95 (rs13290387) was associated with increased incidence of IS in northern Chinese Han populations. This is an initial study to indicate that PAPP-A (rs13290387) might contribute to IS susceptibility in northern Chinese Han populations.

Elevated pregnancy-associated plasma protein A predicts myocardial dysfunction and death in severe sepsis

BACKGROUND

Pregnancy-associated plasma protein A (PAPPA) is an emerging biomarker used in various medical fields but has yet to be evaluated in critical care medicine. This study evaluates the value of PAPPA as a biomarker in predicting myocardial dysfunction and 28-day mortality in patients with severe sepsis.

METHODS

Serum concentrations of PAPPA and traditional cardiac biomarkers including cardiac troponin I (cTnI) and B-type natriuretic peptide (BNP) were measured on admission in 118 severely septic patients. The value of PAPPA for the diagnosis of sepsis-related myocardial dysfunction (SRMD) and for the prediction of 28-day mortality was subsequently evaluated using statistical methods.

RESULTS

PAPPA was elevated (≥4.5 ng/mL) in 76 (64.4%) patients; patients with elevated PAPPA were more likely to have SRMD (76.3% vs. 38.1%, P < 0.001). By comparison of the area under the curve (AUC) in receiver operating characteristics analysis, PAPPA had comparable value (AUC 0.661, P = 0.003) to conventional biomarkers (BNP: AUC 0.699, P < 0.001; cTnI: AUC 0.647, P = 0.007) in the diagnosis of SRMD and offered superior value (AUC 0.771, P < 0.001) over them (all AUC<0.7, P > 0.05) in the prediction of 28-day death. Increased PAPPA (≥5.4 ng/mL) was associated with lower 28-day survival (χ(2) = 19.78, P < 0.001) and independently predicted 28-day mortality in septic patients.

CONCLUSIONS

Serum PAPPA concentration frequently increases in patients with severe sepsis and appears to be associated with SRMD. PAPPA can be used as a novel biomarker for the diagnosis of SRMD and the prediction of outcomes in critically ill patients.

Pregnancy-associated plasma protein A predicts adverse vascular events in patients with coronary heart disease: a systematic review and meta-analysis

INTRODUCTION

Prospective studies about the association between elevated circulating pregnancy-associated plasma protein A (PAPP-A) and adverse vascular events in patients with coronary heart diseases (CHD) are inconsistent. We performed a meta-analysis to clarify this issue.

MATERIAL AND METHODS

We identified prospective studies by searching MEDLINE. The vascular outcomes included all-cause mortality, combination of all-cause mortality and non-fatal myocardial infarction (MI), and combined cardiovascular events. Prospective studies providing multivariable adjusted relative risks (RRs) and their 95% confidence intervals (CIs) of pre-mentioned outcomes were included. A random-effects model was used to calculate the pooled RRs. Subgroup and sensitivity analyses were used to explore the potential sources of heterogeneity or modifiable factors.

RESULTS

Fourteen studies with a total of 12 830 participants were included. Elevated PAPP-A level was associated with all-cause mortality (pooled RR 1.74, 95% CI: 1.45 to 2.09, p < 0.001), combined all-cause mortality and non-fatal MI (RR 1.59, 95% CI: 1.37 to 1.85, p < 0.001) and combined cardiovascular events (RR 1.50, 95% CI: 1.22 to 1.85, p < 0.001). There was no significant heterogeneity. Subgroup and sensitivity analyses showed that the positive association was not affected by follow-up term, CHD type, different assay methods of PAPP-A, or studies with less than 5 adjusted variables.

CONCLUSIONS

Elevated serum PAPP-A level is associated with adverse vascular outcomes in patients with CHD.

Pregnancy-associated plasma protein-A is related to gender and to adipocytokine levels: results of the Health Survey of Catalonia

OBJECTIVE

Pregnancy-associated plasma protein-A (PAPP-A) is a protease promoting IGF1 tissue availability and considered as a new biomarker of cardiovascular disease.

AIM

To evaluate the relationship between PAPP-A concentrations and anthropometric variables, physical activity, smoking status, glucose homoeostasis and adipocytokines in healthy adults.

DESIGN AND METHODS

One hundred and forty-nine subjects (77 women; mean age 39·7 ± 14 years; mean BMI 23·7 ± 1·9 kg/m(2) ) were randomly selected from 8000 adults of The Health Survey of Catalonia. Possible effects of gender, age, body composition, smoking status, physical activity, glucose homoeostasis and adipocytokines on PAPP-A concentrations were assessed.

RESULTS

Pregnancy-associated plasma protein-A was significantly higher in men than in women [1·04 (0·61-0·44) vs 0·61 (0·41-0·90) μIU/ml; P < 0·0001]; there were no differences in relation to physical activity or smoking status. PAPP-A showed a negative correlation with leptin in men (P = 0·01) and women (P = 0·05), and a positive correlation with adiponectin (P = 0·006) in women and a trend (P = 0·073) in men. Homoeostasis model assessment of insulin resistance (HOMA-IR) showed a negative correlation with PAPP-A only in women (P = 0·019). No association was found with blood pressure, IGF1, lipids or glucose in either gender. When a multiple regression analysis was performed including gender, age, BMI, waist-hip ratio, HOMA-IR, adiponectin and leptin as confounders, PAPP-A was independently correlated with adiponectin (β = 0·23; P = 0·02) and leptin (β = -0·33; P = 0·04).

CONCLUSIONS

Our study shows a sexual dimorphism of PAPP-A, and a possible influence of leptin and adiponectin on its concentrations in healthy subjects. The mechanisms responsible for this relationship remain to be determined.

Pathophysiological roles and clinical importance of biomarkers in acute coronary syndrome

Early diagnosis of acute coronary syndrome (ACS) is important to guide appropriate therapy at a time when it is most likely to be of value. Accurate prognostic and risk stratification will facilitate high-risk patients to have early advanced diagnostic investigations and early appropriate interventions in a cost-effective and efficient manner, while those patients at low risk of ACS complications do not need such costly diagnostic tests and unnecessary hospital admission. Recent investigations have demonstrated that elevation of biomarkers upstream from acute-phase biomarkers, biomarkers of plaque destabilization and rupture, biomarkers of myocardial ischemia, necrosis, and dysfunction may provide an earlier assessment of patient risk and identify patients with higher risk of having an adverse event. This review provides an overview of the pathophysiology and clinical characteristics of several well-established biomarkers as well as emerging biomarkers that may have potential clinical utility in patients with ACS. Such emerging biomarkers hold promise and need to be more thoroughly evaluated before utilization in routine clinical practice.

CRP and TNF-α induce PAPP-A expression in human peripheral blood mononuclear cells

Objective. The effects of C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α) on pregnancy-associated plasma protein-A (PAPP-A) expression in human peripheral blood mononuclear cells (PBMCs) require further investigation. Methods. The PAPP-A levels in culture supernatants, PAPP-A mRNA expression, and cellular PAPP-A expression were measured in human PBMCs isolated from fresh blood donations provided by 6 healthy volunteers (4 donations per volunteer). Analyses were conducted by ultrasensitive ELISA, western blotting, and RT-PCR following stimulation with CRP or TNF-α cytokines. Results. PAPP-A mRNA and protein levels after CRP stimulation peaked at 24 hours, whereas peak PAPP-A mRNA and protein levels were achieved after TNF-α stimulation at only 2 and 8 hours, respectively. These findings indicate the dose-dependent effect of CRP and TNF-α stimulation. Actinomycin D treatment completely prevented CRP and TNF-α induction of PAPP-A mRNA and protein expression. Additionally, nuclear factor- (NF-) κB inhibitor (BAY11-7082) potently inhibited both CRP and TNF-α stimulated PAPP-A mRNA and protein expression. Conclusions. Human PBMCs are capable of expressing PAPP-A in vitro, expression that may be regulated by CRP and TNF-α through the NF-κB pathway. This mechanism may play a significant role in the observed increase of serum PAPP-A levels in acute coronary syndrome (ACS).

Gender-specific differences in biomarkers responses to acute coronary syndromes and revascularization procedures

A growing body of gender-related research in coronary artery disease is beginning to gradually elucidate differences between women and men. In patients presenting with acute coronary syndromes (ACS), these sex differences include varying risk factor profiles, accuracy of diagnostic testing, clinical presentations, treatment practices and outcomes. There is also a differential expression of cardiac biomarkers by sex, which remains unexplained. This paper reviews all the available information on the effect of gender on cardiac biomarkers by search of MEDLINE using the terms gender differences, biomarkers, ACS and revascularization procedures. A better understanding of the sex disparities in biomarkers along with all other clinical information is essential to optimal management and patient care in the future.

Pregnancy-associated plasma protein A values in patients with stable cardiovascular disease: use of a new monoclonal antibody-based assay

BACKGROUND

PAPP-A is promising in improving risk stratification and invasive treatment decisions in stable cardiovascular patients. We evaluated the prognostic value of pregnancy-associated plasma protein A (PAPP-A) measured by a novel assay in stable cardiovascular patients.

METHODS

We investigated 228 stable cardiovascular outpatients. Blood was drawn for PAPP-A measurement after echocardiography and ergometry prior to heart catheterization. Angiographically we determined severity as well as qualitative characteristics suspect for vulnerability of coronary lesions. After 1108±297 days, follow-up information was obtained by questionnaire mailings and interviews by phone.

RESULTS

104 patients had coronary stenosis≥70%, 75 had B-type lesions≥50%, 46 showed complex lesions, and 68 were suspected to have vulnerable lesions. Median PAPP-A was 1.76 (interquartile range 1.21, 2.63) μIU/ml in the entire cohort. PAPP-A concentrations did not differ in dependence on coronary artery findings. A cutpoint of 2.7 μIU/ml was derived from receiver-operator characteristics for outcome measures. For this cutoff, Cox proportional hazard models with 19 further clinical variables showed that PAPP-A was predictive for all-cause death (HR 4.73, 95% CI 1.46-15.31, p=0.01), all-cause death or nonfatal infarction (HR 4.01, 95% CI 1.58-10.13, p=0.003) and all-cause death, nonfatal myocardial infarction or hospitalization (HR 1.96, 95% CI 1.03-3.70, p=0.04). The predictive value of PAPP-A did not change substantially after correction for values of cardiac troponin, using a highly sensitive cardiac troponin I research assay.

CONCLUSIONS

PAPP-A, measured by a new, monoclonal antibody-based assay is a promising prognostic marker in patients with stable cardiovascular disease and an indication for heart catheterization.

Candidate biomarkers for the detection of coronary plaque destabilization and rupture

Identification of high-risk patients presenting with chest pain remains challenging. The use of a single biomarker or a panel of biomarkers to detect occult plaque destabilization or rupture without frank infarction would allow for appropriate triage of such patients. Current data suggest that plaque vulnerability is determined by the relationship between forces that increase the size of the lipid core and destabilize the overlying thin fibrous cap. A variety of interrelated pathways are imputed to play important roles in this process of plaque evolution, destabilization, and rupture. These mechanisms include increased systemic and local inflammation, increased oxidative stress, matrix metalloproteinase modulation, and hemodynamic variables related to altered shear stress. Select candidate biomarkers that either reflect or influence these underlying processes and may ultimately have clinical application are highlighted in this review, which focuses on emerging biomarkers to define and predict the risks associated with the complex nature of vulnerable plaque biology.

Cardiac biomarkers - the old and the new: a review

Biomarkers are biological parameters that can be objectively measured and quantified as indicators of normal biologic processes, pathogenic processes, or responses to a therapeutic intervention. Typically thought of as disease process screening, diagnosing, or monitoring tools, biomarkers may also be used to determine disease susceptibility and eligibility for specific therapies. Cardiac biomarkers are protein components of cell structures that are released into circulation when myocardial injury occurs. They play a pivotal role in the diagnosis, risk stratification, and treatment of patients with chest pain and suspected acute coronary syndrome and those with acute exacerbations of heart failure. Cardiac markers are central to the new definition of acute myocardial infarction put forward by the American College of Cardiology and the European Society of Cardiology. Active investigation has brought forward an increasingly large number of novel candidate markers but few have withstood the test of time and become integrated into contemporary clinical care because of their readily apparent diagnostic, prognostic, or therapeutic utility.

Coronary atherosclerotic burden in patients with infection by CagA-positive strains of Helicobacter pylori

OBJECTIVES

Cytotoxic associated gene-A (CagA)-positive strains of Helicobacter pylori emerged as a possible atherosclerotic stimulus. Nevertheless, whether CagA-positivity is associated with more extensive or severe atherosclerotic coronary burden has never been studied.

METHODS

Forty consecutive patients with coronary artery disease (CAD) and twenty consecutive patients with normal coronary arteries undergoing coronary angiography were enrolled. All patients underwent evaluation of classical atherogenic risk factors and assessment of anti-urease B and anti-CagA antibodies titer. Either the severity of coronary stenosis (stenosis score) or the extent of coronary atherosclerosis (extent score) was evaluated in CAD patients.

RESULTS

The anti-CagA antibody titer was significantly higher in patients with CAD as compared with normal coronary arteries patients [85 (10-108.75) vs. 47.3 (17-64) RU/ml, P=0.02], whereas there were no differences in anti-urease B titer between the two groups. A significant correlation was found between anti-CagA antibody titer and extent score (R=0.35, P=0.03), whereas stenosis score was similar (R=0.25, P=0.11). On the contrary, no significant correlation was found between anti-urease B antibody titer and either extent or stenosis score. Moreover, CagA-positive patients had a more extensive CAD (P=0.029) when compared with CagA-negative patients. Interestingly, whereas serum glucose, LDL levels, anti-urease B, and anti-CagA antibodies were predictors of extent score at univariate analysis, at multivariate analysis anti-CagA antibody titer only was an independent predictor of the extent of coronary atherosclerosis (B=0.051, standard error of B=0.042, P=0.04).

CONCLUSION

These results support the association between CagA-positive H. pylori infection and coronary atherosclerotic burden. Further studies are needed to better elucidate the mechanism by which CagA-positive strains may promote atherosclerosis.

Pregnancy-associated plasma protein predicts outcomes of percutaneous coronary intervention in patients with non-ST-elevation acute coronary syndrome

OBJECTIVE

Pregnancy-associated plasma protein A (PAPP-A) may play an important role in the development of acute coronary syndrome. This study aimed to investigate the relationship between the levels of circulating PAPP-A and the mid-term outcomes of percutaneous coronary intervention (PCI) in patients with non-ST-elevation acute coronary syndrome.

METHODS

The circulating PAPP-A levels and high-sensitivity C-reactive protein before PCI were measured in 129 patients with single coronary artery stenosis. The end point of clinical follow-up was cardiac death, nonfatal myocardial infarction, target vessel revascularization, and rehospitalization for angina.

RESULTS

During the follow-up of an average of 20.3 ± 5.2 months, a cardiac event was recorded in 25 patients (19.4%). The levels of PAPP-A (29.85 ± 19.51 mIu/L vs 20.47 ± 14.33 mIu/L, P = .007) and high-sensitivity C-reactive protein (5.63 ± 2.13 mg/L vs 4.11 ± 1.28 mg/L, P = .014) in patients with cardiac events were higher than in those without cardiac events. PAPP-A ≥ 11.33 mIu/L has a strong predictive value for a combined end point (risk ratio = 4.1; 95% confidence interval, 1.0-16.2; P = .037). Patients with lower PAPP-A levels (<11.33 mIu/L) had higher event-free survivals than patients with higher PAPP-A levels (log rank = 9.334, P = .025).

CONCLUSION

Circulating PAPP-A levels predict the mid-term outcomes of PCI in patients with non-ST-elevation acute coronary syndrome and single-vessel stenosis.

Procalcitonin: a novel cardiac marker with prognostic value in acute coronary syndrome

Procalcitonin (PCT) is implicated as an inflammatory marker in early atherosclerosis. In order to investigate the clinical consequences of increased PCT levels in acute coronary syndrome (ACS), 77 patients (29 with non-ST-elevation myocardial infarction [MI], 34 with ST-elevation MI and 14 with unstable angina pectoris) were included and followed up for 6 months. The PCT levels were determined at initial presentation and within 48 h of admission. Five patients died during hospitalization and their PCT levels within 48 h of admission were significantly higher than survivors (n = 72) (0.588 +/- 0.56 versus 0.399 +/- 1.33 ng/ml, respectively). The PCT levels within 48 h post-admission in the nine patients who died within 6 months were also significantly higher compared with the survivors (0.451 +/- 0.44 versus 0.406 +/- 1.37 ng/ml, respectively). It is concluded that higher PCT levels within 48 h post-admission may reflect an inflammatory state that is associated with increased early and 6-month mortality.

Pregnancy-associated plasma protein-A, a marker for outcome in patients suspected for acute coronary syndrome

OBJECTIVES

To examine if pregnancy-associated plasma protein-A (PAPP-A) in patients with chest pain, could identify patients at risk for death or myocardial infarction.

DESIGN AND METHODS

Patients admitted with chest pain and both normal ECG and normal biomarkers were evaluated by serial measurement of PAPP-A. Main outcome measures were mortality and non-fatal myocardial infarction.

RESULTS

Median age of patients included (415) was 67years and 43% were women. The risk of death or non-fatal myocardial infarction after 3 months was 15% in the highest quartile of circulating PAPP-A compared with 3% in the lowest quartile (relative risk 3.7, p<0.01). Corresponding numbers after 1 year were 24% and 10% (relative risk 2.4, p=0.01).

CONCLUSION

In patients admitted with chest pain and both normal ECG and normal biomarkers PAPP-A seems to be valuable for predicting patients at high risk of death or non-fatal myocardial infarction.

Assessing the cost effectiveness of using prognostic biomarkers with decision models: case study in prioritising patients waiting for coronary artery surgery

OBJECTIVE

To determine the effectiveness and cost effectiveness of using information from circulating biomarkers to inform the prioritisation process of patients with stable angina awaiting coronary artery bypass graft surgery.

DESIGN

Decision analytical model comparing four prioritisation strategies without biomarkers (no formal prioritisation, two urgency scores, and a risk score) and three strategies based on a risk score using biomarkers: a routinely assessed biomarker (estimated glomerular filtration rate), a novel biomarker (C reactive protein), or both. The order in which to perform coronary artery bypass grafting in a cohort of patients was determined by each prioritisation strategy, and mean lifetime costs and quality adjusted life years (QALYs) were compared.

DATA SOURCES

Swedish Coronary Angiography and Angioplasty Registry (9935 patients with stable angina awaiting coronary artery bypass grafting and then followed up for cardiovascular events after the procedure for 3.8 years), and meta-analyses of prognostic effects (relative risks) of biomarkers.

RESULTS

The observed risk of cardiovascular events while on the waiting list for coronary artery bypass grafting was 3 per 10,000 patients per day within the first 90 days (184 events in 9935 patients). Using a cost effectiveness threshold of pound20,000- pound30,000 (euro22,000-euro33,000; $32,000-$48,000) per additional QALY, a prioritisation strategy using a risk score with estimated glomerular filtration rate was the most cost effective strategy (cost per additional QALY was < pound410 compared with the Ontario urgency score). The impact on population health of implementing this strategy was 800 QALYs per 100,000 patients at an additional cost of pound 245,000 to the National Health Service. The prioritisation strategy using a risk score with C reactive protein was associated with lower QALYs and higher costs compared with a risk score using estimated glomerular filtration rate.

CONCLUSION

Evaluating the cost effectiveness of prognostic biomarkers is important even when effects at an individual level are small. Formal prioritisation of patients awaiting coronary artery bypass grafting using a routinely assessed biomarker (estimated glomerular filtration rate) along with simple, routinely collected clinical information was cost effective. Prioritisation strategies based on the prognostic information conferred by C reactive protein, which is not currently measured in this context, or a combination of C reactive protein and estimated glomerular filtration rate, is unlikely to be cost effective. The widespread practice of using only implicit or informal means of clinically ordering the waiting list may be harmful and should be replaced with formal prioritisation approaches.

Association of the IGF1/pregnancy-associated plasma protein-A system and adipocytokine levels with the presence and the morphology of carotid plaques in type 2 diabetes mellitus patients with stable glycaemic control

OBJECTIVE

Pregnancy-associated plasma protein-A (PAPP-A) has been implicated in the atherosclerotic process through regulation of local expression of IGF1. In type 2 diabetes mellitus, glycaemic control has been involved in PAPP-A expression. We compared PAPP-A, IGF1, inflammatory markers and adiponectin concentrations in type 2 diabetic patients with and without carotid plaques and evaluated the relationship between these serum parameters and ultrasound carotid markers of atherosclerosis.

METHODS

We studied 125 consecutive type 2 diabetic patients. Clinical data, metabolic variables, hemostatic factors (plasma type-1 plasminogen activator inhibitor, fibrinogen), high-ultrasensitive C reactive protein (hsCRP), tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, adiponectin, IGF1 and PAPP-A were determined. Patients were classified into two groups according to the presence of carotid plaques on ultrasound. Carotid intima-media thickness (IMT) and morphology of carotid plaques were evaluated.

RESULTS

The mean age was 61.5+/-7.3 years and the mean glycated hemoglobin of 6.8+/-0.9%. A total of 60% presented carotid plaques. Both groups were homogeneous in anthropometric data, biochemical determinations and hemostatic factors. Adiponectin, hsCRP, TNF-alpha and IL-6 were similar in both groups. No differences were observed in serum PAPP-A (0.46 (0.22-0.86) vs 0.38 (0.18-0.66) mIU/l and in SDS IGF1 (-0.34+/-1.38 vs -0.67+/-1.35)) in patients with and without carotid plaques respectively. PAPP-A and IGF1 were not correlated with IMT.

CONCLUSIONS

Serum PAPP-A and IGF1 do not appear to be useful serum biomarkers for carotid atherosclerosis in type 2 diabetic patients with stable glycemic control, despite scientific evidence of their local role in atherosclerosis.

PAPP-A as a marker of increased long-term risk in patients with chest pain

OBJECTIVES

Long-term risk stratification in patients presenting with acute coronary syndromes (ACS) is possible by measuring cardiac troponin (cTn). The present study examined whether PAPP-A measured in an emergency department (ED) chest pain population in association with conventional and novel high sensitivity cTn (hs-cTnI) assays can predict long-term mortality.

METHODS

In 320 patients with cTn measurements the earliest heparinized plasma PAPP-A concentration after presentation was used for risk stratification for death by Kaplan-Meier and Cox analyses. Subgroup analyses using the earliest PAPP-A concentrations were also performed in a cohort of subjects with presentation cTnI < or = 99th percentile but with significantly changing cardiac troponin concentrations as measured by the AccuTnI assay and the hs-cTnI assay (n=45 and 120 subjects, respectively).

RESULTS

Subjects with PAPP-A concentrations in the highest tertile were at higher risk for death (HR > 2.00; p < or = 0.05 at 2 years) even after adjusting for cTnI at presentation. In the cohort with cTnI < or = 99th percentile but with changing hs-cTnI concentrations, subjects in the top PAPP-A tertile had a higher probability for death (p=0.02).

CONCLUSION

Early measurement of PAPP-A may identify chest pain patients at higher risk for long-term death. Additional prospective ACS studies are required to fully elucidate PAPP-A's role.

Present and Future Biochemical Markers for Detection of Acute Coronary Syndrome

The use of biochemical markers in the diagnosis and management of patients with acute coronary syndrome has increased continually in recent decades. The development of highly sensitive and cardiac-specific troponin assays has changed the view on diagnosis of myocardial infarction and also extended the role of biochemical markers of necrosis into risk stratification and guidance for treatment. The consensus definition of myocardial infarction places increased emphasis on cardiac marker testing, with cardiac troponin replacing creatine kinase MB as the "gold standard" for diagnosis of myocardial infarction. Along with advances in the use of more cardiac-specific markers of myocardial necrosis, biochemical markers that are involved in the progression of atherosclerotic plaques to the vulnerable state or that signal the presence of vulnerable plaques have recently been identified. These markers have variable abilities to predict the risk of an individual for acute coronary syndrome. The aim of this review is to provide an overview of the well-established markers of myocardial necrosis, with a special focus on cardiac troponin I, together with a summary of some of the potential future markers of inflammation, plaque instability, and ischemia.

Pregnancy-associated plasma protein-A (PAPP-A) and cardiovascular risk

The search for markers to improve risk prediction for individuals at risk of developing serious cardiovascular events is ongoing. New markers of coronary artery disease progression have been identified in recent years, among which, circulating levels of pregnancy-associated plasma protein-A (PAPP-A) offer an interesting profile. PAPP-A may play a role in the development of atherosclerotic lesions and represent also a marker of atheromatous plaque instability and extent of cardiovascular disease. PAPP-A has been shown to be a marker of adverse outcome in both acute coronary syndrome and stable coronary disease patients. The present article reviews currently available evidence supporting a role for PAPP-A as a marker of cardiovascular risk and discusses some of the pitfalls that may limit its use in clinical practice.

Pregnancy associated plasma protein A, a novel, quick, and sensitive marker in ST-elevation myocardial infarction

Traditional biomarkers in acute coronary syndromes reflect myocardial necrosis but not the underlying arteriosclerotic disease. Pregnancy-associated plasma protein A (PAPP-A) is a new biomarker in acute coronary syndromes that detects vulnerable plaques in arteriosclerotic disease and identifies acute coronary syndromes earlier than traditionally used biomarkers. Information regarding circulating PAPP-A levels in patients with ST elevation myocardial infarctions (STEMIs) is limited and contradictory. The aim of the present study was to describe the presence and time-related pattern of circulating PAPP-A levels in patients with STEMIs. Consecutive patients (n = 354) referred for primary percutaneous intervention because of STEMI were included in the study. Blood samples for the analysis of PAPP-A, creatine kinase-MB (CKMB), and troponin T were drawn at admission and every 6 to 8 hours until biomarkers of myocardial necrosis were consistently decreasing. PAPP-A was measured using a newly developed sandwich enzyme-linked immunosorbent assay technique based on 2 monoclonal antibodies. In total, 1,091 PAPP-A, 1,049 troponin T, and 1,016 CKMB samples were analyzed. Mean PAPP-A values at admission were significantly higher in patients with STEMIs than in those with non-ST elevation myocardial infarctions or unstable angina pectoris (27.6 vs 12.2 mIU/L, p <0.01). In samples drawn <2 hours after admission, the sensitivity of PAPP-A was superior (93%) to that of CKMB (60%) and troponin T (61%). In conclusion, PAPP-A levels are elevated in >90% of patients presenting with STEMIs if measured <6 hours after the onset of symptoms or <2 hours of primary percutaneous coronary intervention. In the early stages of STEMI, PAPP-A seems to be a more sensitive marker of myocardial infarction than CKMB and troponin T.