Long-term prognostic utility of PAPP-A and calprotectin in suspected acute coronary syndrome

Circulating Levels of Calprotectin as a Biomarker in Patients With Coronary Artery Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Calprotectin, also known as MRP8/14, is generated by immune cells and is altered in several inflammatory diseases. Studies have assessed their levels in patients with coronary artery disease (CAD) and its subtypes (stable CAD and acute coronary syndrome [ACS]). Herein, we aimed to systematically investigate these associations through a systematic review and meta-analysis.

METHODS

A systematic search was conducted in four online databases, including PubMed, Scopus, Embase, and the Web of Science. Relevant studies were retrieved, screened, and extracted. Random-effect meta-analysis was performed for the calculation of standardized mean difference (SMD) and 95% confidence interval (CI). Blood calprotectin levels were compared between CAD patients and controls, as well as CAD subtypes.

RESULTS

A total of 20 studies were included in the systematic review and meta-analysis, comprising 3300 CAD patients and 1230 controls. Patients with CAD had significantly higher calprotectin levels (SMD 0.81, 95% CI 0.32-1.30, p < 0.01). Similarly, patients with ACS were reported to have higher levels compared to those with stable CAD. However, there was no significant difference in terms of blood calprotectin levels between stable CAD cases and healthy controls. Finally, studies have shown that calprotectin could be used as a diagnostic biomarker of CAD while also predicting major adverse events and mortality in these patients.

CONCLUSION

Based on our findings, calprotectin, as an inflammatory marker, could be used as a possible biomarker for patients with CAD and ACS. These suggest the possibility of pathophysiological pathways for this involvement and warrant further research on these associations as well as their clinical utility.

Procollagen type 1 N-terminal propeptide is associated with adverse outcome in acute chest pain of suspected coronary origin

Background

Extracellular matrix (ECM) is an integral player in the pathophysiology of a variety of cardiac diseases. Cardiac ECM is composed mainly of collagen, of which type 1 is the most abundant with procollagen type 1 N-terminal Propeptide (P1NP) as a formation marker. P1NP is associated with mortality in the general population, however, its role in myocardial infarction (MI) is still uncertain, and P1NP has not been investigated in acute chest pain. The objective of the current study was to assess the role of P1NP in undifferentiated acute chest pain of suspected coronary origin.

Methods and results

813 patients from the Risk in Acute Coronary Syndromes study were included. This was a single-center study investigating biomarkers in consecutively enrolled patients with acute chest pain of suspected coronary origin, with a follow-up for up to 7 years. Outcome measures were a composite endpoint of all-cause death, new MI or stroke, as well as its individual components at 1, 2, and 7 years, and cardiac death at 1 and 2 years. In multivariable Cox regression analysis, quartiles of P1NP were significantly associated with the composite endpoint at 1 year of follow-up with a hazard ratio for Q4 of 1.82 (95% CI, 1.12-2.98). There was no other significant association with outcomes at any time points.

Conclusion

P1NP was found to be an independent biomarker significantly associated with adverse clinical outcome at one year in patients admitted to hospital for acute chest pain of suspected coronary origin. This is the first report in the literature on the prognostic value of P1NP in this clinical setting.

Clinicaltrialsygov Identifier

NCT00521976.

Pregnancy associated plasma protein-A as a prognostic biomarker of all-cause mortality and cardiovascular events in patients presenting with chest pain: a systematic review

AIM

Novel biomarkers have been proposed for identification of patients at greater risk of future adverse events among those presenting with chest pain. In this review, we aim to elucidate the ability of pregnancy associated plasma protein-A (PAPP-A) to predict mortality and other cardiovascular events in this patient population.

METHODS

A literature search of the electronic databases Medline, Scopus, Cochrane Library and ClinicalTrials.gov was performed in order to identify studies investigating the utility of PAPP-A to predict mortality and adverse cardiovascular events in patients with chest pain.

RESULTS

Eight studies met our inclusion criteria. Five of these studies pertained to patients with confirmed ischemic chest pain, while the rest included patients presenting with chest pain possibly due to acute coronary syndrome, irrespectively of the underlying cause. Although the results for long-term events were inconclusive in both groups of patients, higher PAPP-A concentrations were found to be a significant predictor of short-term adverse events in patients with confirmed ischemic chest pain.

CONCLUSIONS

PAPP-A appears to be a potentially useful biomarker for short-term risk stratification of patients presenting with chest pain of ischemic origin. However, there is an eminent need for more standardized clinical studies investigating the prognostic value of this biomarker.

Long-term prognostic utility of pentraxin 3 and D-dimer as compared to high-sensitivity C-reactive protein and B-type natriuretic peptide in suspected acute coronary syndrome

BACKGROUND

Vascular inflammation plays a key role in the development of atherosclerosis and acute coronary syndrome (ACS), and pentraxin 3 (PTX3) is one of several novel, promising markers of inflammation. In addition, D-dimer might serve as a marker of thrombogenesis and a hypercoagulable state following plaque rupture. The present study assesses the prognostic utility of these two biomarkers as compared to high-sensitivity C-reactive protein (hsCRP) and B-type natriuretic peptide (BNP), in addition to conventional clinical risk factors for coronary heart disease in patients with suspected ACS.

METHODS

Chest pain patients with suspected ACS (n = 871) were consecutively included in a prospective, observational study with a follow-up time of 84 months.

RESULTS

At 7-year follow-up, 332 patients had died and 203 had suffered an adverse troponin T-positive, non-fatal cardiac event. In the multivariate analysis, levels of PTX3 above 5.88 ng/mL (median) and D-dimer above 436 µg/L (lower limit upper quartile) independently predicted mortality (HR 1.60 [95% CI 1.10-2.33]; p = 0.014 and HR 1.83 [95% CI 1.20-2.78]; p = 0.005, respectively). Also, BNP levels above 310.75 pg/mL (lower limit upper quartile) (HR 2.16 [95% CI 1.37-3.42]; p = 0.001), but not hsCRP, independently predicted mortality. Only hsCRP and BNP also predicted future myocardial infarction (HR 1.59 [95% CI 1.05-2.40]; p = 0.029 and HR 1.91 [95% CI 1.10-3.31]; p = 0.021, respectively).

CONCLUSION

High levels of PTX3, D-dimer and BNP were found to be independent, long-term predictors of all-cause mortality in chest pain patients with a suspected ACS. hsCRP and BNP also predicted future myocardial infarction.

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.

The effect of heparin on pregnancy associated plasma protein-A concentration in healthy, non-pregnant individuals

OBJECTIVES

The objective of this study was to determine the differences in pregnancy associated plasma protein-A (PAPP-A) concentrations in heparin naive and heparin treated healthy men and non-pregnant women, to find a possible difference in different age groups, and to determine the response in PAPP-A concentration to repeated injections of unfractionated heparin.

DESIGN AND METHODS

Twenty-five healthy, non-pregnant volunteers divided into five groups (determined by gender and age) received 5000 IU unfractionated heparin intravenously. Five young men received an additional 5000 IU after 90 and 180 min. Blood samples to determine PAPP-A concentration and APTT were drawn at different time points.

RESULTS

Injection of heparin elicited increase in and rapid normalization of PAPP-A concentrations in all subjects. The group of 20-30-year-old never-pregnant women had lower responses than the individuals of the four other groups. The difference was not significant (p > 0.05). Repeated injections of heparin caused additional peaks in PAPP-A concentration of about the same sizes as the first peak. We observed an increase in time to normalization of PAPP-A concentration (from 75-90 min to 90-150 min) and APTT levels with repeated injections.

CONCLUSIONS

We observed a rapid normalization of PAPP-A. Our result has a great similarity to the half-life of unfractionated heparin. This result combined with the finding of equally sized peaks in PAPP-A concentration, and that all of this was found in healthy, non-pregnant individuals, suggests that heparin might compete for a binding-site on PAPP-A or with PAPP-A itself for a common receptor in healthy arterial vessels.

Calprotectin and cardiovascular events. A narrative review

OBJECTIVES

Calprotectin, also known as S100A8/A9 complex, is currently considered as a valid biomarker for diagnosis, follow-up and therapeutic monitoring of inflammatory bowel diseases. The attractive evidence that this protein may be actively produced and released by leukocytes (especially neutrophils) and by nonmyeloid cardiovascular cell types has paved the way to a series of studies that have assessed its biology in the setting of cardiovascular disease. The aim of this review was thus to investigate the diagnostic and prognostic utility of this biomarker in cardiovascular disease and in particular in myocardial infarction.

DESIGN AND METHODS

We performed a systematic, electronic search on Medline, Scosus and Web of Science, using the keywords "calprotectin" or "S100A8/A9" or "MRP-8/14" and "myocardial infarction" or "acute coronary syndrome" or "cardiovascular disease", from inception to June 2013. The bibliographic references of articles published in English, French and Italian were reviewed for additional relevant studies.

RESULTS

The data of the current scientific literature seems to confirm that calprotectin is actively secreted in the setting of cardiac ischemia and its concentration is significantly associated with the prognosis. Nevertheless, the evidence provided by recent articles that have assessed its performance for diagnosing acute myocardial infarction, either alone or in combination with troponin, supports the hypothesis that this biomarker may be of limited value for enabling a better or faster diagnosis of cardiac ischemia. Even its putative role as an independent prognostic biomarker of cardiovascular morbidity and death is still largely uncertain.

CONCLUSIONS

It can hence be concluded that calprotectin does not currently meet the requirements for efficient diagnosis and prognostication of patients with cardiovascular disease.

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.