Examination of serum pregnancy-associated plasma protein A clinical value in acute coronary syndrome prediction and monitoring

Pregnancy-associated plasma protein-A is a stronger predictor for adverse cardiovascular outcomes after acute coronary syndrome in type-2 diabetes mellitus

Background

The risk prediction of pregnancy-associated plasma protein-A (PAPP-A) for future cardiovascular (CV) events post acute coronary syndrome (ACS) in patients with type-2 diabetes mellitus (T2DM) was investigated in comparison to other risk factors.

Methods

PAPP-A was measured at hospital admission in 320 consecutive ACS patients (136 with T2DM and 184 without). All patients were followed for 2 years for occurrence of CV death, non-fatal MI or stroke. Effect of PAPP-A on the CV event risk was estimated using Cox regression models. Receiver operating characteristics (ROC) curves were generated to demonstrate the sensitivity and specificity of PAPP-A in predicting CV events.

Results

ACS patients with T2DM had higher PAPP-A (19.29 ± 16.36 vs. 13.29 ± 13.90 ng/ml, p < 0.001) and higher rate of CV events 2 years post ACS (27.2 vs. 13.6%, p = 0.002) than those without. Higher levels of PAPP-A were significantly associated with increased risk of CV events during 2-year follow-up [HR = 2.97 for 1 SD increase in log₁₀(PAPP-A), 95% CI 2.11–4.18, p < 0.001] in T2DM and (HR = 3.16, 95% CI 2.27–4.39, p < 0.001) in non-T2DM. Among patients with T2DM, PAPP-A showed a larger area under the curve (AUC 0.79) that was significantly more predictive than hsCRP (AUC 0.64), eGFR (AUC 0.66) and LVEF < 50% (AUC 0.52); predictive ability did not improve significantly by including those factors into the model.

Conclusions

Patients with T2DM had higher levels of PAPP-A and increased risk of CV events. Elevated PAPP-A compared to other risk factors was a stronger predictor for future CV events 2 years post ACS in patients with T2DM.

Trial registration ISRCTN10805074. Registered on 20 January 2017, retrospectively registered.

Serum pregnancy-associated plasma protein A levels in the first, second and third trimester of pregnancy: relation to newborn anthropometric parameters and maternal tobacco smoking

INTRODUCTION

The purpose of this study was to evaluate the associations of the first, second and third trimester serum pregnancy-associated plasma protein A (PAPP-A) concentrations with neonatal anthropometric parameters. The effect of tobacco smoking during pregnancy on PAPP-A level was also studied.

MATERIAL AND METHODS

One hundred and fifty healthy pregnant women were divided into smoking and tobacco-abstinent groups. Serum PAPP-A level was measured with the KRYPTOR rapid random-access immunoassay analyzer. The relationship between PAPP-A and newborn related outcome as well as markers of estimated intensity of cigarette smoking was evaluated by univariate and multivariate linear regression.

RESULTS

Pregnancy-associated plasma protein A concentration was positively correlated with birth weight in the first (β = 31.6; p < 0.001), second (β = 10.6; p < 0.05), and third (β = 4.6; p < 0.001) trimester of gestation. A significant association between PAPP-A and birth body length and head circumference in the second (β = 0.02; p < 0.05) and third trimester (β = 0.01; p < 0.01) was also found. The serum PAPP-A levels were significantly lower in the smoking than in the tobacco-abstinent group in each trimester of pregnancy (p < 0.001). The largest impact of the number of cigarettes smoked per day on PAPP-A level was found in the second (β = -1.2; p = 0.004) and third trimester (β = -2.6; p = 0.001).

CONCLUSIONS

Maternal serum PAPP-A levels during gestation might be significant predictors for birth weight. Increased PAPP-A concentrations in the second and third trimester appeared to also be predictive for newborn body length and head circumference. Smoking alters maternal PAPP-A levels in all trimesters, with the greatest impact related to the number of cigarettes smoked per day.

A Plaque Disruption Index Identifies Patients with Non-STE-Type 1 Myocardial Infarction within 24 Hours of Troponin Positivity

Background

Markers of plaque destabilization and disruption may have a role in identifying non-STE- type 1 Myocardial Infarction in patients presenting with troponin elevation. We hypothesized that a plaque disruption index (PDI) derived from multiple biomarkers and measured within 24 hours from the first detectable troponin in patients with acute non-STE- type 1 MI (NSTEMI-A) will confirm the diagnosis and identify these patients with higher specificity when compared to individual markers and coronary angiography.

Methods

We examined 4 biomarkers of plaque destabilization and disruption: myeloperoxidase (MPO), high-sensitivity interleukin-6, myeloid-related protein 8/14 (MRP8/14) and pregnancy-associated plasma protein-A (PAPP-A) in 83 consecutive patients in 4 groups: stable non-obstructive coronary artery disease (CAD), stable obstructive CAD, NSTEMI-A (enrolled within 24 hours of troponin positivity), and NSTEMI-L (Late presentation NSTEMI, enrolled beyond the 24 hour limit). The PDI was calculated and the patients’ coronary angiograms were reviewed for evidence of plaque disruption. The diagnostic performance of the PDI and angiography were compared.

Results

Compared to other biomarkers, MPO had the highest specificity (83%) for NSTEMI-A diagnosis (P<0.05). The PDI computed from PAPP-A, MRP8/14 and MPO was higher in NSTEMI-A patients compared to the other three groups (p<0.001) and had the highest diagnostic specificity (87%) with 79% sensitivity and 86% accuracy, which were higher compared to those obtained with MPO, but did not reach statistical significance (P>0.05 for all comparisons). The PDI had higher specificity and accuracy for NSTEMI-A diagnosis compared to coronary angiography (P<0.05).

Conclusions

A PDI measured within 24 hour of troponin positivity has potential to identify subjects with acute Non-ST-elevation type 1 MI. Additional evidence using other marker combinations and investigation in a sufficiently large non-selected cohort is warranted to establish the diagnostic accuracy of the PDI and its potential role in differentiating type 1 and type 2 MI in patients presenting with troponin elevation of uncertain etiology.

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.