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.

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.

Cys327Cys polymorphism of the PAPP-A gene (pregnancy associated plasma protein A) is related to mortality of long term hemodialysis patients

OBJECTIVES

PAPP-A is an independent mortality predictor of long term hemodialysis patients and a prognostic marker of acute coronary syndrome in general population. Cys327Cys PAPP-A polymorphism (SNP) (rs12375498) was found to be of significance in preeclampsia and the C allele of the PAPP-A C/G SNP (rs13290387) was defined as an independent risk factor for acute myocardial infarction. The aim of the study was to test the role of these PAPP-A SNPs in long term hemodialysis patients.

DESIGN AND METHODS

The studied group consisted of 464 subjects - 319 long term hemodialysis patients (183 men, 136 women, 62±14years) and 145 controls (65 men, 80 women, 49±14years). A subgroup of 211 hemodialysis patients (118 men, 93 women, 63±13years) was prospectively followed up for 4.5years. During the follow up, 111 patients died, 51 of them due to cardiovascular events. PAPP-A SNPs were analyzed by DNA sequencing and serum PAPP-A was measured by TRACE.

RESULTS

Both SNPs were in Hardy-Weinberg equilibrium. Allelic and genotype frequencies did not differ between patients and controls and were not related to serum PAPP-A concentrations. Cys327Cys SNP was significant for patients' survival (HR (95% CI): 1.616 (1.110-2.353), nominal p=0.012, corrected p=0.036) while C/G SNP was not.

CONCLUSIONS

Our study shows for the first time the significance of Cys327Cys PAPP-A SNP (rs12375498) for overall mortality of long term hemodialysis patients. Although it does not influence the concentration of PAPP-A it still could affect the correct function of this enzyme which has to be clarified in further studies.

Mortality rates and mortality predictors in patients with symptomatic peripheral artery disease stratified according to age and diabetes

OBJECTIVE

Atherosclerotic peripheral arterial disease (PAD) is one of the most prevalent, morbid, and mortal diseases. The aim of this study was to evaluate mortality rates of patients with atherosclerotic PAD stratified according to age and diabetes and to determine predictors of death.

METHODS

We studied 487 patients with symptomatic PAD consecutively admitted to the hospital. This cohort included the following four patient subgroups: (1) 216 patients with PAD <75 years of age without diabetes mellitus; (2) 115 patients with PAD < 75 years of age with diabetes mellitus; (3) 102 patients with PAD ≥ 75 years of age without diabetes mellitus; and (4) 54 patients with PAD ≥ 75 years of age with diabetes mellitus. Control subjects without atherosclerotic disease were matched to the patients with PAD in a 1:1 design by sex, age (± 2 years), and diabetes mellitus status. Outcome measure was all-cause mortality at 5 years.

RESULTS

Mortality rates at 5 years were 10% in nondiabetic patients with PAD < 75 years of age (vs 5% in control subjects; risk ratio [RR], 2.15; 95% confidence interval [CI], 1.60-4.34); 23% in diabetic patients with PAD < 75 years of age (vs 7% in control subjects; RR, 3.53; 95% CI, 1.80-6.91); 38% in nondiabetic patients with PAD ≥ 75 years of age (vs 22% in control subjects; RR, 2.08; 95% CI, 1.26-3.44); and 52% in diabetic patients with PAD ≥ 75 years of age. Applying multivariate Cox proportional hazards regression analyses (with cardiovascular risk factors, coexisting atherosclerotic disease, clinical stage of PAD, and several biochemical markers as predictor variables), we found the following independent predictors of outcome: in the 216 nondiabetic patients with PAD < 75 years of age, high-sensitivity C-reactive protein (hs-CRP) (RR, 3.04; 95% CI, 1.48-6.26); in the 115 diabetic patients with PAD < 75 years of age, amino-terminal pro-B-type natriuretic peptide (NT-proBNP) (RR, 2.63; 95% CI, 1.65-4.19); in the 102 nondiabetic patients with PAD ≥ 75 years of age, critical limb ischemia (RR, 3.70; 95% CI, 1.82-7.52) and NT-proBNP (RR, 1.93; 95% CI, 1.32-2.82); and in the 54 diabetic patients with PAD ≥ 75 years of age, hs-CRP (RR, 2.61; 95% CI, 1.45-4.67) and NT-proBNP (RR, 3.31; 95% CI, 1.96-5.60).

CONCLUSIONS

Mortality rates at 5 years varied considerably among patients with PAD stratified according to age and diabetes. Predictors of death differed among the four patient subgroups in this study and included critical limb ischemia, hs-CRP, and NT-proBNP. Our results might help to develop future strategies for optimized treatment of hospitalized patients with symptomatic PAD.

Pregnancy-associated plasma protein A as an independent mortality predictor in long-term hemodialysis patients

BACKGROUND/AIMS

Pregnancy-associated plasma protein A (PAPP-A) is a biomarker related to vascular damage. The aim of the study was to focus on PAPP-A and related parameters and their relationship to the prognosis of long-term hemodialysis (HD) patients.

METHODS

This is a prospective observational cohort study which included 261 long-term HD patients followed up for 5 years and 66 healthy subjects. PAPP-A, placental growth factor (PlGF), matrix metalloproteinase 2 and 9 (MMP-2, MMP-9), insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein-4 (IGFBP-4), and cardiac, nutritional and inflammatory parameters were measured at the beginning of the study and tested as predictors of mortality.

RESULTS

PAPP-A, PlGF, IGF-1, IGFBP-4 and MMP-2 were significantly increased in HD patients compared to controls (PAPP-A 27.6 ± 15.5 mIU/l in HD vs. 9.4 ± 2.5 mIU/l in controls, p < 0.001). Increased PAPP-A was a significant independent predictor of overall mortality and mortality due to infection in the multivariate Cox analysis [HR (95% CI): 1.237 (1.060-1.444), p = 0.007, and 1.416 (1.115-1.798), p = 0.004, per standard deviation, respectively]. PAPP-A was not related to cardiovascular mortality.

CONCLUSION

Increased PAPP-A is a significant independent predictor of overall mortality and mortality due to infection but it was not related to cardiovascular mortality in this study.