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.
Interventionelle Kardiologie Spandau, Berlin, Germany.
Olaf
O
Schulz
Markus
M
Reinicke
Jochen
J
Krämer
Gunnar
G
Berghöfer
Ricarda
R
Bensch
Ingolf
I
Schimke
Allan
A
Jaffe
D000368:Aged; D000704:Analysis of Variance; D000792:Angiography; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002318:Cardiovascular Diseases / Q000097:blood* / Q000175:diagnosis / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis* / Q000276:immunology; D011379:Prognosis
D000911:Antibodies, Monoclonal; D011266:Pregnancy-Associated Plasma Protein-A