Background: Pregnancy-associated plasma protein A (PAPP-A) is a potentially proatherosclerotic metalloproteinase, which has been shown to be abundantly expressed in ruptured unstable plaques. However, changes of the PAPP-A blood levels in patients with coronary artery disease (CAD) according to the Gensini score is unknown in Turkish population.
Objective: We hypothesized that pregnancy-associated plasma protein A (PAPP-A) levels might be important in determining the degree of CAD severity and extent according to its relationship with inflammation in the partly unstable plaque area and with proliferative stimulation overall.
Methods: Our study population included 145 consecutive patients, who underwent elective diagnostic coronary angiography because of CAD symptoms such as chest pain or shortness of breath. The severity and the extent of CAD were evaluated using the Gensini score. Plasma PAPP-A concentrations were determined by ELISA.
Results: Among the 145 study patients (mean age 57 ± 10 years; 97 men and 48 women), 80 had mild CAD (Gensini score <20, group 1), 65 had severe CAD (Gensini score ≥ 20, group 2). PAPP-A levels were significantly higher in group 2 than they were in group 1 (2.7 ± 2.7 μg/ml vs. 1.12 ± 1.3 μg/ml, p < 0.001, respectively). PAPPA levels revealed a moderately positive linear correlation with Gensini scores (r = 0.435; p < 0.001). In addition, there was a weak, but still a positive correlation between PAPP-A levels and age (r = 0.174; p = 0.03).
Conclusion: There is still a need for large epidemiological studies to better understand the mechanisms and prognostic roles of both PAPP-A and insulin-like growth factor 1 in asymptomatic subjects and in subjects with well-documented CAD. If the results were promising, the measurement of PAPP-A may become a clinically important tool for risk stratification in patients with chest pain.