Blood Test Predicts Risk of Imminent Cardiac Episode

A blood test that measures pregnancy associated plasma protein-A (PAPP-A) can predict the risk of imminent heart attack or death in patients with acute coronary syndrome (ACS).

The prediction of recurrent ischemic events with high discrimination has been difficult and the PAPP-A assay appears to address a major diagnostic requirement for patients with heart disease and provide physicians with a blood test to predict these events.

Scientists at the Brigham and Women’s Hospital (Boston, MA, USA) enrolled 3,782 patients with non-ST segment elevation (NSTE) – ACS in a study, and followed them for an average on one year. The enzyme PAPP-A was measured in serum by the Active cPAPP-A enzyme-linked immunosorbent assay (ELISA), by personnel blinded to treatment allocation and clinical events. Analytical sensitivity for the Active cPAPP-A assay is 0.18 μIU/mL, and a cut point of 6.0 μIU/mL was chosen from pilot work in a selected cohort.

The results of the study showed that patients with NSTE ACS and an elevated cPAPP-A result were at twice the risk for heart attack or death within 30 days of an initial coronary event, compared to patients without an elevated cPAPP-A result. Patients with a high cPAPP-A result plus elevated values of other blood tests currently used for evaluation of patients in the emergency department with chest pain, were at fivefold risk for heart attack or death within 30 days compared to patients without an elevated CPAPP-A result, but with elevation in other blood markers suggestive of acute myocardial infarction (AMI). The Active cPAPP-A ELISA is a product of Beckman Coulter (Brea, CA, USA).

Marc Bonaca, MD, MPH, a senior author of the study, said, "Our findings add to emerging evidence supporting cPAPP-A as a candidate prognostic marker of recurrent coronary events, and support continued investigation. Hospitalization for recurrent events occurs in up to one in every five patients, but prediction of these events has been difficult. In this context, our findings with cPAPP-A are intriguing for its potential role as a clinical risk predictor." Paula Southwick, PhD, coauthor and group manager of Clinical Research at Beckman Coulter, added, "These results are remarkable and potentially of great clinical significance." The study was published on July 24, 2012, in the Journal of the American College of Cardiology.

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Brigham and Women’s Hospital
Beckman Coulter