A study of carcinoembryonic antigen concentrations in patients with coronary artery disease

Carcinoembryonic antigen (CEA) is a tumour marker whose role is now being evaluated as a biomarker for early diagnosis of acute coronary syndromes. Its levels may rise even prior to rise of established biomarkers of myocardial necrosis. Serum CEA concentrations were measured by double sandwich ELISA method in four groups of subjects with STEMI, NSTEMI/UA (24 patients of NSTEMI and 18 patients of unstable angina), stable angina and healthy controls with 42 males between 40 to 60 years of age in each group. Also qualitative Troponin T assay and CPK-MB concentrations measurement was done in groups with STEMI and NSTEMI/UA and correlations between CEA concentrations and Troponin T and CPK-MB were made. Mean serum CEA concentrations were 5.19 ± 0.39, 3.84 ± 0.34, 3.91 ± 1.40, 1.84 ± 0.35 and 2.12 ± 0.40 ng/ml respectively in groups with STEMI, NSTEMI/UA, UA alone, stable CAD and healthy controls respectively. STEMI, NSTEMI/UA and UA patients had significantly higher concentrations than stable CAD and healthy controls (p < 0.001). CEA concentrations were comparable in stable CAD and healthy controls (p = 1.00). Mean serum CPK- MB concentration in group with STEMI was significantly higher than in NSTEMI/UA group (p < 0.001). Highly significant positive correlation was obtained between mean CEA and CPK-MB concentrations in STEMI (R = 0.866, p < 0.001) and NSTEMI (R = 0.950, p < 0.001), STEMI and NSTEMI combined together (R = 0.781, p < 0.001) NSTEMI and UA together (R = 0.648, p < 0.001), but it was weak and statistically insignificant in UA patients (R = 0.319, p = 0.197). Mean serum concentration 4.69 ± 3.26 ng/ml of CEA in patients with ACS was significantly higher in troponin T positive patients as compared to 3.91 ± 1.40 ng/ml in Troponin T negative patients (p < 0.001). CEA is a sensitive biomarker for early diagnosis of ACS. Its levels correlate with severity of ACS. It may play a crucial role in diagnosis of ACS in patients who present with atypical manifestations or when traditional biomarkers such as CPK-MB and Troponins are not raised.