Variability in platelet response to a single daily dose of 150 mg enteric coated aspirin in a high risk population.

PURPOSE: Previous studies have reported inadequate anti-platelet effect in 0.4-35% of patients taking aspirin. Such studies have arbitrarily defined the terms "semi-responders", "non-responders" or "resistant" to variable doses of aspirin on the basis of absolute values derived from different ex-vivo platelet aggregation (PA) methods. Our objective was to define response to 150-mg dose of aspirin in terms of normally distributed values using an ex-vivo measure of PA in a population at high risk for vascular events. METHODS: We prospectively studied high risk patients with either established coronary artery disease (CAD) or stroke or transient ischemic attack (TIA) or peripheral vascular disease or with multiple atherothrombotic risk factors like diabetes plus one of the following-- hypertension, increased total cholesterol, cigarette smoking, micro-albuminuria, low-high density lipoprotein (HDL), family history of CAD and receiving single 150 mg dose of aspirin daily. PA was assessed by chronolog lumi-aggregometer (490-2D) using arachidonic acid (AA) reagent. RESULTS: 130 patients were studied. The response of subjects to aspirin followed a normal, bell shaped distribution curve with a mean and standard deviation (S.D.) of 13.1 +/- 4.4%. 3.1% patients had PA values more than 2 S.D. of the mean, hence termed as hypo-responders to aspirin while another 3.1% patients had PA values less than 2 S.D. of the mean, hence termed as hyper-responders to aspirin. CONCLUSION: There is minimal inter-individual variability in the response to aspirin when tested with AA as the reagent. The response to aspirin follows a normal Gaussian distribution. The prevalence of hypo-responders to aspirin in high risk population is only 3.1%. This is the first study to document "hypo" and "hyper-responders" to single daily dose of 150 mg aspirin. The clinical relevance of these findings remains to be determined.

Indo Heart Survey on latent abnormal glucose regulation in patients with coronary artery disease without diabetes across India.

BACKGROUND: The Euro Heart Survey on diabetes and heart has demonstrated high prevalence of latent glucose abnormalities in non-diabetic patients with coronary artery disease (CAD) in the European population. The aim of our survey was to assess the prevalence of latent abnormal glucose regulation in adult non-diabetic CAD patients in India. METHODS AND RESULTS: Seven centers distributed across India recruited 350 patients. The diagnosis of CAD was done by coronary angiography showing >50% stenosis in any major epicardial coronary artery or its branches. Oral glucose tolerance test (OGTT) and fasting glucose levels were used to characterize glucose metabolism. Venous plasma glucose was measured before (fasting) and 2 hours after ingestion of glucose. Impaired fasting glucose (IFG) was defined as OGTT (0 minute)>or=100 mg/dl but <126 mg/dl and OGTT (2 hours)<140 mg/dl. Impaired glucose tolerance (IGT) was defined as OGTT (0 minute)<126 mg/dl and OGTT (2 hours)>or=140 mg/dl but <200 mg/dl. Of the 350 patients studied, 176 (50.28%) had impaired glucose regulation (IFG-28 [8%]; IGT-148[42.28%]) and 75 (21.42%) had newly detected Diabetes. In all 251 (71.7%) patients with CAD had previously undetected abnormal glucose regulation. CONCLUSION: This survey demonstrates the presence of abnormal glucose regulation in almost three quarters of the non-diabetic Indian CAD patients. OGTT should be recommended as routine screening test for detecting latent glucose abnormalities in all CAD patients.