Aspirinn doses in diabetics Angiolillo Slide 1 Pharmacodynamic

Aspirinn doses in diabetics - Angiolillo Slide 1 Pharmacodynamic Effects of Different Aspirin Dosing Regimens in Type 2 Diabetes Mellitus Patients with Coronary Artery Disease Davide Capodanno, MD, Aasita Patel, MD, Kodlipet Dharmashankar, MD, José Luis Ferreiro, MD, Masafumi Ueno, MD, Murali Kodali, MD, Salvatore D. Tomasello, MD, Piera Capranzano, MD, Naveen Seecheran, MD, Andrew Darlington, MD, Antonio Tello-Montoliu, MD, Ph. D, Bhaloo Desai, Ph. D, Theodore A. Bass, MD, Dominick J. Angiolillo, MD, Ph. D University of Florida, College of Medicine, Jacksonville, USA Circ Card Interv 2011 Ahead of print

Aspirinn doses in diabetics - Angiolillo Slide 2 Background § The reduced life-span and increased turnover rates of platelets have been suggested to have a contributing role in the differential pharmacodynamic response profiles to antiplatelet therapy in type 2 diabetes mellitus (T 2 DM) patients. § Aspirin has only a 20 -minute half-life and therefore the accelerated thrombopoiesis which characterizes T 2 DM patients does not allow newly generated platelets entering the circulation to be sufficiently exposed to aspirin. Winocour, et al. Eur J Clin Invest. 1994; 24 (Suppl 1): 34 -7 Di Minno G, et al Blood. 1983; 61: 1081 -5 Patrono C. N Engl J Med. 1994; 330: 1287 -94

Aspirinn doses in diabetics - Angiolillo Slide 3 Rationale and objective § It may be hypothesized that an increase in the frequency, rather than the dose, of aspirin administration may be a more effective strategy to inhibit platelet reactivity in diabetic patients as this may enable COX-1 blockade of newly generated platelets § Therefore, the aim of the present pilot investigation was to evaluate how increasing the frequency of aspirin administration, remaining within the daily recommended therapeutic doses, affects antiplatelet responsiveness in T 2 DM patients with coronary artery disease (CAD)

Aspirinn doses in diabetics - Angiolillo Slide 4 Schematic of circadian release of platelets into bloodstream from bone marrow and impact of a single daily dose of aspirin on newly generated platelets in type 2 diabetes mellitus Platelets from patients with type 2 diabetes mellitus (T 2 DM) have a reduced life-span and increased turnover rates, leading to enhanced bone marrow megakaryocyte generation and release of new and hyper-reactive platelets into the bloodstream. Aspirin has only a 20 -minute half-life and therefore the accelerated thrombopoiesis which characterizes T 2 DM patients does not allow newly generated platelets entering the circulation to be sufficiently exposed to aspirin if given once daily. This may lead to a considerable proportion of circulating platelets with uninhibited cyclooxigenase-1 (COX-1) activity that continue to generate high levels of serum thromboxane and therefore promote activation of circulating platelets (acetylated and non-acetylated) via thromboxane receptors (TP) on the platelet surface. A twice daily administration of aspirin may allow newly generated platelets released into the bloodstream to be COX-1 inhibited, thus achieving more optimal blockade of platelet activation processes in T 2 DM.

Aspirinn doses in diabetics - Angiolillo Slide 5 Patients modified their aspirin regimen on a weekly basis according to the following scheme Screening phase run-in phase Visit 1 81 mg od Visit 2 81 mg bid Visit 3 162 mg od Visit 4 162 mg bid Visit 5 325 mg od Pharmacodynamic assessments included: § light transmittance aggregometry (LTA) following arachidonic acid, collagen and adenosine diphosphate (ADP) stimuli § Verify. Now-Aspirin assay; § serum thromboxane B 2 (TXB 2) levels

Aspirinn doses in diabetics - Angiolillo Slide 6 Patient population T 2 DM patients screened N = 82 * Key exclusion criteria • active bleeding or bleeding diathesis Excluded * N = 34 Eligible to participate to the study N = 48 Agreed to participate to the study N = 36 Completed all five treatment regimens and entered the final analysis N = 20 • concomitant use of other antithrombotic drugs • recent treatment (30 days) with a glycoprotein IIb/IIIa antagonist • platelet count 100*106/l • acute coronary or cerebrovascular event within 3 months; • serum creatinine > 2 mg/d. L; • baseline ALT > 2. 5 times the upper limit of normal • Hb. A 1 C > 10%

Aspirinn doses in diabetics - Angiolillo Slide 7 Baseline clinical characteristics (n = 20) Age (years±SD) Male, n (%) BMI (Kg/m 2±SD) Risk factors, n (%) Smoking Hypertension Dyslipidemia Insulin-treated Medical history, n (%) Prior MI Prior stroke Prior CABG Multivessel CAD 59± 7 10 (50) 33± 9 6 (30) 19 (95) 17 (85) 8 (40) 1 (5) 0 (0) 2 (10) 6 (30)

Aspirinn doses in diabetics - Angiolillo Slide 8 Medical therapy (n = 20) Beta-blockers ACE inhibitors Ca 2+ antagonists Lipid-lowering agents CYP 3 A 4 pathway metabolized Non-CYP 3 A 4 pathway metabolized Proton pump inhibitors 11 (55) 18 (90) 11 (55) 8 (40) 0 (0) 5 (25) Laboratory data (n = 20) Platelet count (1, 000/mm 3±SD) Hematocrit (%±SD) Hb. A 1 C (%±SD) Creatinine (g/dl±SD) 241± 66 42± 4 7. 1± 1. 3 1. 0± 0. 3

Aspirinn doses in diabetics - Angiolillo Slide 9 Dose comparison in once daily administration 81 mg od vs. 81 mg Assay od 162 md 325 mg od od 81 mg od vs. 162 mg od 325 mg od P value 162 mg od vs 325 mg od P for trend Arachidonic acid (1 mmol/L), % 2± 0. 9 2± 0. 7 1. 000 Collagen (2 µg/m. L), % 44± 23 39± 14 35± 15 0. 285 0. 083 0. 374 0. 157 ADP (5 µmol/L), % 49± 13 54± 10 54± 11 0. 111 0. 851 0. 612 0. 192 ADP (20 µmol/L), % 66± 7 71± 11 68± 7 0. 033 0. 459 0. 145 0. 109 455± 51 432± 62 431± 58 0. 087 0. 126 0. 922 0. 121 107± 143 41± 79 22± 21 0. 008 0. 030 0. 328 0. 008 VN-ASA, ARU Serum TXB 2, pg/ml Data are expressed as means±SD. ADP indicates adenosine diphosphate; VN-ASA indicates Verify. Now-Aspirin assay; TXB 2 indicates thromboxane B 2

Aspirinn doses in diabetics - Angiolillo Slide 10 Dose comparison in twice daily administration Assay 81 mg bid 162 mg bid P value Arachidonic acid (1 mmol/L), % 2± 0. 5 2± 1. 4 0. 106 Collagen (2 µg/m. L), % 32± 14 33± 14 0. 895 ADP (5 µmol/L), % 54± 13 50± 15 0. 360 ADP (20 µmol/L), % 69± 11 67± 14 0. 476 VN-ASA, ARU 420± 41 423± 52 0. 777 Serum TXB 2, pg/ml 34± 50 19± 21 0. 165 Data are expressed as means±SD. ADP indicates adenosine diphosphate; VN-ASA indicates Verify. Now-Aspirin assay; TXB 2 indicates thromboxane B 2

Aspirinn doses in diabetics - Angiolillo Slide 11 Comparison of single versus staggered daily administration of the same aspirin dose 162 mg Assay 325 mg 81 mg bid 162 mg P od bid Arachidonic acid (1 mmol/L), % 2± 0. 7 2± 0. 5 0. 772 2± 0. 7 2± 1. 4 0. 094 Collagen (2 µg/m. L), % 39± 14 32± 14 0. 060 35± 15 33± 14 0. 490 ADP (5 µmol/L), % 54± 10 54± 13 0. 857 54± 11 50± 15 0. 273 ADP (20 µmol/L), % 71± 11 69± 11 0. 343 68± 7 67± 14 0. 751 432± 62 420± 41 0. 345 431± 58 423± 52 0. 551 41± 79 34± 50 0. 716 22± 21 19± 21 0. 579 VN-ASA, ARU Serum TXB 2, pg/ml Data are expressed as means±SD. ADP indicates adenosine diphosphate; VN-ASA indicates Verify. Now-Aspirin assay; TXB 2 indicates thromboxane B 2

Aspirinn doses in diabetics - Angiolillo Slide 12 Comparison of different aspirin regimens by collagen induced light transmission aggregometry (A) and Verify. Now-ASA (B) 80 70 70 p = 0. 046 60 70 p = 0. 015 60 50 40 40 40 % 50 30 30 30 20 20 20 10 10 10 0 0 81 mg od 81 mg bid 2 ug/m. L collagen-LTA B 162 mg od 162 mg bid 2 ug/m. L collagen-LTA 600 500 p = 0. 004 600 500 p = 0. 016 400 ARU 0 81 mg od 162 mg bid 2 ug/m. L collagen-LTA 600 500 300 p = 0. 044 60 50 % % 80 300 200 200 100 100 0 0 81 mg od 81 mg bid VN-ASA p = 0. 515 400 ARU A 80 0 81 mg od 162 mg bid VN-ASA 162 mg od 162 mg bid VN-ASA

Aspirinn doses in diabetics - Angiolillo Slide 13 Changes in thromboxane B 2 levels across the study phases 300 250 p = 0. 003 pg/ml 200 150 100 50 0 81 od 81 bid 162 od 162 bid 325 od Thromboxane B 2 levels are expressed as pg/ml. Error bars indicate standard deviations of the mean. Error bars indicate standard deviations; od indicates once daily administration; bid indicates twice daily administration.

Aspirinn doses in diabetics - Angiolillo Slide 14 Conclusions • Aspirin dosing regimens are associated with different pharmacodynamic effects in platelets from T 2 DM patients and stable CAD. • In particular, a twice daily low-dose aspirin administration is associated with greater platelet inhibition than a once daily administration as assessed by aspirin sensitive assays, and a dosedependent effect is observed on serum TXB 2 levels. • The clinical implications of a modified aspirin regimen tailored to T 2 DM patients warrants further investigation.

Aspirinn doses in diabetics - Angiolillo Slide 15 Circ Card Interv 2011 Ahead of print