Prospective studies of variable platelet response to aspirin and clinical events.
| Study (year) . | Patients (no.; % female; mean age, y) . | Aspirin dose (mean follow-up period) . | Aspirin resistance assay (prevalence) . | Clinical outcome associated with aspirin resistance . |
|---|---|---|---|---|
| Adapted from Maree and Fitzgerald, with permission.1 | ||||
| Abbreviations: TID, three times a day; OR, overall response; MI, myocardial infarction;CVA, cerebrovascular accident; ASA, aspirin; PCI, percutaneous coronary intervention; CK-MB, creatine kinase isoenzyme MB; HR, hazard ratio | ||||
| Resistance defined as persistent aggregation to ADP and collagen. | ||||
| †Resistence defined as mean aggregation ≥70% with 10 μM ADP and mean aggregation of ≥20% with 0.5 mg/mL arachidonic acid. | ||||
| ‡Propyl gallate agonist, resistance defined as ≥550 aspirin response units. | ||||
| §Resistence defined as 2 of 3 assays positive. | ||||
| Grotemeyer et al16 (1993) | Prior CVA (180; 41; 58) | 500 mg TID (2 y) | Platelet reactivity test (33%) | OR 14.53 (5.16–40.9); P < .0001 Risk of stroke, MI or vascular death |
| Mueller et al17 (1997) | Intermittent claudication (100; 30; 62.5) | 100 mg/d (1.5 y) | Corrected whole blood aggregometry* | 87% higher risk of lesion reocclusion post peripheral vascular angioplasty (P = .009) |
| Eikelboom et al18 (2002) | High cardiovascular risk (976; 15.8; 67) | Unspecified (5 y) | Urinary 11-dehydro TXB2 (quartile comparison) | Upper versus lower quartile OR 1.8 (1.2–2.7) Risk of MI, CVA or cardiovascular death |
| Gum et al19 (2003) | Stable coronary artery disease (326; 22.4; 62) | 325 mg/d (1.86 y) | Optical aggregometry (5.2%)† | OR 3.12 (1.1–8.9) Risk of MI, CVA, all cause death |
| Chen et al20 (2004) | Non-urgent PCI (151; 24.5; 64) | 80–325 mg (24 h) | Ultegra rapid platelet function assay- ASA 19.2%‡ | OR 3.29 (1.42–7.59); P < .01 Risk of myonecrosis post PCI (CK-MB = 16 U/L) |
| Poston et al21 (2006) | Patients undergoing off- pump coronary artery bypass grafting (225; 34; 69) | 325 mg/d (30 d) | Thromboelastography§ Whole blood sggregometry (collagen) 11-dehydro-TXB2 (30%) | Early SVG thrombosis - 45% ASA resistant versus patent SVG 20% ASA resistant; P < .05 |
| Ohmori et al22 (2006) | Prior cerebral infarct or ischemic heart disease (140; 53.7; 75.4) | 81 mg (1 y) | Optical aggregometry (collagen) PA-20 platelet aggregation analyzer (quartile comparison) | HR 7.98; P = .008 Risk of cardiovascular events if upper quartile (optical aggregometry) HR 7.76; P = .007 Risk of cardiovascular events (PA-20 analysis) |
| Study (year) . | Patients (no.; % female; mean age, y) . | Aspirin dose (mean follow-up period) . | Aspirin resistance assay (prevalence) . | Clinical outcome associated with aspirin resistance . |
|---|---|---|---|---|
| Adapted from Maree and Fitzgerald, with permission.1 | ||||
| Abbreviations: TID, three times a day; OR, overall response; MI, myocardial infarction;CVA, cerebrovascular accident; ASA, aspirin; PCI, percutaneous coronary intervention; CK-MB, creatine kinase isoenzyme MB; HR, hazard ratio | ||||
| Resistance defined as persistent aggregation to ADP and collagen. | ||||
| †Resistence defined as mean aggregation ≥70% with 10 μM ADP and mean aggregation of ≥20% with 0.5 mg/mL arachidonic acid. | ||||
| ‡Propyl gallate agonist, resistance defined as ≥550 aspirin response units. | ||||
| §Resistence defined as 2 of 3 assays positive. | ||||
| Grotemeyer et al16 (1993) | Prior CVA (180; 41; 58) | 500 mg TID (2 y) | Platelet reactivity test (33%) | OR 14.53 (5.16–40.9); P < .0001 Risk of stroke, MI or vascular death |
| Mueller et al17 (1997) | Intermittent claudication (100; 30; 62.5) | 100 mg/d (1.5 y) | Corrected whole blood aggregometry* | 87% higher risk of lesion reocclusion post peripheral vascular angioplasty (P = .009) |
| Eikelboom et al18 (2002) | High cardiovascular risk (976; 15.8; 67) | Unspecified (5 y) | Urinary 11-dehydro TXB2 (quartile comparison) | Upper versus lower quartile OR 1.8 (1.2–2.7) Risk of MI, CVA or cardiovascular death |
| Gum et al19 (2003) | Stable coronary artery disease (326; 22.4; 62) | 325 mg/d (1.86 y) | Optical aggregometry (5.2%)† | OR 3.12 (1.1–8.9) Risk of MI, CVA, all cause death |
| Chen et al20 (2004) | Non-urgent PCI (151; 24.5; 64) | 80–325 mg (24 h) | Ultegra rapid platelet function assay- ASA 19.2%‡ | OR 3.29 (1.42–7.59); P < .01 Risk of myonecrosis post PCI (CK-MB = 16 U/L) |
| Poston et al21 (2006) | Patients undergoing off- pump coronary artery bypass grafting (225; 34; 69) | 325 mg/d (30 d) | Thromboelastography§ Whole blood sggregometry (collagen) 11-dehydro-TXB2 (30%) | Early SVG thrombosis - 45% ASA resistant versus patent SVG 20% ASA resistant; P < .05 |
| Ohmori et al22 (2006) | Prior cerebral infarct or ischemic heart disease (140; 53.7; 75.4) | 81 mg (1 y) | Optical aggregometry (collagen) PA-20 platelet aggregation analyzer (quartile comparison) | HR 7.98; P = .008 Risk of cardiovascular events if upper quartile (optical aggregometry) HR 7.76; P = .007 Risk of cardiovascular events (PA-20 analysis) |