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Antiplatelet Drug Discontinuation May Increase Stroke Risk

It may be time for reappraisal of routine antiplatelet drug discontinuation before surgeries.

These authors retrospectively examined stroke risk following temporary antiplatelet drug (APD) discontinuation, a standard practice before surgical procedures. During three 1.5-month periods, 320 patients were admitted for intracerebral hemorrhage (ICH), transient ischemic attack (TIA), or ischemic stroke (IS). Patients (or family members) completed a structured questionnaire about drugs taken at the time of hospitalization and any medication changes during the month before hospitalization.

Of the 320 patients, 31 had an ICH; 10 had been on APD therapy (no data on discontinuation were reported). The remaining 289 patients had an IS or TIA; of these, 36% had been taking an APD, and 13 (4.5%) had discontinued the APD during the prior month. Of the 13, 7 had an IS, 6 had a TIA; 11 had taken aspirin, 1 had taken clopidogrel, and 1 had taken aspirin/dipyridamole (time from discontinuation to ischemic event, 6-10 days). The APD had been prescribed for coronary artery disease in 7 patients, stroke in 4, and peripheral artery disease in 2. Ten of the 11 aspirin recipients had strokes classified as atherosclerotic and 1 as lacunar. The authors conclude that stopping an APD is riskier in patients with multiple stroke risk factors than in those without risk factors.

Comment: This is a difficult study to interpret. As the authors note, some stroke patients may not have been identified. Data were virtually absent about risk factors in the 313 stroke patients who were not taking an APD and about how these patients differed from the 13 who had discontinued APDs. The retrospective evaluation and assessment of TIA and IS together may have introduced biases. The percentage of all ischemic events that were TIAs was not provided. The criteria for designating a stroke atherosclerotic were not described, so it is unknown whether these patients had high-grade symptomatic ICA stenosis.

Nonetheless, these observations are intriguing. In a preliminary report, Ferrari identified a similar association between APD discontinuation and acute coronary syndromes (American College of Chest Physicians Meeting, Orlando, October 2003). The clustering of ischemic events at a time when the biologic effect of the APDs should be significantly decreased or absent raises concerns about APD withdrawal triggering ischemic events in this high-risk population. Even if the risk is small, the burden of proof should be to demonstrate that continued administration of APDs constitutes a higher risk than discontinuation.

Recent findings do not demonstrate increased bleeding risk or complications with continued APD therapy during most surgeries (e.g., J Am Dental Assoc 2000; 131:331; Acta Ophthalmologica Scand 2003; 81:38; Mayo Clin Proc 2003; 78:1392; Gastrointestinal Endoscopy 2004; 59:44; Am Heart J 2004; 147:31; and Ann Thoracic Surg 2003; 76:41). Also, data on coronary bypass grafting, though somewhat conflicting, suggest overall that APDs may be continued safely up until the surgery (Ann Thoracic Surg 2000; 70:1986 and Ann Thoracic Surg 2003; 76:41). It may be time for a reappraisal of routine APD discontinuation before surgeries.

— Fenwick T. Nichols, MD

Dr. Nichols is Professor of Neurology and Radiology, Medical College of Georgia, Augusta.

Published in Journal Watch Neurology August 26, 2004

Citation(s):

Sibon I and Orgogozo J-M. Antiplatelet drug discontinuation is a risk factor for ischemic stroke. Neurology 2004 Apr 13; 62:1187-9.

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