Stroke Tied to Withdrawal of Antithrombotic Medication

SAN FRANCISCO — As many as 26,500 ischemic strokes occurring in the United States each year may be associated with patient withdrawal from antithrombotic and antiplatelet medications, according to a study presented at the International Stroke Conference.

Among 2,082 patients in the Cincinnati area who had 2,191 ischemic strokes in 2005, 84 (3.8%) of the strokes occurred in patients who had stopped their medications within 60 days. The first 7 days after withdrawal of antiplatelet or antithrombotic medication appeared to be the most dangerous time, Dr. Jordan Bonomo of the University of Cincinnati reported. Some patients had been on more than one medication simultaneously.

A total of 182 strokes occurred in patients who were either on warfarin or recently had stopped taking the drug. Of the 58 strokes that occurred in those who went off warfarin, 31 were within 7 days of withdrawal, 12 between 8 and 14 days, 8 between 15 and 30 days, and 7 between 31 and 60 days.

Similarly, 896 patients had been taking aspirin around the time of their stroke. Of these, 44 had discontinued aspirin; 24 of the strokes occurred within 7 days after halting aspirin therapy; 7 occurred between 8 and 14 days, 11 between 15 and 30 days, and 2 between 31 and 60 days.

The investigators found a similar pattern among 228 patients who had been taking clopidogrel around the time of their stroke, 21 of whom had gotten off the drug—10 strokes occurred within 7 days of discontinuation, 4 between 8 and 14 days, 5 between 15 and 30 days, and 2 between 31 and 60 days.

Dr. Bonomo noted that the greater Cincinnati area is demographically similar to the overall U.S. population. Therefore, of the 692,000 ischemic strokes that occur annually in the United States, an estimated 26,500 occur in patients who have withdrawn from antithrombotic or antiplatelet medications within 60 days.

Of the 84 strokes, 54 (64%) occurred in patients whose medication had been withdrawn on the order of their physicians.

In most cases, physicians ordered withdrawal because of an upcoming medical procedure or because of bleeding. Among the withdrawals that occurred when the patient stopped their medication on their own, noncompliance and financial burden were the most common causes.

These results “mandate continued review of guidelines for withdrawal of anticoagulant and antiplatelet medication in the peri-procedural period,” Dr. Bonomo said. To investigate these matters further, the National Heart, Lung, and Blood Institute is funding a clinical trial called Effectiveness of Bridging Anticoagulation for Surgery (The BRIDGE Study) that will begin in May 2009.

Dr. Bonomo stated that he had no conflicts of interest to disclose. The study was supported by the National Institute of Neurological Disorders and Stroke.

SAN FRANCISCO — As many as 26,500 ischemic strokes occurring in the United States each year may be associated with patient withdrawal from antithrombotic and antiplatelet medications, according to a study presented at the International Stroke Conference.

Among 2,082 patients in the Cincinnati area who had 2,191 ischemic strokes in 2005, 84 (3.8%) of the strokes occurred in patients who had stopped their medications within 60 days. The first 7 days after withdrawal of antiplatelet or antithrombotic medication appeared to be the most dangerous time, Dr. Jordan Bonomo of the University of Cincinnati reported. Some patients had been on more than one medication simultaneously.

A total of 182 strokes occurred in patients who were either on warfarin or recently had stopped taking the drug. Of the 58 strokes that occurred in those who went off warfarin, 31 were within 7 days of withdrawal, 12 between 8 and 14 days, 8 between 15 and 30 days, and 7 between 31 and 60 days.

Similarly, 896 patients had been taking aspirin around the time of their stroke. Of these, 44 had discontinued aspirin; 24 of the strokes occurred within 7 days after halting aspirin therapy; 7 occurred between 8 and 14 days, 11 between 15 and 30 days, and 2 between 31 and 60 days.

The investigators found a similar pattern among 228 patients who had been taking clopidogrel around the time of their stroke, 21 of whom had gotten off the drug—10 strokes occurred within 7 days of discontinuation, 4 between 8 and 14 days, 5 between 15 and 30 days, and 2 between 31 and 60 days.

Dr. Bonomo noted that the greater Cincinnati area is demographically similar to the overall U.S. population. Therefore, of the 692,000 ischemic strokes that occur annually in the United States, an estimated 26,500 occur in patients who have withdrawn from antithrombotic or antiplatelet medications within 60 days.

Of the 84 strokes, 54 (64%) occurred in patients whose medication had been withdrawn on the order of their physicians.

In most cases, physicians ordered withdrawal because of an upcoming medical procedure or because of bleeding. Among the withdrawals that occurred when the patient stopped their medication on their own, noncompliance and financial burden were the most common causes.

These results “mandate continued review of guidelines for withdrawal of anticoagulant and antiplatelet medication in the peri-procedural period,” Dr. Bonomo said. To investigate these matters further, the National Heart, Lung, and Blood Institute is funding a clinical trial called Effectiveness of Bridging Anticoagulation for Surgery (The BRIDGE Study) that will begin in May 2009.

Dr. Bonomo stated that he had no conflicts of interest to disclose. The study was supported by the National Institute of Neurological Disorders and Stroke.

SAN FRANCISCO — As many as 26,500 ischemic strokes occurring in the United States each year may be associated with patient withdrawal from antithrombotic and antiplatelet medications, according to a study presented at the International Stroke Conference.

Among 2,082 patients in the Cincinnati area who had 2,191 ischemic strokes in 2005, 84 (3.8%) of the strokes occurred in patients who had stopped their medications within 60 days. The first 7 days after withdrawal of antiplatelet or antithrombotic medication appeared to be the most dangerous time, Dr. Jordan Bonomo of the University of Cincinnati reported. Some patients had been on more than one medication simultaneously.

A total of 182 strokes occurred in patients who were either on warfarin or recently had stopped taking the drug. Of the 58 strokes that occurred in those who went off warfarin, 31 were within 7 days of withdrawal, 12 between 8 and 14 days, 8 between 15 and 30 days, and 7 between 31 and 60 days.

Similarly, 896 patients had been taking aspirin around the time of their stroke. Of these, 44 had discontinued aspirin; 24 of the strokes occurred within 7 days after halting aspirin therapy; 7 occurred between 8 and 14 days, 11 between 15 and 30 days, and 2 between 31 and 60 days.

The investigators found a similar pattern among 228 patients who had been taking clopidogrel around the time of their stroke, 21 of whom had gotten off the drug—10 strokes occurred within 7 days of discontinuation, 4 between 8 and 14 days, 5 between 15 and 30 days, and 2 between 31 and 60 days.

Dr. Bonomo noted that the greater Cincinnati area is demographically similar to the overall U.S. population. Therefore, of the 692,000 ischemic strokes that occur annually in the United States, an estimated 26,500 occur in patients who have withdrawn from antithrombotic or antiplatelet medications within 60 days.

Of the 84 strokes, 54 (64%) occurred in patients whose medication had been withdrawn on the order of their physicians.

In most cases, physicians ordered withdrawal because of an upcoming medical procedure or because of bleeding. Among the withdrawals that occurred when the patient stopped their medication on their own, noncompliance and financial burden were the most common causes.

These results “mandate continued review of guidelines for withdrawal of anticoagulant and antiplatelet medication in the peri-procedural period,” Dr. Bonomo said. To investigate these matters further, the National Heart, Lung, and Blood Institute is funding a clinical trial called Effectiveness of Bridging Anticoagulation for Surgery (The BRIDGE Study) that will begin in May 2009.

Dr. Bonomo stated that he had no conflicts of interest to disclose. The study was supported by the National Institute of Neurological Disorders and Stroke.