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Anticoagulation after anterior myocardial infarction and the risk of stroke.

Udell JA, Wang JT, Gladstone DJ, Tu JV - PLoS ONE (2010)

Bottom Line: The primary outcome was four-year ischemic stroke rates compared between anterior and non-anterior MI patients.The use of angiotensin-converting-enzyme inhibitors (HR, 0.65; 95% CI, 0.44-0.95) and beta-blockers (HR, 0.60; 95% CI, 0.41-0.87) were associated with a significant decrease in stroke risk.There was no significant difference in bleeding-related hospitalizations in patients who used warfarin for up to 90 days post-MI.

View Article: PubMed Central - PubMed

Affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada. judell@partners.org

ABSTRACT

Background: Survivors of anterior MI are at increased risk for stroke with predilection to form ventricular thrombus. Commonly patients are discharged on dual antiplatelet therapy. Given the frequency of early coronary reperfusion and risk of bleeding, it remains uncertain whether anticoagulation offers additional utility. We examined the effectiveness of anticoagulation therapy for the prevention of stroke after anterior MI.

Methods and findings: We performed a population-based cohort analysis of 10,383 patients who survived hospitalization for an acute MI in Ontario, Canada from April 1, 1999 to March 31, 2001. The primary outcome was four-year ischemic stroke rates compared between anterior and non-anterior MI patients. Risk factors for stroke were assessed by multivariate Cox proportional-hazards analysis. Warfarin use was determined at discharge and followed for 90 days among a subset of patients aged 66 and older (n = 1483). Among the 10,383 patients studied, 2,942 patients survived hospitalization for an anterior MI and 20% were discharged on anticoagulation therapy. Within 4 years, 169 patients (5.7%) were admitted with an ischemic stroke, half of which occurred within 1-year post-MI. There was no significant difference in stroke rate between anterior and non-anterior MI patients. The use of warfarin up to 90 days was not associated with stroke protection after anterior MI (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.37-1.26). The use of angiotensin-converting-enzyme inhibitors (HR, 0.65; 95% CI, 0.44-0.95) and beta-blockers (HR, 0.60; 95% CI, 0.41-0.87) were associated with a significant decrease in stroke risk. There was no significant difference in bleeding-related hospitalizations in patients who used warfarin for up to 90 days post-MI.

Conclusion: Many practitioners still consider a large anterior-wall MI as high risk for potential LV thrombus formation and stroke. Among a cohort of elderly patients who survived an anterior MI there was no benefit from the use of warfarin up to 90 days post-MI to prevent ischemic stroke. Our data suggests that routine anticoagulation of patients with anterior-wall MI may not be indicated. Prospective randomized trials are needed to determine the optimal antithrombin strategy for preventing this common and serious adverse outcome.

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Related in: MedlinePlus

Adjusted Ischemic Stroke-Free Survival among 1,483 Elderly Patients with Anterior Myocardial Infarction.Survival curves are stratified by warfarin use for up to 90 consecutive days after an anterior MI. The curve in pink represents patients prescribed warfarin (patient received one or more prescriptions for warfarin after discharge). The curve in blue represents patients not prescribed warfarin.
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pone-0012150-g001: Adjusted Ischemic Stroke-Free Survival among 1,483 Elderly Patients with Anterior Myocardial Infarction.Survival curves are stratified by warfarin use for up to 90 consecutive days after an anterior MI. The curve in pink represents patients prescribed warfarin (patient received one or more prescriptions for warfarin after discharge). The curve in blue represents patients not prescribed warfarin.

Mentions: Independent predictors of stroke after anterior MI were determined by multivariate analysis and are reported in Table 4. A previous history of diabetes mellitus (hazard ratio [HR], 2.35; 95% confidence interval [CI], 1.63–3.40) and receiving antiarrhythmic therapy or digoxin (HR, 1.60; 95% CI, 1.01–2.52) were independent predictors of stroke following anterior MI. Receiving a beta-blocker (HR, 0.60; 95% CI, 0.41–0.87) or an ACE inhibitor (HR, 0.65; 95% CI, 0.44–0.95) upon discharge for anterior MI were significant protective factors, but warfarin use for up to 90 days post-MI was not (HR, 0.68; 95% CI, 0.37–1.26). Thirty-seven percent of patients discharged on warfarin were also prescribed an antiarrhythmic agent or digoxin, representing a significant interaction (φ = 0.24, p<0.0001). The adjusted stroke-free survival analysis in patients surviving an anterior MI according to warfarin use is shown in Figure 1.


Anticoagulation after anterior myocardial infarction and the risk of stroke.

Udell JA, Wang JT, Gladstone DJ, Tu JV - PLoS ONE (2010)

Adjusted Ischemic Stroke-Free Survival among 1,483 Elderly Patients with Anterior Myocardial Infarction.Survival curves are stratified by warfarin use for up to 90 consecutive days after an anterior MI. The curve in pink represents patients prescribed warfarin (patient received one or more prescriptions for warfarin after discharge). The curve in blue represents patients not prescribed warfarin.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2921337&req=5

pone-0012150-g001: Adjusted Ischemic Stroke-Free Survival among 1,483 Elderly Patients with Anterior Myocardial Infarction.Survival curves are stratified by warfarin use for up to 90 consecutive days after an anterior MI. The curve in pink represents patients prescribed warfarin (patient received one or more prescriptions for warfarin after discharge). The curve in blue represents patients not prescribed warfarin.
Mentions: Independent predictors of stroke after anterior MI were determined by multivariate analysis and are reported in Table 4. A previous history of diabetes mellitus (hazard ratio [HR], 2.35; 95% confidence interval [CI], 1.63–3.40) and receiving antiarrhythmic therapy or digoxin (HR, 1.60; 95% CI, 1.01–2.52) were independent predictors of stroke following anterior MI. Receiving a beta-blocker (HR, 0.60; 95% CI, 0.41–0.87) or an ACE inhibitor (HR, 0.65; 95% CI, 0.44–0.95) upon discharge for anterior MI were significant protective factors, but warfarin use for up to 90 days post-MI was not (HR, 0.68; 95% CI, 0.37–1.26). Thirty-seven percent of patients discharged on warfarin were also prescribed an antiarrhythmic agent or digoxin, representing a significant interaction (φ = 0.24, p<0.0001). The adjusted stroke-free survival analysis in patients surviving an anterior MI according to warfarin use is shown in Figure 1.

Bottom Line: The primary outcome was four-year ischemic stroke rates compared between anterior and non-anterior MI patients.The use of angiotensin-converting-enzyme inhibitors (HR, 0.65; 95% CI, 0.44-0.95) and beta-blockers (HR, 0.60; 95% CI, 0.41-0.87) were associated with a significant decrease in stroke risk.There was no significant difference in bleeding-related hospitalizations in patients who used warfarin for up to 90 days post-MI.

View Article: PubMed Central - PubMed

Affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada. judell@partners.org

ABSTRACT

Background: Survivors of anterior MI are at increased risk for stroke with predilection to form ventricular thrombus. Commonly patients are discharged on dual antiplatelet therapy. Given the frequency of early coronary reperfusion and risk of bleeding, it remains uncertain whether anticoagulation offers additional utility. We examined the effectiveness of anticoagulation therapy for the prevention of stroke after anterior MI.

Methods and findings: We performed a population-based cohort analysis of 10,383 patients who survived hospitalization for an acute MI in Ontario, Canada from April 1, 1999 to March 31, 2001. The primary outcome was four-year ischemic stroke rates compared between anterior and non-anterior MI patients. Risk factors for stroke were assessed by multivariate Cox proportional-hazards analysis. Warfarin use was determined at discharge and followed for 90 days among a subset of patients aged 66 and older (n = 1483). Among the 10,383 patients studied, 2,942 patients survived hospitalization for an anterior MI and 20% were discharged on anticoagulation therapy. Within 4 years, 169 patients (5.7%) were admitted with an ischemic stroke, half of which occurred within 1-year post-MI. There was no significant difference in stroke rate between anterior and non-anterior MI patients. The use of warfarin up to 90 days was not associated with stroke protection after anterior MI (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.37-1.26). The use of angiotensin-converting-enzyme inhibitors (HR, 0.65; 95% CI, 0.44-0.95) and beta-blockers (HR, 0.60; 95% CI, 0.41-0.87) were associated with a significant decrease in stroke risk. There was no significant difference in bleeding-related hospitalizations in patients who used warfarin for up to 90 days post-MI.

Conclusion: Many practitioners still consider a large anterior-wall MI as high risk for potential LV thrombus formation and stroke. Among a cohort of elderly patients who survived an anterior MI there was no benefit from the use of warfarin up to 90 days post-MI to prevent ischemic stroke. Our data suggests that routine anticoagulation of patients with anterior-wall MI may not be indicated. Prospective randomized trials are needed to determine the optimal antithrombin strategy for preventing this common and serious adverse outcome.

Show MeSH
Related in: MedlinePlus