Occurrence of Secondary Ischemic Events Among Persons With Atherosclerotic Vascular Disease

Abstract

Background and Purpose-Few data exist for large managed care populations on the occurrence of subsequent acute ischemic events in persons with established atherosclerotic vascular disease. We estimated the occurrence of secondary stroke, acute myocardial infarction (AMI), and vascular deaths among 2 large, managed care samples. Methods-With the use of International Classification of Diseases, Ninth Revision, Clinical Modification codes, patients aged Ն40 years and with stroke, AMI, or peripheral arterial disease (PAD) were identified from administrative data of UnitedHealthcare plans during 1995-1998. Stroke, AMI, and PAD cohorts were identified within a commercial insurance sample and a Medicare sample. Cumulative occurrences of subsequent stroke, AMI, or vascular death were estimated by survival analysis. Results-In the stroke commercial cohort (nϭ1631; mean age, 62.1 years), cumulative occurrence of subsequent events was 4.2%, 6.5%, 9.8%, and 11.8% at 0.5, 1, 2, and 3 years, respectively; cumulative secondary event occurrence in the AMI commercial cohort (nϭ6458; mean age, 56.0 years) was 3.5%, 4.8%, 7.3%, and 8.5% and in the PAD commercial cohort (nϭ5813; mean age, 59.2 years) was 1.5%, 2.8%, 4.8%, and 6.5%, respectively. Cumulative secondary event occurrences were even higher in stroke (nϭ1518; mean age, 79.5 years), AMI (nϭ2197; mean age, 76.2 years), and PAD (nϭ5033; mean age, 76.6 years) cohorts of the Medicare sample: 18.1%, 17.0%, and 8.7%, respectively, at 3 years. More than 75% of each stroke cohort's secondary events were strokes; more than 75% of each AMI cohort's secondary events were AMIs. Of the PAD cohorts' secondary events, 27% to 39% were strokes, 48% to 57% were AMIs, and 13% to 16% were vascular deaths. Conclusions-Among these managed care enrollees with existing atherosclerotic vascular disease, subsequent ischemic events represent a significant symptomatic disease burden. Given these findings, it is very important to determine whether secondary prevention strategies are being effectively used to manage patients with diagnosed atherosclerosis.

Antiplatelet Therapy in Cerebrovascular Disease: Implications of MATCH and CHARISMA Results for Cardiologists

“…The risk of stroke was about fourfold greater than that of MI or of other vascular death for patients in both groups, reinforcing findings from earlier studies that people with previous stroke tend to experience recurrent stroke more frequently than MI or other vascular events. 2 Perhaps the most significant finding from MATCH is that the absolute risks of life-threatening and major bleeding were increased with the addition of aspirin to clopidogrel (by 1.3 and 1.4%, respectively). 5 On the basis of these findings, clopidogrel plus aspirin cannot be recommended for high-risk patients with previous stroke or TIA for the prevention of secondary stroke or other vascular events.…”

“…Cardiac factors such as atrial fibrillation, valvular heart disease, coronary artery disease, congestive heart failure, and myocardial infarction (MI) increase stroke risk. 1,2 Because of the array of overlapping symptoms and risk factors, cardiologists frequently care for patients who are at high risk for initial or recurrent stroke. Secondary stroke after initial stroke or transient ischemic attack (TIA) has been reported in approximately 25 to 40% of patients within 5 years of the initial event.…”

Epidemiology of transient ischemic attack and ischemic stroke in patients with underlying cardiovascular disease

“…6, 14 Furthermore, although there have been concerns in the past about acute myocardial infarction (AMI) occurring in these patients, recent data indicate that more than 75% of secondary cardiovascular events in stroke patients are strokes. 14 Vickrey et al 14 estimated the occurrence of stroke, AMI, and vascular death in two large managed care samples (commercial insurance and Medicare) that included patients aged 40 and older who had stroke, AMI, or peripheral arterial disease (PAD). In the stroke commercial-insurance cohort (n = 1,631; mean age, 62.1 years), cumulative occurrence of subsequent events (either stroke, or AMI, or vascular death) was 11.8% at 3 years; cumulative secondary event occurrence in the AMI commercial cohort (n = 6,458; mean age, 56.0 years) was 8.5% at 3 years.…”

“…6, 43 Furthermore, despite frequent concerns about other cardiovascular events in stroke patients, evidence indicates that the most likely event to occur is another stroke, with more than 75% of secondary events in stroke patients being strokes. 14 Transient ischemic attack is a significant independent risk factor for ischemic stroke and carries an average annual risk of approximately 4%. 5 As with ischemic stroke, patients are at greatest risk in the first year following a TIA, with the stroke usually occurring in the same area as the initial TIA.…”

Prevention of vascular events in patients with cerebrovascular disease: Efficacy and appropriate duration of antiplatelet therapy

“…Indeed, three quarters of these patients also show evidence of heart disease. 4,5 Given that cardiologists may be treating patients at high risk for secondary stroke, it is important to keep in mind that most cardiovascular events in patients with a history of stroke are cerebrovascular in nature.…”