Abstract TMP99: Risk of Stroke Recurrence and Silent Myocardial Infarction

Abstract

Background: Prior data suggest that unrecognized or silent myocardial infarction (MI) detected on routine ECG is associated with first-ever stroke, but the impact on stroke recurrence is unknown. We aimed to determine the association of silent MI with stroke recurrence in patients with recent ischemic stroke. Methods: We included all subjects with an index stroke and available baseline ECG enrolled in the Insulin Resistance in Ischemic Stroke (IRIS) trial. Clinical MI was defined as a prior hospitalization for MI. Silent MI was defined as ECG evidence of MI (Q wave or equivalent patterns) without prior hospitalization for MI. The primary outcome was recurrent stroke. Ischemic stroke and ischemic stroke subtype were assessed as secondary outcomes. Multivariate cox regression adjusted for age, sex, race, pioglitazone, and vascular risk factors was performed for analysis. Results: Of 2285 participants analyzed, prior clinical and silent MI were identified in 164 (7.2%) and 94 (4.1%) patients respectively. Over an average of 4.5 years, 209 recurrent strokes occurred with 191 classified as ischemic. In the fully adjusted model, silent MI was associated with stroke (HR 2.27, CI 1.33-3.88) and ischemic stroke (HR 2.08, CI 1.17-3.68) recurrence. Clinical MI was associated with stroke and ischemic stroke recurrence in the unadjusted analysis; however, the association was no longer significant after adjustment (all stroke: HR 1.31, CI 0.81-2.11; ischemic stroke: HR 1.42, CI 0.87-2.32). No association between silent MI and stroke subtype was significant. Discussion: Among patients with a recent ischemic stroke, silent MI is associated with stroke recurrence. Tailored secondary stroke prevention strategies in this population require future investigation.