Myocardial Infarction as a Complication in Acute Stroke: Results from the Austrian Stroke Unit Registry

Background: Patients with transient ischemic attack (TIA) and stroke have an increased risk for subsequent cardiac events including myocardial infarction (MI), which might be associated with a worse clinical outcome. Rapid identification of stroke patients at higher risk for MI might foster intensified cardiac monitoring or certain therapeutic strategies. However, information regarding acute MI as a complication of stroke in the very acute phase is limited. Moreover, there are no systematic data on the occurrence of MI following intracerebral hematoma. We thus aimed to assess the frequency, clinical characteristics and short-term outcome of patients suffering from acute MI in the stroke unit setting. Methods: We analyzed 46,603 patients from 32 Austrian stroke units enrolled in the prospective Austrian Stroke Unit Registry because of TIA/acute stroke over a 6-year period (January 1, 2007 to January 13, 2013). A total of 41,619 patients (89.3%) had been treated for TIA/ischemic stroke and 4,984 (10.7%) for primary intracerebral hemorrhage (ICH). Acute MI was defined according to clinical evaluation, ECG findings and laboratory assessments. Patients with evidence for MI preceding the cerebrovascular event were not considered. Results: Overall, 421 patients (1%) with TIA/ischemic stroke and 17 patients (0.3%) with ICH suffered from MI during stroke unit treatment for a median duration of 3 days. Patients with TIA/ischemic stroke and MI were significantly older, clinically more severely affected and had more frequently vascular risk factors, atrial fibrillation and previous MI. Total anterior circulation and left hemispheric stroke syndromes were more often observed in MI patients. Patients with MI not only suffered from worse short-term outcome including a higher mortality (14.5 vs. 2%; p < 0.001) at stroke unit discharge, but also acquired more stroke complications like progressive stroke and pneumonia. Multivariate analyses identified previous MI and stroke severity at admission (according to the National Institutes of Health and Stroke Scale score) as factors independently associated with the occurrence of MI on the stroke unit. Conclusions: While quite rare in the acute phase after stroke, MI is associated with a poor short-term outcome including a higher mortality. Patients with previous MI and severe stroke syndromes appear to be at particular risk for MI as an early complication in the stroke unit setting. Further studies are needed to determine whethe