Background Acute myocardial infarction (AMI) infrequently occurs after acute stroke. The Heart-brain team approach has a potential to appropriately manage this poststroke cardiovascular complication. However, clinical outcomes of AMI complicating acute stroke (AMI-CAS) with the heart-brain team approach have not been characterized. The current study investigated cardiovascular outcomes in patients with AMI-CAS managed by a heart-brain team. Methods and Results We retrospectively analyzed 2390 patients with AMI at our institute (January 1, 2007-September 30, 2020). AMI-CAS was defined as the occurrence of AMI within 14 days after acute stroke. Major adverse cerebral/cardiovascular events (cardiac-cause death, nonfatal myocardial infarction, and nonfatal stroke) and major bleeding events were compared in subjects with  AMI-CAS and those without acute stroke. AMI-CAS was identified in 1.6% of the subjects. Most AMI-CASs (37/39=94.9%) presented ischemic stroke. Median duration of AMI from the onset of acute stroke was 2 days. Patients with AMI-CAS less frequently received primary percutaneous coronary intervention (43.6% versus 84.7%; P<0.001) and dual-antiplatelet therapy (38.5% versus 85.7%; P<0.001), and 33.3% of them did not receive any antithrombotic agents (versus 1.3%; P<0.001). During the observational period (median, 2.4 years [interquartile range, 1.1-4.4 years]), patients with AMI-CAS exhibited a greater likelihood of experiencing major adverse cerebral/cardiovascular events (hazard ratio [HR], 3.47 [95% CI, 1.99-6.05]; P<0.001) and major bleeding events (HR, 3.30 [95% CI, 1.34-8.10]; P=0.009). These relationships still existed even after adjusting for clinical characteristics and medication use (major adverse cerebral/cardiovascular event: HR, 1.87 [95% CI, 1.02-3.42]; P=0.04; major bleeding: HR, 2.67 [95% CI, 1.03-6.93]; P=0.04). Conclusions Under the heart-brain team approach, AMI-CAS was still a challenging disease, reflected by less adoption of primary percutaneous coronary intervention and antithrombotic therapies, with substantially elevated cardiovascular and major bleeding risks. Our findings underscore the need for a further refined approach to mitigate their ischemic/bleeding risks.