Superimposed Takotsubo and Acute MI (STAMI) Identified as Distinct Overlap Syndrome with Severe Dysfunction

Traditionally, Takotsubo syndrome (TTS) has been defined by the absence of obstructive coronary artery disease, often triggered by severe emotional or physical stress. However, growing evidence points to a complex overlap where acute myocardial infarction (AMI) and TTS can coexist, forming a combined phenotype termed STAMI. This coexistence presents a significant diagnostic challenge, as the clinical presentation can mimic either condition, potentially leading to misdiagnosis or suboptimal management. Understanding STAMI is crucial for accurate risk stratification and tailoring therapeutic strategies, especially given the distinct underlying mechanisms of ischemic injury and stress-induced myocardial stunning.

Researchers conducted a systematic review and pooled analysis of published case reports and case series, identifying 48 patients with simultaneous AMI and TTS reported between 2000 and 2025. The review aimed to summarize available evidence regarding the clinical characteristics, imaging findings, mechanisms, and outcomes of this underrecognized syndrome, referred to as STAMI. Data extraction focused on patient demographics, type of AMI (STEMI vs. NSTEMI), infarct mechanisms, wall-motion abnormalities, biomarker levels, and in-hospital outcomes, providing a comprehensive overview of this complex cardiac presentation.

The analysis of 48 STAMI patients revealed a mean age of 67 years, with 69% being women. STEMI was present in 57% of cases, while NSTEMI accounted for 41%. While atherosclerotic plaque rupture was the predominant infarct mechanism, vasospasm and spontaneous coronary artery dissection collectively contributed to over 20% of presentations. A consistent and critical finding was an anatomical-functional mismatch, where wall-motion abnormalities extended beyond the culprit coronary territory, most commonly manifesting as apical ballooning. Recurrent features included marked QTc prolongation and disproportionately elevated natriuretic peptide levels. Initial left ventricular dysfunction was often severe, but demonstrated substantial recovery during follow-up, supporting the presence of reversible stress-induced myocardial stunning in addition to ischemic injury. Cardiogenic shock occurred in approximately 10% of patients, and in-hospital mortality was 6.3%. This highlights the severe acute presentation but also the potential for recovery.

The most striking finding was the anatomical-functional mismatch, with wall-motion abnormalities extending beyond the culprit coronary territory, indicating a dual pathology of ischemic damage and stress-induced stunning.