The diagnostic value of multimodal imaging for myocardial injury in heat stroke

This study aimed to evaluate and compare the diagnostic and prognostic value of a multimodal imaging approach-integrating echocardiography (US), cardiac magnetic resonance imaging (CMRI), and myocardial perfusion imaging (MPI)-for detecting myocardial injury (MI) secondary to heat stroke (HS).

This single-center retrospective study analyzed data from 187 HS patients (49 with MI, 138 without MI) and 20 healthy controls (HC). The diagnostic accuracy of echocardiography (US), cardiac magnetic resonance (CMR), and MPI, individually and in combination, was evaluated against a composite clinical reference standard. Receiver operating characteristic curve (ROC) compared the HS patients with the MI group (positive cases) against a combined negative group comprising all HS without MI patients and HCs. The association between imaging parameters and a 30-day composite clinical endpoint (all-cause death, heart failure, or significant arrhythmia) was analyzed using logistic regression.

Among single modalities, MPI demonstrated the highest diagnostic efficacy (area under the curve, AUC = 0.788), followed by CMRI (AUC = 0.721) and US (AUC = 0.648). The combination of all three modalities (US + CMRI + MPI) achieved the highest diagnostic performance (AUC = 0.861, sensitivity 85.7%, specificity 87.3%, accuracy 87.0%), significantly outperforming any single modality or dual-modality combination (P < 0.01). Multivariate analysis identified the extent of myocardial necrosis (assessed by CMRI-derived extracellular volume, extracellular volume; Odds Ratio, OR = 5.2, P = 0.003) and the severity of myocardial ischemia (assessed by MPI summed stress score, SSS; OR = 3.8, P = 0.017) as independent predictors of adverse 30-day outcomes.

A multimodal imaging strategy combining US, CMRI, and MPI provides superior diagnostic accuracy for detecting HS-induced myocardial injury compared with any single modality alone. Furthermore, it offers significant prognostic value by identifying the extent of myocardial necrosis and severity of ischemia, which serve as independent risk factors for short-term adverse events. Thus, this approach may facilitate risk stratification and inform clinical decision-making and patient management.