Accurate early risk assessment remains essential for patients presenting with chest pain in emergency departments. A prospective study published in Heart and Lung evaluated whether endothelial function testing using the RHI measured by the Endothelial Peripheral Arterial Tonometry (Endo-PAT) device could improve prognostic accuracy in this population.

The study included 503 patients with non-traumatic chest pain who underwent RHI testing. An RHI value below 1.19 indicated endothelial dysfunction. During a 30-day follow-up, 4.6% of participants developed MACE. Those with MACE had significantly lower RHI values compared with patients without events (1.24 vs. 1.50; p = 0.04).

When RHI was combined with the Thrombolysis in Myocardial Infarction (TIMI) risk score, the area under the receiver Operating Characteristic (ROC) curve reached 0.74, improving sensitivity and negative predictive value to 35% and 96%, respectively. These findings suggest that integrating endothelial function testing with established clinical scoring systems can enhance short-term prognostic evaluation in emergency chest pain management.