A study on the relationship between mMRC dyspnea scale and both risk stratification and poor prognosis in patients with acute pulmonary embolism

Background This study aimed to investigate the value of the modified Medical Research Council (mMRC) dyspnea scale in risk stratification and outcome assessment for patients with acute pulmonary embolism (APE). Methods A retrospective analysis was performed using medical records from a tertiary care center between 2011 and 2023. The study included patients aged 18–80 years who were diagnosed with APE. Participants were categorized into groups based on pulmonary embolism risk stratification, mMRC dyspnea scale, and the presence or absence of adverse outcomes within 1 year, which included in-hospital mortality, all-cause mortality after discharge, and hospital readmission. The associations between the mMRC dyspnea scale and both APE risk stratification and 1-year adverse outcomes were evaluated. The predictive performance of the mMRC dyspnea scale for 1-year adverse prognosis was assessed using receiver operating characteristic (ROC) curve analysis to determine the optimal cut-off threshold. Results The study demonstrated that the mMRC dyspnea scale was significantly positively correlated with risk stratification of APE ( P < 0.05). Moreover, the Qanadli score, systolic blood pressure, cardiac troponin, N-terminal pro-brain natriuretic peptide, and the right-to-left ventricular ratio were significantly associated with higher mMRC scores ( P < 0.05). ROC curve analysis revealed that an mMRC dyspnea grade of 3 was considered the optimal cut-off value for predicting adverse prognosis within 1 year, with an area under the curve of 0.803 ( P < 0.001). Conclusion The mMRC dyspnea scale demonstrates a significant association with risk stratification in patients with APE. An mMRC dyspnea grade of ≥3 is indicative of a higher risk for adverse outcomes within 1 year and may serve as a valuable prognostic indicator for predicting clinical outcomes in APE patients.