Pulmonary artery floating sign: a novel predictor of fatal haemoptysis in pulmonary mucormycosis and its early intervention strategy

Background Massive haemoptysis is a life-threatening complication of pulmonary mucormycosis, often resulting from invasive destruction of pulmonary arteries. Early predictors and preventive strategies remain poorly defined. Methods We retrospectively enrolled all hospitalised patients with pulmonary mucormycosis regardless of haemoptysis between 2019 and 2024. Patients were stratified into non-massive and massive haemoptysis groups. Clinical and radiological variables were compared between groups, and univariable and multivariable logistic regression analyses were performed. Given the limited number of events and separation, Firth’s penalised logistic regression and reduced multivariable models were used to identify robust predictors of massive haemoptysis. Additionally, we explored the feasibility of prophylactic pulmonary artery embolisation (PPAE) in a subset of high-risk patients to evaluate its potential role in preventing fatal haemorrhage. Results Fifty-seven patients with pulmonary mucormycosis were enrolled, and 22 (38.6%) patients had massive haemoptysis, with a mortality rate of 72.7% (16/22). Cavity (68.2% vs 34.3%, p=0.026) and central necrosis (100% vs 74.3%, p=0.009) were significantly more common in the massive haemoptysis group. The pulmonary artery floating sign (PAFS) was observed in 81.8% (18/22) of the massive haemoptysis group versus 31.4% (11/35) of the non-massive haemoptysis group (p<0.001), and was the only independent predictor (adjusted OR 6.20, 95% CI 1.68 to 28.49). Five high-risk patients, including three with floating sign, underwent PPAE; only one subsequently died of bleeding. Conclusion The PAFS is a novel and independent predictor of massive haemoptysis in pulmonary mucormycosis. Its early identification may support early risk stratification and inform consideration of PPAE in selected high-risk patients.