Novel insights into pulmonary embolism with negative D-dimer results.

A patient in his mid-40s presented with exertional dyspnoea and pleuritic chest pain persisting for 6 weeks. Despite repeated normal investigations, including D-dimer tests, chest X-rays, serial troponins and ECGs, a CT pulmonary angiogram (CTPA) was performed to rule out pulmonary embolism (PE) or other pulmonary abnormalities, revealing a left main pulmonary artery thrombus with no evidence of right ventricular strain. The patient was managed with oral rivaroxaban 15 mg two times per day for 21 days followed by 20 mg once daily for 6 months. The patient showed full recovery at the 6-month follow-up. This case highlights the diagnostic challenges in patients with persistent symptoms, low risk of venous thromboembolisms (VTEs) and normal initial investigations. It is novel because previous case reports of PE with negative D-dimer results have predominantly involved patients with identifiable risk factors, such as prior VTEs, malignancy or other conditions that increase the likelihood of PE. In contrast, this case demonstrates that PE can occur even in the absence of these risk factors, emphasising the importance of clinical diligence and the use of advanced imaging in diagnosing PE in atypical presentations.