Pulmonary thromboembolism with right‐sided thrombus‐in‐transit: A case of successful systemic thrombolysis

A thrombus-in-transit across the right-sided cardiac chambers is a rare clinical condition that often presents with acute pulmonary thromboembolism (PTE). Although management guidelines exist for acute PTE, there is no consensus on the ideal treatment for a thrombus-in-transit. Surgical therapy, catheter-directed or systemic thrombolysis, and intravenous anticoagulation have all been attempted with variable success. This case highlights a right-sided thrombus-in-transit with an acute PTE without hemodynamic instability managed with systemic thrombolysis. A middle-aged man in his 40s presented to the emergency room with complaints of shortness of breath (NYHA class III) for the past 4 days. He had been on a five-hour flight 5 days back, and his symptoms began 24 h after his air travel. On initial physical examination, he was tachycardic (pulse rate—124/min) with a blood pressure of 130/94 mm of Hg. He had tachypnoea at rest (respiratory rate—26/min) with an oxygen saturation of 92% in the room air. The rest of the cardiovascular and respiratory system examination was grossly unremarkable. Also, a unilateral right lower limb swelling was noted. The electrocardiogram showed sinus tachycardia and the chest x-ray had no significant abnormalities. Lab investigations, however, revealed an elevated D-dimer level (3948 ng/mL). With the given clinical picture, acute pulmonary thromboembolism (PTE) was suspected.1 A transthoracic echocardiogram (TTE) revealed mildly dilated right-sided cardiac chambers with a 41 × 24 mm thrombus-in-transit across the tricuspid valve and another large thrombus lodged at the left branch pulmonary artery hilum (Figure 1A,B and Video 1). On visual estimation, the right ventricular function appeared impaired. A computed tomography-pulmonary angiogram (CTPA) confirmed the findings. Further, a venous Doppler ultrasound of lower limbs demonstrated a thrombus across the right superficial femoral and popliteal veins. Although the absence of hemodynamic instability with right ventricular dysfunction and normal troponin levels placed the patient in an intermediate-low risk group and management guidelines dictated anticoagulation alone,1, 2 a thrombus-in-transit is a special scenario that predicts future massive PTE and is reported to have a mortality rate exceeding 25%.3 Hence, after a detailed discussion, systemic thrombolysis was deemed most suitable and the patient was thrombolysed with intravenous Alteplase (100 mg over 2 h). The patient's tachycardia and tachypnoea eventually settled, and a follow-up TTE at 48 h showed complete resolution of thrombi both in the right-sided cardiac chambers and pulmonary artery (Figure 1C,D and Video 2). The patient was discharged on oral Warfarin (target INR: 2–3) in hemodynamically stable condition. None. Informed consent was obtained from the patient for the submission of the case image and videos.