Clinically suspected acute recurrent pulmonary embolism: a diagnostic challenge

Area of Science:

• Medical Diagnostics
• Cardiology
• Pulmonary Medicine

Background:

• Pulmonary embolism (PE) diagnosis strategies are validated primarily in treatment-naive patients.
• The diagnostic accuracy of established algorithms in patients with a history of PE remains uncertain.
• Recurrent PE poses a significant risk, necessitating reliable diagnostic methods.

Purpose of the Study:

• To evaluate the safety and efficacy of a diagnostic algorithm for ruling out acute recurrent PE.
• To assess a sequential approach involving a clinical decision rule (CDR), D-dimer testing, and computed tomography (CT).
• To determine the incidence of recurrent venous thromboembolism in patients with a negative diagnostic workup.

Main Methods:

• Prospective diagnostic outcome study involving 3,306 patients with suspected PE.
• Application of a diagnostic algorithm: CDR (score ≤4) + D-dimer (≤500 ng/ml) or CT scan.
• Primary outcome: incidence of acute recurrent venous thromboembolism within three months in untreated patients with negative tests.

Main Results:

• Of 259 patients with a history of PE, 234 were not on anticoagulants.
• The algorithm ruled out PE in 82 patients (35%) via CDR/D-dimer, with 0% thrombotic events.
• CT scans ruled out PE in 127 patients (54%); one fatal PE occurred (0.8%) in a patient with a negative CT.

Conclusions:

• A diagnostic algorithm combining CDR, D-dimer, and CT is safe for ruling out acute recurrent PE in patients with a prior PE history.
• This approach effectively identifies patients who do not require anticoagulation for recurrent PE.
• The study supports the use of this algorithm in clinical practice for managing patients with a history of PE.