Stopping anticoagulation for isolated or incidental pulmonary embolism: the STOPAPE RCT protocol

Area of Science:

• Pulmonary vascular disease
• Clinical trial methodology
• Health economics

Background:

• Increased diagnosis of subsegmental pulmonary embolism (PE) with CTPA.
• Diagnostic challenges with older V/Q scanning.
• Equipoise regarding optimal treatment due to bleeding risks of anticoagulation.

Purpose of the Study:

• Compare withholding anticoagulation vs. 3-month anticoagulation for isolated subsegmental PE.
• Assess recurrent thromboembolism and major bleeding rates.
• Evaluate clinical acceptability and cost-effectiveness.

Main Methods:

• Individually randomised controlled trial with blinded endpoint assessment.
• Powered for non-inferiority for VTE and superiority for bleeding.
• Included a qualitative study on patient/clinician acceptability and radiologist diagnostic accuracy assessment.

Main Results:

• The STOPAPE trial was stopped prematurely due to low recruitment.
• No outcome data are available for this trial.
• Separate publications will detail qualitative findings and collected data.

Conclusions:

• The study could not provide definitive outcome data due to premature termination.
• Further research is needed to establish optimal management strategies.
• Qualitative data on acceptability and diagnostic accuracy will be reported separately.