Predicting Venous Obstruction in Patients with an IECD

Background:
Access vein obstruction in patients with an implanted electronic cardiac device (IECD) is common. The existence of venous thrombosis and obstruction can render procedures requiring lead addition more complex. Therefore, diagnosis of venous occlusion is important for correct procedure planning.

We observed that collateral vessels can be seen on the chest wall over the area of venous obstruction and depends of it severity. This prospective case-control study was set to verify the predictive value of this observation.

Objective:
Assess whether increased number and prominence of superficial vessels observed clinically can predict venous obstruction in patients undergoing replacement or upgrading of an IECD.

Methods:
Patients presenting to the EP laboratory and scheduled to undergo a procedure involving existing IECD were included. Superficial vessels over the upper anterior chest were assessed by two independent observers and assigned a score ranging from 1 - none seen to 4 - prominent. Venous obstruction severity was then assessed by performing bilateral contrast venographies.

Results:
The study included 26 patients who underwent a total of 49 venographies. Inter-Observer correlation (Spearman’s ρ) was 0.795 (P<0.001) indicating a strong inter-observer agreement.

To predict a normal venography, the Ideal cut off point was at a collateral score of 1.75 yielding a sensitivity of 0.714, a specificity of 0.857, and a negative predictive value of 88.2% (76.9-93.7).

To predict a vein occlusion, the ideal cut off point was a score of 2.75 yielding a sensitivity of 0.357, specificity of 0.971 and a positive predictive value of 83.3% (46.9-96.5).

Conclusions:
In this work we demonstrate the clinical importance of a simple physical sign for the management of patients referred for IECD replacement or upgrading.

A negative superficial vessel score has a strong predictive value for patent subclavian vein.

A highly positive score has a strong predictive value for vein occlusion.