Reversal of cardiopulmonary exercise intolerance in patients with post-thrombotic obstruction of the inferior vena cava

Background: It is unclear whether cardiopulmonary exercise intolerance in patients with chronic obstruction of the inferior vena cava (IVC) is reversible following endovascular IVC reconstruction.

Methods: In 17 patients (mean age 45 ± 15 years, 71% men) with post-thrombotic syndrome due to IVC obstruction and preserved left ventricular ejection fraction (mean 58 ± 3%), we performed cardiopulmonary exercise testing before and 3 months after IVC reconstruction (mean 4.1 ± 1.5 implanted stents). The median time from latest episode of deep vein thrombosis to intervention was 150 (interquartile range 102-820) days.

Results: At baseline, 12 (71%) patients reported New York Heart Association (NYHA) class II or III symptoms, 76% did not achieve >85% of predicted oxygen uptake at peak exercise (mean 61.8 ± 13.7%). After IVC reconstruction, the following changes were observed at anaerobic threshold: work rate increased by 14.6 W, 95%CI (-0.7; 30.0), oxygen uptake increased by 1.8 ml/kg, 95%CI (0.3; 3.3). Oxygen pulse increased by 1.95 ml per beat, 95%CI (1.12; 2.78), corresponding to a mean relative increase of 22.5%, 95%CI (12.4; 32.7) (p < 0.001). The following changes were observed at peak exercise: work rate increased by 48.1 W, 95%CI (27.8; 68.4), oxygen uptake increased by 6.4 ml/kg, 95%CI (3.8; 9.1). Oxygen pulse increased by 2.68 ml per beat, 95%CI (1.60; 3.76), corresponding to a mean relative increase of 29.4%, 95%CI (17.7; 41.2) (p < 0.001). At follow-up, 5 (29%) patients remained in NYHA class II.

Conclusions: In patients with chronic IVC obstruction, cardiopulmonary exercise intolerance as a result of impaired cardiac filling is at least partially reversible following endovascular IVC reconstruction.

Study registration: URL: https://clinicaltrials.gov. Unique identifier: NCT02433054.