Venous Clinical Severity Score has a suboptimal ability to detect improvement after iliac vein stenting across three years of follow-up.

OBJECTIVE

Venous Clinical Severity Score (VCSS) is currently the gold standard for measuring the severity of chronic venous disease, especially in patients with chronic proximal venous outflow obstruction (PVOO) secondary to non-thrombotic iliac vein lesions. Change in VCSS composite scores is often used to quantitatively measure the degree of clinical improvement after venous interventions. This study sought to assess the discriminative ability, sensitivity, and specificity of change in VCSS composites for detecting clinical improvement after iliac venous stenting.

METHODS

A registry of 433 patients who underwent iliofemoral vein stenting for chronic PVOO from August 2011 to June 2021 was retrospectively analyzed. These 433 patients had follow-up exceeding 1 year after the index procedure. Change in VCSS composite and clinical assessment scores (CAS) were used to quantify improvement after venous interventions. CAS is an assessment by the operating surgeon based on patient self-reporting to assess the degree of improvement at each clinic visit compared with before the index procedure longitudinally across the treatment course of a patient. Patients are rated as worse (-1), no change (0), mildly improved (+1), significantly improved (+2), and asymptomatic/complete resolution (+3) at every follow-up visit as compared with their disease severity prior to the procedure based on patient self-report. This study defined improvement as CAS >0 and no improvement as CAS ≤0. VCSS was then compared with CAS. Receiver operative characteristic curve and area under the curve (AUC) were used to evaluate change in VCSS composite for its ability to discriminate between improvement and no improvement after intervention at each year of follow-up.

RESULTS

Change in VCSS was a suboptimal measure for discriminating clinical improvement (1-year AUC, 0.764; 2-year AUC, 0.753; 3-year AUC, 0.715). Across all three time points, a change in VCSS threshold of +2.5 maximized the sensitivity and specificity of the instrument to detect clinical improvement. At 1 year, change in VCSS at this threshold was able to detect clinical improvement at a sensitivity of 74.9% and specificity of 70.0%. At 2 years, VCSS change had a sensitivity of 70.7% and specificity of 66.7%. At 3 years of follow-up, VCSS change had a sensitivity of 76.2% and specificity of 58.1%.

CONCLUSIONS

Across 3 years, change in VCSS exhibited a suboptimal ability to detect clinical improvement in patients undergoing iliac vein stenting for chronic PVOO with considerable sensitivity but variable specificity at a threshold of 2.5.