Supervised Exercise Therapy or Endovascular Revascularization for Patients with Intermittent Claudication Due to an Iliac Artery Obstruction? the Super Study

Introduction - The optimal treatment strategy for patients with intermittent claudication (IC) due to an iliac artery obstruction is as yet unclear. Should patients be referred for immediate Percutaneous Transluminal Angioplasty (PTA) or supervised exercise therapy (SET) and deferred PTA if SET fails? Methods - This multi-center randomized controlled trial included 240 patients from 18 hospitals in the Netherlands with IC due to a > 50% common or external iliac artery stenosis or occlusion, and a walking distance 100-300 meters on a treadmill (3.2 km/h, 10% incline). Patients were randomly allocated to PTA with or without stent, or SET, stratified for maximum walking distance (MWD) at baseline and concomitant SFA stenosis or occlusion. PTA was carried out according to local practice. SET comprised a 6 months program supervised by a dedicated physiotherapist twice a week during the first 12 weeks, once a week during the next 8 weeks and once every two weeks during the last 4 weeks. Primary endpoints were MWD on a treadmill (3.2 km/h, 10% incline) and disease specific quality of life (Qol) measured with the VascuQol questionnaire after 1 year follow-up. Analysis was performed according to the intention-to-treat principle. To take into account the repeated measurements structure of the data differences between MWD and VascuQol sumscore were assessed with a linear mixed model with a Toeplitz covariance structure. Results - Between November 2010 and May 2015, 114 patients were allocated to SET, 126 to PTA. Compliance to SET was poor; after 1 month 75/114 (66%) patients attended the program, declining to 68/114 (60%) and 57/114 (50%) after 3 and 6 months, respectively. Ten (8%) of the patients allocated to PTA did not receive the intervention, which was technically successful in 112/116 (97%) of the remaining patients. Five patients had a minor complication after PTA and 6 a major complication necessitating endovascular or surgical resolution. Some 90/114 (79%) patients allocated to SET completed one year follow-up, and 104/126 (83%) allocated to PTA. The mean MWD improved from 187 to 561 meters in the SET group and from 196 to 574 meters in the PTA group, (p=0.693) The VascuQol sumscore improved from 4.24 in the SET group to 5.58, and from 4.28 in the PTA group to 5.88, (p=0.048). Yet, in both groups the improvement in VascuQol sumscore was more than the minimally important clinical difference of 1.19 (derived from 100 participants of the SUPER study). Some 33/114 (29%) of patients allocated to SET had a PTA within one year, and 2/114 (2%) additional surgical revascularization (SR). Some 10/126 (8%) patients allocated to PTA had an additional PTA within one year and another 10/126 (8%) had SR. Conclusion - Both a strategy of immediate PTA, and SET with deferred PTA in case of SET failure improve MWD on a treadmill and disease specific Qol of patients with IC due to an iliac artery obstruction. It seems reasonable to start with SET in these patients and accept a 30% failure rate. The cost-effectiveness analysis of this RCT will further define clinical decision making.