The Oslo Balloon Angioplasty versus Conservative Treatment Study (OBACT)

Abstract

Objectives To compare the effect of optimal medical treatment only (OMT) with OMT combined with percutaneous transluminal angioplasty (OMTϩPTA) in patients with intermittent claudication (IC).Design A single centre prospective, randomised study. Quality of life (QoL) was the primary outcome measure. Secondary measures were anklebrachial-index (ABI), treadmill walking distances and mortality.Methods From a total of 434 patients considered for inclusion into the trial, only 56 patients with disabling IC fulfilled the inclusion criteria. The patients were randomised into treatment groups consisting of 28 patients each and followed for 2 years. ABI and treadmill walking distances were measured in addition to the visual analogue scale (VAS) for pain evaluation, and QoL assessment using the Short Form (SF-36 and Claudication Scale (CLAU-S).Results The demographic data in the 2 groups were almost identical. After 2 years of follow-up the ABI, the treadmill walking distances and the VAS were significant improved in the group treated with OMTϩPTA, compared to the group treated with OMT only (pϽ0.01 for all). Furthermore, some variables from the QoL assessment also showed a significant improvement in favour of the OMTϩPTA group (pϽ0.05 for all).Conclusion The advantage of conducting a single centre study and adhering to very strict inclusion criteria was illustrated by the homogenous demographic data of the two groups. This partly outweighed the disadvantage of having included a relatively small number of patients. Early intervention with PTA in addition to OMT seems to have a generally more positive effect compared to OMT only, on haemodynamic, functional as well as QoL aspects during the first 2 years in patients with IC.

Beneficial effects of 1-year optimal medical treatment with and without additional PTA on inflammatory markers of atherosclerosis in patients with PAD. Results from the Oslo Balloon Angioplasty versus Conservative Treatment (OBACT) study

“…The patients were eligible to enter this study if they were Ͻ80 years, had suffered from symptomatic IC for a minimum period of 3 months prior to evaluation, had an ankle-brachial index (ABI) Ͻ0.9 without rest pain and/or ulcers, had a subjective pain-free walking distance (PFWD) Ͻ400 m, were able to exercise on a treadmill, had no previous vascular or endovascular surgery, did not suffer from diabetic ulcer or renal insufficiency (defined as s-creatinine Ͼ150 mol/l), and were not on oral anticoagulant medication, or suffering from a physical or mental disorder expecting to impede compliance and follow-up. 20 The 56 patients fulfilling the inclusion criteria were randomized in accordance with a computerized randomization list by use of consecutively numbered sealed envelopes to OMT (n ϭ 28) or OMT ϩ PTA (n ϭ 28) and followed for 3 and 12 months.…”

“…The methods used for angiography, measurement and calculation of the ABI, and treadmill testing have previously been described in detail. 20,29 In brief: the ABI was measured after a 5-minute rest period in the supine position. Blood cuffs were placed over each brachial artery and above each malleolus, and a handheld Doppler probe was used to measure systolic blood pressures in the brachial arteries, the anterior tibial arteries and the posterior tibial arteries.…”

“…The present investigation is a part of The Oslo Balloon Angioplasty vs Conservative Treatment (OBACT) study. 20 …”