Reintervention as a clinical trial endpoint after peripheral arterial bypass surgery.

Abstract

Graft patency is usually the primary endpoint in studies of peripheral arterial bypass surgery, but gives only a limited indication of clinical outcome. The aim of this study was to evaluate reintervention as a study endpoint after femorodistal bypass surgery. The database from a multicentre, prospectively planned study of 517 patients undergoing femorodistal bypass for severe ischaemia was used to investigate the predictive value of technical endpoints. Clinical symptoms, graft patency, vascular interventions and clinical outcomes were recorded for 12 months after operation. Complete follow-up data were obtained on 498 patients (96 per cent). Success in terms of patients' need for reintervention agreed with clinical outcome in 90 (95 per cent confidence interval (c.i.) 87-93) per cent of cases. Primary and secondary patency agreed with the clinical outcome in 80 (95 per cent c.i. 77-84) and 81 (95 per cent c.i. 78-85) per cent of patients respectively. However, the best agreement with clinical outcome was obtained from the composite endpoint of 'patient alive without reintervention': 92 (95 per cent c.i. 90-94) per cent. Recording the number of patients who did not need reintervention for 12 months after femorodistal bypass gave a more accurate assessment of the number with clinical improvement than was obtained by recording bypass graft patency. Inclusion of patient survival in a composite endpoint increased the clinical relevance of this endpoint in patients with severe ischaemia who had femorodistal bypass surgery.