National Audit of Thrombolysis for Acute Leg Ischemia (NATALI): clinical factors associated with early outcome

Abstract

Objective: The National Audit of Thrombolysis for Acute Leg Ischemia (NATALI) database is a consecutive series of patients who underwent intra-arterial thrombolysis to treat acute leg ischemia in one of 11 centers in the United Kingdom. The purpose of the study was to analyze the factors associated with outcome after 30 days.

Methods: The data were collected over 10 years on standard pro formas, and registration was completed at the end of 1999. Since then, data from each unit have been verified and missing data included when available. Univariate and multivariate analyses were performed, with the outcomes of amputation-free survival (AFS), amputation with survival, and death.

Results: A total of 1133 thrombolytic events were included. Outcome results at 30 days for the entire group were AFS, 852 (75.2%); amputation, 141 (12.4%); and death, 140 (12.4%). Results for the entire group improved from the first half of the database, when AFS ranged from 65% to 75%, to almost 80% for the last few years of the study, although this was not statistically significant. Preintervention factors associated with lower AFS at multivariate analysis included diabetes (P =.002), increasing age (P <.001), short-duration ischemia (P =.027), Fontaine grade (P =.001), and ischemia with neurosensory deficit (P =.004). AFS was improved in patients receiving warfarin sodium at the time of the arterial occlusion (P =.04). Mortality was higher in women (P =.006) and in older patients (P <.001), and in patients with native vessel occlusion (P <.001), emboli (P =.02), or a history of ischemic heart disease (P <.001). Amputation risk was greatest in younger men (P <.001) and in patients with more severe ischemia (P =.02), graft occlusion (P <.001), or native vessel thrombotic occlusion (P =.02).

Conclusion: Experienced surgeons and radiologists can achieve an AFS of about 80% in selected patients with acute leg ischemia. Information from the NATALI database can be used in selection of an appropriate intervention in the individual patient.