Methods:
A prospective database of CLI patients was established during pre-screening of CLI patients for phase 1b stem cells therapy clinical trial [7]. CLI patients, attending the vascular service at a tertiary university hospital in the West of Ireland between April 2015 and April 2018, were included in the study. CLI was defined clinical presentation with rest pain (Rutherford class 4) and/or tissue loss (Rutherford class 5 and 6) for at least 2 weeks with proven underlying vascular occlusive disease. Patients presenting with acute limb ischemia were excluded from the study.
The following demographic data and medical comorbidities were recorded: age, gender, smoking status, diabetes, hypertension, hyperlipidaemia, cardiac disease (including ischemic heart disease and heart failure), cerebrovascular disease (including transient ischemic attack and stroke), chronic obstructive pulmonary disease (COPD)/ asthma, and chronic kidney disease.
Patients were divided to two groups: “Revascularization group” and “Conservative management group”. The revascularization group included all patients who had either surgical or endovascular intervention as the primary treatment for CLI. The conservative management group included patients classified as “no-option” due to unfavourable anatomy for intervention or medical comorbidities. This group also included patients for whom revascularization was recommended but who improved on best medical therapy and modification of risk factors prior to intervention.
The end point of the study was defined as: the date of last follow-up, or date of death, or date of major amputation (below or above the knee). The study outcomes were overall survival and amputation-free survival.
The statistical analysis was performed using StatsDirect 3 ( Llumina Press 2010). The descriptive data was expressed as mean and standard deviation and compared using student t test. Fisher extract test was used for analysis of categorical data. Statistical significance was set as p value < 0.05. OS and AFS for the two groups were estimated by Kaplan-Meier survival curves with the differences between the groups analysed by the Breslow-Wilcoxon method.
The study protocol was approved by the Research Ethics Committee at Galway University Hospital and General Data Protections Regulations were followed.