Relation between serum cotinine levels and trophic lesions in patients with critical limb ischemia: a pilot study

Aim: To evaluate if smoking, quantified by the serum cotinine levels, is related to the evolution of patients with critical limb ischemia (CLI).Method: A pilot study was conducted on CLI patients who addressed at the Second Surgery Clinic of the Emergency County Hospital, Cluj-Napoca, Romania between November 2015 and December 2016. The sample of patients was split into two groups using the threshold of 15 ng/mL for the serum level of cotinine (low cotinine level - LCL vs. high cotinine level - HCL). Furthermore, the ROC analysis was conducted to identify the threshold of cotinine level able to discriminate between CLI patients with and without trophic lesions.Results: The mean age of patients was 60.7 ± 10.5 years with a significantly higher percentage of male patients (84%). A significant association was identified between urban origin and serum cotinine level, which is related to the increased number of cigarettes smoked per day among urban participants. Excepting necrectomy and toe disarticulation, no differences were found between LCL and HCL group regarding symptoms, signs or comorbidities. In smokers with CLI (38/43), a serum cotinine cut-off of 9.765 ng/mL was observed on eight out of 10 CLI patients with necrectomy and five out of 28 patients without necrectomy.Conclusion: Our study showed higher serum cotinine levels associated with a higher number of smoked cigarettes and necrectomy in patients with CLI. The serum cotinine could be a fair screening test for necrectomy in smokers CLI patients.