The Effect of Cytisine Treatment for Smoking Cessation on Cardiovascular Function in Adult Smokers

Introduction: Pharmacological interventions can enhance smoking cessation success and long-term abstinence. Cytisine, a plant derived alkaloid, is a selective partial agonist at alpha-4 beta-2 nicotinic acetylcholine receptors, which are crucial in nicotine dependence. Aim of the Study The primary objective of this observational study is to evaluate the efficacy of cytisine in a standard 25-day dosing regimen among adult smokers and users of alternative nicotine products (e-cigarettes or heated tobacco). The study will assess the impact of cytisine on cardiovascular function, including arterial stiffness, cardiac deformation, and endothelial glycocalyx integrity. The secondary aim is to determine relapse rates post-treatment, treatment side effects, and new cardiovascular events during the treatment period and at six-month follow-up. Materials and Methods: This observational study will recruit smokers visiting the smoking cessation unit at the 2nd Department of Cardiology, Attikon University Hospital, Athens. All participants will receive counseling and treatment from the attending physician. A minimum of 200 participants will be enrolled, categorized into: • At least 50 receiving cytisine in the standard dosing regimen: Days 1-3: 1 tablet every 2 hours (6 tablets daily) Days 4-12: 1 tablet every 2.5 hours (5 tablets daily) Days 13-16: 1 tablet every 3 hours (4 tablets daily) Days 17-20: 1 tablet every 5 hours (3 tablets daily) Days 21-25: 1-2 tablets daily * At least 50 receiving nicotine replacement therapy * At least 50 receiving prolonged cytisine therapy (3 mg, three times daily for 12 weeks) * At least 50 who do not intend to quit smoking (control group) Assessments will be conducted at baseline, one month, and six months post-recruitment. The following measurements will be performed: A. Arterial Stiffness: Pulse wave velocity (cf-PWV) using the Complior device to measure arterial stiffness, Augmentation index and pulse wave velocity using the Arteriograph device via brachial artery cuff. B. Endothelial Glycocalyx Integrity: Perfused boundary region (PBR) assessment of sublingual microvasculature using a Sidestream Dark Field (SDF) camera. C. Cardiac Function: Left ventricular ejection fraction (LVEF), myocardial strain (GLS), and myocardial work assessment via speckle-tracking echocardiography (Echopac 203, GE Horten Norway).The investigators will also calculate myocardial work (MW) using pressure-strain loop analysis. D. Oxidative Stress: Plasma malondialdehyde (MDA) and protein carbonyl (PC) levels measured via spectrophotometry. E. Smoking Cessation Monitoring: Exhaled carbon monoxide (CO) measured using a commercial device (Smokelyzer, Bedfont Scientific Ltd.). This study aims to provide valuable insights into cytisine's effectiveness in smoking cessation and its impact on cardiovascular health.