Aortic Elasticity and Cardiac Electrophysiological Balance in Opioid Users Receiving Buprenorphine/Naloxone Maintenance Therapy

<b>Background</b>: Opioid dependence treated with buprenorphine/naloxone is associated with increased cardiovascular risk; however, data regarding aortic elasticity and cardiac electrophysiological balance during long-term maintenance therapy remain limited. This study investigated aortic stiffness and distensibility in individuals receiving buprenorphine/naloxone (Suboxone), and examined their associations with echocardiographic and electrocardiographic parameters, including the index of cardiac electrophysiological balance (iCEB and iCEBc). <b>Methods</b>: A retrospective cohort analysis was conducted, including 130 intravenous opioid users receiving Suboxone and 150 age- and sex-matched healthy controls. All participants underwent clinical evaluation, transthoracic echocardiography, resting 12-lead electrocardiography, and 24-h ambulatory blood pressure monitoring. <b>Results</b>: Compared to controls, opioid users demonstrated significantly higher aortic distensibility (median 0.019 vs. 0.015, <i>p</i> < 0.001) and lower aortic stiffness (median 52.31 vs. 64.66, <i>p</i> < 0.001). Patients receiving Suboxone for more than 18 months exhibited higher diastolic blood pressure (<i>p</i> = 0.044), mean arterial pressure (<i>p</i> = 0.046), and pulmonary artery pressure (<i>p</i> = 0.022). Aortic elasticity indices showed strong correlations with blood pressure and echocardiographic parameters. In the overall cohort, Suboxone use duration was not significantly correlated with aortic stiffness or distensibility parameters, while a weak negative correlation was observed with ferritin levels (r = -0.231, <i>p</i> = 0.008). In subgroup analysis of long-term users (>18 months), a moderate positive correlation was observed between therapy duration and iCEB values (r = 0.367, <i>p</i> = 0.001). <b>Conclusions</b>: Chronic buprenorphine/naloxone therapy appears to be associated with changes in aortic elasticity, blood pressure, and mild electrophysiological alterations. These results support the use of non-invasive vascular and electrocardiographic evaluations for cardiovascular risk monitoring and stratification among patients receiving opioid maintenance therapy.