en Cardiology Cardiology Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="color:#0033ff;"><strong><em>Background</em></strong><em>:</em></span> To assess the influence of the COVID-19 (Coronavirus Disease 2019<strong>)</strong> pandemic on treatment adherence by patients with CHF (Chronic heart failure) and to determine the factors associated with changing adherence during home-isolation.<br> <span style="color:#0033ff;"><strong><em>Methods</em></strong><em>:</em></span> The survey was conducted in patients participating in the COMPLIANCE study (ClinicalTrials.gov. NCT04262583). Thirty-one patients, included into the COMPLIANCE study before March 1, 2020, were interviewed through phone calls. A modified adherence scale of the National Society for Evidence-Based Pharmacotherapy was used, which permits to assess overall adherence, adherence to particular drugs and the main causes for non-adherence.<br> <span style="color:#0033ff;"><strong><em>Results</em></strong><em>:</em></span> In the whole group of patients, only a tendency to reduced overall adherence was registered during the COVID-19 pandemic (р=0,256). Significant differences in the rate of adherence deterioration were revealed for angiotensin-converting enzyme (ACE) inhibitors (p=0.031) and for statins (p=0.002). The reasons for non-adherence were lack of opportunity to contact with physician, inability to perform investigations necessary for correcting prescribed pharmacotherapy, and side effects.<br> <span style="color:#0033ff;"><strong><em>Conclusion</em></strong><em>:</em></span> A tendency to deterioration of adherence to prescribed pharmacotherapy was revealed during the COVID-19 pandemic. A significant decline in adherence was registered to ACE-inhibitors and statins.</span></span> adherence to treatment, period of home-isolation, COVID-19, chronic heart failure, factors of non- adherence 199 203 http://caspjim.com/browse.php?a_code=A-10-2137-1&slc_lang=en&sid=1 Sergey Yu. Martsevich sergeymartsevich@mail.ru 100319475328460035502 100319475328460035502 No Department of Preventive Pharmacotherapy, National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per. 10, Moscow, Russia Yulia V. Lukina yuvlu@mail.ru 100319475328460035503 100319475328460035503 No Department of Preventive Pharmacotherapy, National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per. 10, Moscow, Russia Natalia P. Kutishenko nkutishenko@gmail.com 100319475328460035504 100319475328460035504 No Department of Preventive Pharmacotherapy, National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per. 10, Moscow, Russia Elmira T. Guseynova e.guseinova@mail.ru 100319475328460035505 100319475328460035505 Yes Department of Preventive Pharmacotherapy, National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per. 10, Moscow, Russia