Tehran University of Medical Sciences Immunology and Genetics Journal 2645-4831 4 2 2021 06 22 87 94 Nasim Ramzi Student Research Committee, Alborz University of Medical Sciences, Karaj, Iran; Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran. Shahrooz Yazdani Cardiovascular Research Center, Alborz University of Medical Sciences, Karaj, Iran. Hamed Talakoob Cardiovascular Research Center, Alborz University of Medical Sciences, Karaj, Iran. Seyed Erfan Rasouli Non-Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran Hossein Karim Cardiovascular Research Center, Alborz University of Medical Sciences, Karaj, Iran Gholamreza Azizi Non-Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran. 2021 05 29 2021 09 11 Background: The common variable immune deficiency (CVID) is known as the most prevalent symptomatic primary immune deficiency (PID) diseases, which is characterized by hypogammaglobulinemia with variable infectious and noninfectious manifestations. In this study, the researchers aimed to evaluate the frequency of cardiac disorders and investigate its association with other manifestations in CVID patients. Method: A total of 337 CVID patients registered in the Iranian Primary Immunodeficiency Registry were evaluated in this study. The questionnaire was completed for all patients to collect the participants’ demographic data, clinical manifestations and laboratory finding. The analysis was performed between the two groups of the study including CVID patients with cardiac manifestation and those without it. Results: The prevalence rate of cardiac manifestation was calculated to be 9.1%. pericardial and myocardial diseases and pulmonary hypertension were the most prevalent complications. CVID patients with a history of cardiac problem had significantly higher prevalence rates of otitis media, lymphoproliferative disorders, splenomegaly, hepatomegaly, failure to thrive and lower numbers of CD8+ T cells and CD19+ B cells compared to the patients without cardiac disorders. Notably, no significant differences were observed in immunoglobulins serum levels, CD3+ and CD4+ T cells between the patients with and without cardiac manifestation. Conclusion: Regular echocardiographic evaluation and of CVID patients for cardiac complications especially for inflammatory cardiac disease, heart failure and pulmonary hypertension, is critical to reduce the risk of heart disease. https://igj.tums.ac.ir/index.php/igj/article/view/72 https://igj.tums.ac.ir/index.php/igj/article/download/72/71