Ivabradine as an add-on drug in the management of tetralogy of Fallot

Background. Clinical presentations in tetralogy of Fallot (TOF) patients are variable and depend on the severity of right ventricular outflow obstruction, size of pulmonary arteries, and associated cardiac abnormalities. Symptomatic infants and children waiting for surgery usually suffer from recurrent hypercyanotic spells, exercise intolerance, and aggravation of cyanosis and hypoxia by exertion. The purpose of the study was to determine the role of ivabradine in the management of symptomatic patients with TOF as an add-on treatment with β-blockers (propranolol). Materials and methods. This clinical trial was conducted at Al Zahraa Teaching Hospital and Al Najaf Cardiac Center (Najaf, Iraq) from January 2023 to May 2024. It included 100 infants and children diagnosed with TOF. Fifty patients were assigned to the control group who received placebo, and 50 patients to the study group who received ivabradine. Patients were admitted to the hospital for observation 24–48 hours after the starting dose of therapy. Follow-up was after one week for the first visit, then every 2 weeks, with echocardiography, electrocardiography, vital signs, and oxygen saturation recorded at each visit. Results. 90 % of patients were responding to treatment in the study group, and there was a significant association between the type of drug used and the response (P < 0.001); non-responders (46 %) took propranolol only. A significant increase was found in the O2 saturation after treatment from the baseline in both groups (P < 0.001). There was a significant association between drugs used and adverse events in children (P = 0.011). Conclusions. Administration of ivabradine in combination with propranolol to control symptoms of TOF proves to be beneficial therapy with minimal adverse events.