The effect of ivabradine versus metoprolol on reducing heart rate in coronary CT-angiography candidates: A double-blind randomized clinical trial

To assess the effect of ivabradine versus metoprolol on reducing heart rate in coronary CT-angiography candidates

This is a Phase III double-blind randomized clinical trial with a control group with parallel groups, in which eligible patients will be randomly assigned to the intervention and control groups using block randomization.

This study will be conducted at the Farshchian Heart Hospital in Hamadan city, involving 92 eligible patients who are candidates for coronary CT-angiography. The patients will be randomly assigned to the intervention and control groups through the block randomization. This trial will be double-blinded.

Inclusion criteria: Age 18 to 80 years Coronary CT angiography candidate Heart rate higher than 70 beats per minute one hour before starting CT angiography Exclusion criteria: Systolic blood pressure lower than 100 mm Hg History of coronary bypass surgery Chronic obstructive pulmonary disease

Intervention group 1: Ivabradine tablets 7.5 mg one dose. If the heart rate does not decrease after one hour, the dose will be repeated. Intervention group 2: Metoprolol 50 mg tablet, one dose. If the heart rate does not decrease after one hour, the dose will be repeated.

Primary outcome: Heart rate, systolic and diastolic blood pressure

In this study, random assignment of patients to the intervention and control groups will be carried out using block randomization. To achieve this, four sheets of paper will be prepared - two with the name of the intervention and two with the name of the control. These paper sheets will be pooled and placed in a container. Patients will be selected one at a time without replacement, and for each patient, a paper sheet will be randomly drawn from the container. After each draw, the paper sheets will be returned to the container, and the process will be repeated until the desired sample size is reached.

Both the medications and placebos will have the same shape. Consequently, patients will remain unaware of the type of intervention they receive. Moreover, the randomization process will be conducted by a separate individual from the one who examines the patients, ensuring that the examining person remains unaware of the intervention. Therefore, the trial will be conducted as a double-blind study.