The aim of this study is to investigate the effect of stress ball application during coronary angiography on anxiety, procedure-related fear, physiological parameters, and comfort. The study is designed as a prospective, randomized controlled clinical trial. The study population will consist of patients scheduled to undergo coronary angiography at Tarsus State Hospital. The sample size was calculated based on the post-test anxiety score effect size (Cohen's d = 0.43) reported in the study by Yüksel and Güneş (2024), which examined the effect of stress ball application on anxiety and pain levels during angiography procedures. Using a significance level of α = 0.05 and a statistical power of 90% (1-β = 0.90), the required sample size was calculated as 59 participants. To account for potential attrition, the sample size was increased by 10%, resulting in a final sample of 64 participants (intervention group: n = 32; control group: n = 32). Data will be collected using the Descriptive Characteristics Form, State Anxiety Inventory, Procedure-Related Fear Scale, Physiological Parameters Monitoring Form, and Comfort Assessment Form. Upon admission to the coronary angiography unit and before the procedure, all participants will complete the Descriptive Characteristics Form, State Anxiety Inventory, Procedure-Related Fear Scale, and Physiological Parameters Monitoring Form. These assessments will be administered by researcher NÇ.

In addition to routine care, patients in the intervention group will be instructed to squeeze a medium-resistance stress ball, hold the squeeze while counting to five, then release it, and repeat this cycle throughout the angiography procedure. Researcher GB will be responsible for implementing the intervention.

Patients in the control group will receive only the unit's standard care. Routine care includes pre-procedural patient education, assessment of vital signs, verification of intravenous line patency, preparation of the vascular access site, and standard patient monitoring throughout the procedure. Care will be provided according to the standard care protocol routinely implemented in the hospital's coronary angiography unit.

Immediately after the procedure, the State Anxiety Inventory, Procedure-Related Fear Scale, Physiological Parameters Monitoring Form, and Comfort Assessment Form will be administered by researcher NÇ.