The goal of this retrospective cohort study Is to Primarily be platelet transfusion frequency and postoperative bleeding risk, analysis using descriptive and inferential statistics in all eligible patients admitted to the cardiac intensive care unit (CICU) for open-heart surgery were included of both gender, age group of 30-80 years. The main questions it aims to answer are:

• How was the frequency of platelet transfusion during the index admission evaluated?
• How was post-operative bleeding risk measured?
• What does 24-hour chest drain output indicate in this context?
• How was packed cell volume (PCV) transfusion used as an outcome measure?

The Cardiac Intensive Care Unit (CICU) at a tertiary care facility in Karachi, Pakistan, served as the site of this retrospective cohort study. Every procedure adhered to institutional policies, and safe data management and de-identification preserved confidentiality. Consecutive sampling was employed due to the retrospective methodology, and the sample included all eligible CICU patients who had heart surgery during the study period. The study included patients on dual antiplatelet treatment (DAPT: aspirin and/or clopidogrel) with the last dose within five days before to surgery, as well as adults between the ages of thirty and eighty undergoing heart surgery with cardiopulmonary bypass (CPB).

Inclusion Criteria:

• CICU patients who underwent cardiac surgery
• Adults aged 30-80 years undergoing cardiac surgery with cardiopulmonary bypass
• Patients who received dual antiplatelet therapy, last dose within 5 days before surgery

Exclusion Criteria:

• BMI > 40 kg/m²
• Repeat open-heart surgery (reoperation)
• Transferred open-chest procedures
• Active liver disease
• Chronic lung disease
• Dialysis dependence
• Intra-aortic balloon pump (IABP) in place pre- or post-operatively
• Major neurological deficit within the past 6 months
• Incomplete clinical records

All eligible patients admitted to the cardiac intensive care unit (CICU) for open-heart surgery were included.