Hemostatic agents are widely used in cardiac and vascular surgery to support intraoperative bleeding control. Despite their clinical relevance and substantial economic impact, little is known about real-world patterns of use, adherence to evidence-based recommendations, and the alignment between clinicians' perceived knowledge and actual decision-making.

HAEMOVAX is a single-center mixed-methods observational study conducted at IRCCS Galeazzi-Sant'Ambrogio Hospital, Milan, Italy. The study combines an anonymous survey of cardiovascular surgeons with a retrospective audit of institutional hemostatic agent consumption. The primary objective is to evaluate the appropriateness of hemostatic agent selection using a Knowledge-Practice Alignment Score (KPA-Score) derived from standardized clinical vignettes based on current EACTS and ESA recommendations. Secondary objectives include assessment of usage patterns, barriers to appropriate use, concordance between declared practice and real-world consumption, and opportunities for evidence-based standardization.

Hemostatic agents are routinely used in cardiac and vascular surgery to support local bleeding control and facilitate surgical hemostasis. Their use may influence several clinically relevant outcomes, including perioperative blood loss, transfusion requirements, operative time, reintervention for bleeding, and postoperative complications. In addition to their clinical implications, topical hemostatic agents represent a significant component of procedural costs in cardiovascular surgery.

Despite their widespread use, evidence regarding real-world utilization patterns remains limited. Available literature is largely derived from industry-sponsored randomized trials designed to evaluate the efficacy of individual products in selected procedural settings. Consequently, little is known about how hemostatic agents are actually selected and utilized in routine clinical practice, the degree of adherence to contemporary evidence-based recommendations, and the potential discrepancy between clinicians' perceived knowledge and their decision-making in standardized clinical scenarios.

Furthermore, many institutions lack formal protocols governing the selection of hemostatic agents according to surgical indication, bleeding severity, or patient-specific factors. This may contribute to substantial variability in practice patterns, inefficient resource allocation, and inconsistent application of current guideline recommendations. Understanding these factors is essential to support evidence-based standardization strategies and optimize both clinical and economic outcomes.

The HAEMOVAX study is a single-center mixed-methods observational study conducted at IRCCS Galeazzi-Sant'Ambrogio Hospital, Milan, Italy. The study consists of three complementary components: (1) an anonymous structured survey administered to cardiac and vascular surgeons; (2) a retrospective audit of institutional hemostatic agent consumption derived from pharmacy and operating room supply records; and (3) a qualitative thematic analysis of narrative clinical cases reported by participants.

The primary objective is to evaluate the appropriateness of hemostatic agent selection using the Knowledge-Practice Alignment Score (KPA-Score). The KPA-Score is calculated from responses to five standardized clinical vignettes representing common cardiovascular surgical scenarios. Appropriateness is defined as concordance between the participant's selected hemostatic strategy and recommendations derived from contemporary EACTS and ESA guidelines. Individual KPA-Scores range from 0% to 100%, with scores of 60% or greater considered indicative of appropriate hemostatic agent selection.

Secondary objectives include characterization of self-reported utilization patterns of hemostatic agents, assessment of perceived barriers to appropriate use, evaluation of concordance between declared practice and institutional consumption data, estimation of opportunities for evidence-based standardization, and identification of factors associated with lower KPA-Scores. Qualitative analysis will be performed to explore themes not fully captured by structured survey questions, including decision-making processes, institutional barriers, and perceptions regarding product effectiveness and availability.

All attending surgeons, fellows, and residents affiliated with the Cardiac Surgery and Vascular Surgery Units will be eligible to participate. Survey responses will be collected anonymously. Consumption data will be analyzed in aggregated form at the unit level. No patient-identifiable information will be collected or analyzed.

Study findings are expected to provide a comprehensive assessment of the appropriateness of hemostatic agent use within a high-volume cardiovascular surgical center and to identify opportunities for educational interventions, institutional protocol development, resource optimization, and evidence-based standardization of clinical practice.

Inclusion Criteria:

• Physicians with a surgical role in the Departments of Cardiac Surgery or Vascular Surgery at IRCCS Galeazzi-Sant'Ambrogio, Milan Including attending surgeons, consultant surgeons, and surgical residents
• Active participation in cardiovascular operative procedures during the study period (or within the preceding 12 months)
• Employment at the study institution at the time of survey administration Willingness to participate and complete the anonymous structured questionnaire

Exclusion Criteria:

• Non-surgical healthcare personnel (e.g., nurses, anesthesiologists, administrative staff, or allied health professionals)
• Surgeons not involved in operative cardiovascular practice during the study period
• External collaborators or visiting surgeons without regular clinical activity at the institution
• Individuals who do not provide informed consent for participation in the anonymous survey
• Questionnaires with missing or incomplete vignette responses preventing calculation of the KPA-Score

The study population includes all cardiovascular surgery staff (cardiac and vascular surgeons, including attending surgeons and residents) employed at IRCCS Galeazzi-Sant'Ambrogio, Milan. Participation is voluntary and anonymous. The study uses a census sampling approach, targeting the entire eligible professional population within the institution. No patient-level participants are included.

Individual participant data (IPD) will not be shared, as the study involves an anonymous cross-sectional survey of healthcare professionals and aggregated institutional audit data without patient-level datasets.