The goal of this observational study is to evaluate whether serum Lipoprotein(a) [Lp(a)] levels are associated with coronary artery calcium (CAC) score measured by multi-slice computed tomography (MSCT) in adults undergoing cardiac risk assessment.

The main questions it aims to answer are:

• Is there a correlation between elevated Lp(a) levels and higher CAC scores?
• Does Lp(a) provide additional predictive value for subclinical atherosclerosis beyond traditional cardiovascular risk factors?

Participants will:

• Undergo a non-contrast MSCT scan to measure CAC score.
• Provide a blood sample for measurement of Lp(a) and routine lipid profile.
• Have baseline clinical and demographic data collected, including cardiovascular risk factors.

Lipoprotein(a) [Lp(a)] is a genetically determined lipoprotein particle structurally similar to LDL, with an additional apolipoprotein(a) component. Elevated Lp(a) levels have been identified as an independent and causal risk factor for atherosclerotic cardiovascular disease (ASCVD). The pro-atherogenic, pro-thrombotic, and pro-inflammatory properties of Lp(a) contribute to plaque development and vascular calcification.

Coronary artery calcium (CAC) score, assessed by non-contrast multi-slice computed tomography (MSCT), is a widely validated imaging biomarker of subclinical coronary atherosclerosis. CAC burden strongly predicts future cardiovascular events and is frequently used for individualized risk stratification. Recent studies suggest that individuals with elevated Lp(a) may also demonstrate higher CAC scores and faster progression of coronary calcification. However, the strength and consistency of this association remain insufficiently defined across different populations.

This observational study is designed to evaluate the correlation between serum Lp(a) levels and CAC score in adult participants undergoing cardiovascular risk assessment. Participants will undergo non-contrast MSCT scanning for CAC scoring, fasting blood sampling for Lp(a) and routine lipid profile, and collection of baseline demographic and clinical risk factors. Multivariable analyses will assess the independent relationship between Lp(a) and CAC score, as well as the potential incremental predictive value of Lp(a) beyond traditional risk factors such as LDL-C, hypertension, diabetes, and smoking.

We hypothesize that higher Lp(a) levels will be associated with higher CAC scores, independent of conventional cardiovascular risk factors, and that patients with both elevated Lp(a) and high CAC (≥100) will represent the subgroup at greatest risk for ASCVD. Demonstrating this relationship may improve cardiovascular risk stratification and highlight the importance of integrating Lp(a) measurement with imaging-based assessment in the early prevention of ASCVD.

Inclusion Criteria:

• 1-adults aged 40-70

  • 2- classified as intermediate cardiovascular risk (10-20% 10 years ASCVD risk)
  • 3-undergoing MsCT for suspected coronary artery disease
  • 4- ability to provide informed consent

Exclusion Criteria:

• 1- known CAD or prior revascularization

  • 2-history of myocardial infarction or stroke
  • 3- statin or PCK9 inhibitor use in the past 3 months
  • 4-renal insufficiency (eGFR < 45ml/min/1.73m2)
  • 5-active inflammation or autoimmune disease

The study population will include adult men and women aged 40 to 70 years who are classified as having intermediate cardiovascular risk (10-20% estimated 10-year ASCVD risk). Participants will be those referred for non-contrast multi-slice CT (MSCT) for suspected coronary artery disease and who are able to provide informed consent.

Patients will be excluded if they have known coronary artery disease, prior myocardial infarction, prior coronary revascularization, or history of stroke. Additional exclusions include recent use of statins or PCSK9 inhibitors within the past 3 months, renal insufficiency (eGFR <45 mL/min/1.73m²), or active inflammatory or autoimmune disease.