Usefulness of Coronary Artery Calcium to Identify Adults of Sufficiently High Risk for Atherothrombotic...

Area of Science:

• Cardiology
• Preventive Medicine
• Pharmacology

Background:

• Low-dose rivaroxaban demonstrated efficacy in secondary prevention of atherosclerotic cardiovascular disease (ASCVD) within the COMPASS trial.
• The role of oral anticoagulants in primary prevention of ASCVD remains undefined.
• Coronary artery calcium (CAC) scoring is a tool for assessing subclinical atherosclerosis.

Purpose of the Study:

• To evaluate if CAC scoring can identify high-risk primary prevention adults who may benefit from low-dose rivaroxaban for ASCVD event prevention.
• To model the number needed to treat (NNT) and number needed to harm (NNH) for low-dose rivaroxaban in primary prevention stratified by CAC scores.

Main Methods:

• Utilized data from 5,196 Multiethnic Study of Atherosclerosis (MESA) cohort participants not on antiplatelet or anticoagulant therapy.
• Applied relative risk ratios from the COMPASS trial to MESA cohort absolute event rates.
• Stratified NNT and NNH by calculated ASCVD risk and baseline CAC scores to estimate net clinical benefit.

Main Results:

• Participants with CAC ≥300 exhibited an ASCVD event rate of 20 per 1000 patient-years, comparable to the COMPASS control arm.
• CAC score was independently associated with ASCVD outcomes (p <0.001 for trend) but not independently with major bleeding risk.
• Predicted 5-year NNT was 75 for CAC 100-299 and 45 for CAC ≥300, with corresponding NNH values of 252 and 98.

Conclusions:

• CAC scoring aids in distinguishing potential ASCVD event reduction benefits from bleeding risks associated with low-dose rivaroxaban.
• Identifies very high-risk primary prevention adults without established cardiovascular disease who may achieve net benefit from low-dose rivaroxaban therapy.