From the Guidelines
The Major Adverse Cardiovascular Events (MACE) score is calculated by counting the occurrence of predefined cardiovascular events, such as cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke, within a specific timeframe, often expressed as a percentage of patients experiencing at least one MACE component or as an event rate per patient-years of follow-up. The MACE score is not a single standardized calculation method but rather a composite endpoint used in clinical trials and research to assess cardiovascular outcomes. MACE typically includes a combination of cardiovascular events, and the specific components included may vary between studies and clinical contexts. To determine the risk category of a patient, which can inform the calculation of their MACE score, clinicians can use the number of cardiovascular risk factors, as outlined in a clinical practice guideline published in the BMJ in 2022 1. This guideline categorizes patients into low, moderate, and high risk based on the number of cardiovascular risk factors, with corresponding estimated five-year risks of MACE. Some key points to consider when calculating MACE score include:
- The components of MACE, which may include cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and other events like hospitalization for unstable angina or heart failure
- The timeframe over which the events are counted
- The expression of the results, which may be as a percentage of patients experiencing at least one MACE component or as an event rate per patient-years of follow-up. The concept of MACE is valuable because it captures multiple important cardiovascular outcomes together, providing a more comprehensive picture of cardiovascular health, as seen in the guideline recommendations for the use of pcsk9 inhibitors and ezetimibe for the reduction of cardiovascular events 1.
From the Research
Calculating MACE Score
To calculate the Major Adverse Cardiovascular Events (MACE) score, several components need to be considered, including cardiovascular death, hospitalization for myocardial infarction, or ischemic stroke 2. The method of calculation may vary depending on the specific definition of MACE used in a study.
Components of MACE
The traditional three-point MACE definition includes:
- Acute myocardial infarction (AMI)
- Stroke
- Cardiovascular death 3 However, some studies may use different components or additional points, such as unstable angina or heart failure.
Calculation Methods
There is no single, universally accepted method for calculating the MACE score. Some studies use a Cox proportional hazards regression model to evaluate the association between risk factors and MACE 2, 4. Others may use a composite measure, such as the PAD-medical score, which takes into account the control of low-density lipoprotein cholesterol, blood pressure, blood glucose, smoking, and prescription of an anti-platelet 4.
Risk Factors
Several risk factors have been associated with an increased risk of MACE, including:
- Diabetes 5
- Heart failure 5
- Higher Charlson index 5
- Older age 5
- Presence of atherosclerotic disease in multiple vascular beds 2
Limitations
It's essential to note that the 10-year MACE observations may underestimate the 20-year total cardiovascular burden, particularly in younger women 6. Additionally, the variability in MACE definitions and components used across observational studies can prohibit the comparison, replication, and aggregation of findings 3.