Does higher risk of heart disease always translate to cardiac events?

Although Black patients have a higher risk of coronary artery disease (CAD) than their white counterparts, they don't necessarily have higher incidence of major adverse cardiac events, according to research published December 22 in JAMA Cardiology.

"We found that Black participants had a higher cardiovascular risk burden but less-prevalent epicardial coronary artery disease on coronary CT angiography compared with [white] participants," noted a team led by Dr. Lili Zhang of Massachusetts General Hospital in Boston.

Black individuals tend to have a higher risk of CAD morbidity and mortality compared with white individuals -- differences that may be due to a higher burden of heart disease risk factors as well as disparities in socioeconomic status and healthcare access, Zhang and colleagues wrote.

But less clear is whether racial differences among patients with symptomatic stable chest pain translate into major adverse cardiac events (i.e., death, myocardial infarction, or hospitalization for unstable angina).

The researchers sought to investigate this question via a study that consisted of data from 1,071 Black individuals and 7,693 non-Hispanic white individuals with stable chest pain who underwent coronary CT angiography and were included in the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial. The main outcome was occurrence of major adverse cardiac events (MACE) over a median follow up of two years.

The team found that although Black individuals had higher cardiovascular risk -- due in part to comorbidities such as hypertension and diabetes -- they had a similar rate of MACE over two-year follow-up as white individuals. In fact, Black patients had lower coronary calcium scores, rates of stenosis, and rates of high-risk plaque.

Rates of major cardiovascular events and heart disease risk factors by race
Measure	Black individuals	White individuals	p-value
Major adverse cardiovascular events rate over 2-year follow-up period	3%	3.2%	0.84
Coronary artery calcium score greater than 0	45.1%	63.2%	0.001
Coronary stenosis greater than or equal to 50%	8.7%	14.6%	0.001
High-risk plaque	37.6%	52.4%	0.001

The study results highlight that there's more to learn about the relationship between risk factors and disease, according to Zhang and colleagues.

"[Our finding that] Black individuals had more cardiovascular risk factors, yet less coronary plaque on coronary CT angiography and similar two-year major adverse cardiac events, underscores the limits of our understanding of the relationship between risk factors and plaque in Black and [white] persons," the group concluded.