Asymptomatic coronary atherosclerosis linked to 8-fold higher risk for heart attack

Key takeaways:

• Subclinical, obstructive coronary atherosclerosis was associated with an elevated risk for myocardial infarction in asymptomatic adults.
• Risk for MI or death was higher in adults with extensive subclinical coronary atherosclerosis.

Subclinical, obstructive coronary atherosclerosis was linked to a more than 8-fold elevated risk for myocardial infarction in asymptomatic adults aged 40 years or older, according to researchers.

Andreas Fuchs, MD, PhD, of the department of cardiology at Copenhagen University Hospital–Rigshospitalet, and colleagues wrote that coronary atherosclerosis can develop at an early age and remain latent in the body for many years.

Coronary atherosclerosis is “the key pathobiological process” that is responsible for the development of myocardial infarction, and together, these conditions define ischemic heart disease, the researchers wrote. Subclinical coronary atherosclerosis comes before ischemic heart disease, and can evolve at an early age, even years before the clinical disease develops.

“For more than 50 years, obstructive coronary artery disease, defined as a luminal coronary stenosis of 50% or greater, has been considered a key feature of elevated risk,” they wrote. “In the past decades, however, the extent of atherosclerosis in the coronary tree as well as specific morphologic features of the atherosclerotic plaque have been acknowledged as important risk factors.”

Fuchs and colleagues conducted a prospective observational cohort study to define characteristics of subclinical coronary atherosclerosis linked to the development of MI in 9,533 asymptomatic participants aged at least 40 years without CVD. Their findings were recently published in Annals of Internal Medicine.

“We tested the hypothesis that characteristics of subclinical coronary atherosclerosis are associated with an increased risk for MI in asymptomatic persons without known ischemic heart disease,” they wrote.

The researchers used coronary computed tomography angiography to assess subclinical coronary atherosclerosis. Coronary atherosclerosis was then characterized by extent and luminal obstruction (obstructive being defined as greater than 50% luminal stenosis).

Fuchs and colleagues found that just over half — 54% — of the participants did not have subclinical coronary atherosclerosis, and, of the 46% who did, 10% had obstructive disease. Additionally, of those diagnosed, the condition was found more frequently in men than women (61% vs. 36%).

The researchers noted that, in the median follow-up of 3.5 years, 71 participants had an MI and 193 died. MI risk was higher in those with obstructive (adjusted relative risk [aRR] = 9.19; 95% CI, 4.49-18.11) and extensive (aRR = 7.65; 95% CI, 3.53-16.57) disease and highest in those with both extensive and obstructive subclinical coronary atherosclerosis (aRR = 12.48; 95% CI, 5.50-28.12) or obstructive-nonextensive (aRR = 8.28; 95% CI, 3.75-18.32).

“Obstructive subclinical coronary atherosclerosis was associated with a more than 8-fold increased risk for MI, and the risk for either death or MI was increased 2-fold in persons with extensive subclinical coronary atherosclerosis,” they wrote.

Fuchs and colleagues also wrote that, regardless of degree of obstruction, the risk for the composite end point of death or MI was increased in those with extensive disease: obstructive-extensive (aRR = 3.15; 95% CI, 2.05-4.83) and nonobstructive-extensive (aRR = 2.7 95% CI, 1.72-4.25).

“Identification of luminal obstructive or extensive subclinical coronary atherosclerosis, which we have shown are associated with high risk, provides potentially clinically relevant, incremental risk assessment in patients without suspected or known ischemic heart disease undergoing cardiac CT and/or electrocardiogram-gated chest CT for other clinical indications,” they wrote.

In an accompanying editorial, Michael McDermott, MBChB, a cardiology research fellow at the University of Edinburgh, and David E. Newby, DM, PhD, British Heart Foundation Duke of Edinburgh Chair of Cardiology, wrote that “this exceptional and important study now provides a benchmark against which to observe the contemporary natural history of coronary artery disease.”

“It also provides invaluable data about event rates and prevalence of asymptomatic coronary artery disease that will inform public health prevention strategies and ongoing clinical trials of targeting preventative therapies in persons screened for occult coronary artery disease,” McDermott and Newby wrote.

References:

• Fuchs A, et al. Ann Intern Med. 2023;doi:10.7326/M22-3027.
• McDermott M, et al. Ann Intern Med. 2023; doi:10.7326/M23-0533.