CTA-detected coronary artery disease associated with increased risk for myocardial infarction
Danish researchers used computed tomography angiography (CTA) to diagnose obstructive coronary atherosclerosis in 9,533 asymptomatic patients ages 40 years or older without known cardiovascular disease.
Asymptomatic middle-aged patients without known cardiovascular disease but with subclinical obstructive coronary atherosclerosis had a more than eightfold elevated risk for myocardial infarction, a study found.
Danish researchers studied 9,533 asymptomatic patients ages 40 years or older without known cardiovascular disease and used computed tomography angiography (CTA) to diagnose obstructive coronary atherosclerosis. Coronary atherosclerosis was described by luminal obstruction (nonobstructive or obstructive [≥50% luminal stenosis]) and extent (nonextensive or extensive [one-third or more of the coronary tree]). The primary outcome was myocardial infarction, and the secondary outcome was a composite of death or myocardial infarction. Results were published March 28 by Annals of Internal Medicine.
The study included 5,114 patients (54%) with no subclinical coronary atherosclerosis, 3,483 (36%) with nonobstructive disease, and 936 (10%) with obstructive disease. Within a median follow-up of 3.5 years (range, 0.1 to 8.9 years), 193 patients died and 71 had myocardial infarction. The risk for myocardial infarction was higher in those with obstructive and those with extensive disease (adjusted relative risk [RR], 9.19 [95% CI, 4.49 to 18.11] and 7.65 [95% CI, 3.53 to 16.57], respectively). Patients with obstructive-extensive subclinical coronary atherosclerosis (adjusted RR, 12.48; 95% CI, 5.50 to 28.12) or obstructive-nonextensive disease (adjust RR, 8.28; 95% CI, 3.75 to 18.32) had the highest risk for MI. The risk for the composite end point of death or myocardial infarction was higher regardless of the degree of obstruction in patients with extensive disease.
The researchers noted that finding luminal obstructive or extensive subclinical coronary atherosclerosis provides potentially clinically relevant, incremental risk assessment in patients without suspected or known ischemic heart disease. “This could apply in patients having electrocardiogram-gated chest CT for procedural planning before atrial fibrillation ablation, left atrial appendage closure, and invasive treatment of heart valve disease, in addition to patients examined for suspected aortopathy,” they wrote. “Such patients with obstructive and/or extensive subclinical coronary atherosclerosis could benefit from referral to intensified cardiovascular primary prevention therapy.”
An accompanying editorial stated that this research provides an opportunity to study the contemporary natural history of coronary artery disease in the absence of intervention, where neither patient nor clinician are aware of scan findings.
“This exceptional and important study now provides a benchmark against which to observe the contemporary natural history of coronary artery disease,” the editorialists wrote. “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,” such as the DANE-HEART and SCOT-HEART 2 trials.