Background:
Coronary atherosclerosis, also known as coronary artery disease (CAD) and coronary heart disease (CHD), may develop at an early age and remain asymptomatic and hidden for many years. It is still not known how common silent CAD is in a general population and how risky it is.
Study Design:
Prospective observational cohort study.
Study Setting:
Copenhagen General Population Study, Denmark.
Study Participants:
9533 asymptomatic persons aged 40 years or older without known ischemic heart disease. More than half were women. The average age was 60 years.
Study Measurements:
Subclinical coronary atherosclerosis was assessed with coronary computed tomography angiography conducted blinded to treatment and outcomes.
Coronary atherosclerosis was characterized according to luminal obstruction (nonobstructive or obstructive [≥50% luminal stenosis]) and extent (nonextensive or extensive [one-third or more of the coronary tree]). T
The primary outcome was myocardial infarction (MI or heart attack), and the secondary outcome was a composite of death or MI.
Study Results:
A total of 5114 (54%) persons had no subclinical coronary atherosclerosis.
On the other hand, 3483 (36%) had nonobstructive disease, and 936 (10%) had obstructive disease, for a total of 46% of participants with silent CAD.
Within a median follow-up of 3.5 years, 193 persons died and 71 had myocardial infarction.
The risk for MI was increased in persons with obstructive (risk 9X elevated) and extensive (risk 8X elevated) disease.
The highest risk for MI was noted in persons with obstructive-extensive subclinical coronary atherosclerosis (risk 12X elevated) or obstructive-nonextensive (risk 8X elevated).
Study Conclusion:
In asymptomatic persons with an average of 60 years old, subclinical, coronary atherosclerosis was found in about half of study subjects.
In those with “obstructive” silent CAD, there was associated a more than 8-fold elevated risk for myocardial infarction.