Prevalence of coronary atherosclerosis in asymptomatic population

Atherosclerosis and especially coronary atherosclerosis is the leading cause of mortality and morbidity in the industrial world. Major advances in medical, interventional and surgical therapy, together with effective secondary prevention, has resulted in extended life expectancy and an improvement in the quality of life of most patients with clinical coronary artery disease. Despite these achievements, the prevalence of coronary artery disease seems to remain high. However, the exact data on the prevalence of coronary atherosclerosis or clinical coronary artery disease are extremely diverse (Table 1). Autopsy studies in humans, who died from a non-cardiac cause, revealed manifest coronary artery disease in 4·5% and initial morphological (clinically silent) signs of aortic and coronary atherosclerosis in 50–100% of the young population below 35 years. Clinical and/or ECG signs of coronary artery disease were found in 3–9% of the general population in north India. Non-invasive tests are well designed for screening due to their non-invasive nature; however, their low specificity and sensitivity in asymptomatic populations leads to extremely variable results: the prevalence varies between 2·5 and 31·7%. The gold standard for the detection of significant coronary atherosclerosis is still coronary arteriography. Due to its invasive nature, it is not possible to use it for screening entirely asymptomatic (healthy) populations. Thus, only data from patients with other forms of cardiac diseases and without symptoms of coronary artery disease are known: the prevalence of significant coronary atherosclerosis among valvular/ congenital heart disease patients is 4·5%, among mitral valve prolapse patients 13·5% and among heavy smokers with emphysema referred for lung volume reduction surgery 15%. Enbergs et al. in this issue present a relatively large group of 331 patients referred for catheter ablation therapy of cardiac arrhythmias. They underwent routine coronary arteriography as part of a diagnostic catheterization procedure. Despite the relatively high proportion of patients with chest pain unrelated to arrhythmias (21% of the group) and the higher then expected use of ‘coronary’ drugs, the prevalence of significant coronary artery disease (defined as at least one vessel with >50% stenosis) was low (7·3%) and was only slightly higher than among valvular/congenital heart disease. Furthermore, among patients without chest pain the prevalence was only 3·8% and the severity of lesions was very mild. Thus, this paper confirmed the low prevalence of obstructive coronary atherosclerosis in asymptomatic humans and provides a good scientific basis for the avoidance of routine coronary arteriography in this particular arrhythmia population.