Monckeberg calcification of coronary arteries: a string of pearls

Abstract

Coronary artery calcium scores are derived from cardiac-gated noncontrast computed tomography scans that are used in cardiac risk stratification. However, an elevated calcium score does not always translate to coronary artery luminal obstruction. Our case demonstrates an extremely high coronary artery calcium score despite nonobstructive coronaries on angiogram.

Introduction

Coronary artery calcium (CAC) scores are derived from cardiac-gated noncontrast computed tomography (CT) scans that are used for atherosclerotic cardiovascular risk stratification. Studies have suggested that elevated CAC scores (Agatston score >400) are associated with higher rates of major adverse cardiovascular events [1]. We present the case of a patient with an extremely high CAC score despite nonobstructive coronaries on angiography.

Case description

A very active 72-year-old man who performs cardiovascular exercise up to 75 minutes per day without symptoms presented with concerns of his cardiac risk given his family history of coronary artery disease. A computed tomography angiography was done and demonstrated extensive, severe coronary artery calcification without severe stenosis. The CAC score was calculated to be 7086 (Fig. 1). The left circumflex artery has severe calcification in the AV groove (Fig. 1A). The proximal to mid left anterior descending artery shows severe calcification (Fig. 1B). The first diagonal artery is densely calcified at its origin (Fig. 1C). The right coronary artery is also densely calcified (Fig. 1D). Due to the elevation in the CAC score, accurate vessel analysis was difficult, and the patient underwent a coronary angiogram. The coronary angiogram revealed a large dominant right coronary artery and left main artery branching into the left circumflex and left anterior descending arteries with significant calcified coronary artery disease but no obstructive stenosis (Figs. 2A and B). The patient continued aspirin, high intensity statin, and his current exercise routine with close follow-up for symptoms. The patient was seen in clinic four months later, and he remained adherent with treatment plan without symptoms.

Fig. 1.

Computed tomography angiography. (A) Left circumflex artery with severe calcification in the atrioventricular groove. (B) Proximal to mid left anterior descending artery with severe calcification. (C) First diagonal artery densely calcified at its origin. (D) Right coronary artery is densely calcified.

Fig. 2.

Coronary angiogram demonstrating calcified coronary artery disease without obstructive stenosis. (A) Large, dominant right coronary artery. (B and C) Two views of left main artery branching into left circumflex and left anterior descending arteries.

Discussion

One possible explanation for the patient's findings is calcification of the tunica media of the coronary arteries, akin to Monckeberg's sclerosis. This disease typically affects small- and medium-sized arteries causing stiffening of the arterial wall without thrombosis or luminal obstruction. Monckeberg's sclerosis most commonly affects the peripheral arteries of limbs and is associated with other comorbidities such as diabetes and chronic kidney disease [2]. Our patient, however, had normal renal function, no evidence of metabolic disease, and the coronary arteries were affected as opposed to the peripheral arteries. To our knowledge, this is one of the highest CAC scores with nonobstructive coronary artery disease reported. This case demonstrates that an extremely high CAC score may not always distinguish high risk obstructive plaque from stable calcified lesions. Individual cases and the patient's clinical picture should be considered in decision-making on further management.

Patient consent statement

The patient has given written, informed consent for the publication of this case. Further, no personal or identifying information is included in the manuscript or accompanying images.