Spotty calcification as a marker of accelerated progression of coronary atherosclerosis: insights from serial intravascular ultrasound

Objectives: The purpose of this study was to determine atheroma progression in patients with spotty calcification.

Background: Although extensively calcified atherosclerotic lesions have been proposed to be clinically quiescent, the presence of spotty calcification within plaque has been reported to be associated with an increased incidence of ischemic cardiovascular events. The relationship between spotty calcification and disease progression has not been investigated.

Methods: A total of 1,347 stable patients with angiographic coronary artery disease underwent serial evaluation of atheroma burden with intravascular ultrasound imaging. Patients with spotty calcification were identified based on the presence of lesions (1 to 4 mm in length) containing an arc of calcification of <90°. Clinical characteristics and disease progression were compared between patients with spotty calcification (n = 922) and those with no calcification (n = 425).

Results: Patients with spotty calcification were older (age 56 years vs. 54 years; p = 0.001), more likely to be male (68% vs. 54%; p = 0.01), and have a history of diabetes mellitus (30% vs. 24%; p = 0.01) and myocardial infarction (28% vs. 20%; p = 0.004), and have lower on-treatment high-density lipoprotein cholesterol levels (48 ± 16 mg/dl vs. 51 ± 17 mg/dl; p = 0.001). Patients with spotty calcification demonstrated a greater percent atheroma volume (PAV) (36.0 ± 7.6% vs. 29.0 ± 8.5%; p < 0.001) and total atheroma volume (174.6 ± 71.9 mm(3) vs. 133.9 ± 64.9 mm(3); p < 0.001). On serial evaluation, spotty calcification was associated with greater progression of PAV (+0.43 ± 0.07% vs. +0.02 ± 0.11%; p = 0.002). Although intensive low-density lipoprotein cholesterol and blood pressure lowering therapy slowed disease progression, these efficacies were attenuated in patients with spotty calcification.

Conclusions: The presence of spotty calcification is associated with more extensive and diffuse coronary atherosclerosis and accelerated disease progression despite use of medical therapies.