Abstract P225: Calcification of the Splenic, Internal and External Iliac, and Breast Arteries and Risk of All-cause Mortality
Authors: Hendriks Eva J , de Jong Pim A , Beulens Joline W , van der Schouw Yvonne T , Criqui Michael H , Allison Matthew , Ix Joachim H 
Published: July 2021

Introduction:
Prognostic consequences of and risk factors for coronary and aortic calcification are well known. Less is known about the consequences of and risk factors for calcification in other arteries.

Hypothesis:
We hypothesize that calcifications in the splenic, internal and external iliac, and breast arteries (in females) have different risk factor profiles, and that calcification in these beds is associated with mortality.

Methods:
We conducted a case cohort study from 5196 individuals who self-referred for whole body computed tomography (CT). We selected a random sub-cohort of 395 individuals. Our cases were 298 individuals who died during a median follow-up of 9.4 years. CT scans were scored for splenic, internal and external iliac, and, in females, breast artery calcification. The associations between risk factors and presence or absence of calcification in each vascular bed in the random sub-cohort was evaluated using logistic regression. Using both the sub-cohort and death cases, we used Prentice-weighted Cox proportional hazards models to assess associations of calcification in each bed with mortality.

Results:
Within the random sub-cohort, prevalence of calcification was 11.6% (46 of 395) in the splenic, 47.9% (187 of 390) in the internal iliac and 9.5% (37 of 390) in the external iliac arteries. Among the 163 women, 3.7% had breast artery calcification. In multivariable models, age (OR 1.62 [95%CI 1.04-2.54] per 10 years), diabetes (OR 5.80 [95%CI 1.37-24.61]), log-transformed abdominal aortic calcium (AAC) (OR 1.36 [95%CI 1.09-1.70]) and log-transformed CAC score (OR 1.38 [95%CI 1.13-1.68]) were independently associated with splenic artery calcification. Age (OR 1.60 [95%CI 1.09-2.33], male gender (OR 3.86 [95%CI 2.09-7.15]), AAC (OR 1.44 [95%CI 1.28-1.62]) and CAC score (OR 1.23 [95%CI 1.08-1.39]) were associated with internal iliac artery calcium. Smoking (current vs. never OR 9.87 [95%CI 2.24-43.61]) and AAC (OR 1.96 [95%CI 1.24-3.11]) were associated with external iliac artery calcium. For the breast arteries, numbers were too small to fit these multivariable models. Although calcification in the splenic, internal, and external iliac arteries were significantly associated with mortality in unadjusted models, these associations were attenuated and no longer statistically significant after adjusting for cardiovascular risk factors. Among women, breast artery calcification was associated with mortality independent of traditional CVD risk factors and a 0-5 score of the number of calcified vascular beds out of the carotids, coronaries, abdominal and thoracic aorta and common iliacs (HR 5.67 [95%CI 1.50-21.41]).

Conclusions:
Calcification in the splenic, internal and external iliac arteries was strongly associated with calcification in the abdominal aorta. In females, breast artery calcification was strongly and independently associated with mortality.