Lower limb arterial calcification (LLAC) scores in patients with symptomatic peripheral arterial disease are associated with increased cardiac mortality and morbidity

• Published in: PloS one 2017-09, Vol.12 (9), p.e0182952-e0182952
• Main Authors: Chowdhury, Mohammed M, Makris, Gregory C, Tarkin, Jason M, Joshi, Francis R, Hayes, Paul D, Rudd, James H F, Coughlin, Patrick A
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Amputation; Arteriosclerosis; Atherosclerosis; Atherosclerosis - diagnostic imaging; Atherosclerosis - pathology; Audit departments; Biology and Life Sciences; Calcification; Calcification (ectopic); Cardiovascular disease; Cardiovascular diseases; Computed tomography; Computed Tomography Angiography; Coronary artery disease; Coronary Artery Disease - etiology; Coronary Artery Disease - mortality; Coronary vessels; Diabetes; Diabetes mellitus; Diagnostic systems; Drug dosages; Family medical history; Female; Follow-Up Studies; Heart; Heart attacks; Heart diseases; Heart Diseases - diagnosis; Heart Diseases - etiology; Heart Diseases - mortality; Hospitals; Humans; Kidney transplantation; Lower Extremity - pathology; Male; Medical imaging; Medicine and Health Sciences; Middle Aged; Morbidity; Mortality; Patients; Peripheral Arterial Disease - complications; Peripheral Arterial Disease - diagnosis; Peripheral Arterial Disease - pathology; Reproducibility of Results; Research and Analysis Methods; Retrospective Studies; ROC Curve; Severity of Illness Index; Tomography; Vascular Calcification - pathology; Vascular surgery
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0182952

The association of coronary arterial calcification with cardiovascular morbidity and mortality is well-recognized. Lower limb arterial calcification (LLAC) is common in PAD but its impact on subsequent health is poorly described. We aimed to determine the association between a LLAC score and subsequent cardiovascular events in patients with symptomatic peripheral arterial disease (PAD). LLAC scoring, and the established Bollinger score, were derived from a database of unenhanced CT scans, from patients presenting with symptomatic PAD. We determined the association between these scores outcomes. The primary outcome was combined cardiac mortality and morbidity (CM/M) with a secondary outcome of all-cause mortality. 220 patients (66% male; median age 69 years) were included with follow-up for a median 46 [IQR 31-64] months. Median total LLAC scores were higher in those patients suffering a primary outcome (6831 vs. 1652; p = 0.012). Diabetes mellitus (p = 0.039), ischaemic heart disease (p = 0.028), chronic kidney disease (p = 0.026) and all-cause mortality (p = 0.012) were more common in patients in the highest quartile of LLAC scores. The area under the curve of the receiver operator curve for the LLAC score was greater (0.929: 95% CI [0.884-0.974]) than for the Bollinger score (0.824: 95% CI [0.758-0.890]) for the primary outcome. A LLAC score ≥ 4400 had the best diagnostic accuracy to determine the outcome measure. This is the largest study to investigate links between lower limb arterial calcification and cardiovascular events in symptomatic PAD. We describe a straightforward, reproducible, CT-derived measure of calcification-the LLAC score.