Calcification of the abdominal aorta as an independent predictor of cardiovascular events: a meta-analysis.
BACKGROUND
Abdominal aortic calcification (AAC) is a common finding in patients with atherosclerosis.


OBJECTIVE
The aim of this study was to demonstrate the incremental value of AAC in predicting long term cardiovascular (CV) outcome by conducting a meta-analysis of observational studies.


METHODS
MEDLINE and Cochrane databases.


METHODS
Longitudinal studies with at least 2 years of follow-up, reporting the influence of AAC on CV outcome of general population patients.


METHODS
Four separate end points-coronary events, cerebrovascular events, all CV events and CV related death-were tested for their relationship with AAC at baseline, using weighted random effects meta-analysis. Heterogeneity was calculated using Q and I(2) statistic tests. Publication bias was assessed by funnel plot symmetry and trim and fill methods. The importance of calcium quantification was also explored (sensitivity analysis).


RESULTS
10 studies were included. An increased relative risk (RR) was found for all end points: for coronary events (five studies, n=11250) 1.81 (95% CI 1.54 to 2.14); for cerebrovascular events (four studies, n=9736) 1.37 (1.22 to 3.54); for all CV events (four studies, n=4960) 1.64 (1.24 to 2.17); and for CV death (three studies, n=4986) 1.72 (1.03 to 2.86). Analysis of studies presenting results in categories (no/minimal, moderate and severe calcification) revealed a stepwise increase in the RR for all end points. Significant heterogeneity was found in the included studies. Sources of heterogeneity were identified in the publication date, duration of follow-up, and mean age and gender differences in the included patient cohorts.


CONCLUSIONS
Existing data suggest that AAC is a strong predictor of CV related events or death in the general population. The predictive impact is greater in more calcified aortas. The generalisability of the meta-analysis is limited by heterogeneity in the coronary events, all CV events and CV death end points.
Department of Vascular Surgery, Erasmus University Medical Centre, 's-Gravendijkwal 230, Rotterdam, The Netherlands.
Frederico
F
Bastos Gonçalves
Michiel T
MT
Voûte
Sanne E
SE
Hoeks
Michel B
MB
Chonchol
Eric E
EE
Boersma
Robert J
RJ
Stolker
Hence J M
HJ
Verhagen
D001012:Aorta, Abdominal; D001018:Aortic Diseases / Q000150:complications; D002114:Calcinosis / Q000150:complications*; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D014943:Global Health; D006801:Humans; D015994:Incidence; D012307:Risk Factors