Fractal analysis of retinal microvasculature and coronary heart disease mortality.
OBJECTIVE
Fractal analysis provides a global assessment of vascular network architecture. We examined the relationship of retinal vascular fractal dimension (D(f)) with coronary heart disease (CHD) mortality.


RESULTS
We examined the relationship of D(f) with 14-year CHD mortality in a prospective, population-based cohort of 3303 participants aged 49 years or older. D(f) was measured from digitized fundus photographs using computer-automated methods; CHD mortality was documented from Australian National Death Index records. Mean D(f) in this population was 1.441 (standard deviation, 0.024). Over 14 years, there were 468 (14.2%) CHD deaths. Participants with suboptimal D(f) (lowest and highest quartiles) had 50% higher 14-year CHD mortality than those with optimal D(f) (middle quartiles), after adjusting for age, blood pressure, and other risk factors. Among participants aged ≤ 70 years, suboptimal D(f) was associated with a nearly two-fold higher risk of CHD mortality [adjusted hazard ratio (HR) 1.89, 95% confidence interval (CI), 1.25, 2.84 for the lowest quartile and HR 1.87, CI 1.30, 2.69 for the highest quartile, compared with middle quartiles].


CONCLUSIONS
D(f) is a novel means of quantifying microvascular branching that independently predicted 14-year CHD mortality. These findings suggest that suboptimal microvascular branching may play a role in development of clinical cardiovascular disease.
Centre for Vision Research, Department of Ophthalmology, University of Sydney, Sydney, NSW, Australia.
Gerald
G
Liew
Paul
P
Mitchell
Elena
E
Rochtchina
Tien Yin
TY
Wong
Wynne
W
Hsu
Mong Li
ML
Lee
Alan
A
Wainwright
Jie Jin
JJ
Wang
D000368:Aged; D003327:Coronary Disease / Q000401:mortality* / Q000473:pathology; D005240:Feasibility Studies; D005260:Female; D017709:Fractals; D006801:Humans; D008297:Male; D055806:Microvessels / Q000473:pathology*; D008875:Middle Aged; D011446:Prospective Studies; D012164:Retinal Diseases / Q000401:mortality / Q000473:pathology*; D012171:Retinal Vessels / Q000473:pathology*; D012307:Risk Factors; D012737:Sex Factors