Background
KDIGO (Kidney Disease: Improving Global Outcomes) guidelines recommend lateral abdominal radiographs to assess vascular calcification in incident dialysis patients. However, nearly all dialysis patients in the US receive chest radiographs at dialysis inception which may provide readily available information on coronary artery calcification (CAC) and aortic arch calcification (AAC). We determined the prevalence of CAC and AAC visible on plain chest radiographs and their associations with mortality in our dialysis population.
Study Design
Retrospective Analysis
Setting & Participants
93 participants who received maintenance hemodialysis at the San Diego VAMC in 2009–2010
Predictor
Presence of CAC and AAC as evaluated by a radiologist
Outcome
All cause mortality
Results
The average age was 64; 22% were African-American, and 97% were male. CAC and AAC prevalence were 25% and 58%, respectively. During 20 months’ follow-up, 28% died. CAC was strongly associated with mortality in models including cardiovascular (HR, 2.41; 95% CI 1.04–5.59) and dialysis-related (HR, 2.86; 95% CI 1.24–6.6) risk factors. AAC was associated with a HR of 5.25 (95% CI, 1.46–17.72) in cardiovascular risk-factor adjusted models and 7.31 (95% CI, 2.03–26.34) in dialysis models. When CAC and AAC were both included in models, both CAC (HR, 3.40; 95% CI, 1.24–9.36) and AAC (HR, 6.23; 95% CI, 1.64–23.66) remained significantly associated with mortality.
Limitations
The study sample is relatively small and mostly male.
Conclusions
CAC and AAC are highly prevalent on chest radiographs in dialysis patients, and strongly associated with mortality independent of one another. Since these images are nearly ubiquitous, inexpensive, and often already obtained for other indications, they should be considered for risk assessment in hemodialysis patients. Future studies are required to determine whether CAC or AAC on chest radiography is additive or duplicative of the risk of aorto-iliac calcification on lateral abdominal radiographs currently suggested by KDIGO.