65 The novel plasma biomarker desmosine, a marker of elastin breakdown, is an independent predictor of abdominal aortic aneurysm events independent of aneurysm size
Research output: Contribution to journal › Meeting abstract › peer-review
Abdominal aortic aneurysm (AAA) is the thirteenth leading cause of death and occurs in 5% of men between the ages of 65 and 74 years. Currently, patients at risk for AAA are offered ultrasound screening and surveillance, and when appropriate (size >55 mm or expansion rate >10 mm/year), elective AAA repair. Despite this surveillance, prediction of patients likely to have AAA rupture is difficult, with many AAAs rupturing before reaching 55 mm or having unpredictable expansion rates. A serum biomarker that could predict AAA events would be extremely valuable. Desmosine is an amino acid cross-link that is released into the bloodstream when there is elastin breakdown. We hypothesised that plasma desmosine (pDES) might be associated with events in patients with AAA. Methods We evaluated pDES levels in 239 patients with AAA recruited to the MA3RS study (NCT01749280). Patients had 6 monthly visits with abdominal ultrasound performed at each visit. A panel of biomarkers related to vascular integrity was also obtained. Patients were followed up for clinical events including AAA rupture, repair and mortality. Results The cohort was predominantly male (87.4%). Mean AAA diameter was 50.6±8.0 mm. pDES was significantly correlated with ultrasound AAA diameter (r=0.27, p<0.0001). In total 13 patients had an emergency AAA event and 20 had MACE (AAA event +CV mortality). pDES was a major predictor of both AAA events (HR 4.97, 95% CI 1.05–23.64, p=0.044) and MACE (HR 5.92, 95% CI 1.73–20.26, p=0.005) independent of AAA diameter, with patients with the highest tertiles of pDES having the worst outcome. pDES was significantly more associated with AAA events than the next best biomarker, MMP-9 (AUC 0.70 vs 0.60, p<0.001). pDES was associated with improvement in risk prediction when added to AAA diameter with a significant improvement in both net reclassification index (p=0.013) and integrative discrimination increment (p<0.001). Conclusion pDES was an independent predictor of adverse outcome in patients with AAA and may be the first non-invasive serum biomarker to predict events in this group of patients.