Neutrophil to lymphocyte ratio predicts perioperative mortality following open elective repair of abdominal aortic aneurysms.

OBJECTIVES

This study assesses the predictive value of neutrophil to lymphocyte ratio (NLR) in relation to 30-day and overall mortality following open abdominal aortic aneurysm (AAA) repairs. In addition, it assess assesses any correlation between NLR and age, size of the AAA and gender.

METHODS

Patients undergoing elective or urgent open repair of their AAA by a single surgeon during a 10-year period were included. A pre-operative NLR of >5 was regarded as abnormal.

RESULTS

350 consecutive patients underwent AAA repair. 52 had an NLR>5. 30-day mortality rate was 12/52 (23%) in the NLR>5 group and 20/298 (6.7%) in the NLR<5 group (p = 0.0007). All deaths in the NLR>5 group were due to myocardial infarction. The median NLR was higher in those that died within 30 days at 4.2 [IQR: 2.6-7.5] versus 2.8 [IQR: 2.1-3.8] (p = 0.0001). Overall mortality at 10 years, in the NLR>5 group - 26/52 (50%) was significantly greater than that of the NLR<5 group - 102/298 (34.2%) (p = 0.043). Median NLR of those dying during follow-up was significantly higher in those with a baseline NLR>5 at 3.2 (IQR 2.5-4.6) versus 2.6 (IQR: 2.0-3.6) in those surviving (p = 0.00004). No difference was found between NLR and age, aneurysm size or gender.

CONCLUSION

Pre-operative NLR>5 appears to be a significant predictor of both 30-day mortality and long-term outcome in elective and urgent open AAA surgery. It is plausible the NLR is identifying a group with sub-clinical cardiovascular disease at risk of peri-operative myocardial infarction.