Elevated Pre-Transplant Neutrophil to Lymphocyte Ratio is Associated with Increased Vasoplegia Syndrome in Cardiac Transplantation

Abstract

Purpose Neutrophil to lymphocyte ratio (NLR), calculated from a CBC, is a marker of systemic inflammation and long-term risk in chronic illness, including heart failure (HF). Vasoplegia syndrome is a severe vasodilatory shock state after cardiac surgery. Patients undergoing heart transplantation (HTx) may be at an increased risk of vasoplegia due to inflammatory cytokine release secondary to HF. The role of NLR as a predictive marker for vasoplegia in patients undergoing HTx has not been studied. Methods Retrospective review of consecutive patients who underwent HTx from 7/2016 to 7/2018. Patients with conditions or treatments known to affect WBC count were excluded. Pre-HTx NLR was calculated from day of HTx and stratified by tertile. Vasoplegia was defined as vasopressor administration for > 24 hours to maintain mean arterial pressure > 65 mmHg for hypotension not attributed to other etiologies within 48 hours of HTx. The primary outcome was rates of vasoplegia between tertiles. Results 78 patients underwent HTx of which 70 met inclusion criteria. 18 patients had vasoplegia. Vasoplegia occurred in 8.7% (n=2) in the 1st tertile, 25% (n=6) in the 2nd tertile and 43.4% (n= 10) in the 3rd tertile (comparison 1st vs 3rd tertile, p=0.04) (Figure). In a multivariate analysis, adjusted for prior LVAD, patients in the 3rd tertile had higher rates of vasoplegia (adjusted OR 2.47, 95% CI 1.87-4.55) compared to the 1st. Mean NLR in patients without vasoplegia was 3.68±0.48 compared to 6.72±1.7 in patients with vasoplegia (p=0.019). There was no demographic or medical comorbidity difference other than hypothyroidism (p=0.04) between groups. Conclusion Vasoplegia is associated with elevated pre-HTx NLR compared to patients without vasoplegia. Chronic inflammation due to HF may play a role in the development of post-HTx vasoplegia. NLR is an inexpensive tool which clinicians may use pre-HTx to stratify which patients are at an increased risk of development of vasoplegia post-HTx.