Value of Pre-Procedural Lymphocyte-to-Monocyte Ratio for Predicting New Cerebral Ischemic and Haemorrhagic Lesions Observed after Transcatheter Aortic Valve Implantation: A Pilot Study

Introduction: TAVI (Transcatheter Aortic Valve Implantation) represents the gold standard technique for the treatment of symptomatic severe aortic stenosis in patients at elevated surgical risk. This intervention is consistently associated with ischemic and haemorrhagic complications. In almost 60 % of the procedure, new cerebral ischemic lesions are observed on systematic magnetic resonance imaging (MRI) and it could speed up cognitive impairment. The lymphocyte-to-monocyte ratio (LMR), a new inflammatory marker, has been recently associated with ischemic burden in cardiovascular diseases.

Objective: To study LMR changes before and after TAVI and investigate if LMR could be a predictive factor of new ischemic and haemorrhagic cerebral lesions after TAVI.

Methods: Patients admitted for TAVI who accepted to be included in the METHYSTROKE study (NCT02972008) undergo cerebral MRI the day before the intervention and a second one 3 days after the procedure in order to observe the occurrence of ischemic and haemorrhagic cerebral lesions. LMR was gathered the day before (D0) and the day after TAVI (D1) from complete blood cell count.

Results: A total of 124 patients were included in the present study (mean age was 82 ± 5.2 (SEM) years and 46% were male). Between D0 and D1, we observed a decrease in lymphocytes rate (mean (SD) : 1.25 (0.58) vs 1.14 (0.52) G/L, p=0.02) whereas the rate of monocytes raises (0.51 (0.27) vs 0.85 (0.42) G/L, p<0.0001). Between D0 and D1, the LMR significantly falls (3.1 (0.24) vs 1.51 (0.75), p<0.0001). New ischemic lesions occurred in 80 patients among the 124 (64.5%); LMR is significantly lower at D0 in patients who developed new cerebral ischemic lesions (2.30 (0.8) versus 2.97 (1.2), p=0.03). Each raise of pre-procedure LMR of a range of 0.1 increases the risk of post-operative cerebral ischemic lesions of 5.5 % (OR= 0.46, IC 95% 0.22-0.97, p=0.04). On the other side, 31 patients developed new haemorrhagic lesions on post-operative cerebral MRI (25%). Pre-procedure LMR was not significantly different among patients with and without haemorrhagic post-procedural cerebral complications (2.38 (0.93) vs 2.42 (1.1)).

Conclusion: This study demonstrated that LMR decreases during TAVI and that pre-procedure LMR, a simple, readily available and low-cost biomarker, could be a predictive factor of post-TAVI new cerebral ischemic lesions.