Correlation between staging classification of aortic stenosis based on the extent of cardiac damage and platelet indices.

Background: Platelets play a key role in the natural history of aortic stenosis (AS) and after transcatheter aortic valve implantation (TAVI). An echo-based staging system stratifies patients with severe AS into 5 groups according to the associated cardiac damage phenotype. We aimed to correlate these AS stages with platelet indices in post-TAVI patients.

Methods: Patients with severe AS who underwent TAVI and were admitted to intensive cardiac care unit (ICCU) were prospectively identified and divided into 5 groups according to extra-valvular cardiac damage [no extravalvular cardiac damage (Stage 0), left ventricular damage (Stage 1), left atrial or mitral valve damage (Stage 2), pulmonary vasculature or tricuspid valve damage (Stage 3), or right ventricular damage (Stage 4)]. Baseline characteristics and complete blood count including mean platelet volume (MPV) and immature platelet fraction (IPF) were collected within 2 h after the procedure and analyzed in relation to aortic stenosis staging.

Results: A total of 220 patients were included. The mean age was 81 years old and 112 (50.9%) were female. Two (1%) patients were classified in stage 0; 34 (15%) in stage 1; 48 (22%) in stage 2; 49 (22%) in stage 3 and 87 (40%) in stage 4. Higher mean MPV values were correlated with higher AS staging (10.8 fL, 11 fL, 11.3 fL and 10.8 fL in stages 1, 2, 3 and 4, respectively, P = 0.02) as well as lower hemoglobin values (12 mg/dl, 11.6 mg/dl, 11 mg/dl and 11.3 mg/dl in stages 1, 2, 3 and 4, respectively P = 0.04). Mean IPF values were 5.3%, 5.58%, 5.57% and 4.83% in stage 1, 2, 3 and 4, respectively (P = 0.4). In a multivariate logistic regression model only MPV (OR = 2.6, P = 0.03) and body mass index (BMI) (OR = 1.17, P = 0.004) were correlated with higher staging (0-3) of AS.

Conclusions: Although IPF and MPV levels increased in stages 0-3, there was a decrease in indices in stage 4, (probably due to bone marrow dysfunction) in this end-stage population. Higher levels of MPV and lower levels of hemoglobin were independently correlated with higher stages (0-3) of AS.