Predictors and clinical impact of pre-existing and acquired thrombocytopenia following transcatheter aortic valve replacement.

BACKGROUND: Data are limited regarding transcatheter aortic valve replacement (TAVR)-related thrombocytopenia (TP). We sought to thoroughly characterize the presence, clinical impact, and severity of TP associated with TAVR.

METHODS AND RESULTS: Data were collected from 90 patients who underwent TAVR using the Edwards SAPIEN valve (59 TF, 29 TA, 2 Tao). Platelet counts were evaluated peri-procedurally and for 8 days following TAVR. Platelet levels were compared and patients were divided into a no TP (No-TP) group 1, acquired (new) TP (NTP) group 2, pre-existing (pre-TAVR) TP (PTP) group 3, and further stratified based on the severity of TP: mild (M) TP (100-149 × 10(3) cell/µL) and moderate-severe (MS) TP (<100 × 10(3) cell/µL). Pre-TAVR point prevalence and post-TAVR incidence of TP were 40% and 79%, respectively (P < 0.001); nadir platelet count in all groups occurred day 4 post-TAVR. Baseline predictors for developing MS TP in groups 2-3 included baseline TP, leaner body mass, smaller pre-procedural aortic valve area, higher peak aortic jet velocity, and worsening baseline renal function. Development of "major" TP (nadir platelet count <100 × 103 cell/µL, ≥50% decrease) predicted a higher risk of major vascular complications (OR 2.78 [95% CI, 1.58-3.82]) and major bleeding (OR 3.18 [95% CI, 1.33-5.42]) in group 3.

CONCLUSION: TAVR-related TP is predictable and classification by PTP and TP severity prior to TAVR allows for better risk stratification in predicting in-hospital clinical outcomes. Major TP in the presence of worsening TP is predictable and is associated with worse clinical outcomes. © 2014 Wiley Periodicals, Inc.