Predictor and Mid-Term Outcome of Clinically Significant Thrombocytopenia After Transcatheter Aortic Valve Selection

Thrombocytopenia after sutureless and standard stented aortic valve replacement: a retrospective analysis of risk factors, clinical course, and early outcome

OBJECTIVES

Thrombocytopenia following Perceval aortic valve replacement has been described previously with variable outcome. Studies have lacked a robust analysis of platelet fluctuation and factors affecting it. We aimed to statistically describe the trend in thrombocyte variability as compared with conventional aortic valve replacement, and to assess predictors as well as impact on associated outcomes.

METHODS

One hundred consecutive patients with first-time Perceval were retrospectively compared to 219 patients after Perimount Magna Ease valve replacement. The primary outcome was the serial thrombocyte count on day 0-6. Generalized estimating equations were used to analyse the data using fixed-effect models: for the effect of the post-operative day on platelet count, and random-effect models estimating both time-variant (platelets) and time in-variant variables (valve type, age, LV function, pre-op platelet level).

RESULTS

Perceval patients were older (72 ± 1 vs 68 ± 1 years, p < 0.01) with higher NYHA status (3(2-3) vs 2(1-2), p < 0.001). Mean platelet count in the sutureless group was lowest on day 2 (91.9 ± 31.6 vs 121.7 ± 53.8 × 103 µl-1), and lower on day 4 (97.9 ± 44) and 6 (110.6 ± 61) compared to the conventional group (157.2 ± 60 and 181.7 ± 79) but did not result in a higher number of transfusions, bleeding or longer hospital stay (p > 0.05). Reduced platelet count was a strong predictor of red cell transfusion in the conventional (p = 0.016), but not in the sutureless group (p = 0.457). Age (Coef -1.025, 95%CI-1.649--0.401, p < 0.001) and CPB-time (Coef 0.186, 95%CI-0.371--0.001, p = 0.048) were predictors for lower platelet levels.

CONCLUSION

Considering the older patient profile treated with Perceval, postoperative thrombocytopenia does not impact on outcome in terms of transfusions, complications or hospital stay.

Restoration of von Willebrand factor after transcatheter aortic valve replacement-A possible cause for posttranscatheter aortic valve replacement thrombocytopenia?

OBJECTIVES

The aim of the current study was to analyze the clinical and procedural predictors of thrombocytopenia and the relationship between the decrease in platelet count (DPC) and change in vWF function (ΔvWF) after transcatheter aortic valve replacement (TAVR).

BACKGROUND

TAVR often causes temporary thrombocytopenia. At the same time, TAVR leads to a restoration of von Willebrand factor (vWF) function.

METHODS

One hundred and forty-one patients with severe aortic stenosis undergoing TAVR were included in the study. Platelet count and vWF function (vWF:Ac/Ag ratio) were assessed at baseline and 6 h after TAVR. Thrombocytopenia was defined as platelet count <150/nL.

RESULTS

Median platelet count at baseline was 214/nL (interquartile range [IQR]: 176-261) and decreased significantly to 184/nL (IQR: 145-222) 6 h after TAVR. The number of patients with thrombocytopenia increased from 12.8% at baseline to 29.1% after 6 h. DPC 6 h after TAVR showed a significant correlation with ΔvWF (r = - 0.254, p = 0.002). Patients with DPC > 20% had significantly higher ΔvWF (10.9% vs. 6.5%, p = 0.021). Obese patients showed a significantly lower DPC (11.8% vs. 19.9%, p = 0.001). In multivariate analysis, ΔvWF 6 h after TAVR was the only significant predictor for DPC > 20% (p = 0.017).

CONCLUSIONS

The restoration of vWF after TAVR is a significant predictor for DPC after TAVR. An increased platelet consumption due to vWF restoration could play a key role in the development of thrombocytopenia after TAVR.

Predictive model for severe thrombocytopenia after transfemoral transcatheter aortic valve replacement

The aim of this study was to develop a predictive model for severe thrombocytopenia after transfemoral transcatheter aortic valve replacement (TAVR). A total of 155 patients treated with TAVR at our center were retrospectively enrolled in this study. The incidence of severe thrombocytopenia after TAVR was 25.16%, and most patients suffered from severe thrombocytopenia on 4 days after procedure. Multivariate regression analysis showed that weight <60 kg, New York Heart Association Functional Classification (NYHAFC IV), major vascular complications, and lower first post-procedural platelet count were independent risk factors for severe thrombocytopenia after TAVR. The c-statistic for the area under the curve was 0.758, the sensitivity was 0.744, the specificity was 0.784, and the negative predictive value of the model was 91.38%. The overall predictive value was 76.77%. The predictive model developed from this cohort data could effectively identify patients at high risk of severe thrombocytopenia after TAVR, and might be applicable to patients with aortic regurgitation (AR) and severe thrombocytopenia with different definitions.

A New Definition of Thrombocytopenia Following Transcatheter Aortic Valve Implantation: Incidence, Outcome, and Predictors

Background: The aim of this study was to assess the incidence, outcomes, and risk factors associated with thrombocytopenia following TAVI according to a corrected platelet count (CPC), to avoid the bias of hemodilution/concentration. Methods: We analyzed patients who underwent TAVI in our center between 2009 and 2018. The study population were divided into three groups: none (NT), mild (MT), and severe (ST) postoperative thrombocytopenia. Primary outcomes were bleedings, length of hospital stay, and mortality. A multivariate logistic regression was performed to assess risk factors for ST. Results: A total of 907 patients were included in the analysis. MT was observed in 28.1% and ST in 2.6% of all patients. The following clinical outcomes were recorded: incidence of life-threatening and major bleeding (NT = 14.2%, MT = 20.8%, ST = 58.3%), the median length of hospital stay (NT = 8, MT = 10, ST = 14 days), in-hospital mortality (NT = 3.9%, MT = 6.3%, ST = 16.7%), and the overall significance in comparison with NT (p < 0.05). The logistic regression showed ST was associated with preoperative CPC, transapical access, diabetes mellitus, and the critical preoperative state. Conclusions: Worse clinical outcomes are associated with both MT and ST after TAVI. In particular, ST is associated with higher in-hospital and 30-day mortality. Management of modifiable baseline and procedural variables may improve this outcome.

Perioperative platelet reduction after sutureless or stented valve implantation: results from the PERSIST-AVR controlled randomized trial

OBJECTIVES

Platelet count reduction is a common but not fully understood phenomenon after aortic valve replacement (AVR) with bioprosthesis implantation. The aim of the present study was to investigate the occurrence and the clinical impact of platelet count reduction in patients receiving the Perceval bioprosthesis compared to those receiving standard sutured stented bioprosthetic aortic valve in a randomized, controlled AVR study.

METHODS

PERceval Sutureless Implant versus STandard Aortic Valve Replacement is a prospective, randomized, adaptive, open-label trial. Patients were randomized (March 2016-September 2018) to AVR with a sutureless or stented valve. Ad hoc analyses have been performed to evaluate the occurrence of platelet count reduction and the clinical impact of the platelet variations in the 2 groups.

RESULTS

The Perceval group showed a higher platelet reduction than the control group (46% vs 32%). The phenomenon was transient in both groups, with a slow recovery of the platelet count by hospital discharge. No differences were observed between groups regarding need of transfusions, blood loss, major bleeding and stroke events.

CONCLUSIONS

The Perceval sutureless aortic bioprosthesis implantation is associated with higher rate of transient platelet reduction as compared to stented bioprostheses for AVR. However, the platelet count reduction is transient and the decline does not affect the patient's clinical outcomes. Current explanations for this phenomenon are speculative, and further investigations are required to elucidate it.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02673697-ClinicalTrials.gov-4 February 2016.

Thrombocytopenia Complicating Transcatheter Aortic Valve Implantation: Differences Between Two New-Generation Devices

Thrombocytopenia after TAVI is common and clinically detrimental. Retrospectively, we observed Portico recipients had a more profound platelet drop than Evolut recipients. We thus investigated periprocedural platelet damage and/orpro-inflammatory state in 64 TAVI recipients at baseline and after implantation. Platelet damage was assessed by annexin V staining and monocyte-phagocytic phenotype was assessed according to CD14/CD36 expression. Serum cytokines were measured in 20 patients. The formaldehyde-based storage solution altered platelets. When, before being loaded onto the delivery system, Portico underwent one additional flushing to those recommended, the receiving patients showed thrombocytopenia, platelet damage, and CD36-monocyte count were mitigated. A general increase in IL-6 was recorded in overall TAVI recipients, but a high serum level of IL-8, a potent thrombocytopenia inducer, was measured in Portico recipients only, including those with extra-rinsed valve. Our study suggests a platelet-injury effect by storage-solution and generates the hypothesis of a role for the biomaterial in stimulating innate-immunity. Larger prospective studies are needed.

Quantitative and Qualitative Platelet Derangements in Cardiac Surgery and Extracorporeal Life Support

Thrombocytopenia and impaired platelet function are known as intrinsic drawbacks of cardiac surgery and extracorporeal life supports (ECLS). A number of different factors influence platelet count and function including the inflammatory response to a cardiopulmonary bypass (CPB) or to ECLS, hemodilution, hypothermia, mechanical damage and preoperative treatment with platelet-inhibiting agents. Moreover, although underestimated, heparin-induced thrombocytopenia is still a hiccup in the perioperative management of cardiac surgical and, above all, ECLS patients. Moreover, recent investigations have highlighted how platelet disorders also affect patients undergoing biological prosthesis implantation. Though many hypotheses have been suggested, the mechanism underlying thrombocytopenia and platelet disorders is still to be cleared. This narrative review aims to offer clinicians a summary of their major causes in the cardiac surgery setting.

Predictors of short-term thrombocytopenia after transcatheter aortic valve implantation: a retrospective study at a single Japanese center

OBJECTIVE

Thrombocytopenia is common after transcatheter aortic valve implantation (TAVI) and is associated with mortality and major complications, although the underlying mechanisms are unclear. This retrospective single-center study aimed to identify factors associated with the decrease in platelet count (DPC) after TAVI in Japanese patients. Patients with severe aortic valve stenosis who underwent transfemoral TAVI between March 2014 and August 2019 were grouped according to DPC values of < 50% or ≥ 50% (DPC = 100% × [baseline platelet count-nadir platelet count]/[baseline platelet count]). Multivariable logistic regression analysis was performed to identify factors associated with a DPC of ≥ 50%.

RESULTS

Among the 131 patients who underwent transfemoral TAVI, 74 patients (56%) had a DPC of ≥ 50%, and 57 patients (44%) had a DPC of < 50%. Significant risk factors for a DPC of ≥ 50% were older age, lower body mass index (BMI), and use of balloon-expandable valves (BEV). The multivariable analysis revealed that a DPC of ≥ 50% was independently predicted by low BMI (adjusted odds ratio: 0.884, 95% confidence interval: 0.785-0.997; P = 0.039) and BEV use (adjusted odds ratio: 3.014, 95% confidence interval: 1.003-9.056; P = 0.045). Platelet count monitoring after TAVI, especially when using BEV devices, is essential for Japanese patients with low BMI.