Effect of transcatheter (via femoral artery) aortic valve implantation on the platelet count and its consequences

Acquired Thrombocytopenia in Contemporary Transcatheter Aortic Valve Prosthesis

BACKGROUND

 Postprocedural thrombocytopenia is a known phenomenon following transcatheter aortic valve implantation (TAVI). The aim of this study is to evaluate whether postinterventional platelet kinetics differ when comparing the current generation of balloon-expandable valve (BEV) and self-expanding valve (SEV) prostheses.

METHODS

 We performed a retrospective analysis of patients undergoing TAVI at our facility between 2017 and 2019. Patients were stratified according to the type of prosthesis used: BEV or SEV. Hematocrit-corrected platelet counts were calculated to account for dilution. Nadir platelet counts (lowest recorded platelet count), drop platelet counts (DPC; highest relative platelet drop from baseline), and severity of thrombocytopenia during the discourse and at discharge were assessed.

RESULTS

 Of the 277 included patients, 212 received SEV and 65 BEV. BEV patients were younger (81.8 ± 4.4 years vs 79.7 ± 6.8 years, p = 0.03). Further demographic characteristics were similar between groups. Implanted SEV were larger (p < 0.001) and had shorter procedural times (p < 0.01). There were no significant differences in postprocedural discourse. Postinterventional platelet drop was more pronounced in BEV patients in several evaluated metrics: mean DPC (24.3 ± 10.9% vs 18.8 ± 14.8%, p < 0.01), patients with DPC > 30% (n = 19, 29.2%, vs n = 33, 15.6%, p = 0.02), and also when comparing platelet kinetics.

CONCLUSION

 Despite improvements in outcome, the current generation of balloon-expandable TAVI prostheses carries a predisposition for postprocedural thrombocytopenia even when the effects of dilution are accounted for.

Is dynamic change in mean platelet volume related with composite endpoint development after transcatheter aortic valve replacement?

Aortic valve stenosis (AS) is the most common valvular disease, and surgical or transcatheter aortic valve replacement (TAVR) are the treatment options. Diminish in platelet production or dysfunction may occur due to shear stress, advanced age, and other coexisting diseases in AS patients. Bleeding is one of the complications of TAVR and associated with increased mortality. MPV (mean platelet volume) indicates platelet's thrombogenic activity. Overproduction or consumption of platelets in various cardiac conditions may affect MPV values. We aimed to investigate the pre and postprocedure MPV percentage change (MPV-PC) and its association with post-TAVR short-term complications. A total of 204 patients who underwent TAVR with a diagnosis of severe symptomatic AS were included. The mean age was 78.66 ± 6.45 years, and 49.5% of patients were women. Two groups generated according to composite end point (CEP) development: CEP(+) and CEP(-).110 patients(53.9%) formed CEP(+) group. Although baseline MPV and platelet levels were similar between groups, MPV was increased ( P  < 0.001) and platelet was decreased ( P  < 0.001) significantly following the procedure when compared to baseline. MPV-PC was significantly higher in the VARC type 2-4 bleeding ( P   =  0.036) and major vascular, access-related, or cardiac structural complication groups ( P   =  0.048) when CEP subgroups were analyzed individually. Regression analysis revealed that diabetes mellitus [ P   =  0.044, β: 1.806 odds ratio (95% confidence interval): 1.016-3.21] and MPV-PC [ P   =  0.007,β: 1.044 odds ratio (95% confidence interval): 1.012-1.077] as independent predictors of CEP development at 1 month after TAVR. The MPV increase following TAVR may be an indicator of adverse outcomes following TAVR procedure within 1-month.

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.

Changes in platelet function and coagulation after transcatheter aortic valve implantation evaluated with thromboelastography

Introduction

The possibility of hypercoagulability during the perioperative period of transcatheter aortic valve implantation (TAVI) has been noted; however, there is still a controversy regarding the appropriate perioperative antithrombotic therapy. The study investigated coagulation and platelet functions during the TAVI perioperative period using thromboelastography (TEG) 6s platelet mapping.

Methods

A prospective observational study was conducted on 25 patients undergoing TAVI. TEG platelet mapping was performed at three time points: on admission to the operating room (before heparinisation), on postoperative day (POD) 1 and on POD 3. Perioperative changes observed included: maximum clot strength (MA_HKH), clot strength without platelet function (MA_ActF), time to initiation of clots formation by coagulation factors (R_HKH) and platelet function (G_p). G_p is activated by thrombin, and not affected by antiplatelet agents. It is calculated as [(5000×MA_HKH)/(100 – MA_HKH)] − [(5000×MA_ActF)/(100 – MA_ActF)]. Finally, MA_ADP/AA and G_ADP/AA, which reflect clot strength and platelet aggregation mediated by ADP/thromboxane A₂ receptors, respectively, were also examined using the same method as for G_p.

Results

MA_HKH continued to decrease until POD 3, indicating antithrombotic change after TAVI. G_p continuously decreased for 3 days after TAVI, while MA_ActF increased significantly on POD 3. Furthermore, R_HKH shortened on POD 1 and POD 3, suggesting increased coagulation capacity after TAVI. Finally, G_ADP in clopidogrel-naive patients was reduced for 3 days after TAVI, while G_AA in aspirin-naive patients showed no significant change perioperatively.

Conclusions

In this study involving TEG platelet mapping, coagulation capacity increased while platelet function decreased, resulting in antithrombotic change for 3 days after TAVI. The ADP receptor system may be implicated in the decreased platelet function. These results may be useful for considering optimal perioperative antithrombotic therapy in TAVI.

Trends in Transfemoral Aortic Valve Implantation Related Thrombocytopenia

Background: TAVI related thrombocytopenia (TAVI-rTP) is still very common. The aim of this study was to compare the incidence, characteristics and impact of reduced platelet counts (RPC) after TAVI between an earlier and contemporary period. Methods: the patients enrolled were those experiencing severe symptomatic aortic stenosis who underwent TAVI between January 2010 and December 2019. The exclusion criteria were no available blood tests and periprocedural death. Results: 334 patients (mean age 81.9 ± 6.7 years) were enrolled. For the earlier period, the mean RPC was 33 ± 15%, and in the contemporary period (2016–2019) it was 26 ± 14%. In the early group, we found that 62% of the patients had decreased platelet counts of more or equal to 30% in comparison to 33% in the contemporary period. The time of the procedure and the amount of the contrast that had been used in the later period were associated with significant RPCs (p value = 0.002 and 0.028, respectively). An RPC of 30% or more was associated with the increased risks of life-threatening bleeding, vascular complications and death within 30 days. Conclusion: contemporary TAVI-rTP continued to be a common phenomenon in our cohort. However, severe thrombocytopenia was significantly less frequent. An RPC of 30% or more is associated with a poor 30-day outcome.

Baseline mean platelet volume is a strong predictor of major and life-threatening bleedings after transcatheter aortic valve replacement

BACKGROUND

Bleeding following transcatheter aortic valve replacement (TAVR) has important prognostic implications. This study sought to evaluate the impact of baseline mean platelet volume (MPV) on bleeding events after TAVR.

METHODS AND RESULTS

Patients undergoing TAVR between February 2010 and May 2019 were included. Low MPV (L-MPV) was defined as MPV ≤10 fL and high MPV (H-MPV) as MPV >10 fL. The primary endpoint was the occurrence of major/life-threatening bleeding complications (MLBCs) at one-year follow-up. Among 1,111 patients, 398 (35.8%) had L-MPV and 713 (64.2%) had H-MPV. The rate of MLBCs at 1 year was higher in L-MPV patients compared with H-MPV patients (22.9% vs. 17.7% respectively, p = 0.034). L-MPV was associated with vascular access-site complications (36.2% vs. 28.9%, p = 0.012), early (<30 days) major bleeding (15.6% vs. 9.4%, p<0.01) and red blood cell transfusion >2 units (23.9% vs. 17.5%, p = 0.01). No impact of baseline MPV on overall death, cardiovascular death and ischemic events (myocardial infarction and stroke) was evidenced. Multivariate analysis using Fine and Gray model identified preprocedural hemoglobin (sHR 0.84, 95%CI [0.75-0.93], p = 0.001), preprocedural L-MPV (sHR 1.64, 95%CI [1.16-2.32], p = 0.005) and closure time adenosine diphosphate post-TAVR (sHR 2.71, 95%CI [1.87-3.95], p<0.001) as predictors of MLBCs.

CONCLUSIONS

Preprocedural MPV was identified as an independent predictor of MLBCs one year after TAVR, regardless of the extent of platelet inhibition and primary hemostasis disorders.

Association between time-related changes in routine blood morphological parameters and renal function after transcatheter aortic valve implantation - a preliminary study

Introduction

Transcatheter aortic valve implantation (TAVI) although minimally invasive is still accompanied by changes in blood morphological parameters, some of them linked to unfavorable outcomes.

Aim

To find any association between changes in blood morphology reflecting an inflammatory response and acute kidney injury (AKI).

Material and methods

This study involved 176 consecutive transfemoral TAVI patients with a mean age of 78.4 ±7.0 years. Serum creatinine concentration (CREA) and blood morphology were analyzed in the blood samples taken before the procedure, then approximately 1, 24, 48 and 72 hours after the procedure, and lastly at the time of discharge. Post-procedural maximal or minimal values (max/min) and max/min-to-bs ratio of the laboratory parameters were also calculated.

Results

Leucocyte (WBC) and neutrophil (NEUT) counts increased significantly after the procedure whereas lymphocyte (LYMPH) counts declined markedly, reaching the highest or lowest values 24 hours after the procedure. A significant increase in neutrophil-to-lymphocyte ratio (NLR) was observed. Platelet count (PLT) dropped to a minimum at 72 hours after TAVI but at discharge did not return to the admission level. TAVI was associated with a marked increase in CREA with a peak at 48 hours after the procedure (135.7 ±75.9 μM/l). Patients with AKI (n = 65; 36.9%) presented more pronounced variations in relative changes in counts of all blood morphological parameters. A positive moderate (r = 0.412) correlation between maximal NLR and relative CREA changes was noted.

Conclusions

TAVI is associated with significant changes in blood morphological parameters that reflect an inflammatory response. They are more pronounced among subjects with post-procedural AKI.

Spleen Size and Thrombocytopenia After Transcatheter Aortic Valve Implantation

The pathophysiology of thrombocytopenia after transcatheter aortic valve implantation (TAVI) thrombocytopenia is still poorly understood. We assessed the association of spleen size with acquired thrombocytopenia in patients undergoing TAVI. We included 732 patients who underwent TAVI with new generation transcatheter heart valves (THVs) at our center from February 2016 to July 2019. We measured splenic volume index in consecutive patients derived from multidetector row computed tomographic datasets. Patients were stratified according to post-TAVI thrombocytopenia, which was defined as a decline in platelet count (DPC) ≥50% at nadir, and evaluated regarding baseline characteristics and outcome parameters. After the procedure, platelet counts declined from 212.9 ± 67.4 × 10⁹/L at baseline to 138.8 ± 49.8 × 10⁹/L at nadir after a median of 2 days (interquartile range [IQR] 2 to 3). Of all patients, 10.1% showed a DPC ≥50%. Compared with patients with DPC <50%, patients with DPC ≥50% had significantly lower splenic volume index (95.5 ml/m² [IQR 78.0 to 123.7] vs 85.8 ml/m² [IQR 71.4 to 102.6], p = 0.008). A multivariable analysis revealed that the splenic volume index was negatively associated with a DPC ≥50% (OR 0.89, 95% CI 0.82 to 0.97, p = 0.005), independent of the type of THV (balloon-expandable THV: OR 2.06, 95% CI 1.13 to 3.76, p = 0.02), major bleeding (OR 13.40, 95% CI 3.58 to 50.40, p <0.001), blood transfusion (OR 3.63, 95% CI 1.54 to 8.56, p = 0.003), or postprocedural paravalvular leakage ≥moderate (OR 5.48, 95% CI 1.23 to 24.40, p = 0.03). Furthermore, DPC ≥50% was independently associated with 1-year mortality (HR 3.36, 95% CI 1.66 to 6.81, p <0.001). In conclusion, acquired thrombocytopenia remains prevalent in modern TAVI patients. Spleen size appears to be associated with the occurrence of thrombocytopenia after TAVI, which is independently correlated with 1-year mortality.

Contemporary transcatheter aortic valve implantation related thrombocytopenia

BACKGROUND

Transcatheter aortic valve implantation related thrombocytopenia (TAVI-rTP) is an inevitable phenomenon. However, no study has been performed on TAVI-rTP in the current setting of extended clinical indications combined with technology improvements.

METHODS

Patients with severe symptomatic aortic stenosis who underwent transfemoral TAVI, from January 2016 to December 2019 were enrolled.

RESULTS

Two-hundred and one consecutive patients (mean age 81.1 ± 7.1 years, 96 men) enrolled. Platelet count was recorded before and after aortic valve implantation. Dropped platelet count (DPC) occurred in all but 11 patients who were included. Two groups were created: DPC <30 and DPC ≥30%. DPC was compared with in-hospital major adverse cardiovascular events. The mean DPC was 26 ± 14%. We found that 67 patients (33.3%) had DPC of more or equal to 30%. In the univariable analysis, the time of the procedure (94.4 ± 32.7 vs 79.4 ± 21.9, p = .002), the amount of the contrast used (125.4 ± 55.4 vs 108.4 ± 44.1, p = .02) and the residual AV gradient (13.3 ± 7.2 vs 14.7, p = .05) were related to a DCP ≥30%. A DPC ≥30% was associated with increased risk of life-threatening/major bleeding (11.9% vs 1.5%, p = .001), major vascular complications (16.4% vs 5.2% p = .009) and death (3.0% vs 0%, p = .044) at 30 days. After multivariable analysis, the factors associated with a higher DPC were time and contrast.

CONCLUSION

Contemporary TAVI-rTP in this cohort of patients continues to be a common phenomenon but severe thrombocytopenia is less frequent. Patients developing a DPC ≥30% are associated with poor outcomes at 30 days.

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.

Impact of postprocedural thrombocytopenia on mortality after transcatheter aortic valve implantation

AIMS

We performed a meta-analysis of currently available studies investigating the impact of postprocedural thrombocytopenia on mortality after transcatheter aortic valve implantation (TAVI).

METHODS

All studies researching the impact of postprocedural thrombocytopenia on mortality after TAVI were identified after searching PubMed and Web of Science through July 2019. The outcome of interest was early (in-hospital or 30-day) and overall (1- to 2-year) all-cause mortality after TAVI. From each study, the number of deaths in both patients with major (moderate/severe or higher postprocedural drop platelet counts defined in each study) and nonmajor (no/minor or lower drop platelet counts defined in each study) postprocedural thrombocytopenia was extracted. Then, odds ratios (ORs) of mortality for major vs. no/minor thrombocytopenia and their confidence intervals were generated. Alternatively, ORs and hazard ratios of mortality for major vs. no/minor thrombocytopenia (if available, adjusted) were directly extracted. Study-specific estimates were pooled in both the fixed-effect and random-effects models.

RESULTS

The principal pooled analysis demonstrated that postprocedural thrombocytopenia was associated with statistically significant increases in early (OR, 3.79; P for effect <0.00001; P for heterogeneity = 0.89) and overall mortality (OR/hazard ratio, 1.22; P for effect = 0.009; P for heterogeneity = 0.17) in the fixed-effect model. All sensitivity analyses did not substantively alter the results of the principal analysis. No funnel plot asymmetry of the principal analysis was detected (P for early mortality = 0.88; P for overall mortality = 0.14), which suggested probably no publication bias.

CONCLUSION

Postprocedural thrombocytopenia is associated with increased early and overall mortality after TAVI.

Evaluation of Acquired Thrombocytopenia According to the Balloon-Expandable Versus Self-Expandable Valves in Patients Undergoing Transcatheter Aortic Valve Replacement

In patients with severe aortic stenosis, the data about the incidence of acquired thrombocytopenia according to the use of balloon-expandable or self-expandable valves are limited. We investigated the relationship between the post-transcatheter aortic valve replacement (TAVR) thrombocytopenia and the balloon-expandable or self-expandable valves. A total of 127 consecutive patients who underwent TAVR were retrospectively analyzed. Among the study population, 61 (48%) patients underwent TAVR with the balloon-expandable valve and the 66 (52%) patients with the self-expandable valve. Procedural success did not differ between the groups (P = .575). The access site complications and in-hospital mortality were the same across the groups (P = .225 and P = .466). However, paravalvular (PV) leaks were significantly higher in the self-expandable valve group (P = .007). Among all, 65 patients experienced thrombocytopenia, which was more frequent in the self-expandable valve group (63.6 vs 37.7%, P = .005). In multivariate analyses, admission platelet count, PV leak, and self-expandable valve deployment were the predictors of thrombocytopenia (P = .001, P = .002, and P = .021, respectively). The present study showed a higher incidence of acquired thrombocytopenia in the self-expandable valve group. Although the procedural success was similar between the groups, postprocedural PV leaks were more common in the self-expandable valve group.

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

BACKGROUND

The frequency and predictors of thrombocytopenia after transcatheter aortic valve implantation (TAVI) are unclear.Methods and Results:This study enrolled 342 patients undergoing TAVI (245 with a percutaneous transfemoral approach, 65 with transfemoral surgical cutdown, and 32 with a non-transfemoral approach). Balloon-expandable and self-expanding valves were implanted in 235 and 107 patients, respectively. Platelet counts started to drop immediately, reaching a nadir 2-4 days after TAVI. Clinically significant thrombocytopenia (CSTP) was defined as a platelet count ≤50×10⁹/L at the time of the nadir or both a platelet count between 80 and 51×10⁹/L and a decrease in platelet count ≥50%. CSTP occurred in 16.7% patients. Approach site and TAVI valve selection significantly predicted CSTP. In multivariate analysis, independent predictors of CSTP were liver cirrhosis (odds ratio [OR] 7.22; 95% confidence interval [CI] 1.05-49.82), baseline platelet count ≤120×10⁹/L (OR 2.98; 95% CI 1.20-7.38), multiple blood transfusions (OR 4.03; 95% CI 1.72-9.41), and the use of balloon-expandable valves (OR 2.38; 95% CI 1.04-5.46). Kaplan-Meier survival analysis with a generalized Wilcoxon test revealed that mid-term (2 years) mortality was greater for patients with than without CSTP (31.4% vs. 15.5%; P=0.008).

CONCLUSIONS

TAVI-related CSTP was not rare and was associated with poor mid-term outcomes. CSTP was not only caused by patients' comorbidities and TAVI complications, but also related to TAVI procedural factors.

Blood Disorders in Patients Undergoing Transcatheter Aortic Valve Replacement: A Review

Transcatheter aortic valve replacement (TAVR) is well established for treating patients with severe aortic stenosis considered at intermediate to high surgical risk. Blood disorders such as anemia, thrombocytopenia, and acquired type 2A von Willebrand disease are relatively frequent in TAVR candidates, and multiple studies to date have highlighted their potential clinical association with mortality and/or bleeding complications post-TAVR. The present review provides an overview of various blood disorders observed pre- and post-TAVR, with special focus on their incidence, etiology, clinical association, and management.

Effect on Mortality of Systemic Thromboinflammatory Response After Transcatheter Aortic Valve Implantation

After transcatheter aortic valve implantation (TAVI) there is consistently identified decrease in platelets accompanied by a leucocyte (white blood cell, WBC) increase. We aimed to analyze the prognostic value of early platelet and WBC count changes (thromboinflammatory response) after successful TAVI. Among 432 consecutive patients [median 83.0 years of age, 63.4% women], platelets and WBCs were measured before and for 7 days post-TAVI. Follow-up was 36.9 (21.4 to 48.0) months. Platelet decrease (∆%Platelet-max) and parallel WBC increase (∆%WBC-max) were seen at days 1 to 3. Both ∆%Platelet-max ≤-37.6% and ∆%WBC-max >72.5% predicted mortality (area under the curve = 0.569 and area under the curve = 0.626). The 30-day and 1-year mortality (13.1% and 26.2%) were highest among 28% patients with a greater decrease in platelets and a greater increase in WBCs; intermediate (0.9% and 12.3%) among 52.5% patients with either a greater decrease in platelets or a greater increase in WBCs, but not both; and lowest (0% and 6.6%) among 19.5% patients with a lesser decrease in platelets and a lesser increase in WBCs (p <0.001). Estimated 4-year mortality rates were 53.7% versus 36.2% versus 24.5%, respectively, p <0.001. Bleeding, surgical wounds, acute kidney, and brain injury predicted a more intense thromboinflammatory response, whereas use of the newer generations had the opposite effect. In conclusion, substantial thromboinflammatory response identified after successful TAVI predicts a higher long-term mortality.

Clopidogrel pretreatment may reduce early acquired thrombocytopenia after transcatheter aortic valve replacement (TAVR)

Transcatheter aortic valve replacement (TAVR) causes early acquired thrombocytopenia on postoperative Days 1 and 2 in 30-50% of patients. While usually transient and rarely severe, early acquired thrombocytopenia is strongly associated with 30-day and 1-year post-TAVR outcomes, including mortality. Observation from a prospective registry suggests pretreatment with the P2Y₁₂ receptor inhibitor clopidogrel before TAVR reduces the frequency and magnitude of early acquired thrombocytopenia. If a protective effect of clopidogrel pretreatment on early thrombocytopenia can be confirmed, then further study to determine if this translates into improved TAVR outcomes is warranted.

In-Hospital Outcomes After Transcatheter Aortic Valve Implantation in Patients With Versus Without Chronic Thrombocytopenia

Patients with chronic thrombocytopenia (cTCP) were excluded from the pivotal transcatheter aortic valve implantation (TAVI) trials. The National Inpatient Sample was queried and propensity score matching was performed to evaluate the prevalence and impact of cTCP on in-hospital clinical outcomes after TAVI. The main outcome was in-hospital mortality in patients with versus without cTCP. Among 38,855 TAVI hospitalizations, 7,105 had a diagnosis of cTCP (18.3%). In-hospital mortality was similar in both groups (OR_adjusted 0.79; 95% confidence interval [CI] 0.57 to 1.09); however, cTCP was associated with higher risk of acute kidney injury (OR_adjusted 1.29; 95% CI 1.08 to 1.54), vascular complications (OR_adjusted 1.99; 95% CI 1.22 to 3.25), perioperative blood product transfusion (OR_adjusted 1.69; 95% CI 1.42 to 2.01), cardiac tamponade (OR_adjusted 4.04; 95% CI 1.51 to 10.82), cardiogenic shock (OR_adjusted 1.52; 95% CI 1.07 to 2.15), and use of extracorporeal membrane oxygenation (OR_adjusted 2.32; 95% CI 1.1 to 4.9). In conclusion, cTCP is common in patients who underwent TAVI and is associated with worse postprocedure clinical outcomes, however, with similar in-hospital mortality.

Peri-procedural hemostasis disorders in surgical and transcatheter aortic valve implantation

Introduction

Despite their high effectiveness, surgical aortic valve replacement (AVR) and transcatheter aortic valve implantation (TAVI) are associated with substantial risk of bleeding. Although procedure-related hemostasis disorders might be crucial for safety of both procedures, the amount of data on the peri-procedural status of hemostasis in patients with aortic valve stenosis (AS) subjected to AVR and TAVI is negligible.

Aim

To investigate the profile of peri-procedural hemostasis in elderly patients with AS, subjected to aortic valve prosthesis implantation.

Material and methods

We performed a prospective analysis of global hemostasis using ROTEM thromboelastometry and platelet reactivity assessment using impedance aggregometry in 30 consecutive patients ≥ 70 years old subjected to AVR and TAVI. All tests were performed within 24 h before, directly and 24 h after the procedures.

Results

Surgical aortic valve replacement was characterized by transient hypofibrinogenemia and von Willebrand factor (vWF) depletion, which quickly recovered within 24 h after AVR. Transcatheter aortic valve implantation was characterized by substantial alteration of platelet function and vWF depletion with significant platelet reactivity impairment and increase in platelet sensitivity to antiplatelet agent, early after the procedure. TAVI-related hemostasis alterations were not recovered at 24 h after the procedure.

Conclusions

Surgical and transcatheter aortic valve replacement procedures are associated with substantial and diverse peri-procedural hemostasis disorders. Since hemostasis disorders related to TAVI are mainly characterized by impaired platelet function, early dual antiplatelet prophylaxis after TAVI requires careful consideration.

Peri-procedural thrombocytopenia after aortic bioprosthesis implant: A systematic review and meta-analysis comparison among conventional, stentless, rapid-deployment, and transcatheter valves

BACKGROUND

Thrombocytopenia has been shown to occur soon after surgical biological aortic valve replacement (AVR), and recently reported also after transcatheter valve implantation (TAVI). The mechanism underlying this phenomenon is still unknown, and its clinical impact on the peri-operative outcome has been poorly investigated.

METHODS

A systematic review and a meta-analysis of all available studies reporting data about peri-procedural thrombocytopenia on isolated bio-AVR, comparing rapid-deployment (RDV), stentless (stentless-AVR), and TAVI vs. stented (stented-AVR) valves, have been performed.

RESULTS

Fifteen trials (2.163 patients) were included in the meta-analysis. Perioperative platelet reduction ranged from 35% to 55% in stented-AVR, from 60% to 77% in stentless-AVR, from 53% to 60% in RDV, and from to 21% to 72% in TAVI (apparently, balloon-expandable valves more frequently associated to thrombocytopenia). Stented-AVR required more red blood cells transfusion than stentless-AVR (P < 0.0001), whereas no difference has been found between RDV and stented-AVR. Platelet transfusion rate was very low in all surgical groups. No difference has been found in RDV and stentless-AVR vs. stented-AVR, in terms of reoperation for bleeding, and length-of-intensive care unit or hospital stay.

CONCLUSIONS

Thrombocytopenia-related major adverse events were mainly reported in TAVI patients, whereas clinically meaningless in surgical patients. Transient peri-procedural thrombocytopenia is common after bio-AVR, regardless of prosthesis's type or implant modality. It should receive appropriate monitoring and focused investigations.

Preprocedural P2Y12 inhibition and decrease in platelet count following transcatheter aortic valve replacement

BACKGROUND

Thrombocytopenia after transcatheter aortic valve replacement (TAVR) is associated with adverse clinical outcomes. Whether preprocedural P2Y₁₂ inhibition prevents postprocedural thrombocytopenia is uncertain.

METHODS

This retrospective analysis identified consecutive patients (n = 266) undergoing TAVR between November 2016 and July 2017. Preprocedure clopidogrel load ≥300 mg or maintenance P2Y₁₂ inhibitor therapy defined preprocedural P2Y₁₂ inhibition. Patients who did not consent for the registry (n = 8), with baseline severe thrombocytopenia (<90 × 10³  platelets/μL; n = 14), or without baseline platelet count (n = 4) were excluded. The primary outcome was proportion of patients who developed >20% decrease in platelet count from baseline to day 1 post-TAVR.

RESULTS

Patients with (n = 134) versus without (n = 106) preprocedural P2Y₁₂ inhibition had no differences in platelet count at baseline. Patients with preprocedural P2Y₁₂ inhibition had a significantly lower proportion of the primary outcome (34.3% vs. 57.5%, p = .001) and a lower absolute decrease in platelet count (32.8 × 10³ vs. 45.8 × 10³  platelet/μL, p = .01). Of patients without baseline thrombocytopenia (n = 198), a numerically lower rate of patients with versus without preprocedural P2Y₁₂ inhibition developed thrombocytopenia on day 1 post-TAVR (25.5% vs. 36.4%, p = .1).

CONCLUSION

Patients who received preprocedural P2Y₁₂ inhibition prior to TAVR were less likely to demonstrate a decrease in platelet count after TAVR. Prospective studies to further understand the clinical implication of these findings are warranted.

Comparison of the Frequency of Thrombocytopenia After Transfemoral Transcatheter Aortic Valve Implantation Between Balloon-Expandable and Self-Expanding Valves

Thrombocytopenia after transcatheter aortic valve implantation (TAVI) is common and has been related to worse clinical outcomes. Comparison of platelet kinetics among different types of valves is limited. Our objectives were to analyze the differences in drop platelet count (DPC) between balloon-expandable valves (BEVs) and self-expanding valves and their prognostic implications after TAVI. Patients who underwent transfemoral TAVI from 2008 to 2016 were included. Exclusion criteria were severe baseline thrombocytopenia and periprocedural death. Postprocedural platelet counts were collected. Two groups were created: DPC ≤30 and DPC >30%. Valve Academic Research Consortium-2 criteria were used to define outcomes. Study population included 609 patients (age 84.7 ± 6.0, 46.6% males). The mean DPC was 32.5 ± 13.9%. The DPC was higher in the BEV arm (33.9 ± 14.2 vs 30.7 ± 13.4%, p = 0.006), and the nadir was reached later in comparison to the self-expanding valve arm (3.0 ± 1.3 vs 2.5 ± 1.1 days, p <0.001). After multivariable analysis, the use of BEV, known coronary artery disease, and left ventricle ejection fraction were the factors associated with a higher rate of DPC >30%. At 30 days, the DPC >30% was related with a higher rate of life-threatening and/or major bleeding (6.8 vs 2.1%, p = 0.009) and death (3.5 vs 0.8%, p = 0.036). At 1 year, the difference in mortality disappeared. In conclusion, in this cohort of patients, the use of BEV seems to be associated with a higher risk of DPC after TAVI. A DPC ≥30% was related with increased risk of life-threatening and/or major bleeding and death at 30 days. Larger and prospective studies are needed to understand this phenomenon.

Thrombocytopenia After Aortic Valve Replacement: Comparison Between Sutureless Perceval S Valve and Perimount Magna Ease Bioprosthesis

Introduction

The incidence of postoperative thrombocytopenia after aortic valve replacement (AVR) with the Perceval S Sutureless bioprosthesis remains unclear. The aim of this study was to report thrombocytopenia associated with the use of sutureless AVR.

Methods

The data was collected retrospectively for patients who had isolated AVR with sutureless Perceval S valve (Group A: 72 patients) and was compared with patients who underwent isolated sutured AVR with Perimount Magna Ease Bioprosthesis (Group B: 101 patients) in our institution between June 2014 and January 2017.

Results

Cardiopulmonary bypass and cross-clamp time were significantly shorter in group A. Maximum drop in platelet count was 58% mean (day 2.3) in group A versus 44% mean (day 1.7) in group B (P=0.0001). Absolute platelet count on postoperative day 1-6 in group A was significantly less than in group B (P≤0.05). Platelet count recovered to preoperative value in 44% patients in group B versus only in 26% patients in group A at discharge (P=0.018). Moderate thrombocytopenia occurs more often in group A (41% vs. 26%) (P=0.008) while severe thrombocytopenia (<50 x 10⁹) was observed in 6% in group A but never in group B. Platelets (P=0.007) and packed red blood cells (P=0.009) transfusion was significantly higher in the group A.

Conclusion

The implantation of sutureless Perceval aortic valves was associated with a significant drop in platelet count postoperatively with slow recovery and higher platelets and packed red blood cells transfusion requirements. A prospective randomised trial is needed to confirm our findings.

Thrombocytopenia after transcatheter aortic valve implantation. A comparison between balloon-expandable and self-expanding valves

BACKGROUND

Thrombocytopenia after transcatheter aortic valve implantation (TAVI) is common and has been related to higher mortality and major complications. No comparison between balloon-expandable (BEV) and self-expanding valves (SEV) regarding drop platelet count (DPC) has been reported to date. The objectives of this study were to analyze the differences in DPC between BEVs or SEVs and their prognostic implications in clinical outcomes.

METHODS

We retrospectively analyzed patients undergoing TAVI. Platelet counts after TAVI were collected. Two groups were created: DPC ≤ 30% and DPC > 30%. VARC-2 criteria were used to define outcomes.

RESULTS

Study population was composed of 195 patients (age 77.5 ± 6.7, 57.4% males). All of them but one experienced DPC (mean DPC 31.9 ± 15.3%). DPC was significantly higher among the patients treated with BEV compared to those treated with SEV (36.3 ± 15.1% vs 27.7 ± 14.4, P < 0.001). After multivariate analysis, the use of BEV was independently associated with a higher rate of DPC > 30% (67.4% vs 36.0%; OR 3.4; 95% CI, 1.42-8.16). At 30 days, the DPC > 30% was associated with a higher rate of life-threatening/major bleeding, major vascular complications, in-hospital sepsis and mortality. At one year, there were no statistically significant differences in the mortality rate between groups (6.35% vs 10.0%, HR 1.54; 95% CI, 0.56-4.25).

CONCLUSIONS

In this study, the use of BEV was associated with a higher risk of DPC after TAVI. A DPC rate > 30% was associated with an increased risk of major complications at 30 days.

Risk of reduced platelet counts in patients with nonalcoholic fatty liver disease (NAFLD): a prospective cohort study

Background

The production of peripheral platelet is mainly regulated by thrombopoietin, which is a glycoprotein hormone predominantly synthesized in the liver. Previously, many studies have reported that there was an inverse correlation between the degree of chronic viral hepatitis and the peripheral platelet count. However, the effect of nonalcoholic fatty liver disease (NAFLD) on the peripheral platelet counts remains unclear.

Methods

With 1303 participants from “The prevention of MS and multi-metabolic disorders in Jiangsu province of China (PMMJS)” cohort study, we investigated the associations between NAFLD and the risk of platelet counts reduction in Chinese adults. The paired-samples T test was used to explore the platelet counts changes between baseline and follow-up. Multivariate logistic regression was used to examine the association between presence of NAFLD and the risk of platelet reduction by calculating the odds ratios (ORs) and 95% confidence interval (CI).

Results

After five years of follow-up, platelet counts were markedly reduced from 220.6 ± 42.22 (10⁹/L) at baseline to 208.41 ± 40.70 (10⁹/L) at follow-up in NAFLD group (P < 0.0001). However, platelet counts were slightly lowered from 213.2 ± 43.26(10⁹/L) at baseline to 211.8 ± 41.65 (10⁹/L) at follow-up in non-NAFLD people (P = 0.2349). Meanwhile, there was a significant association between NAFLD and the risks of platelet count reduction, even after adjustment for confounding variables (OR: 1.68, 95% CI: 1.06–2.67). Additionally, among the participants with BMI ≤ 23 kg/m² and SUA ≤ 344.3 μmol/L, the NAFLD participants have an increased risk of platelet count reduction compared to the persons in non-NAFLD group.

Conclusions

Our present results suggested that NAFLD individuals have an increased risk of platelet counts reduction.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0865-7) contains supplementary material, which is available to authorized users.

Realistic Vascular Replicator for TAVR Procedures

Transcatheter aortic valve replacement (TAVR) is an over-the-wire procedure for treatment of severe aortic stenosis (AS). TAVR valves are conventionally tested using simplified left heart simulators (LHS). While those provide baseline performance reliably, their aortic root geometries are far from the anatomical in situ configuration, often overestimating the valves' performance. We report on a novel benchtop patient-specific arterial replicator designed for testing TAVR and training interventional cardiologists in the procedure. The Replicator is an accurate model of the human upper body vasculature for training physicians in percutaneous interventions. It comprises of fully-automated Windkessel mechanism to recreate physiological flow conditions. Calcified aortic valve models were fabricated and incorporated into the Replicator, then tested for performing TAVR procedure by an experienced cardiologist using the Inovare valve. EOA, pressures, and angiograms were monitored pre- and post-TAVR. A St. Jude mechanical valve was tested as a reference that is less affected by the AS anatomy. Results in the Replicator of both valves were compared to the performance in a commercial ISO-compliant LHS. The AS anatomy in the Replicator resulted in a significant decrease of the TAVR valve performance relative to the simplified LHS, with EOA and transvalvular pressures comparable to clinical data. Minor change was seen in the mechanical valve performance. The Replicator showed to be an effective platform for TAVR testing. Unlike a simplified geometric anatomy LHS, it conservatively provides clinically-relevant outcomes and complement it. The Replicator can be most valuable for testing new valves under challenging patient anatomies, physicians training, and procedural planning.

Can Blood Biomarkers Help Predicting Outcome in Transcatheter Aortic Valve Implantation?

Transcatheter aortic valve implantation (TAVI) has become the method of choice for patients with severe aortic valve stenosis, who are ineligible or at high risk for surgery. In this high risk patient population, early and late mortality and rehospitalization rates after TAVI are still relatively high. In spite of recent improvements in procedural TAVI, and establishment of risk models for poor outcome, determining individual risk remains challenging. In this context, current data from several small studies strongly suggest that blood biomarkers of myocardial injury, cardiac mechanical stretch, inflammation, and hemostasis imbalance might play an important role by providing informations on patient risk at baseline, and postprocedural progression of patient clinical conditions from days up to years post-TAVI. Although the role of biomarkers for predicting survival post-TAVI remains to be validated in large randomized studies, implementing biomarkers in clinical practice might improve risk stratification, thereby further reducing TAVI-associated morbidity and mortality.

Perioperative thrombocytopenia predicts poor outcome in patients undergoing transcatheter aortic valve implantation

PURPOSE

To determine the time point at which thrombocytopenia after TAVI procedure is an indicator of the worst prognosis, with special consideration of perioperative platelet and coagulation activation as its potential causes.

METHODS

Thirty two patients (mean age 78.5±7.9years, 62% females) qualified for TAVI procedure were prospectively evaluated. Platelet counts were assessed at baseline and for the next three postoperative (POD) days. Platelet activation was evaluated by P-selectin (PS, serum, ELISA) and platelet factor 4 (PF-4, CTAD plasma), and blood coagulation activation by prothrombin fragments 1+2 (F1+2, plasma, ELISA). Composite end point (CEP) including death and the need of cardiovascular rehospitalization was assessed after a mean of 14.1±6.7months.

RESULTS

During the follow up period half of the patients reached CEP. Thrombocytopenia was more profound and frequent in patients with CEP as compared to those without (p<0.05). No differences regarding either the biomarkers of platelet (PS, PF-4) or coagulation (F1+F2) activation between the groups with and without CEP were found. Patients with moderate-to-severe thrombocytopenia at baseline had worse prognosis (log-rank test, p=0.0003). Based on the receiver operating characteristic curve analysis, the differences between platelet count on each postoperative day and the baseline count did not have any predictive value in CEP occurrence.

CONCLUSIONS

Patients with thrombocytopenia following TAVI procedure have poor prognosis, however, the changes on the particular days are not more important than initial platelet count. Further studies are needed to evaluate platelet and blood coagulation activation as potential causes of thrombocytopenia and impaired prognosis related to it.

Predictors of Thrombocytopenia after Self-Expandable Transcatheter Aortic Valve Replacement: A Single-Center Experience from China

OBJECTIVES

The importance of thrombocytopenia (TP) has been discussed previously. However, data are still limited, especially on predictors of TP. We sought to investigate predictors of TP after transcatheter aortic valve replacement (TAVR), in particular, clinically significant TP.

METHODS

We reviewed a total of 123 consecutive patients undergoing TAVR in our medical center. They were stratified into 3 groups according to the nadir platelet count post-TAVR: no/mild TP, moderate TP, and severe TP. Clinically significant TP, also known as major TP, was defined as moderate-to-severe TP (a nadir platelet count <100 × 109/L and a >50% decrease in platelet count).

RESULTS

Baseline platelet, baseline hemoglobin, general anesthesia (GA), valve malpositioning and post-TAVR left ventricular ejection fraction were found to be predictors of post-TAVR nadir platelet count. Major TP was associated with a higher risk of major bleeding (OR 3.524, 95% CI 1.546-8.031) and 1-month mortality (OR 11.226, 95% CI 1.208-104.328). Age (OR 1.110, 95% CI 1.014-1.215) and GA (OR 6.494, 95% CI 2.058-20.408) were predictors of major TP.

CONCLUSION

Post-TAVR nadir platelet count can be predicted based on baseline and procedural data. Old age and GA contribute to clinically significant TP.

Antithrombotic treatment in patients undergoing transcatheter aortic valve implantation (TAVI)

Transcatheter aortic valve implantation (TAVI) is an established treatment option for symptomatic patients with severe aortic valvular disease who are not suitable for conventional surgical aortic valve replacement. Despite improving experience and techniques, ischaemic and bleeding complications after TAVI remain prevalent and impair survival in this generally old and comorbid-rich population. Due to changing aetiology of complications over time, antiplatelet and anticoagulant therapy after TAVI should be carefully balanced. Empirically, a dual antiplatelet strategy is generally used after TAVI for patients without an indication for oral anticoagulation (OAC; e. g. atrial fibrillation, mechanical mitral valve prosthesis), including aspirin and a thienopyridine. For patients on OAC, a combination of OAC and aspirin or thienopyridine is generally used. This review shows that current registries are unfit to directly compare antithrombotic regimens. Small exploring studies suggest that additional clopidogrel after TAVI only affects bleeding and not ischemic complications. However, these studies are lack in quality in terms of Cochrane criteria. Currently, three randomised controlled trials are recruiting to gather more knowledge about the effects of clopidogrel after TAVI.

Platelet activation is less enhanced in the new balloon expandable Edwards Sapien 3 valve compared to its predecessor model (Edwards Sapien XT)

Stroke and thromboembolic events after transfemoral aortic valve replacement (TAVR) continue to be a problem. The aim of our study was to compare platelet aggregation (Agg) and platelet activation (PA) observed with two different catheter valves, the ESV-XT and the newer ESV-3 valve in patients (pts) undergoing TAVR on dual antiplatelet therapy (DAPT). A total of 174 patients with severe aortic stenosis and high surgical risk successfully underwent TAVR (60 ESV-XT; 114 ESV-3). Platelet Agg and PA (CD62P expression) were evaluated before and the following three days after TAVR under DAPT. Platelet Agg was inhibited to the same extent in both valve types and there was no significant difference in platelet drop between both valve types between day 0 and day 3 [ESV-XT vs ESV-3: median (25th-75th percentile): platelet count (x1000): 55 (42–74) vs 61(42–93), p=0.280]. However, there was an enhanced CD62P expression directly after TAVR with the ESV-XT compared to the ESV-3 [CD62P (MIF): 7.4 (6.8–8.6) vs 6.6 (6–7.9), p=0.014]. Surface expression of platelet CD62P was associated with the occurrence of residual aortic regurgitation (AR) and was significantly higher in patients with residual AR [CD62P (mild AR) vs CD 62P (no or trace AR): 7.9 (7.3–9.1) vs 7.1 (6.4–8.0), p < 0.001)]. PA was significantly enhanced in patients with the ESV-XT compared to the ESV-3 valve and was associated with the amount of residual AR which was significantly reduced by ESV-3. This may have implications for thromboembolic events following TAVR procedure

Thrombocytopenia associated with TAVI-The summary of possible causes

Thrombocytopenia (TP) following transcatheter aortic valve implantation (TAVI) procedure is a common phenomenon but the underlying mechanisms are neither well known nor described. Postinterventional severe TP is related to worse early and late outcome. Moreover, the statement of enhanced platelet and coagulation activation might justify even stronger antiplatelet and anticoagulation therapy following TAVI procedure. Thus, the examination of the pathomechanisms responsible for TP post TAVI seems to be crucial. Several hypotheses have been raised. TP can be caused by insufficient production or impaired platelet renewal. On the other hand, increased platelet activation, consumption and destruction might also be responsible for TP. These findings, mostly related to the procedure alone, need further investigation. Here, we summarize the potential multifactorial causes of post TAVI thrombocytopenia.

The causes of thrombocytopenia after transcatheter aortic valve implantation

INTRODUCTION

Even though thrombocytopenia following transcatheter aortic valve implantation (TAVI) has been described, further investigation of this phenomenon is needed.

AIMS

To determine which factors may explain the fall in platelet count that occurs after implantation of a TAVI device, including markers of platelet and blood coagulation activation.

MATERIAL AND METHODS

32 patients without previous indications for dual antiplatelet therapy (mean age 78.5±7.9 years, 62% females) with severe aortic valve stenosis (mean gradient 54.6±16.9mmHg) who qualified for TAVI procedure (Edwards Sapien XT) were prospectively analyzed. Platelet counts were analyzed before the surgery, on the day of the procedure and for the three following postoperative days (POD 1 to 3). To assess platelet activation P-selectin (PS, serum) and platelet factor 4 (PF-4, CTAD plasma) were measured, whereas for the evaluation of coagulation activation prothrombin fragments 1+2 (F1+2, plasma) were assessed before the procedure, on POD-1 and POD-3 (ELISA).

RESULTS

During the postoperative period a significant platelet count drop, the most evident on POD-2, was observed followed by a platelet count raise. The platelet count drop correlated directly with the amount of iodinated contrast agent (r=0.42, p=0.016) and inversely with baseline mean platelet volume (r=-0.37, p=0.046). Neither clinical nor perioperative parameters, except contrast medium, influenced platelet count decrease. No significant differences regarding the concentration of the evaluated markers in patients with and without thrombocytopenia were found. PF-4 and F1+2 significantly changed during the study (p<0.05). Greater acute PF-4 decrease correlated with greater acute platelet count drop (r=0.48, p=0.043), and during the study slower PF-4 increase correlated with higher platelet count increase on POD-3 (r=-0.505, p=0.032). Lower baseline PS correlated with lower baseline platelet count and higher platelet count increase on POD-3 (r=0.45, p=0.04 and =-0.55, p=0.02, respectively). No significant correlations between F1+2 concentrations and platelet count changes have been found.

CONCLUSIONS

Platelet reduction shortly after TAVI procedure is related to the amount of contrast agent applied during the procedure. Platelet activation and blood coagulation along with impaired baseline platelet renewal might be the mechanisms of thrombocytopenia following TAVI procedure.

Thromboinflammatory response and predictors of outcomes in patients undergoing transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has been increasingly used to treat patients with symptomatic aortic stenosis. Despite improvements in valve deployment, patients that have undergone TAVR are at high risk for major adverse events following the procedure. Blood cell numbers, platelet function, and biomarkers of systemic inflammation were analyzed in 58 patients undergoing TAVR with the Edward's SAPIEN valve. Following valve deployment, platelet count and agonist-induced platelet activity declined and plasma markers of systemic inflammation (interleukin-6 and S100A8/A9) increased. Baseline platelet activity prior to TAVR correlated with perioperative changes plasma interleukin-6 levels. Moreover, perioperative changes in plasma inflammatory markers predicted the decline in platelet count in the days following the TAVR procedure. Additionally, a significant effect of gender on platelet count following TAVR and was observed. Finally, post-procedural mortality was associated with sustained thrombocytopenia after TAVR. Our findings suggest that TAVR elicits a thromboinflammatory state that may contribute to post-procedural thrombocytopenia. Importantly, our results add to the growing body of literature that suggests the thromboinflammatory changes that occur early after TAVR may predict long-term outcomes.

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.

Acquired thrombocytopenia after transcatheter aortic valve replacement: clinical correlates and association with outcomes

AIMS

This study aimed to evaluate incidence and correlates for low platelet count after transcatheter aortic valve replacement (TAVR) and to determine a possible association between acquired thrombocytopenia and clinical outcomes.

METHODS AND RESULTS

Patients undergoing TAVR from two medical centres were included in the study. They were stratified according to nadir platelet count post procedure: no/mild thrombocytopenia, ≥100 × 10(9)/L; moderate, 50-99 × 10(9)/L; and severe, <50 × 10(9)/L. A total of 488 patients composed of the study population (age 84.7 ± 7.5 years). At a median time of 2 days after TAVR, 176 patients (36.1%) developed significant thrombocytopenia: 149 (30.5%) moderate; 27 patients (5.5%) severe. Upon discharge, the vast majority of patients (90.2%) had no/mild thrombocytopenia. Nadir platelet count <50 × 10(9)/L was highly specific (96.3%), and a count <150 × 10(9)/L highly sensitive (91.2%), for predicting 30-day death (C-statistic 0.76). Patients with severe acquired thrombocytopenia had a significantly higher mortality rate at 1 year (66.7% for severe vs. 16.0% for no/mild vs. 20.1% for moderate; P < 0.001). In multivariate logistic regression, severe thrombocytopenia was independently associated with 1-year mortality (hazard ratio 3.44, CI: 1.02-11.6; P = 0.046).

CONCLUSIONS

Acquired thrombocytopenia was common after TAVR and was mostly resolved at patient discharge. The severity of thrombocytopenia after TAVR could be used as an excellent, easily obtainable, marker for worse short- and long-term outcomes after the procedure.

Incidence and implications of idiopathic thrombocytopenia following transcatheter aortic valve replacement with the Edwards Sapien(©) valves: a single center experience

OBJECTIVES

To determine the incidence and etiology of thrombocytopenia following transcatheter Aortic valve replacement (TAVR).

BACKGROUND

the use of TAVR in the United States has grown rapidly. Anecdotally, thrombocytopenia following TAVR with the Sapien valves has been observed, though little is known about this phenomenon.

METHODS

All patients treated with TAVR using a Sapien valve or who underwent isolated balloon aortic valvuloplasty (BAV) at Brigham and Women's Hospital from October 2009 through November 2012 were analyzed. Post-procedure thrombocytopenia severity was stratified as none (>150,000 cells/μL), mild (100-150,000), and moderate to severe (<100,000). Summary statistics and simple comparisons were evaluated. Linear regression models were used to identify patient or procedural factors associated with platelet count nadir.

RESULTS

112 TAVR and 105 BAV patients were analyzed. Following TAVR the prevalence of thrombocytopenia was 69% and the incidence of new thrombocytopenia was 45% compared to 37% and 17% respectively following BAV (P < 0.01). Similar results were found across all strata of thrombocytopenia severity. Post-TAVR platelet nadirs were greater by 1,840 cells/μL for each 1% increase in STS score (P = 0.03) and 670 cells/μL greater for each 1 mmHg increase in pre-TAVR mean aortic stenosis gradient. Among TAVR patients, thrombocytopenia appears to spontaneously resolve an average of 8 days post-procedure. No differences in clinical outcomes based on thrombocytopenia severity were observed except for an increased use of blood products (P = 0.05).

CONCLUSIONS

Thrombocytopenia following TAVR with the Edwards' Sapien valves is a frequent but generally self-limited process. The etiology of this phenomenon is unknown.