Bioprosthetic valve fracture during valve-in-valve transcatheter aortic valve replacement: multicenter propensity matched analysis

Background

Valve-in-valve (ViV) transcatheter aortic valve implantation (TAVI) can be completed by bioprosthetic valve fracture (BVF) to reduce final transvalvular gradients. The aim was to compare outcomes in ViV-TAVI patients with versus without BVF.

Methods

Consecutive patients undergoing ViV-TAVI procedure in four international centers were included, from 2010 to 2021. We used a 1:2 propensity score-matching method to compare postprocedural hemodynamic, complications, and long-term outcomes. Patients were matched for baseline characteristics, time since prior surgery, and characteristics of surgical bioprothesis (type and size).

Results

A total of 390 patients were analyzed, including 40 BVF. Propensity matching 1:2 yielded 38 patients in BVF group and 76 patients in no-BVF group. There was no difference in procedural complications rate and in-hospital deaths (5.1%) between the two groups. Post-procedural hemodynamic parameters significantly improved using BVF: aortic valve area (1.4 cm2 [IQR: 1.23 to 2.3] vs. 1.3 cm2 [IQR: 1.05 to 1.61], p=0.008), mean aortic gradient (12mmHg [IQR: 7.5 to 16.5] vs. 17mmHg [IQR: 11 to 22], p=0.008) and peak velocity (2.2m/s [IQR: 1.8 to 2.7] vs. 2.6m/s [IQR: 2.2 to 3.1], p=0.027). BVF had an additional benefit in the smallest surgical valve (≤21 mm). The use of BVF was independently associated with improved hemodynamic parameters. Overall survival in the matched cohort was 87.8±3.7% at 2-year follow-up, without difference between groups (87.5±6.9% in the BVF group vs. 88.4±4.2% in the no-BVF group, p=0.85).

Conclusion

Compared to ViV-TAVI alone, BVF was safe and improved immediate hemodynamic and long-term outcomes, especially in patients with small surgical aortic bioprosthesis.

Funding Acknowledgement

Type of funding sources: None.

O-159 Uniform communication by nurses and midwives in anticipation of an IVF treatment

Study question

How do patients perceive the pre-IVF treatment communication by the nursing and midwifery team and how do they evaluate implemented optimization?

Summary answer

Patient satisfaction with the pre-IVF treatment communication by the nursing and midwifery team improved from 86% to 98% after implementation of standardized written patient information.

What is known already

Nurses are the main point of contact for patients undergoing medically assisted reproduction techniques (Applegarth et al., 2008). Morris (2001) suggested that infertility nurses could more specifically be involved in informative counselling in anticipation of the fertility treatment. Specific training for nurses and midwives would be required in order to achieve that central role in effective fertility counselling (Applegarth et al., 2012). However, little has been published in peer reviewed literature on how to assess and improve these pre-IVF treatment information sessions.

Study design, size, duration

The pre-IVF communication by the nurse/midwife was assessed by female patients with a self-developed questionnaire (cohort 1). The nursing and midwifery team was subsequently informed about the results of the questionnaire and efforts were undertaken to optimise future patient communication. Four years later, a follow-up questionnaire assessed patient satisfaction about the intervention (cohort 2). Each cohort comprised fifty patients and nurses and midwives were blinded for patient participation to the study.

Participants/materials, setting, methods

The study was performed at an academic fertility centre and was approved by the Investigational Review Board. Data were collected with SurveyMonkey (pre intervention) and REDCap (post intervention). A descriptive analysis of the cohorts and patient feedback was performed. The intervention consisted of (1) the optimization of patient information documents if needed (2) providing a training to the nursing and midwifery staff, and (3) a follow-up questionnaire in a second cohort of female fertility patients.

Main results and the role of chance

The first questionnaire revealed that overall, patients were satisfied with the informative counselling session in anticipation of the IVF treatment. However, some patients indicated that they received a lot of information at once and that specific information that was of relevance for the further treatment (e.g. oocyte pick-up) was sometimes missed. Also, the data showed that not all patients received the same information. Therefore, all information that patients needed during an IVF treatment was gathered into a patient binder. It was supplemented with a timeline of the whole IVF trajectory, QR codes to movies explaining the administration of medication, and answers to common patients’ questions. It was possible to individualize the content of the binder per patient. Ideally, patients received this binder before the informative counselling session so they could read the content in advance. The binder was developed by a member of the nursing and midwifery team and was reviewed by the medical, laboratory, and administrative staff. Then, the nursing and midwifery team was trained on the use of the patient binder. The follow-up questionnaire revealed that patient satisfaction with the pre-IVF treatment counselling was 98% after the optimization of patient documentation (compared to 86% before the optimization).

Limitations, reasons for caution

Eligible patients were recruited by the treating physician. As no records were kept of the number of solicited patients for this study, no assessment of the response rate is possible. The cohorts were self-selected and limited in size and could therefore not reflect the general patient population.

Wider implications of the findings

A patient questionnaire and follow-up is a useful tool for a centre specific assessment and improvement of pre-IVF nurse/midwife communication with patients. Clinics could make efforts to invest in complete and written information and ask colleagues of the nursing and midwifery team to be involved in its creation.

Trial registration number

NCT04420169

P1838Thrombocytopenia under ECMO and Shear-induced shedding of platelet receptor Glycoprotein-(GP)Ialpha

Background

Several mechanisms are suspected to thrombocytopenia under Extracorporeal Membrane Oxygenation (ECMO) such as platelet-consumption or sepsis. Shedding of glycoprotein-(GP)Ibα is a recently identified mechanism of platelet clearance. ECMO generates high shear stress forces that could impact GPIbα-shedding. We hypothesized that ECMO continuous-flow devices could directly induce thrombocytopenia through shear-induced GPIbα-shedding.

Aims

Determine if ECMO induce GpIb-shedding in vitro and in vivo and determinates the kinetic evolution of platelet-count and GpIb-shedding after patient's implantation.

Methods

Platelet GPIbα-shedding was first investigated in vitro using a high-shear pump loop model. Plasma with normal platelet count (plasma-NPC) was obtained by dilution of platelet-rich plasma obtained from healthy donors in fresh-frozen-plasma. Samples were collected before and after (5, 30, 60 and 180 min) perfusion at 37°C of plasma-NPC at intermediate and high speed (2.6 and 3.6 L min–1 respectively, n=4 each). Platelet count and GPIbα-shedding were next investigated in 20 ECMO patients before/after implantation (WITECMO trial) and in 20 healthy volunteers. The geometric mean-fluorescence-intensity (gMFI) of platelet GPIbα (PE-staining) and GPIX (FITC-staining) was measured with a Navios flow cytometer (Beckman Coulter, Miami, FL). Results are expressed as GPIbα/GPIX gMFI-ratio.

Results

A significant time-dependent loss of GPIbα/GPIX gMFI-ratio was already apparent after 30 min in vitro and was significantly more pronounced at high-speed compared to intermediate-speed (pANOVA<0.001 and p<0.01 at 180 min respectively). GPIbα/GPIX gMFI-ratio was significantly increased in ECMO patients compared to healthy subjects 1- and 24-hour after implantation (p<0.001). A significantly lower platelet count was observed 1 hour after ECMO implantation (−23% vs baseline, p<0.01) with a further significant decrease at 24-hours (−53% vs baseline, p<0.0001).

Figure 1. A. Significant time-dependent loss of platelet GPIbα/GPIX gMFI-ratio (pANOVA <0.001) assessed by flow-cytometry after 30 min of perfusion at 3.6 L/min with a high-shear continuous-flow device in vitro. B. Representative experiment showing the apparition of a platelet sub-population with loss of GPIbα expression after 30 min of perfusion at 3.6 L/minwith a high-shear continuous-flow device in vitro.

Circulatory support devices: fundamental aspects and clinical management of bleeding and thrombosis

Circulatory support devices are increasingly being used to overcome cardiac or respiratory failure. Long-term devices are used either as a 'bridge to transplant' to support patients who are unable to wait any longer for a heart transplant, or, more recently, as 'destination therapy' for older patients suffering from end-stage heart failure and who have contraindications to heart transplantation. Short-term support devices for high-risk percutaneous coronary intervention, or as a 'bridge for decision' for patients suffering from refractory cardiogenic shock, have also been developed. The clinical benefit of such assist devices has been demonstrated in several important studies, but, unfortunately, thrombotic and bleeding complications are two major clinical issues in patients requiring these devices. Overcoming these issues is of major importance to allow the safe and broad use of these devices, and to consider them as true alternatives to heart transplantation. The present review focuses on thrombotic and bleeding complications, and describes how the risk of thrombosis and bleeding may vary according to the clinical indication, but also according to the type of device. We describe the current knowledge of the mechanisms underlying the occurrence of these complications, provide some guidance for choosing the most appropriate anticoagulation regimen to prevent their occurrence for each type of device and indication, and provide some recommendations for the management of patients when the complication occurs.