Transcatheter mitral valve-in-valve implantation: a 10-year single center experience

Background

Transcatheter mitral valve-in-valve (TMVIV) appears a reasonable alternative to surgical redo mitral valve replacement in patients with degenerated mitral prosthesis and high surgical risk with favorable early and mid-terms outcomes. Long-term outcomes are limited by high mortality in a comorbid population.

Purpose

We aimed to evaluate early prosthesis hemodynamic performance and late clinical outcomes following TMVIV.

Methods

All patients who underwent TMVIV for degenerated surgical mitral bioprostheses from 2011 to 2020 in our center were included. Prospectively collected demographic, clinical, procedural, and imaging variables were analyzed. Clinical and echocardiographic outcomes were defined according to Mitral Valve Academic Research Consortium (MVARC) definitions and assessed at 30-day and at the latest follow-up available.

Results

A total of 67 patients were included; mean age 76.9±9.6 years, mean STS score 11.0±6.2%, 53.7% male (n=36). Mechanisms of bioprosthetic failure were mitral stenosis (n=32, 47.8%), mitral regurgitation (n=24, 35.8%), and mixed (n=11, 16.4%). Mean time from mitral valve surgery to TMVIV was 10.2±4.3 years. Access was mostly transapical (n=45; 67.2%), followed by transseptal (n=22; 32.8%). Following the first transseptal procedure in 2016; transseptal access accounted for the majority of procedures (22 of 37 cases, 59.4%).

Technical success was achieved in 65 patients (97.0%). Mean hospitalization was 9.2±10.0 days; shorter with the transseptal as opposed to the transapical approach (6.3±8.1 days versus 11.0±10.5 days, p=0.001). At 30-day echographic follow-up, mean mitral valve gradient was 7.3±2.7 and 1 patient (1.9%) had mitral regurgitation >mild.

At 30-day follow-up, 3 patients had died (4.5%); due to left ventricular outflow tract obstruction (1), heart failure (1), and stroke (1). New pacemakers were required in 2 patients (3.0%) and pacemaker lead dislodgement occurred in 1 patient (1.5%), 4 patients (6.2%) were hospitalized for heart failure. At a median follow-up of 3.8 years [1.7–5.1], 29 patients had died (43.3%), valve thrombosis was found in 6 (8.9%) and endocarditis in 4 patients (6.2%). Mitral valve reintervention was performed in 4 patients (6.2%); redo TMVIV due to valve migration in 1 (1.9%), surgical valve replacement in 1 (1.9%), and delayed redilation with a non-compliant balloon due to underexpansion in 2 patients (3.8%).

Conclusion

TMVIV is associated with acceptable 30-day mitral valve hemodynamics. Long-term mortality remains high in this high-surgical risk comorbid group.

Funding Acknowledgement

Type of funding sources: None.

Geometrical predictors of small virtual neoLVOT size in functional mitral regurgitation

Background

LVOT obstruction is a potentially lethal complication of transcatheter mitral valve replacement (TMVR). An anticipated neoLVOT area of <2cm2 is presumed to imply prohibitive risk. Measurement of the anticipated neoLVOT can be time consuming and requires specialist software to facilitate virtual valve implantation.

Purpose

To determine simple geometrical predictors of prohibitive neoLVOT size.

Methods

165 consecutive, non-calcific FMR patients referred to a transcatheter heart valve program were analysed. Segmentation of the mitral annulus and left heart geometry was performed using CT. Suitability for a default D-shaped TMVR was determined by proprietary annular inclusion criteria. Systolic neoLVOT area was determined via virtual valve implantation of the default TMVR.

Results

Sufficient image data for annular and neoLVOT suitability assessment was available in 152 patients. 105 patients (69%) were suitable for TMVR based on annular measurements. Of these, neoLVOT area was >2cm2 in 88 (84%). Overall, compared to patients not suitable for TMVR (n=64), those suitable had larger ventricles with lower LVEF, and larger annuli (table 1). Using binomial logistic regression involving the variables within table 1, LVESD was the sole statistically significant variable to predict neoLVOT area of <2cm2 (p=0.02). LVESD <48mm had 82% sensitivity and 94% specificity for the presence of prohibitive neoLVOT (figure 1).

Conclusion

Smaller LVESD is a strong predictor of small neoLVOT, and hence LVOT obstruction post default D-shaped TMVR implantation. This simple measure may therefore be used to streamline patient selection for advanced pre-procedural imaging analysis.

Predicting NeoLVOT size <2 cm2

Funding Acknowledgement

Type of funding source: None

Failure after osteosynthesis of trochanteric fractures. Where is the limit of osteoporosis?

SUMMARY

The aim of this study is to identify osteoporosis values, beyond which there is a high risk of osteosynthesis failure. Bone mineral density (BMD) of 30 cadaveric femora with a pertrochanteric fracture osteotomy was correlated to the risk of cut out after osteosynthesis on a biomechanical testing approach. For a BMD less than 250 mg/cm(3), there is a high risk of fixation failure after surgical treatment of pertrochanteric fractures. This value can be regarded as a reference value for future experimental and clinical studies.

INTRODUCTION

Despite continuous modification of intramedullary load carriers for the surgical stabilization of trochanteric fractures, cut out remains the most frequent complication. The aim of this experimental study was to identify threshold osteoporosis values, beyond which there is a high risk of osteosynthesis failure.

METHODS

Bone mineral density (BMD) of 30 cadaveric femora was recorded for the femoral head by QCT measurement. Subsequently, a standardized osteotomy mimicking an unstable trochanteric type fracture was stabilized by intramedullary nailing. The constructs were loaded axially at a force of 2,100 N up to 20,000 cycles. Cut out at the femoral head was documented by radiograph. Statistical evaluation of the cohort group was performed by calculation of relative risk in relation to the BMD values.

RESULTS

In total, there were six cases of cut out after 10,000 cycles. The incidence of cut out for BMD less than 250 mg/cm(3) was 0.55 (5 of 9) and for BMD greater than 250 mg/cm(3), it was 0.05 (1 of 21). Therefore, the relative risk of cut out for BMD <250 mg/cm(3) is 11× greater than for a BMD >250 mg/cm(3). After 20,000 cycles, an additional test caused one cut out (relative risk of cut out for a BMD <250 mg/cm(3) 5.8).

CONCLUSIONS

For a BMD less than 250 mg/cm(3), there is a high risk of fixation failure after surgical treatment of pertrochanteric fractures. Although this value is based on an experimental in vitro study design with all its associated limitations, it can be regarded as a reference value for future experimental and clinical studies.

Multidetector computed tomography in transcatheter aortic valve implantation. Where we stand

Degenerative calcific aortic stenosis represents the most common valve abnormality with increasing incidence in the elderly. Studies have shown that aortic stenosis is a fatal disease with a high cardiovascular death rate if untreated. However, many patients are encumbered with multiple comorbidities making them high-risk candidates for surgical aortic valve replacement, which is the hitorical treatment of choice. Transcatheter aortic valve implantation (TAVI) has seen rapid advancements over the last number of years with over 50000 TAVI procedures being performed in 40 countries with excellent prognosis proving TAVI to be a feasible alternative therapy to traditional surgical aortic valve replacement to treat high-risk patients. In addition to clinical suitability, imaging plays an essential role for optimal patient selection and to help select the appropriate prosthesis and to help reduce the likelihood of complications and adverse events. Fundamental to the procedure success, is the non-invasive assessment of the aortic annulus, the evaluation of the aortic root and the determination of the access to the aortic annulus. Among different imaging modalities that have been employed, multidetector computed tomography (MDCT) is increasingly used because of its capability of 3-dimentional (3D) determination of the non-circular nature of the aortic annulus as well as the complex aortic root anatomy. Additionally, MDCT provides a deep understanding of the structural integrity of the transcatheter aortic valve and enables the evaluation of the prosthesis location after TAVI and identification of post procedure complications. In this article, we discuss the current role of MDCT in pre-TAVI evaluation but also in the guidance of the procedure and in post-procedure follow-up.

[Clinical courses of trisomy 18 (Edwards syndrome) - an update]

BACKGROUND

In current literature the prognosis of trisomy 18 is mainly described as inevitably lethal. After intervention of parental organisations infants have been treated with cardio surgery in the USA, later in Europe as well with good results. We report the consequences of this and similar developments on our pre- und postnatal approach after diagnosis in our department. PATIENTS AND CASE REPORTS: 2 parents decided to carry the child to term after the recommendation for abortion. According to standard perinatological aspects one child was vaginally delivered, the second with Caesarean section. After informed consent with the parents we planned a supportive management without more resuscitation than stimulation and ventilation by mask. Both children could be stabilised with nasal CPAP. The first one had been operated on a double outlet right ventricle at the age of 6 months, the second needed to be operated for diaphragm hernia. The third child had been delivered by emergency Caesarean section. A bilateral choanal atresia had been operated in the first week of life, a double outlet right ventricle at the age of 15 days. One child is fed by a nasogastric tube, one is bottle-fed and one had a percutanous gastric tube until he died due to septicaemia, all have statomotorically retardation and had periods of pulmonary hypertension. The social situation of the families is characterised by a stable parental relationship and a safe socio-economical status. None of the children had an acute lethal malformation.

DISCUSSION

In single cases a prospective management in patients with trisomy 18 can be possible. Besides medical issues, the emotional parental wish, their social network and economical status are crucial.

CONCLUSION

The prognosis of trisomy 18 is poor. 3 patients and 20 months do not allow any general statements. However, our recent experience and the courses in the recent literature show that in single cases a more prospective management is possible.

[CT Angiography for the pre- and postoperative evaluation of the thoracic aorta]

CT angiography is the imaging modality of choice for the pre- and postsurgical evaluation of patients with pathologies of the thoracic aorta. The purpose of this review is to familiarize the reader with the technical principle, recent technical developments and requirements for specific examination protocols and image interpretation, and to highlight common pathologies and findings.

Bilateral contrast-enhanced MR angiography of the hand: diagnostic image quality of accelerated MRI using echo sharing with interleaved stochastic trajectories (TWIST)

OBJECTIVES

To evaluate the image quality of time-resolved contrast-enhanced MRA (tr-MRA) employing echo-sharing with stochastic trajectories for the bilateral examination of the hands.

METHODS

In this institutional review-board approved study, Tr-MRA was compared with multiphasic contrast-enhanced MRA (mp-MRA) featuring sub-systolic venous compression in 20 healthy volunteers at 3.0 T using the following settings: TR/TE: 2.8/1.2 ms, flip angle: 25°, acceleration factor: 4, effective voxel size: 0.9 × 0.8 × 0.9 cm, acquisition time 4.9 s per 3D volume.

RESULTS

With tr-MRA the arterial first-pass contrast agent transit is clearly seen. On average the contrast agent arrived 34 s post-injection and reached the proper digital arteries after 44 s. The mean arterio-venous window was 13 s. Bilateral contrast enhancement was asynchronous in 56-62%. On a semiquantitative scale (0 = non-sufficient to 4 = excellent) tr-MRA (mp-MRA) yielded an average ranking of 2.8-3.6 (3.1-3.8) in the greater and intermediate sized segments and 1.3-2.0 (1.6-2.3) in the proper digital arteries.

CONCLUSION

Compared with established multiphasic ce-MRA, time-resolved MRA allows a four times faster acquisition. It reflects the natural haemodynamics of the hand arteries with no need for sub-systolic venous compression and may be beneficial in the detection of hand circulation disorders. Image quality is comparable to mp-MRA. In both techniques depiction of the proper digital arteries is limited.