Short versus conventional hydration for prevention of kidney injury during pre-TAVI computed tomography angiography.

BACKGROUND: Computed tomography angiography (CTA) is required in the work-up for transcatheter aortic valve implantation (TAVI). However, CTA may cause contrast-induced acute kidney injury (CI-AKI). We hypothesised that a short (1 h, 3 ml/kg/h sodium bicarbonate) hydration protocol is not inferior to conventional (24 h, 1 ml/kg/h saline) hydration in avoiding a decline in renal function in patients with impaired renal function. METHODS AND RESULTS: Single-centre randomised non-inferiority trial in patients with impaired renal function who underwent pre-TAVI CTA. Patients were randomised on a 1:1 ratio to short hydration (SHORT; 1 h sodium bicarbonate, 3 ml/kg/h) or conventional hydration (CONV; 24 h saline, 1 ml/kg/h). Outcomes included percentage change in serum creatinine until 2-6 days after CTA with a non-inferiority margin of 10% and an increase on the Borg dyspnoea scale ≥1 point. Seventy-four patients were included. Increase in creatinine was 6 µmol/l (95% CI 2.5-9.3) in the SHORT versus 2 µmol/l (95% CI-1.4 to 6.3) in the CONV arm (p = 0.167). The percentage change was 4.6% (95% CI 2.0-7.3%) in the SHORT arm versus 2.5% (95% CI: 0.8 to 5.8%) in the CONV arm. The difference in percentage increase in creatinine between the two arms was 2.1% (95% CI: 2.0-6.2%; p-value non-inferiority: <0.001). CI-AKI and a need for dialysis were not observed. An increase of ≥1 point on the Borg scale (dyspnoea scale ranging from 1 (lowest) to 10 (highest)) was seen in 1 patient in the SHORT arm versus 5 patients in the CONV arm (2.9% vs 16.1%, p = 0.091). CONCLUSION: For patients with impaired renal function undergoing pre-TAVI CTA, a short 1­h, low-volume hydration protocol with sodium bicarbonate is not inferior to conventional 24-h, high-volume saline hydration.

Trends in patient characteristics and clinical outcome over 8 years of transcatheter aortic valve implantation.

AIM: In the evolving field of transcatheter aortic valve implantations (TAVI) we aimed to gain insight into trends in patient and procedural characteristics as well as clinical outcome over an 8­year period in a real-world TAVI population. METHODS: We performed a single-centre retrospective analysis of 1,011 consecutive patients in a prospectively acquired database. We divided the cohort into tertiles of 337 patients; first interval: January 2009-March 2013, second interval: March 2013-March 2015, third interval: March 2015-October 2016. RESULTS: Over time, a clear shift in patient selection was noticeable towards lower surgical risks including Society of Thoracic Surgeons predicted risk of mortality score and comorbidity. The frequency of transfemoral TAVI increased (from 66.5 to 77.4%, p = 0.0015). Device success improved (from 62.0 to 91.5%, p < 0.0001) as did the frequency of symptomatic relief (≥1 New York Heart Association class difference) (from 73.8 to 87.1%, p = 0.00025). Complication rates decreased, including in-hospital stroke (from 5.0 to 2.1%, p = 0.033) and pacemaker implantations (from 10.1 to 5.9%, p = 0.033). Thirty-day mortality decreased (from 11.0 to 2.4%, p < 0.0001); after adjustment for patient characteristics, a mortality-risk reduction of 72% was observed (adjusted hazard ratio [HR]: 0.28, 95% confidence interval [CI]: 0.13-0.62). One-year mortality rates decreased (from 23.4 to 11.4%), but this was no longer significant after a landmark point was set at 30 days (mortality from 31 days until 1 year) (adjusted HR: 0.69, 95% CI: 0.41-1.16, p = 0.16). CONCLUSION: A clear shift towards a lower-risk TAVI population and improved clinical outcome was observed over an 8­year period. Survival after TAVI improved impressively, mainly as a consequence of decreased 30-day mortality.

Autopsy after transcatheter aortic valve implantation.

Autopsy after transcatheter aortic valve implantation (TAVI) is a new field of interest in cardiovascular pathology. To identify the cause of death, it is important to be familiar with specific findings related to the time interval between the procedure and death. We aimed to provide an overview of the autopsy findings in patients with TAVI in their medical history divided by the timing of death with specific interest in the added value of autopsy over a solely clinically determined cause of death. In 8 European centres, 72 cases with autopsy reports were available. Autopsies were divided according to the time interval of death and reports were analysed. In 32 patients who died ≤72 h postprocedure, mortality resulted from cardiogenic or haemorrhagic shock in 62.5 and 34.4%, respectively. In 31 patients with mortality >72 h to ≤30 days, cardiogenic shock was the cause of death in 51.6% followed by sepsis (22.6%) and respiratory failure (9.7%). Of the nine patients with death >30 days, 88.9% died of sepsis, caused by infective endocarditis in half of them. At total of 12 patients revealed cerebrovascular complications. Autopsy revealed unexpected findings in 61.1% and resulted in a partly or completely different cause of death as was clinically determined. Autopsy on patients who underwent TAVI reveals specific patterns of cardiovascular pathology that clearly relate to the time interval between TAVI and death and significantly adds to the clinical diagnosis. Our data support the role of autopsy including investigation of the cerebrum in the quickly evolving era of cardiac device technology.

Automatic segmentation of the aortic root in CT angiography of candidate patients for transcatheter aortic valve implantation.

Transcatheter aortic valve implantation is a minimal-invasive intervention for implanting prosthetic valves in patients with aortic stenosis. Accurate automated sizing for planning and patient selection is expected to reduce adverse effects such as paravalvular leakage and stroke. Segmentation of the aortic root in CTA is pivotal to enable automated sizing and planning. We present a fully automated segmentation algorithm to extract the aortic root from CTA volumes consisting of a number of steps: first, the volume of interest is automatically detected, and the centerline through the ascending aorta and aortic root centerline are determined. Subsequently, high intensities due to calcifications are masked. Next, the aortic root is represented in cylindrical coordinates. Finally, the aortic root is segmented using 3D normalized cuts. The method was validated against manual delineations by calculating Dice coefficients and average distance error in 20 patients. The method successfully segmented the aortic root in all 20 cases. The mean Dice coefficient was 0.95 ± 0.03, and the mean radial absolute error was 0.74 ± 0.39 mm, where the interobserver Dice coefficient was 0.95 ± 0.03 and the mean error was 0.68 ± 0.34 mm. The proposed algorithm showed accurate results compared to manual segmentations.

Imaging for approach selection of TAVI: assessment of the aorto-iliac tract diameter by computed tomography-angiography versus projection angiography.

The choice of preferred access route for transcatheter aortic valve implantation (TAVI) is mainly guided by the minimal aorto-femoral tract diameter. Currently, projection angiography (XA) and CT-angiography (CTA) are used interchangeably to assess this diameter in the TAVI work-up. We aimed to assess the agreement of XA and CTA diameter measurements in TAVI candidates. Diameters of 700 aorta-iliac segments of 102 TAVI candidates were analyzed on both XA and CTA. The diameters on XA were measured manually, for the CTA-based analysis semi-automated segmentation software was used. Paired sample T test was used to evaluate differences in diameter measurements between the modalities. Disagreement on the suitability for a transfemoral (TF)-TAVI approach was identified. The interobserver agreement for both measurements was assessed by calculating the intraclass correlation coefficient (ICC). The average diameters were 10.1 ± 1.8 mm and 8.4 ± 1.7 for XA and CTA respectively. The mean paired difference was 1.73 mm (p < 0.001). For 18 patients (17.6 %) diameters measured on CTA images, were bilaterally less than 6 mm, whilst XA indicated a minimum diameter exceeding 6 mm. For both modalities, the interobserver agreement was excellent (ICC 0.95). Diameters measured semi-automatically on CTA were statistically significantly smaller compared to XA. This should be acknowledged in the work-up for selecting the most appropriate approach for TAVI. In our population 17.6 % of patients would have been denied a transfemoral TAVI based on CTA measurements, whilst XA suggested diameters sufficient for a TF approach.