ACURATE neo2 Versus SAPIEN 3 Ultra Transcatheter Heart Valve in Severe Aortic Valve Calcification: A Propensity-Matched Analysis

BACKGROUND

Comparative data on transcatheter self-expanding ACURATE neo2 (NEO2) and balloon-expandable SAPIEN 3 Ultra prostheses in technically challenging anatomy of severe aortic valve calcified aortic annuli are scarce.

METHODS

A total of 1987 patients with severe native aortic stenosis treated with the self-expanding NEO2 (n=1457) or balloon-expandable SAPIEN 3 Ultra (n=530) from January 2017 to April 2023 were evaluated. The primary end point was procedural outcome according to the Valve Academic Research Consortium 3 definitions. Propensity matching defined 219 pairs with severe calcification (calcium density cutoff, 758 AU/cm2) of the native aortic valve.

RESULTS

Technical success (90.4% versus 91.8%; risk difference, 1.4% [95% CI, -4.4 to -7.2]; P=0.737) and device success at 30 days (80.8% versus 75.8%; risk difference, -5.0% [95% CI, -13.2 to 3.1]; P=0.246) were comparable between NEO2 and SAPIEN 3 Ultra. The rate of severe prosthesis-patient mismatch (1.1% versus 10.1%; risk difference, 10.0% [95% CI, 4.0-13.9]; P<0.001) and mean transvalvular gradient ≥20 mm Hg (2.8% versus 14.3%; risk difference, 11.5% [95% CI, 5.8-17.1]; P<0.001) was lower with NEO2. The rate of more-than-mild paravalvular leakage or valve-in-valve due to paravalvular leakage was significantly higher (6.2% versus 0.0%; risk difference, 6.2% [95% CI, -10.1 to -2.7]; P=0.002), and there was a tendency for a higher rate of device embolization or migration (1.8% versus 0.0%; risk difference, -1.8% [95% CI, -4.1 to 0.4]; P=0.123) with NEO2. Multivarate regression revealed no independent impact of transcatheter heart valve selection on device success (odds ratio, 0.93 [95% CI, 0.48-1.77]; P=0.817).

CONCLUSIONS

In patients with severely calcified annuli, supraannular implantation of NEO2 showed hemodynamic advantages. Nevertheless, NEO2 was associated with a higher incidence of relevant paravalvular leakage and a numerically higher rate of device embolization than SAPIEN 3 Ultra in this particular patient group.

Comparison of the New-Generation Self-Expanding NAVITOR Transcatheter Heart Valve with Its Predecessor, the PORTICO, in Severe Native Aortic Valve Stenosis

BACKGROUND

Third-generation transcatheter heart valves (THVs) are designed to improve outcomes. Data on the new intra-annular self-expanding NAVITOR are scarce.

AIMS

The aim of this analysis was to compare outcomes between the PORTICO and the NAVITOR systems.

METHODS

Data from 782 patients with severe native aortic stenosis treated with PORTICO (n = 645) or NAVITOR (n = 137) from 05/2012 to 09/2022 were evaluated. The clinical and hemodynamic outcomes of 276 patients (PORTICO, n = 139; NAVITOR, n = 137) were evaluated according to VARC-3 recommendations.

RESULTS

Rates of postprocedural more-than-mild paravalvular leakage (PVL) were significantly lower for NAVITOR than for PORTICO (7.2% vs. 1.5%, p = 0.041). In addition, severe bleeding rates (27.3% vs. 13.1%, p = 0.005) and major vascular complications (5.8% vs. 0.7%, p = 0.036) were lower in the NAVITOR group. The mean gradients (7 vs. 8 mmHg, p = 0.121) and calculated aortic valve areas (1.90 cm² vs. 1.99 cm², p = 0.235) were comparable. Rates of PPI were similarly high in both groups (15.3 vs. 21.6, p = 0.299).

CONCLUSIONS

The NAVITOR demonstrated favorable in-hospital procedural outcome data, with lower rates of relevant PVL, major vascular complications, and severe bleeding than its predecessor the PORTICO and preserved favorable hemodynamic outcomes.

Procedural Outcomes of a Self-Expanding Transcatheter Heart Valve in Patients with Porcelain Aorta

BACKGROUND

Severe calcification of the ascending aorta increases the peri-operative risk for neurological complications in patients with severe aortic stenosis. Transcatheter aortic valve implantation (TAVI) seems to be an optimal treatment option in these patients. However, the impact of the extent of aortic calcification on procedural and neurological outcomes during TAVI is unclear.

METHODS

Data from 3010 patients with severe native aortic valve stenosis treated with ACURATE neo/neo2 from May 2012 to July 2022 were evaluated and matched by 2-to-1 nearest-neighbor matching to identify one patient with porcelain aorta (PA) (n = 492) compared with two patients without PA (n = 984). PA was additionally subdivided into circumferential (classic PA) (n = 89; 3.0%) and non-circumferential (partial PA) (n = 403; 13.4%) calcification. We compared outcomes according to VARC-3 criteria among patients with and without PA and identified predictors for occurrence of stroke in the overall population.

RESULTS

Technical success (88.5% vs. 87.4%, p = 0.589) and device success at 30 days (82.3% vs. 81.5%, p = 0.755) after transcatheter ACURATE neo/neo2 implantation according to VARC-3 definition was high and did not differ between non-calcified aortas or PA. The rate of in-hospital complications according to VARC-3-definitions was low in both groups. Rates of all stroke (3.2% (n = 31) vs. 2.6% (n = 13), p = 0.705) or transitory ischemic attacks (1.1% vs. 1.2%, p = 1.000) did not differ significantly. Thirty-day all-cause mortality did not differ (3.0% vs. 3.2%, RR 1.1; p = 0.775). Overall device migration/embolization (OR 5.0 [2.10;11.87]), severe bleeding (OR 1.79 [1.11;2.89]), and major structural cardiac complications (OR 3.37 [1.32;8.57]) were identified as independent predictors for in-hospital stroke in a multivariate analysis after implantation of ACURATE neo/neo2.

CONCLUSION

A porcelain aorta does not increase the risk of neurological complications after transfemoral ACURATE neo/neo2 implantation. Based on these findings, transfemoral ACURATE neo/neo2 implantation is safe in these particularly vulnerable patients.

Procedural Outcomes of a Self-Expanding Transcatheter Heart Valve in Small Annuli

BACKGROUND

Self-expanding transcatheter valves (THV) seem superior to balloon-expanding valves in regard to the incidence of prosthesis-patient mismatch (PPM). Data on the occurrence of PPM with the ACURATE neo/neo2 system as a representative of self-expanding prostheses in very small annuli, even below the applicable instructions for use (IFU), are scarce.

METHODS

Data from 654 patients with severe native aortic stenosis treated with the smallest size ACURATE neo/neo2 valve (size S, 23 mm) at two German high-volume centers from 06/2012 to 12/2021 were evaluated. We compared clinical and hemodynamic outcomes among patients with implantation in adherence to the recommended sizing (on-label n = 529) and below the recommended sizing range (off-label n = 125) and identified predictors for PPM in the overall population. BMI-adjusted PPM was defined according to VARC-3 recommendations.

RESULTS

Post-procedure, the mean gradient (10.0 mmHg vs. 9.0 mmHg, p = 0.834) and the rate of paravalvular leakage (PVL) ≥ moderate (3.2% vs. 2.8%, p = 0.770) were similar between on-label and off-label implantations. The rate of moderate to severe PPM (24%) was comparably low in ACURATE neo/neo2 S, with a very low proportion of severe PPM whether implanted off- or on-label (4.9% vs. 3.8%, p = 0.552). Thirty-day all-cause mortality was higher among patients with off-label implantations (6.5% vs. 2.3%, p = 0.036). In the subgroup of these patients, no device-related deaths occurred, and cardiac causes did not differ (each 5). Besides small annulus area and high BMI, a multivariate analysis identified a greater cover index (OR 3.26), deep implantation (OR 2.25) and severe calcification (OR 2.07) as independent predictors of PPM.

CONCLUSIONS

The ACURATE neo/neo2 S subgroup shows a convincing hemodynamic outcome according to low mean gradient even outside the previous IFUs without a relevant increase in the rate of PVL or PPM. In addition to known factors such as annulus area and BMI, potential predictors for PPM are severe annulus calcification and implantation depth. Nevertheless, the ACURATE neo/neo2 system seems to be a reliable option in patients with very small annuli.

Multi-Center Comparison of Two Self-Expanding Transcatheter Heart Valves: A Propensity Matched Analysis

Background: During the last years, several transcatheter aortic heart valves entered the clinical market and are commercially available. The prostheses differ regarding several technical and functional aspects. However, little is known regarding head-to-head comparative data of the ACURATE neo and the PORTICO valve prostheses. Objectives: The aim of this study was to compare two self-expanding transcatheter aortic heart valves (THV), the ACURATE neo and the PORTICO, with regard to in-hospital and 30-day outcomes, as well as early device failures. Methods: A total of 1591 consecutive patients with severe native aortic valve stenosis from two centers were included in the analyses and matched by 1:1 nearest neighbor matching to identify one patient treated with PORTICO (n = 344) for each patient treated with ACURATE neo (n = 344). Results: In-hospital complications were comparable between both valves, including any kind of stroke (ACURATE neo = 3.5% vs. PORTICO = 3.8%; p = 1.0), major vascular complications (ACURATE neo = 4.5% vs. PORTICO = 5.4%; p = 0.99) or life-threatening bleeding (ACURATE neo = 1% vs. PORTICO = 2%; p = 0.68). The rate of device failure defined by the VARC-2 criteria were comparable, including elevated gradients and moderate-to-severe paravalvular leakage (ACURATE neo = 7.3% vs. PORTICO = 7.6%; p = 1.0). However, the need for permanent pacemaker implantation (PPI) was significantly more frequent after the use of PORTICO THV (9.5% vs. 18.7%; p = 0.002). Conclusions: In this two-center case-matched comparison, short-term clinical and hemodynamic outcomes showed comparable results between PORTICO and ACURATE neo prostheses. However, PORTICO was associated with a significant higher incidence of PPI.

Sclerostin as a potential novel biomarker for aortic valve calcification: an in-vivo and ex-vivo study

BACKGROUND AND AIM OF THE STUDY

Sclerostin is a key negative regulator of bone formation. It was hypothesized that sclerostin might also play a potential role in the development of aortic valve calcification (AVC). The study aim was to evaluate serum sclerostin levels in patients with different degrees of AVC compared to a healthy control group, and to investigate local sclerostin expression in explanted calcified and non-calcified aortic valves.

METHODS

A prospective cross-sectional study was performed in 115 patients (mean age 74 +/- 7 years) with echocardiographically proven AVC. Sclerostin serum levels were measured using ELISA and compared to values obtained from a healthy control population. For quantification of AVC, all patients of the study cohort underwent non-contrast-enhanced dual-source computed tomography (DSCT). Immunohistochemistry (IHC) staining for sclerostin and mRNA sclerostin expression was analyzed in 10 calcified aortic valves and 10 non-calcified age-matched control valves.

RESULTS

Patients with AVC showed significantly higher sclerostin serum levels as compared to healthy controls (0.94 +/- 0.45 versus 0.58 +/- 0.26 ng/ml, p < 0.001). A significant correlation between sclerostin serum levels and Agatston AVC scores as assessed by DSCT was observed (r = 0.62, p < 0.001) in the study cohort. IHC revealed positive sclerostin staining in nine calcified valves, in contrast to negative staining for sclerostin in all non-calcified valves. Quantitative real-time PCR confirmed the increased sclerostin expression on mRNA level, with a significant up-regulation of sclerostin mRNA (fold change 150 +/- 52, p < 0.001) expression being shown in calcified aortic valves compared to non-calcified control valves. Co-staining experiments revealed that sclerostin-expressing cells co-express the major osteogenic transcription factor Runx2 and the extracellular matrix protein osteocalcin.

CONCLUSION

Patients with AVC showed increased sclerostin serum levels compared to a healthy reference population, and it was revealed that the severity of AVC may be linked to increased sclerostin serum levels. Moreover, the PCR and staining data demonstrated an increased sclerostin expression in parallel to prototypic markers of osteogenic transdifferentiation, indicating a role of sclerostin in the valvular calcification process.

Two-year mortality after transcatheter aortic valve implantation versus medical therapy for high-surgical risk or inoperable aortic stenosis patients

BACKGROUND AND AIM OF THE STUDY

Transcatheter aortic valve implantation (TAVI) has become a therapeutic option for the treatment of high-risk or inoperable patients with symptomatic severe aortic stenosis. The study aim was to compare the two-year mortality of high-risk or inoperable patients treated by TAVI compared to medical therapy, in a single-center setting.

METHODS

A total of 135 consecutive patients (58 males, 77 females; mean age 80 +/- 6 years; logistic EuroSCORE 21 +/- 13%) who had undergone TAVI was compared to 135 patients (60 males, 75 females; mean age 79 +/- 3 years; logistic EuroSCORE 21 +/- 19%) who had undergone medical treatment before TAVI became available. The one- and two-year follow up mortalities were recorded for each group. In the TAVI group, the patient characteristics were analyzed for predictors of mortality.

RESULTS

Sixteen patients (12%) in the TAVI group and 10 (7%) in the medically treated group died within 30 days of intervention or presentation (p = 0.303). At the one-year follow up, 28 TAVI patients (21%) and 69 medically treated patients (41%) died (p < 0.001). At the two-year follow up, 41 TAVI patients (30%) and 80 medically treated patients (59%) died (p < 0.001). Log-rank analysis demonstrated a significant survival benefit after TAVI compared to medical treatment during the total follow up period. Univariate predictors of death at the two-year follow up included medical therapy, logistic EuroSCORE, and pulmonary hypertension. Medical therapy remained the only independent predictor of two-year mortality in a multivariate analysis (OR 3.343; 95% CI 2.021-6.234, p < 0.001).

CONCLUSION

In high-surgical risk or inoperable symptomatic aortic stenosis patients, the one- and two-year follow up mortalities of patients treated with TAVI was significantly lower than after medical therapy. Predictors of mortality, in addition to treatment strategy, were pulmonary hypertension and EuroSCORE.

Can cardiac surgery cause hypopituitarism?

Apoplexy of pituitary adenomas with subsequent hypopituitarism is a rare but well recognized complication following cardiac surgery. The nature of cardiac on-pump surgery provides a risk of damage to the pituitary because the vascular supply of the pituitary is not included in the cerebral autoregulation. Thus, pituitary tissue may exhibit an increased susceptibility to hypoperfusion, ischemia or intraoperative embolism. After on-pump procedures, patients often present with physical and psychosocial impairments which resemble symptoms of hypopituitarism. Therefore, we analyzed whether on-pump cardiac surgery may cause pituitary dysfunction also in the absence of pre-existing pituitary disease. Twenty-five patients were examined 3-12 months after on-pump cardiac surgery. Basal hormone levels for all four anterior pituitary hormone axes were measured and a short synacthen test and a growth hormone releasing hormone plus arginine (GHRH-ARG)-test were performed. Quality of life (QoL), depression, subjective distress for a specific life event, sleep quality and fatigue were assessed by means of self-rating questionnaires. Hormonal alterations were only slight and no signs of anterior hypopituitarism were found except for an insufficient growth hormone rise in two overweight patients in the GHRH-ARG-test. Psychosocial impairment was pronounced, including symptoms of moderate to severe depression in 9, reduced mental QoL in 8, dysfunctional coping in 6 and pronounced sleep disturbances in 16 patients. Hormone levels did not correlate with psychosocial impairment. On-pump cardiac surgery did not cause relevant hypopituitarism in our sample of patients and does not serve to explain the psychosocial symptoms of these patients.

Inflammatory response in transapical transaortic valve replacement

OBJECTIVE

Transapical aortic valve implantation (TA-AVI) has become a fast growing alternative to conventional aortic valve replacement (cAVR) particularly for patients burdened with serious comorbidities. We investigated whether the inflammatory response triggered by TA-AVI reflects the less invasive nature of this procedure.

METHOD

In this prospective observational study 25 patients undergoing aortic valve replacement (AVR; 15 cAVR and 10 TA-AVI) were included. Serial plasma cytokine concentrations (IL-6, IL-8, and IL-10) were measured by commercially available enzyme-linked immunosorbent assay kits at six different time points before, during, and after surgery.

RESULTS

Plasma levels of all three cytokines increased during and after both procedures and returned to baseline before the patient's discharge. Peak values of IL-6 were 258 ± 113 pg/mL in AVR patients versus 111 ± 101 pg/mL in TA-AVI patients and were reached 12 hours after surgery. For IL-8, peak values were 51 ± 29 pg/mL 1 hour after surgery in AVR patients versus 15 ± 20 pg/mL on wound closure in TA-AVI patients. Plasma levels of IL-6 and IL-8 were significantly reduced in the TA-AVI group as compared with cAVR. IL-10 is markedly activated in both groups yet its induction is more prominent in AVR patients with peak values of 51 ± 28 pg/mL for AVR versus 24 ± 18 pg/mL for TA-AVI on wound closure.

CONCLUSION

TA-AVI compared with cAVR results in a significant reduction but not elimination of a systemic inflammatory response, which is attributable to cardiopulmonary bypass-dependent and bypass-independent factors.

PAS-Port® clampless proximal anastomotic device for coronary bypass surgery in porcelain aorta

OBJECTIVES

The severely calcified so-called porcelain aorta is one of the most dangerous and challenging findings in patients requiring coronary bypass surgery. Several techniques and technologies have been invented to handle this potentially lethal disease. We report on our initial experience with the PAS-Port® automated proximal clampless anastomotic device (Cardica, Inc., Redwood City, CA, USA), especially focussing on these patients.

METHODS

PAS-Port® anastomoses (for saphenous vein grafts) were performed in 17 patients undergoing coronary artery bypass graft (CABG) surgery. Of these, eight presented with the entity of porcelain aorta. In two patients, the diagnosis was previously known, in six cases heavily calcified aortas prohibiting any clamp manoeuvre were incidentally found intra-operatively. The site of anastomosis was determined by palpation and in individual cases with epi-aortic echocardiography. Other indications for PAS-Port® were localised dissection, acute myocardial infarction and partial sternotomy. Multislice computed tomography (CT) was performed in every patient to evaluate graft and anastomoses patency and appearance.

RESULTS

All 25 PAS-Port® anastomoses were triggered successfully. Two patients developed neurological deficits (prolonged reversible ischaemic neurological deficits, (PRIND)), with use of cardiopulmonary bypass (CPB) being the major predisposing factor (p=0.02). Graft patency could be affirmed in all grafts by multislice CT in all patients.

CONCLUSIONS

PAS-Port® anastomoses can be performed quickly, easily and, above all, safely in conditions prohibiting aortic clamping. Short-term results are excellent. Clear visualisation of anastomoses using multislice CT is an important advantage of the PAS-Port® device.

Aortic valve calcifications on chest films: how much calcium do I need?

OBJECTIVE

Aortic valve calcifications (AVC) as seen on conventional chest films or on CT are associated with aortic valve stenosis (AVS). The absence of AVC on chest films does not exclude high grade AVS. The aim of this study was to analyse if there is a threshold for the detection of AVC from conventional chest films in patients suffering from high grade AVS.

METHODS AND RESULTS

The explanted aortic valves of 29 patients (16 male, mean age 72.3 +/- 11.5 years) with high grade AVS were examined by dual-source CT. AVC were quantified using the Agatston AVC score. In all patients conventional chest films obtained the day before surgery were evaluated for the presence of AVC. Results were analysed with students t-test, Spearman's rank correlation and ROC analysis. On conventional chest films AVC were visible in 18 patients. On CT all specimen presented with AVC with an Agatston AVC score ranging from 40.7 to 1870 (mean 991.3 +/- 463.1). In patients with AVC visible on chest films the AVC score was significantly higher (1264.0 +/- 318.2) when compared with patients without visible calcifications (544.9 +/- 274.4; P < 0.0001). There was a strong correlation between the AVC score and the visibility of AVC on chest films (r = 0.781). ROC analysis identified an ideal threshold of 718 for AVC score to separate conventional chest films with and without visible AVC.

CONCLUSION

Unlike in coronary calcifications, there is a threshold for identifying AVC from conventional chest films. This finding may be of diagnostic value, as conventional chest films may be used to semiquantitatively evaluate the extent of AVC.

Comparison of two-dimensional and three-dimensional imaging techniques for measurement of aortic annulus diameters before transcatheter aortic valve implantation

AIMS

Different two-dimensional (2D) and three-dimensional (3D) imaging techniques are used for procedure planning and selection of prosthesis size before transcatheter aortic valve implantation. This study sought to compare different 2D and 3D imaging techniques and determine the accuracy of 3D transoesophageal echocardiography (TEE) for accurate analysis of aortic annulus dimensions.

METHODS

In 49 consecutive patients with severe aortic stenosis undergoing transcatheter aortic valve implantation angiography, 2D transthoracic echocardiography (TTE), 2D and 3D TEE, and dual-source CT (DSCT) were performed to determine aortic annulus diameters. TTE and 2D TEE provided only one diameter of the aortic annulus. Angiography, DSCT and 3D TEE allowed measurement of diameters in sagittal and coronal views. The distance between aortic annulus and left main coronary artery ostium was measured by angiography, DSCT and 3D TEE.

RESULTS

Sagittal diameters determined by angiography, TTE, 2D TEE, 3D TEE and DSCT were smaller than coronal diameters determined by angiography, 3D TEE and DSCT. Coronal and sagittal diameters determined by 3D TEE were in high agreement with corresponding measurements by DSCT (23.60±1.89 vs 23.46±2.07 mm and 22.19±1.96 vs 22.27±2.01 mm, respectively; mean±SD). There was a high correlation between DSCT and 3D TEE for the definition of coronal and sagittal aortic annulus diameters (r=0.88, SEE=0.89 mm and r=0.77, SEE=1.26 mm, respectively). Correlation of 3D TEE (13.47±1.67 mm) and DSCT (13.64±1.82 mm) in the analysis of the distance between aortic annulus and left main coronary artery ostium was better (r=0.54, SEE=1.55 mm) than between angiography (14.85±3.84 mm) and DSCT (r=0.35, SEE=1.77 mm).

CONCLUSIONS

3D imaging techniques should be used to evaluate aortic annulus diameters, as 2D imaging techniques, providing only a sagittal view, underestimate them. 3D TEE provides measurements of aortic annulus diameters similar to those obtained by DSCT.

Influence of aortic dimensions on the hemodynamic performance of small aortic valve prostheses: impact on patient/prosthesis mismatch

BACKGROUND

Since Doppler echocardiography takes no account of pressure recovery, the true hemodynamic burden of aortic valve prostheses remains vague. The purpose of this study was to elucidate the methodological error of Doppler gradient estimation by means of a model demonstrating the different influence of aortic root diameters on net and Doppler gradients, respectively. This matters especially in small valves and the related patient/prosthesis mismatch calculation.

METHODS

Two bileaflet small aortic valve prostheses (19 mm SJM Regent® and On-X® valve) were tested using a pulsatile circulatory mock loop simulator with two different aortic models: one with statistically normal diameters according to annular size, another one simulating an aortic aneurysm of 50 mm. Doppler and simultaneously recorded net gradients as well as systolic energy losses were obtained for different hemodynamic conditions.

RESULTS

In all measurements a significant amount of pressure recovery was observed. In cases of aortic aneurysm systolic energy loss increased significantly for each cardiac output at each heart rate ( P < 0.0028), reflected by a significant ( P < 0.0001) increase in net gradients. The corresponding Doppler gradients were unchanged. This indicates significantly less pressure recovery ( P < 0.0001) in the aneurysmatic aorta.

CONCLUSIONS

Geometry of the ascending aorta considerably alters aortic valve hemodynamic parameters. The hemodynamic function of small aortic valve prostheses, especially with corresponding normal outflow dimensions, is much better than expected from Doppler gradients. Thus, calculation of a patient/prosthesis mismatch can be misleading.

Impact of transcutaneous aortic valve implantation on myocardial deformation

AIMS

To define the impact of transcutaneous aortic valve implantation (TAVI) using the CoreValve prosthesis on myocardial deformation in a serial echocardiographic study with analysis of strain and strain rate.

METHODS

In 36 patients (83 ± 6 years; EuroScore: 26 ± 13%) with severe aortic stenosis scheduled for CoreValve implantation serial echocardiographic studies pre- and postintervention (within 1 month) were performed. Midparasternal short-axis and three apical views were acquired. Using customized computer software which allows automatic frame-by-frame tracking of acoustic markers during the heart cycle circumferential, radial, and longitudinal strain (CS, RS, and LS) and strain rate (CSR, RSR, and LSR) were calculated for each segment in a 16 segment model of the left ventricle.

RESULTS

Longitudinal strain, systolic, and early diastolic longitudinal strain rate increased significantly within 1 month after TAVI (LS from -15.8 ± 3.6% to -17.6 ± 3.1%; P < 0.001; LSR(S) from -1.03 ± 0.21 s(-1) to -1.21 ± 0.19 s(-1); P < 0.001 and LSR (E) from -1.15 ± 0.42 s(-1) to 1.51 ± 0.44 s(-1); P < 0.001). Circumferential strain and strain rate values remained unchanged after CoreValve implantation. RS (29.1 ± 17.1 to 34.0 ± 15.8%; ns), RSR (S) (1.56 ± 0.69 to 1.91 ± 0.87 s(-1); ns) and RSR(E) (-1.56 ± 0.78 to -1.81 ± 0.82 s(-1); ns) increased only nonsignificantly after TAVI. Analysis of covariance showed only chronic kidney disease to have a relevant impact on early diastolic LSR (P = 0.01).

CONCLUSIONS

Mainly longitudinal mechanics respond to unloading of the left ventricle after TAVI for severe aortic stenosis while radial and circumferential deformation is substantially unchanged. Pacemaker implantation or onset of left bundle brunch block after TAVI do not influence early myocardial deformation parameters.

Evaluation of aortic root for definition of prosthesis size by magnetic resonance imaging and cardiac computed tomography: implications for transcatheter aortic valve implantation

BACKGROUND

This study sought to compare cardiac magnetic resonance imaging (CMR) with dual source computed tomography (DSCT) for analysis of aortic root dimensions prior to transcatheter aortic valve implantation (TAVI). In addition, the potential impact of CMR and DSCT measurements on TAVI strategy defined by 2D-transesophageal echocardiography (TEE) was evaluated.

METHODS

Aortic root dimensions were measured using CMR and DSCT in 58 patients referred for evaluation of TAVI. The TAVI strategy (choice of prosthesis size and decision to implant) was based on 2D-TEE annulus measurements.

RESULTS

CMR and DSCT aortic root measurements showed an overall good correlation (r=0.86, p<0.001 for coronal aortic annulus diameters). There was also a good correlation between TEE and CMR as well as between TEE and DSCT for measurement of sagittal aortic annulus diameters (r=0.69, p<0.001). However, annulus diameters assessed by TEE (22.1±2.3mm) were significantly smaller than coronal aortic annulus diameters assessed by CMR (23.4±1.8mm, p<0.001) or DSCT (23.6±1.8, p<0.001). Regarding TAVI strategy, the agreement between TEE and sagittal CMR (kappa=0.89) as well as sagittal DSCT measurements (kappa=0.87) was statistically perfect. However, decision based on coronal CMR- or MSCT measurements would have modified TAVI strategy as compared to a TEE based choice in a significant number of patients (22% to 24%).

CONCLUSION

In patients referred for TAVI, CMR measurements of aortic root dimensions show a good correlation with DSCT measurements and thus CMR may be an alternative 3D-imaging modality. Aortic annulus measurements using TEE, CMR and DSCT were close but not identical and the method used has important potential implications on TAVI strategy.

Comparison of direct planimetry of mitral valve regurgitation orifice area by three-dimensional transesophageal echocardiography to effective regurgitant orifice area obtained by proximal flow convergence method and vena contracta area determined by color Doppler echocardiography

Direct measurement of anatomic regurgitant orifice area (AROA) by 3-dimensional transesophageal echocardiography was evaluated for analysis of mitral regurgitation (MR) severity. In 72 patients (age 70.6 ± 13.3 years, 37 men) with mild to severe MR, 3-dimensional transesophageal echocardiography and transthoracic color Doppler echocardiography were performed to determine AROA by direct planimetry, effective regurgitant orifice area (EROA) by proximal convergence method, and vena contracta area (VCA) by 2-dimensional color Doppler echocardiography. AROA was measured with commercially available software (QLAB, Philips Medical Systems, Andover, Massachusetts) after adjusting the first and second planes to reveal the smallest orifice in the third plane where planimetry could take place. AROA was classified as circular or noncircular by calculating the ratio of the medial-lateral distance above the anterior-posterior distance (≤1.5 compared to >1.5). AROA determined by direct planimetry was 0.30 ± 0.20 cm², EROA determined by proximal convergence method was 0.30 ± 0.20 cm², and VCA was 0.33 ± 0.23 cm². Correlation between AROA and EROA (r = 0.96, SEE 0.058 cm²) and between AROA and VCA (r = 0.89, SEE 0.105 cm²) was high considering all patients. In patients with a circular regurgitation orifice area (n = 14) the correlation between AROA and EROA was better (r = 0.99, SEE 0.036 cm²) compared to patients with noncircular regurgitation orifice area (n = 58, r = 0.94, SEE 0.061 cm²). Correlation between AROA and EROA was higher in an EROA ≥0.2 cm² (r = 0.95) than in an EROA <0.2 cm² (r = 0.60). In conclusion, direct measurement of MR AROA correlates well with EROA by proximal convergence method and VCA. Agreement between methods is better for patients with a circular regurgitation orifice area than in patients with a noncircular regurgitation orifice area.

Evaluation of a synergistic handheld instrument for resternotomy controlled by an integrated optical sensor

Re-Sternotomy is an important part of many interventions in cardiac or thoracic surgery. It is performed close to critical structures such as the ascending aorta or the heart with an inherent high risk of serious damage. In this paper, a system for improving the safety of this surgical procedure is presented. A soft tissue preserving saw is combined with automatic depth regulation. The depth is controlled on the basis of the optical characteristics (visible light) of the tissue aligned to the saw blade, which is analyzed using a color sensor. Detection of the blades' position in the bone during the cutting process is possible through the integration of an optical fiber into the tip of the saw blade. The automatic depth control is realized using a hysteresis controller running on a real time system. To show the feasibility of this approach, the sensor technology was integrated into a prototypal sternal saw and evaluated on artificial bone. As part of the experiments the influence of water for cooling and dust particles from the process on the systems control stability were analyzed. The system performed stable and accurate. Future research will focus on the control algorithm and cadaver trials.

Electrocardiographic and imaging predictors for permanent pacemaker requirement after transcatheter aortic valve implantation

BACKGROUND AND AIM OF THE STUDY

Pacemaker (PM) implantation is a possible requirement after transcatheter aortic valve implantation (TAVI). The study aim was to evaluate the electrocardiographic and imaging predictors of the need for PM implantation after TAVI.

METHODS

A total of 80 consecutive patients (mean age 82 +/- 6 years) who had been referred for TAVI were included in the study. Transfemoral TAVI was performed in 58 patients (CoreValve ReValving; 72%), while 22 patients (28%) underwent transapical TAVI using the Edwards SAPIEN valve. Patient characteristics, and the frequency of atrioventricular (AV) block, right bundle branch block (RBBB) and left bundle branch block (LBBB), were evaluated for the prediction of PM implantation after TAVI. In addition, the severity and distribution of aortic valve calcification (AVC) were assessed by calculating the Agatston AVC score for the total aortic valve, as well as for each cusp, using dual-source computed tomography.

RESULTS

Pre-procedural RBBB was present in six patients (8%), while eight patients (10%) showed pre-procedural LBBB. In 20 of the 80 patients (25%), a new LBBB was observed after TAVI. In 17 TAVI patients (21%; only CoreValve patients) there was an indication for permanent PM implantation that was related to complete AV block (n = 13) or complete RBBB or LBBB with AV delay (n = 4). Four of six patients (67%) with pre-procedural RBBB received a PM after TAVI. Multivariate logistic regression analysis revealed that only prosthesis type (r = 0.30, p = 0.01) and pre-procedural RBBB (r = 0.4, p = 0.02) were significantly associated with the need for permanent PM implantation after TAVI.

CONCLUSION

TAVI is frequently associated with new conduction disturbances. A higher incidence of new LBBB and of permanent PM requirement occurred with the CoreValve ReValving system. There was no relationship between the severity or distribution of AVC and the need for PM implantation after TAVI. Patients with pre-procedural RBBB are deemed to be at risk for PM implantation after TAVI.

Stent-based, off-pump creation of an apico-aortic conduit

An apico-aortic conduit (AAC) is an alternative therapy in patients with aortic valve stenosis and severe concomitant disease. We investigated whether it is feasible to create an apico-aortic conduit off-pump with a newly developed, stent-based coring- and cannulation-device in the animal model. A new self-expandable, stent equipped and hooked prosthesis and a sheath enabling both airtight removal of tissue and introduction of the prosthesis were designed and experimentally investigated in six pigs. Hemodynamic- and echocardiographic investigations were performed without and with aortic stenosis. In three animals MRI was performed. There was no significant blood loss, no relevant contamination with air and no hemodynamic depression during the whole procedure. It was possible to yield the entire cardiac output through the conduit after creating a high grade aortic stenosis. Autopsy revealed an excellent anchorage of the prosthesis. Neither relevant intracavitary injury nor thrombotic formation was seen. This study proves the feasibility of a stent-based, off-pump creation of an AAC. The principle of this approach might be used for other purposes.

Correction of CoreValve position using snare traction from a right brachial artery access

Significant paravalvular aortic regurgitation is among the most important limitations of the interventional revalving techniques for the treatment of severe aortic stenosis. We report on the treatment of a patient with severe paravalvular regurgitation following CoreValve implantation by prolonged snare traction from the right brachial artery. Snare traction resulted in upward motion of the valve with subsequent reduction of aortic regurgitation from grades III/IV to grade I.

Association of aortic valve calcification severity with the degree of aortic regurgitation after transcatheter aortic valve implantation

BACKGROUND

This study sought to examine a possible relationship between the severity of aortic valve calcification (AVC), the distribution of AVC and the degree of aortic valve regurgitation (AR) after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS).

METHODS

57 patients (22 men, 81 ± 5 years) with symptomatic AS and with a logistic EuroSCORE of 24 ± 12 were included. 38 patients (67%) received a third (18F)-generation CoreValve® aortic valve prosthesis, in 19 patients (33%) an Edwards SAPIEN™ prosthesis was implanted. Prior to TAVI dual-source computed tomography for assessment of AVC was performed. To determine the distribution of AVC the percentage of the calcium load of the most severely calcified cusp was calculated. After TAVI the degree of AR was determined by angiography and echocardiography. The severity of AR after TAVI was related to the severity and distribution of AVC.

RESULTS

There was no association between the distribution of AVC and the degree of paravalvular AR after TAVI as assessed by angiography (r = -0.02, p = 0.88). Agatston AVC scores were significantly higher in patients with AR grade ≥ 3 (5055 ± 1753, n = 3) than in patients with AR grade < 3 (1723 ± 967, p = 0.03, n = 54). Agatston AVC scores > 3000 were associated with a relevant paravalvular AR and showed a trend for increased need for second manoeuvres. There was a significant correlation between the severity of AVC and the degree of AR after AVR (r = 0.50, p < 0.001).

CONCLUSION

Patients with severe AVC have an increased risk for a relevant AR after TAVI as well as a trend for increased need for additional procedures.

Chronic augmentation of the parasympathetic tone to the atrioventricular node: a nonthoracotomy neurostimulation technique for ventricular rate control during atrial fibrillation

INTRODUCTION

The right inferior ganglionated plexus (RIGP) selectively innervates the atrioventricular node. Temporary electrical stimulation of this plexus reduces the ventricular rate during atrial fibrillation (AF). We sought to assess the feasibility of chronic parasympathetic stimulation for ventricular rate control during AF with a nonthoracotomy intracardiac neurostimulation approach.

METHODS AND RESULTS

In 9 mongrel dogs, the small endocardial area inside the right atrium, which overlies the RIGP, was identified by 20 Hz stimulation over a guiding catheter with integrated electrodes. Once identified, an active-fixation lead was implanted. The lead was connected to a subcutaneous neurostimulator. An additional dual-chamber pacemaker was implanted for AF induction by rapid atrial pacing and ventricular rate monitoring. Continuous neurostimulation was delivered for 1-2 years to decrease the ventricular rate during AF to a range of 100-140 bpm. Implantation of a neurostimulation lead was achieved within 37 +/- 12 min. The latency of the negative dromotropic response after on/offset or modulation of neurostimulation was <1 s. Continuous neurostimulation was effective and well tolerated during a 1-2 year follow-up with a stimulation voltage <5 V. The neurostimulation effect displayed a chronaxie-rheobase behavior (chronaxie time of 0.07 +/- 0.02 ms for a 50% decrease of the ventricular rate during AF).

CONCLUSION

Chronic parasympathetic stimulation can be achieved via a cardiac neurostimulator. The approach is safe, effective, and well tolerated in the long term. The atrioventricular nodal selectivity and the opportunity to adjust the negative dromotropic effect within seconds may represent an advantage over pharmacological rate control.

Treatment of right heart failure with a new microaxial blood pump

Isolated postcardiotomy right ventricular failure is rare but associated with a high mortality. Therefore, new developments reducing this mortality are necessary. We report our first successful clinical use of a new paracardiac right ventricular microaxial blood pump which was developed for postcardiotomy right heart failure.