Guido Dohmen

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.

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.

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.

Incidence and predictors of left bundle branch block after transcatheter aortic valve implantation

OBJECTIVE The aim of this study was to evaluate the frequency and predictors of left bundle branch block (LBBB) after Transcatheter Aortic Valve Implantation (TAVI) using CoreValve and Edwards SAPIEN prosthesis. METHODS 154 consecutive patients (53 male, mean age 81 ± 7 years) with severe symptomatic aortic stenosis underwent TAVI. Transfemoral AVI (CoreValve) was performed in 72 patients (47%). Transapical AVI (Edwards SAPIEN valve) was done with in n=82 patients (53%). Patient characteristics, valvular and left ventricular outflow tract geometry from pre- and postprocedural imaging (computed tomography, transesophageal echocardiography and callipered angiography) and procedural characteristics were evaluated to define predictors of new LBBB after TAVI. PATIENTS Preprocedural LBBB was present in 15 patients (n=5 CoreValve, n=10 in Edwards SAPIEN). In 40 of 139 patients (29%) a new LBBB was observed after TAVI. The frequency of new LBBB was higher with CoreValve n=27 (38%) than with Edwards SAPIEN implantation n=13 (16%; p=0.006). Patients with new LBBB had larger valve implantation depth into the left ventricular outflow tract (9.0 ± 2.9 vs. 4.4 ± 2.5mm, p<0.001). In 18 of 40 patients (45%) the new LBBB was persistent at 30days. Predictors of new LBBB were prosthesis implantation depth into the left ventricular outflow tract (OR=1.185 95% CI 1.064-1.320 per additional mm implantation depth; p=0.002) and use of CoreValve prosthesis (OR=2.639 95% CI 1.314-5.813; p=0.007). CONCLUSION TAVI is frequently associated with new LBBB. There is a higher frequency of persistent LBBB with the CoreValve system. Implantation depth is a critical factor for the development of new LBBB.

Impact of prior percutaneous coronary intervention on the outcome of coronary artery bypass surgery: A multicenter analysis

OBJECTIVES Do prior percutaneous coronary interventions adversely affect the outcome of subsequent coronary artery bypass grafting? We investigated this effect on a multicenter basis. METHODS Eight cardiac surgical centers provided outcome data of 37,140 consecutive patients who underwent isolated first-time coronary bypass grafting between January 2000 and December 2005. Twenty-two patient characteristics and outcome variables were retrieved. Three groups of patients were analysed for in-hospital mortality and in-hospital major adverse cardiac events: patients without a previous percutaneous coronary intervention, with 1 previous intervention, and with 2 or more previous percutaneous coronary interventions before bypass grafting. A total of 29,928 patients with complete information for prior percutaneous coronary intervention underwent final analysis. Unadjusted univariate and risk-adjusted multivariate logistic regression analysis as well as computed propensity score matching were performed, based on 14 major risk factors to correct for and minimize selection bias. RESULTS A total of 10.3% of patients had 1 previous percutaneous coronary intervention, and 3.7% of patients had 2 or more previous interventions. Risk-adjusted multivariate logistic regression analysis revealed a significant association of 2 or more previous percutaneous coronary interventions with in-hospital mortality (odds ratio [OR], 2.0; confidence interval [CI], 1.4-3.0; P = .0005) and major adverse cardiac events (OR, 1.5; CI, 1.2-1.9; P = .0013). After propensity score matching, conditional logistic regression analysis confirmed the results of adjusted analysis. A history of 2 or more previous percutaneous coronary interventions was significantly associated with in-hospital mortality (OR, 1.9; CI, 1.3-2.7; P = .0016) and major adverse cardiac events (OR, 1.5; CI, 1.2-1.9; P = .0019). CONCLUSIONS Multicenter analysis confirms that a history of multiple previous percutaneous coronary interventions increases in-hospital mortality and the incidence of major adverse cardiac events after subsequent coronary artery bypass grafting. Critical discussion of the treatment strategy in these patients is warranted.

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.

Thirty-day outcome after transcatheter aortic valve implantation compared with surgical valve replacement in patients with high-risk aortic stenosis: a matched comparison.

BackgroundTranscatheter aortic valve implantation (TAVI) has become a therapeutic alternative to surgery for the treatment of severe aortic stenosis in high-surgical risk patients. The aim of this study was to compare 30-day mortality of high-risk patients treated by TAVI versus surgical aortic valve replacement. MethodsA total of 175 patients (60 men; mean age, 80±6 years; Euroscore 21±13%) having undergone TAVI were compared with 175 matched patients (76 men; mean age, 79±3 years; Euroscore 17±9%), which have undergone conventional aortic valve replacement and were deemed to be high-risk patients by the cardiothoracic surgeons. Thirty-day mortality and major adverse events were recorded in both groups. Patients’ characteristics were analyzed for predictors of mortality in the TAVI group. ResultsTwenty-one patients (12%) in the TAVI group and 13 patients (8%) in the surgical group died within 30 days of the procedure (P=0.165). Two patients (1%) in the TAVI group and one patient (0.5%) in the conventional surgery group had a major stroke (P=1.0). Seven patients (4%) in the TAVI group and 25 patients (14%) in the conventional surgery group required dialysis post procedure (P=0.0013). The average length of stay in the intensive care unit was lower in the TAVI group compared with the conventional surgical group (3.3±3.1 vs. 6.6±10.5 days; P<0.001). Age was the only independent predictor of mortality in the TAVI group (odds ratio=1.009; 95% confidence interval: 1.001–1.018 per additional year; P=0.0186) and in the total study population (odds ratio=1.007; 95% confidence interval: 1.001–1.013 per additional year; P=0.0186). ConclusionIn high-surgical risk patients, TAVI can be performed at a mortality risk comparable with conventional surgery with a reduced length of post interventional intensive care unit stay and less need for dialysis.

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. (Echocardiography 2011;28:397‐401)

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.

A new approach to interventional atrioventricular valve therapy

OBJECTIVE Transcatheter replacement or repair of mitral valve regurgitation has proved demanding. We aimed for a new approach to anchor a biologic heart valve in the mitral position by inserting a valve-carrying hollow body into the left atrium. This approach was investigated in both a simulation and an animal model. METHODS After creating a mold representing the porcine left atrium from the pulmonary veins as far as the mitral valve, a nitinol skeleton was sutured onto interlaced yarns of polyvinylidene fluoride fitting the mold. The resulting device was equipped with a commercially available stentless valve (25 mm) and investigated in a simulator regarding basic functionality. Furthermore, the device was implanted in 8 female pigs through incision of the left atrium during extracorporeal circulation. Before implantation, artificial regurgitation was created by means of excision from the posterior mitral leaflet. Hemodynamic, echocardiographic, and radiologic examinations followed. For a postmortem examination, the entire heart and the lungs were excised. RESULTS We could demonstrate the functionality of the heart valve in a complex, collapsible, and self-expanding hollow body. The device adapted to the surrounding structures, leading to an exclusion of the left atrium. Sufficient treatment of mitral regurgitation was monitored hemodynamically and by means of echocardiographic analysis, although overall visualization remained difficult. Therefore in 4 animals computed tomographic scans were performed. Autopsy revealed proper positioning without major trauma to the surrounding structures. CONCLUSION Anchoring an additional heart valve in the atrioventricular position does not necessarily need to be performed in the heart valve structure itself. Placement of an additional valve in the mitral position is feasible through this approach.