Aortic annulus area assessment by multidetector computed tomography for predicting paravalvular regurgitation in patients undergoing balloon-expandable transcatheter aortic valve implantation: a comparison with transthoracic and transesophageal echocardiography

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is a valid alternative to surgery in high-risk patients with severe aortic stenosis. Aortic annulus (AoA) sizing is crucial for TAVI success. The aim of the study was to compare AoA dimensions measured by multidetector computed tomography (MDCT) vs those obtained with transthoracic (TTE) and transesophageal echocardiography (TEE) for predicting paravalvular aortic regurgitation (PVR) after TAVI.

METHODS

Aortic annulus maximum diameter, minimum diameter, and area were assessed using MDCT and compared with TTE and TEE diameter and area for predicting PVR after TAVI in 151 patients (45 men, age 81.2 ± 6.4 years).

RESULTS

Aortic annulus maximum, minimum diameter, and area detected by MDCT were 25.04 ± 2.39 mm, 21.27 ± 2.10 mm, and 420.87 ± 76.10 mm(2), respectively. Aortic annulus diameter and area measured by TTE and TEE were 21.14 ± 1.94 mm and 353.82 ± 64.57 mm(2) and 22.04 ± 1.94 mm and 384.33 ± 67.30 mm(2), respectively. A good correlation was found between AoA diameters and area evaluated by MDCT vs TTE and TEE (0.61, 0.65, and 0.69 and 0.61, 0.65, and 0.70, respectively), with a mean difference of 3.90 ± 1.98 mm, 0.13 ± 1.67 mm, and 67.05 ± 55.87 mm(2) and 3.0 ± 2.0 mm, 0.77 ± 1.70 mm, and 36.54 ± 56.43 mm(2), respectively. Grade ≥2 PVR occurred in 46 patients and was related to male gender, higher body mass index, preprocedural aortic regurgitation, and lower mismatch between the nominal area of the implanted prosthesis and AoA area detected by MDCT.

CONCLUSIONS

Mismatch between prosthesis area and AoA area detected by MDCT is a better predictor of PVR as compared with echocardiography mismatch. Specific MDCT-based sizing recommendations should be developed.

Feasibility and accuracy of a comprehensive multidetector computed tomography acquisition for patients referred for balloon-expandable transcatheter aortic valve implantation

BACKGROUND

The aim of this study was to assess the accuracy of a comprehensive multidetector computed tomography (MDCT) evaluation of the aortic annulus (AoA), coronary artery disease (CAD), and peripheral vessels in patients referred for transcatheter aortic valve implantation (TAVI).

METHODS

In 60 patients referred for TAVI, the following parameters were assessed with 64-slices MDCT and compared with transesophageal echocardiography (TEE), invasive coronary angiography (ICA), and peripheral angiography: AoA maximum diameter (Max-AoA-D(MDCT)), minimum diameter (Min-AoA-D(MDCT)), and area; lumen morphology index ([Max-AoA-D(MDCT)/Min-AoA-D(MDCT)]); length of the left, right, and non-coronary aortic leaflets; degree (grades 1-4) of aortic leaflet calcifications; distance between AoA and left main coronary ostium and between AoA and right coronary ostium CAD and peripheral vessel disease.

RESULTS

The Max-AoA-D(MDCT) and Min-AoA-D(MDCT) were 25.1 ± 2.8 and 21.2 ± 2.2 mm, respectively, with high correlation versus AoA diameter measured with TEE (r = 0.82 and 0.86, respectively). The area of AoA, systolic and diastolic lumen morphology index were 410 ± 81.5 mm(2), 1.19 ± 0.1 and 1.22 ± 0.11, respectively. Aortic leaflet calcification score was 3.3 ± 0.5. The lengths of left, right, and non-coronary aortic leaflets were 14.2 ± 2.4, 13.7.1 ± 2.1, and 14.5 ± 2.6 mm, whereas distances between AoA and the left main coronary ostium and between AoA, and the right coronary ostium were 13.7 ± 2.9 and 15.8 ± 3.5 mm, respectively. Feasibility, negative predictive value, and accuracy for CAD detection versus ICA were 87%, 100% (CI 100-100), and 96% (95% CI 94-100), respectively. All patients (N = 17) who were ineligible for TAVI were correctly detected by MDCT.

CONCLUSIONS

A comprehensive MDCT evaluation of patients referred for TAVI is feasible, provides more accurate assessment than TEE of AoA morphology, and may replace peripheral angiography in all patients and ICA in patients without significant CAD.

Non infective severe aortic paravalvular leakage 7 years after surgery: the role of suture technique

We report a case of redo aortic prosthesis replacement for a severe paravalvular leak (PVL) in a man operated with continuous suture technique 7 years earlier. The severe aortic regurgitation was due to the rupture of the suture. In spite of operations to replace malfunctioning heart valves are common procedures and performed all over the world from more than 50 years, there is still an open debate about the most suitable suture technique. In this case report, we'll discuss if the suture technique has a role in preventing or leading complications as severe PVL.

Left atrial reverse remodeling and functional improvement after mitral valve repair in degenerative mitral regurgitation: a real-time 3-dimensional echocardiography study

BACKGROUND

Severe mitral regurgitation is often associated with left atrium (LA) enlargement, which is a well-known predictor of adverse cardiovascular outcomes. However, only few data are available on the effect of mitral valve (MV) repair on LA size. The aim of this study was to evaluate, using real-time 3-dimensional echocardiography, the changes in LA volumes after MV repair.

METHODS

A total of 65 patients with severe mitral regurgitation due to MV prolapse and scheduled for repair at an early stage were enrolled. Before the procedure, real-time 3-dimensional echocardiography was performed to assess LA volumes (maximum, before atrial active contraction [preA], and minimum). The same evaluation was repeated 6 months and 1 year after MV repair. Twenty healthy subjects matched for age and gender were enrolled as a control group.

RESULTS

Before MV repair, patients showed significantly higher values of LA volumes (maximum 43 ± 14 mL/m², preA 33 ± 12 mL/m², minimum 23 ± 11 mL/m²) as compared to controls (maximum 22 ± 6 mL/m², preA 13 ± 4 mL/m², minimum 8 ± 3 mL/m²). Six months after the operation, LA volumes significantly decreased (maximum 25 ± 8 mL/m², preA 18 ± 8 mL/m², minimum 13 ± 5 mL/m²), with a further reduction at 1-year follow-up (maximum 23 ± 7 mL/m², preA 15 ± 7 mL/m², minimum 11 ± 5 mL/m²), resulting in values similar to controls. The extent of LA reverse remodeling was inversely correlated with age (r = -0.42) and postoperative transmitral mean pressure gradient (r = -0.32), whereas a positive correlation was found with the reduction in left ventricular volume after MV repair (r = 0.35).

DISCUSSION

In patients with severe mitral regurgitation due to MV prolapse, MV repair, when performed at an early stage, results in a significant LA reverse remodeling.

Do statins improve outcomes and delay the progression of non-rheumatic calcific aortic stenosis?

CONTEXT

It is not known whether statin treatment improves clinical outcomes and reduces aortic stenosis progression in non-rheumatic calcific aortic stenosis.

OBJECTIVE

A meta-analysis of studies was performed comparing statin therapy with placebo or no treatment on outcomes and on aortic stenosis progression echocardiographic parameters.

DATA SOURCES

The authors searched Medline and Pubmed up to January 2010.

DATA EXTRACTION

Two independent reviewers independently abstracted information on study design (prospective vs retrospective or randomised vs non-randomised), study and participant characteristics. Fixed and random effects models were used. A-priori subanalyses assessed the effect of statins on low-quality (retrospective or non-randomised) and on high-quality (prospective or randomised) studies separately.

RESULTS

Meta-analysis identified 10 studies with a total of 3822 participants (2214 non-statin-treated and 1608 statin-treated); five studies were classified as prospective and five as retrospective; concerning randomisation, three trials were randomised whereas seven were not. No significant differences were found in all-cause mortality, cardiovascular mortality or in the need for aortic valve surgery. Lower-quality (retrospective or non-randomised) studies showed that, in statin-treated patients, the annual increase in peak aortic jet velocity and the annual decrease in aortic valve area were lower, but this was not confirmed by the analysis in high-quality (prospective or randomised) studies. Statins did not significantly affect the progression over time of peak and mean aortic gradient.

CONCLUSIONS

Currently available data do not support the use of statins to improve outcomes and to reduce disease progression in non-rheumatic calcific aortic valve stenosis.

Serial changes in left ventricular shape following early mitral valve repair

Mitral valve (MV) repair has become the preferred treatment for mitral regurgitation associated with degenerative MV disease. Although the functional benefits of early MV repair are known, the associated alterations in left ventricular (LV) shape have not been studied. The aim of this study was to evaluate serial changes in LV performance and 3-dimensional (3D) shape after MV repair using a new analytic technique. Fifty patients (mean age 59 +/- 12 years) with severe asymptomatic mitral regurgitation and ejection fractions >55% who underwent MV repair were enrolled. Transthoracic real-time 3D echocardiography was performed the day before and 6 and 12 months after MV repair. An age-matched control group of 50 normal subjects was studied for comparison. Endocardial surfaces were extracted to compute 3D shape indexes of sphericity and conicity, which were compared in patients between different time points and versus the normal group. Postoperatively, LV volumes were decreased compared to presurgical values. Ejection fractions were slightly decreased 6 months after surgery but had restored by 12 months. These changes were associated with modifications in end-diastolic LV shape: before surgery, compared to normal controls, sphericity was augmented and conicity was decreased; at 6 months, these shape changes were reversed, with no further improvements at 12 months. In conclusion, patients with asymptomatic mitral regurgitation and preserved LV function already exhibit changes in LV shape. Early MV repair leads to near normal morphology after surgery, indicating the benefits of this procedure. Real-time 3D echocardiography and novel 3D shape analysis allow detailed serial examination of the complex relation between LV performance and shape.

C-kit+ cardiac progenitors exhibit mesenchymal markers and preferential cardiovascular commitment

AIMS

The heart contains c-kit(+) progenitors that maintain cardiac homeostasis. Cardiac c-kit(+) cells are multipotent and give rise to myocardial, endothelial and smooth muscle cells, both in vitro and in vivo. C-kit(+) cells have been thoroughly investigated for their stem cell activity, susceptibility to stress conditions and ageing, as well as for their ability to repair the infarcted heart. Recently, expression of mesenchymal stem cell (MSC) markers and MSC differentiation potency have been reported in cardiac progenitor cells. Based on this evidence, we hypothesized that c-kit(+) cells may have phenotypic and functional features in common with cardiac MSCs.

METHODS AND RESULTS

Culture of cells obtained from enzymatic dissociation of heart auricle fragments produced a fast-growing fibroblast-like population expressing mesenchymal markers. C-kit(+) cells co-expressing MSC markers were identified in this population, sorted by flow cytometry and cultured in the presence or the absence of unselected cardiac cells from the same patients. Subsets of c-kit(+) cells also co-expressed MSCs markers in vivo, as detected by immunofluorescence analysis of auricle tissue. Ex vivo expanded c-kit(+) cells produced osteoblasts and adipocytes, although less preferentially than bone marrow-derived MSCs, possessed vascular smooth muscle cell features and were induced to differentiate into endothelium-like and cardiac-like cells.

CONCLUSION

In line with previous findings, our results indicate that c-kit(+) cardiac progenitors are primitive stem cells endowed with multilineage differentiation ability. They further suggest a possible relationship between these cells and a heart-specific MSC population with cardiovascular commitment potential.

Pre-operative transthoracic real-time three-dimensional echocardiography in patients undergoing mitral valve repair: accuracy in cases with simple vs. complex prolapse lesions

AIMS

The aim of this study, undertaken in patients who underwent mitral valve (MV) repair surgery, was to evaluate the accuracy of pre-operative three-dimensional (3D) transthoracic echocardiography (TTE) in the evaluation of MV pathology in cases with simple or complex lesions.

METHODS AND RESULTS

Two hundred consecutive patients with severe mitral regurgitation due to degenerative MV prolapse underwent a complete 3DTTE the day before surgery. Three-dimensional TTE data were compared with MV surgical inspection. Three-dimensional echocardiography was feasible in a relatively short time (5 ± 3 min) with good (67%) and optimal (21%) imaging quality in the majority of cases. Three-dimensional TTE allowed an accurate identification (95% accuracy) of all MV lesions. Seventy-three (36.5%) patients had simple lesions at 3DTTE and 71 of them (97.2%) underwent a simple surgical procedure; 127 (63.5%) had complex lesions at 3DTTE and, in these cases, surgeons performed either simple procedures (48%) or complex procedures (47.2%) or valve replacement in 4.7% (after a first attempt for repair).

CONCLUSION

Three-dimensional TTE is feasible, not time-consuming, and accurate in identifying cases with simple vs. complex MV lesions.

Percutaneous cardiopulmonary support for catheter ablation of unstable ventricular arrhythmias in high-risk patients

BACKGROUND AND PURPOSE

In patients with severe cardiomyopathy, recurrent episodes of nontolerated ventricular tachycardia (VT) or electrical storm (ES) frequently cause acute heart failure and cardiac death; the suppression of the arrhythmia is therefore lifesaving, but feasibility of catheter ablation (CA) is precluded by the adverse hemodynamic conditions together with the characteristics of the arrhythmia that interdicts efficacious mapping. The use of the percutaneous cardiopulmonary support (CPS) for circulatory assistance may allow patient's stabilization and enhance efficacy and safety of CA in this emergency setting.

PATIENTS AND METHODS

19 patients (19 males; mean age 61 +/- 6 years; chronic ischemic cardiomyopathy, eleven patients; primary dilated cardiomyopathy, six patients; arrhythmogenic right ventricular dysplasia/ cardiomyopathy, two patients) with recurrent nontolerated VT episodes undergoing CPS-assisted CA were retrospectively evaluated. Twelve patients had acute hemodynamic failure refractory to inotropic agents and ventilatory assistance, seven patients had undergone a failing nonconventional CA procedure. 14 patients presented with ES, and in twelve the procedure was undertaken under emergency conditions within 24 h from admission. Patients were ventilated under general anesthesia and assisted by a multidisciplinary team. The CPS system consisted in a Medtronic Bio-Medicus centrifugal pump and in a Maxima Plus oxygenator, a 15-F arterial cannula, and a 17-F venous cannula.

RESULTS

Flows between 2 and 3 l/min were activated after induction of 56/62 forms of nontolerated VT, achieving hemodynamic stabilization in all patients. CA was mainly guided by conventional activation mapping and was effective in abolishing 45/56 supported VTs; in 10/19 patients all clinical VTs were suppressed by CA. Mean procedural time was 4 h and 20 min. Complete stabilization was achieved in 13 patients (68%) without VT recurrence during a 7-day in-hospital monitoring. A significant clinical improvement was observed in two patients (11%); one patient (5%) with persistent VT episodes acutely died after heart transplant. At a mean follow-up of 42 months (range 15-60 months), 5/18 patients (28%) were free from VT recurrence, 7/18 (39%) had a clear clinical improvement with reduced implantable cardioverter defibrillator interventions. 5/14 patients (36%) had ES recurrence; among them, three died because of acute heart failure. No serious CPS-related complications were observed.

CONCLUSION

The CPS warrants acceptable hemodynamic stabilization and efficacious mapping in high-risk patients undergoing CA for unstable VT in the emergency setting. Safety and efficacy of this technique translate into significant clinical improvement in the majority of patients. Even if only relatively invasive, CPS should be reserved to patients with ES or intractable arrhythmia causing acute heart failure; moreover, the need for an experienced team of multidisciplinary operators implies that its use is restricted to selected high-competency institutions.

Real-time three-dimensional transoesophageal echocardiography: a new intraoperative feasible and useful technology in cardiac surgery

A new generation of transoesophageal echocardiographic probes with a novel matrix array technique has been recently introduced, allowing three-dimensional (3D) presentation of cardiac structures in real-time. This new tool may potentially provide fast and complete 3D information about cardiac structures improving spatial orientation and overcoming limitations of offline 3D technologies. The aim of this study was to demonstrate the feasibility and usefulness of real-time 3D transoesophageal echocardiography (TOE) for the intraoperative evaluation of cardiac surgery procedures. One-hundred patients underwent transoesophageal echocardiographic examination during cardiac surgery as a part of their routine clinical practice. In the intraoperative pre- and post-cardiopulmonary bypass periods complete 2D and 3D transoesophageal examinations were performed. Feasibility and duration of examinations, and immediate additional anatomical value of 3D versus 2D-TOE were annotated intraoperatively. Image quality, additional clinical value of 3D- compared to standard 2D-TOE and the accuracy in the description of mitral valve pathology by a surgeon and an echocardiographer were evaluated off-line. No complications related to transoesophageal examination occurred and successful intubation was achieved in all 100 patients. Therefore, 200 examinations were performed and analysed considering the pre- and post-cardiopulmonary bypass periods. The mean number of acquisitions per patient was 16 +/- 14, including 3D real-time, zoom, full-volume and colour full volume modalities. The duration of the 3D examination was 16 +/- 10 min and the mean image quality score 2.8 +/- 0.7 (in a scale 1-4). In 36 out of 100 cases (36%) 3D-TOE provided additional anatomical information. The surgeon evaluated 3D images easier and more accurately than 2D images (88% vs. 76% in the evaluation of mitral valve scallop). Real-time 3D TOE may be used routinely for the intraoperative evaluation of cardiac surgery. Imaging with this new probe facilitates intraoperative evaluation of several surgical procedures with an additional clinical value in selected cases.