Recomendações para Avaliação por Imagens das Próteses Valvares Cardíacas / Recommendations for the Imaging Assessment of Prosthetic Heart Valves

Disfunção de prótese valvar cardíaca (PVC) é rara, porém é uma potencial ameaça à vida. Estabelecer o exato mecanismo da disfunção da PVC é desafiador, no entanto é essencial para determinar a estratégia terapêutica apropriada. Na prática clinica, uma abordagem abrangente que integra vários parâmetros de morfologia e função avaliados pelo eco transtorácico 2D/3D e transesofágico são fundamentais para detectar e quantificar a disfunção da PVC. A cinefluoroscopia, a tomografia computadorizada com multidectetores, a ressonância magnética cardíaca, e em menor escala, a imagem nuclear, são ferramentas complementares para o diagnóstico e abordagem das complicações das PVC. Este documento apresenta recomendações para o uso de imagem em multimodalidade para avaliação das PVCs

Normal values for Doppler echocardiographic assessment of prosthetic valve function after transcatheter aortic valve replacement: a systematic review and meta-analysis.

Transcatheter aortic valve replacement has emerged as valuable treatment modality for patients with severe aortic stenosis and an unacceptable risk/benefit ratio for open heart surgery, but particularities specific to TAVR and a rapidly growing number of available TAVR prosthesis make post-procedural assessment of valve function challenging. Aim of the present analysis was to collect and pool all available data currently in the literature regarding normal doppler values for transcatheter prosthetic heart valves and to provide a comprehensive overview. A PRISMA checklist-guided systematic review and meta-analysis of prospective observational studies or national and device specific registries or randomized clinical trials was conducted. Studies were identified by searching PUBMED, SCOPUS, Cochrane Central Register of Controlled Trials and LILACs from January 2000 to March 2017. Out of 240 abstracts, 155 studies reporting echocardiographic parameter for twelve different valves prosthesis in a total of 27,159 patients were in included in this meta-analysis. The means and standard deviations of peak velocity, peak gradient, mean gradient and effective orifice were extracted and pooled from the included studies. The pooled means and standard deviations for all available TAVR prosthesis were classified according to implanted valve size and time since implantation. The present study firstly describes a pooled analysis of normal values for all available TAVR prosthesis in order to empower treating physicians with a reliable tool to perform follow-up echocardiographic assessment in TAVR patients and to safely identify patients with prostheses dysfunction.

Recommendations for the imaging assessment of prosthetic heart valves: a report from the European Association of Cardiovascular Imaging endorsed by the Chinese Society of Echocardiography, the Inter-American Society of Echocardiography, and the Brazilian Department of Cardiovascular Imaging.

Prosthetic heart valve (PHV) dysfunction is rare but potentially life-threatening. Although often challenging, establishing the exact cause of PHV dysfunction is essential to determine the appropriate treatment strategy. In clinical practice, a comprehensive approach that integrates several parameters of valve morphology and function assessed with 2D/3D transthoracic and transoesophageal echocardiography is a key to appropriately detect and quantitate PHV dysfunction. Cinefluoroscopy, multidetector computed tomography, cardiac magnetic resonance imaging, and to a lesser extent, nuclear imaging are complementary tools for the diagnosis and management of PHV complications. The present document provides recommendations for the use of multimodality imaging in the assessment of PHVs.

Multimodality Imaging Strategies for the Assessment of Aortic Stenosis: Viewpoint of the Heart Valve Clinic International Database (HAVEC) Group.

Aortic stenosis is the most frequent valvular heart disease. In aortic stenosis, therapeutic decision essentially depends on symptomatic status, stenosis severity, and status of left ventricular systolic function. Surgical aortic valve replacement or transcatheter aortic valve implantation is the sole effective therapy in symptomatic patients with severe aortic stenosis, whereas the management of asymptomatic patients remains controversial and is mainly based on individual risk stratification. Imaging is fundamental for the initial diagnostic work-up, follow-up, and selection of the optimal timing and type of intervention. The present review provides specific recommendations for utilization of multimodality imaging to optimize risk stratification and therapeutic decision-making processes in aortic stenosis.

Two-dimensional strain for the assessment of left ventricular function in low flow-low gradient aortic stenosis, relationship to hemodynamics, and outcome: a substudy of the multicenter TOPAS study.

BACKGROUND: Decision making in patients with low flow-low gradient aortic stenosis mainly depends on the actual stenosis severity and left ventricular function, which is of prognostic importance. We used 2-dimensional strain parameters measured by speckle tracking at rest and during dobutamine stress echocardiography to document the extent of myocardial impairment, its relationship with hemodynamic variables, and its prognostic value. METHODS AND RESULTS: In 47 patients with low flow-low gradient aortic stenosis, global peak systolic longitudinal strain (PLS) and peak systolic longitudinal strain rate (PLSR) were analyzed. PLS and PLSR at rest and peak stress were -7.56±2.34% and -7.41±2.89% (P=NS) and -0.38±0.12 s(-1) and -0.53±0.18 s(-1) (P<0.001), respectively. PLS and PLSR inversely correlated with left ventricular ejection fraction at rest (rs=-0.52; P<0.0001 and -0.38; P=0.008) and peak stress (rs=-0.39; P=0.007 and -0.45; P=0.002). The overall 2-year survival rate was 60%. Univariate predictors of survival were peak stress left ventricular ejection fraction (P=0.0026), peak stress PLS (P=0.0002), peak stress PLSR (P<0.0001), and N-terminal pro-B-type natriuretic peptide (P<0.0001). Three hierarchically nested multivariable Cox regression models were constructed-model 1: The Society of Thoracic Surgeons score as an indicator of clinical risk (area under the receiver operating characteristic=0.59); model 2: model 1+N-terminal pro-B-type natriuretic peptide and peak stress left ventricular ejection fraction (area under the receiver operating characteristic=0.83; incremental P<0.0001); model 3: model 2+peak stress PLSR (area under the receiver operating characteristic=0.89; incremental P=0.035). CONCLUSIONS: In patients with low flow-low gradient aortic stenosis, 2-dimensional strain parameters are strong predictors of outcome. Peak stress PLSR may add incremental prognostic value beyond what is obtained from N-terminal pro-B-type natriuretic peptide and peak stress left ventricular ejection fraction. A larger study is needed to confirm these findings.

Doppler echocardiographic assessment of valvular regurgitation severity by measurement of the vena contracta: an in vitro validation study.

BACKGROUND: Noninvasive quantitation of valvular regurgitation remains a difficult problem. Measurements of the vena contracta (VC) by color Doppler echocardiography have been proposed but limited data are available on the actual accuracy of this method. METHODS: To evaluate how closely the color Doppler VC reflects the true fluid dynamic VC and the anatomic regurgitant orifice and whether this measurement is affected by flow changes, various models of valvular regurgitation were studied in an in vitro flow circuit. The VC diameter was measured with color Doppler using two different ultrasound systems (Agilent Sonos 5500; Agilent Technologies Inc, Palo Alto, Calif and Vingmed CFM 800; GE Healthcare, Chalfront St Giles, UK). Optical planimetry of the anatomic regurgitant orifice was performed, the true VC diameter was determined by laser particle flow visualization. RESULTS: Because of flow contraction, the true VC diameter was consistently smaller than the anatomic regurgitant orifice diameter. Anatomic orifice and true VC only marginally changed with flow rate. The diameter of the color Doppler VC, however, not only overestimated the anatomic orifice diameter by 45% to 60% and the true VC diameter by 130% to 160%, but was also highly affected by the flow rate and the ultrasound system. Despite these limitations a color Doppler VC diameter of 0.77 cm or more (Agilent) and 0.89 cm or more (Vingmed) detected severe regurgitation with a sensitivity of 93% and 84% and a specificity of 96% and 79%, respectively. CONCLUSIONS: Color Doppler estimates of the VC markedly overestimate regurgitant orifice and true VC. In contrast to the true VC, Doppler measurements are significantly affected by flow rate and by the ultrasound system used. Nevertheless, they allow semiquantitative assessment of valvular regurgitation separating severe from nonsevere regurgitation with acceptable accuracy.

Hand-held miniaturized cardiac ultrasound instruments for rapid and effective bedside diagnosis and patient screening.

RATIONALE, AIMS AND OBJECTIVES: Technological progress in recent years has made it possible that ultrasound industry can now offer affordable, portable and battery-operated ultrasound systems the size of a laptop computer. The purpose of this study was to compare these hand-carried ultrasound instruments with standard echocardiography in order to investigate the facility of a rapid bedside diagnosis in patients with suspected or known cardiovascular disease. METHODS: Fifty consecutive patients were studied with miniaturized ultrasound equipment (SonoHeart) and a conventional scanner (Acuson Sequoia) in a blinded manner. All studies were performed by three board-certified cardiologists skilled and experienced in echocardiographic practice. Investigators were not aware of any previous medical reports. RESULTS: With the new system, adequate images could be obtained in all patients. Left ventricular and left atrial diameters measured with the hand-held system correlated well with those obtained with conventional scanning: r = 0.87, mean difference 3.12 +/- 2.7 mm and r = 0.84, mean difference 2.8 + 2.4 mm, respectively. The presence of left ventricular dysfunction, regional wall motion abnormalities, relevant valvular regurgitation (moderate or more) or valve stenosis was correctly diagnosed in all patients. However, there was a tendency towards underestimating the extent of wall motion abnormalities particularly in patients difficult to image. Discrepancies also frequently occurred in patients with trivial or mild regurgitation, where false-positive and false-negative findings were described. CONCLUSION: Currently available hand-held echocardiography systems can facilitate rapid bedside diagnosis and patient screening. However, this recent development in echocardiography also raises a number of questions and its actual impact on general clinical practice still remains to be evaluated.

Normal values for Doppler echocardiographic assessment of heart valve prostheses.

Assessment of normal and abnormal function of heart valve prostheses remains challenging. Doppler echocardiography has been shown to allow hemodynamic evaluation in various clinical settings and has become the most widely used tool to assess prosthetic valve function. Prosthetic valves, even when they function normally, are to some degree obstructive to the blood flow. The normal values of gradients, pressure half-time, and effective orifice area depend on valve type and valve size. Doppler assessment of prosthetic valve function, thus, requires specification of valve type and valve size, and knowledge of the normal values. This study provides an updated overview on the available data of normal values to facilitate adequate interpretation of Doppler data.