Transcatheter native mitral valve replacement (TMVR) is a novel procedure that has the potential to overcome some of the current limitations associated with the transcatheter edge-to-edge mitral valve (MV) repair technique. The aim of this study was to describe the key steps in periprocedural echocardiographic guidance of TMVR with the Tendyne system, emphasizing potential caveats and areas of difficulty. The imaging pathway can be schematized in four fundamental steps: baseline evaluation of mitral regurgitation (MR), preprocedural screening and planning, intraprocedural guidance, and follow-up. Baseline evaluation of MR in TMVR includes the guidelines-recommended imaging pathway of MR assessment. A dedicated preprocedure cardiac multimodality imaging screening and planning for TMVR is able to determine patient eligibility according to the anatomic characteristics and measurements, provide information for appropriate valve sizing, and detect features that can predispose to potential hazard or complications. Cardiac computed tomography and two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE) are the main actors in this phase. The road map for intraprocedural TMVR guidance includes the following: (1) apical access assessment: 2D TEE assessment of the site for optimal left ventricular apical access as planned by the preprocedural computed tomography; (2) support for catheter and sheath localization, trajectory, and positioning; and (3) valve positioning and radial orientation. Thereafter, the prosthesis is withdrawn toward the left ventricle and deployed intra-annularly. Post-deployment includes assessment for correct clocking and hemodynamics, perivalvular leakage, and left ventricular outflow tract obstruction. Two-dimensional and 3D TEE and fluoroscopy provide intraprocedural guidance. The follow-up of the Tendyne device includes the guidelines-recommended imaging pathway of bioprosthesis. Knowledge of multimodality imaging use is key for the interventional imagers and crucial in the success of the procedure.

Thrombosis and coagulopathy have been found to be the most prevalent complications in patients with COVID-19. Thromboprophylaxis to prevent thromboembolic events is recommended for hospitalized COVID-19 patients. Heparin-induced thrombocytopenia (HIT) is a known complication of heparin use. This study aimed to determine the incidence of HIT among admitted patients with confirmed COVID-19 by PCR. In this study, two different HIT assays, rapid immunoassay (STic Expert HIT, Stago) and H-PF4 specific enzyme-linked immunosorbent assay (Asserachrom ® HPIA -IgG), were performed. Of 200 patients with confirmed COVID-19, we identified 49 patients who met the possibility of HIT (low platelet count and high D-Dimer level). Only five (10.2%) had a positive HIT rapid test. However, none of the tested samples tested positive by ELISA. Thrombosis was reported in two of five (40%) patients. Further extensive studies are required to determine the prevalence and clinical significance of a positive HIT test among patients with COVID-19.

The interaction between the implanter team and the imager team is critical to the success of transcatheter native mitral valve replacement (TMVR), a novel interventional procedure in the therapeutic arsenal for mitral regurgitation. This imaging scenario necessitates the addition of a new dedicated professional figure, dubbed "the interventional imager," with specific expertise in structural heart disease procedures. As its clinical application grows, knowledge of the various imaging modalities used in the TMVR procedure is required for the interventional imager and beneficial for the interventional implanter team. The purpose of this review is to describe the key steps of the procedural imaging pathway in TMVR using the Tendyne mitral valve system, with an emphasis on echocardiography. Pre-procedure cardiac multimodality imaging screening and planning for TMVR can determine patient eligibility based on anatomic features and measurements, provide measurements for appropriate valve sizing, plan/simulate the access site, catheter/sheath trajectory, and prosthesis positioning/orientation for correct deployment, and predict the risks of potential procedural complications and their likelihood of success. Step-by-step echocardiographic TMVR intraoperative guidance includes: apical access assessment; support for catheter/sheath localization, trajectory and positioning, valve positioning and clocking; post deployment: correct clocking; hemodynamic assessment; detection of perivalvular leakage; obstruction of the left ventricular outlet tract; complications. Knowledge of the multimodality imaging pathway is essential for interventional imagers and critical to the procedure's success.

A 63–year–old female known case of diabetes, hypertension, dyslipidemia and chronic kidney disease underwent mitral valve (MV) replacement because of severe regurgitation (RGT). Few weeks after, she was admitted due to decreased level of consciousness, drowsiness, abdominal distension and fever. Laboratory investigations showed positive blood cultures for Staphylococcus aureus and elevated inflammatory markers. Brain computed tomography (CT) revealed multiple infarcts due to systemic embolization. Transthoracic echocardiography (TTE) showed bioprosthesis (BP) leaflets coated by a mass causing significant obstruction (peak/mean=17/8 mmHg) with mild intravalvular RGT. Mild thickening of aortic valve (AV) cusps with mild RGT and moderate tricuspid RGT were also noted. Left and right ventricles were normal in size and function. A transesophageal echocardiography (TEE) (Figure 1) showed BP leaflets coated by a mass with a mobile vegetation attached on the atrial surface (10x9mm) causing severe obstruction and mild intravalvular RGT. A periaortic abscess, surrounding the left and the non–coronary cusps and involving the mitro–aortic fibrosa was also found. A fistula between the aortic root and the left atrium was detected by color Doppler and CW Doppler (systodiastolic high velocity shunt) (Figure 1). Further three dimensional (3D) analysis allowed to anatomically locate the position of the fistula which started close to the ostium the left coronary (LC) artery, passing through the mitroaortic fibrosa and opening anteriorly next to the strut of the BP (Figure 2). Contrast cardiac CT was advised but it was not performed to avoid further kidney impairment. The consensus was to perform redo–surgery. Therefore, the patient underwent MV cleaning of abscessual area, reconstruction of the aortic annulus with AV replacement. A coronary artery bypass surgery on LC artery was also necessary as the ostium was narrowed during the reconstruction of the area. Echocardiographic findings were confirmed at surgery. In our case 3DTEE accurately delineated cardiac anatomy and provided crucial anatomic details useful in the surgical planning. It is also important to highlight that the diagnosis may be challenging as the jet may be misinterpreted as mitral RGT. In this context, 3D imaging offers incremental value, as it is able to offer a clear view of the mitral valve.3DTEE was particularly helpful in our setting because the patient was at high risk to perform contrast study.