Faculty Bibliography

OBJECTIVES/OBJECTIVE:The aim of this study was to clarify the dynamics of the mitral annulus throughout the cardiac cycle and its relevance to transcatheter mitral valve replacement (TMVR) sizing and case selection. BACKGROUND:Limited data are available regarding the relevance of mitral annular (MA) and neo-left ventricular outflow tract (LVOT) dynamics in the overall population presenting with significant mitral valve disease. METHODS:Patients attending a combined surgical-transcatheter heart valve clinic for severe symptomatic mitral valve disease were assessed using multiphase computed tomography. The relative influence of MA and neo-LVOT dynamics to TMVR case selection was studied. RESULTS:A total of 476 patients with significant mitral valve disease were evaluated. In 99 consecutive patients with severe mitral regurgitation, a 10-phase assessment showed that the mitral annulus was on average largest in late systole. On comparing maximal MA dimension with late systolic dimension, TMVR size assignment changed in 24.2% of patients. If the average MA perimeter was used to determine sizing, 48.5% were excluded because of MA dimension being too large; in a multiphase assessment of the neo-LVOT, an additional 16.2% were excluded on the basis of neo-LVOT dimension. In an expanded series of 312 consecutive patients, selection protocol influenced anatomical exclusion: a manufacturer-proposed early systolic approach excluded 69.2% of patients, whereas a late systolic approach excluded 82.7% of patients, the vast majority because of large mitral annuli. CONCLUSIONS:Contemporary TMVR can treat only a minority of patients with severe mitral regurgitation, principally because of limitations of large MA dimension.

OBJECTIVES/OBJECTIVE:We report the 30-day outcomes from the roll-in cohort of the CLASP IID trial, representing the first procedures performed by each site. BACKGROUND:The currently enrolling CLASP IID/IIF pivotal trial is a multicenter, prospective, randomized trial assessing the safety and effectiveness of the PASCAL transcatheter valve repair system in patients with clinically significant MR. The trial allows for up to three roll-in patients per site. METHODS:Eligibility criteria were: DMR ≥3+, prohibitive surgical risk, and deemed suitable for transcatheter repair by the local heart team. Trial oversight included a central screening committee and echocardiographic core laboratory. The primary safety endpoint was a 30-day composite MAE: cardiovascular mortality, stroke, myocardial infarction (MI), new need for renal replacement therapy, severe bleeding, and non-elective mitral valve re-intervention, adjudicated by an independent clinical events committee. Thirty-day echocardiographic, functional, and quality of life outcomes were assessed. RESULTS:A total of 45 roll-in patients with mean age of 83 years and 69% in NYHA class III/IV were treated. Successful implantation was achieved in 100%. The 30-day composite MAE rate was 8.9% including one cardiovascular death (2.2%) due to severe bleeding from a hemorrhagic stroke, one MI, and no need for re-intervention. MR≤1+ was achieved in 73% and ≤2+ in 98% of patients. 89% of patients were in NYHA class I/II (p < .001) with improvements in 6MWD (30 m; p = .054) and KCCQ (17 points; p < .001). CONCLUSIONS:Early results representing sites with first experience with the PASCAL repair system showed favorable 30-day outcomes in patients with DMR≥3+ at prohibitive surgical risk.

BACKGROUND:Patients with renal insufficiency have poor short-term outcomes after transcatheter aortic valve replacement (TAVR). METHODS:Retrospective chart review identified 575 consecutive patients not on hemodialysis who underwent TAVR between September 2014 and January 2017. Outcomes were defined by VARC-2 criteria. Primary outcome of all-cause mortality was evaluated at a median follow-up of 811 days (interquartile range 125-1,151). RESULTS:Preprocedural glomerular filtration rate (GFR) was ≥60 ml/min in 51.7%, 30-60 ml/min in 42.1%, and < 30 ml/min in 6.3%. Use of transfemoral access (98.8%) and achieved device success (91.0%) did not differ among groups, but less contrast was used with lower GFR (23 ml [15-33], 24 ml [14-33], 13 ml [8-20]; p < .001). Peri-procedural stroke (0.7%, 2.1%, 11.1%; p < .001) was higher with lower GFR. Core lab analysis of preprocedural computed tomography scans of patients who developed a peri-procedural stroke identified potential anatomic substrate for stroke in three out of four patients with GFR 30-60 ml/min and all three with GFR <30 ml/min (severe atheroma was the most common subtype of anatomical substrate present). Compared to GFR ≥60 ml/min, all-cause mortality was higher with GFR 30-60 ml/min (HR 1.61 [1.00-2.59]; aHR 1.61 [0.91-2.83]) and GFR <30 ml/min (HR 2.41 [1.06-5.48]; aHR 2.34 [0.90-6.09]) but not significant after multivariable adjustment. Follow-up echocardiographic data, available in 63%, demonstrated no difference in structural heart valve deterioration over time among groups. CONCLUSIONS:Patients with baseline renal insufficiency remain a challenging population with poor long-term outcomes despite procedural optimization with a transfemoral-first and an extremely low-contrast approach.

OBJECTIVES/OBJECTIVE:To describe the use of orbital atherectomy to prepare iliofemoral vessels for large-bore access prior to transcatheter aortic valve replacement (TAVR). BACKGROUND:Transfemoral (TF)-TAVR has been shown to be at least equivalent to surgery. Nevertheless, many patients do not qualify for the TF approach due to severe iliofemoral occlusive disease. The use of an atherectomy device in order to facilitate TF-TAVR has only been reported in case reports. METHODS:We performed 1000 TAVR procedures from June 2017 to October 2019. Patient demographics, procedural characteristics, computed tomography characteristics, and short-term outcomes were recorded. Hostile access was defined as luminal size <5 mm, or <5.5 mm along with the presence of >270° calcification. The primary endpoint was the ability to successfully deliver a transcatheter valve via the intended pretreated access site. RESULTS:During the study period, 6 subjects (0.6%) required alternative access and 68 patients (6.8%) were considered to have a hostile iliofemoral anatomy that required vessel preparation prior to TAVR. Forty-eight patients (70.6%) had angioplasty only and 20 patients (29.4%) required atherectomy and angioplasty. Out of 20 patients treated with atherectomy, successful TF delivery of the valve was achieved in 19 patients (95%). There was no in-hospital mortality or stroke. There were no perforations. One subject required placement of a self-expandable stent due to severe dissection. CONCLUSION/CONCLUSIONS:Orbital atherectomy used for vessel preparation is a safe and very effective technique to facilitate TF-TAVR in patients with hostile peripheral anatomy.

Left ventricular outflow tract (LVOT) obstruction in hypertrophic cardiomyopathy (HCM) is often caused by systolic anterior motion (SAM) of the mitral valve caused by the interplay between increased left ventricular (LV) wall thickness and an abnormal mitral valve anatomy and geometry. Three-dimensional (3D) echocardiographic imaging of the mitral valve has revolutionized the practice of cardiology, paving the way for new methods to see and treat valvular heart disease. Here we present the novel and incremental value of 3D transesophageal echocardiography (TEE) of SAM visualization. This review first provides step-by-step instructions on acquiring and optimizing 3D TEE imaging of SAM. It then describes the unique and novel findings using standard 3D TEE rendering as well as dynamic mitral valve modeling of SAM from 3D data sets, which can provide a more detailed visualization of SAM features. The findings include double-orifice LVOT caused by the residual leaflet, the dolphin smile phenomenon, and delineation of SAM width. Finally, the review discusses the essential role of 3D TEE imaging for preprocedural assessment and intraprocedural guidance of surgical and novel percutaneous treatments of SAM.

Glucose 6-phosphate dehydrogenase (G6PD) deficiency facilitates human coronavirus infection due to glutathione depletion. G6PD deficiency may especially predispose to hemolysis upon coronavirus disease-2019 (COVID-19) infection when employing pro-oxidant therapy. However, glutathione depletion is reversible by N-acetylcysteine (NAC) administration. We describe a severe case of COVID-19 infection in a G6PD-deficient patient treated with hydroxychloroquine who benefited from intravenous (IV) NAC beyond reversal of hemolysis. NAC blocked hemolysis and elevation of liver enzymes, C-reactive protein (CRP), and ferritin and allowed removal from respirator and veno-venous extracorporeal membrane oxygenator and full recovery of the G6PD-deficient patient. NAC was also administered to 9 additional respirator-dependent COVID-19-infected patients without G6PD deficiency. NAC elicited clinical improvement and markedly reduced CRP in all patients and ferritin in 9/10 patients. NAC mechanism of action may involve the blockade of viral infection and the ensuing cytokine storm that warrant follow-up confirmatory studies in the setting controlled clinical trials.

Background Computed tomography (CT) has become the standard of care for assessment for the suitability for transcatheter mitral valve replacement (TMVR); however, variation in mitral annular measurements across the cardiac cycle has thus far been poorly studied. Because of this, currently TMVR assessment is cumbersome and involves the assessment of multiple phases. We sought to further understand variation in mitral annular dimensions with the cardiac cycle and assess its potential implications for Methods A total of 118 patients presented to the heart valve clinic and underwent CT for possible TMVR assessment and were consecutively studied with multiphase CT. The mitral annulus was measured in 10 phases using 3mensio mitral planning software and several parameters collected including perimeter, area, anterior-posterior (AP) dimension and commissure-commissure (CC) dimension. Results Of the 118 patients screened, 83.9% had predominant MR, 10.2% mixed MS/MR and 5.9% predominant MS. Changes in perimeter, Area, AP and CC dimensions are shown (figure). Comparison of largest and smallest mean measurements for each phase for perimeter, Area, AP and CC dimensions showed a 2.02%, 4.36%, 8.09% and 2.86% variation respectively. Conclusion In contrast to the dynamism of the aortic annulus and neo-LVOT, the mitral annulus does not vary significantly. This may allow limitation of radiation restricting CT acquisitions to mid-systole where the neo-LVOT is smallest. [Figure presented]
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