Comprehensive Myocardial Assessment by Computed Tomography: Impact on Short-Term Outcomes After Transcatheter Aortic Valve Replacement.

BACKGROUND: Quantification of myocardial changes in severe aortic stenosis (AS) is prognostically important. The potential for comprehensive myocardial assessment pre-transcatheter aortic valve replacement (TAVR) by computed tomography angiography (CTA) is unknown. OBJECTIVES: This study sought to evaluate whether quantification of left ventricular (LV) extracellular volume-a marker of myocardial fibrosis-and global longitudinal strain-a marker of myocardial deformation-at baseline CTA associate with post-TAVR outcomes. METHODS: Consecutive patients with symptomatic severe AS between January 2021 and June 2022 who underwent pre-TAVR CTA were included. Computed tomography extracellular volume (CT-ECV) was derived from septum tracing after generating the 3-dimensional CT-ECV map. Computed tomography global longitudinal strain (CT-GLS) used semi-automated feature tracking analysis. The clinical endpoint was the composite outcome of all-cause mortality and heart failure hospitalization. RESULTS: Among the 300 patients (80.0 ± 9.4 years of age, 45% female, median Society of Thoracic Surgeons Predicted Risk of Mortality score 2.80%), the left ventricular ejection fraction (LVEF) was 58% ± 12%, the median CT-ECV was 28.5% (IQR: 26.2%-32.1%), and the median CT-GLS was -20.1% (IQR: -23.8% to -16.3%). Over a median follow-up of 16 months (IQR: 12-22 months), 38 deaths and 70 composite outcomes occurred. Multivariable Cox proportional hazards model, accounting for clinical and echocardiographic variables, demonstrated that CT-ECV (HR: 1.09 [95% CI: 1.02-1.16]; P = 0.008) and CT-GLS (HR: 1.07 [95% CI: 1.01-1.13]; P = 0.017) associated with the composite outcome. In combination, elevated CT-ECV and CT-GLS (above median for each) showed a stronger association with the outcome (HR: 7.14 [95% CI: 2.63-19.36]; P < 0.001). CONCLUSIONS: Comprehensive myocardial quantification of CT-ECV and CT-GLS associated with post-TAVR outcomes in a contemporary low-risk cohort with mostly preserved LVEF. Whether these imaging biomarkers can be potentially used for the decision making including timing of AS intervention and post-TAVR follow-up will require integration into future clinical trials.

Feasibility of Redo-Transcatheter Aortic Valve Replacement in Sapien Valves Based on In Vivo Computed Tomography Assessment.

BACKGROUND: Our aim was to assess the feasibility of repeat transcatheter aortic valve (TAV) replacement for degenerated Sapien3 (S3) prostheses by simulating subsequent implantation of S3 or Evolut, using in vivo computed tomography-based sizing and the impact on coronary and patient-prosthesis mismatch risks. METHODS: Computed tomography scans from 356 patients with prior S3 TAV replacement implantation were analyzed. The in vivo sizing for second TAV based on averaged area of 3 levels of outflow, mid (narrowest) and inflow, was compared with in vitro recommendations, that is, same size as index S3 for second S3 and 1 size larger for Evolut. Risks of coronary obstruction and patient-prosthesis mismatch were determined by valve-to-aorta distance and estimated effective orifice area, respectively. RESULTS: Overall, the majority of patients (n=328; 92.1%) had underexpanded index S3 with an expansion area of 94% (91%-97%), leading to significant differences in size selection of the second TAV between in vivo and in vitro sizing strategies. Expansion area <89% served as a threshold, resulting in 1 size smaller than the in vitro recommendations were selected in 45 patients (13%) for S3-in-S3 and 13 (4%) for Evolut-in-S3, while the remaining patients followed in vitro recommendations (P<0.01, in vivo versus in vitro sizing). Overall, 57% of total patients for S3-in-S3 simulation and 60% for Evolut-in-S3 were considered low risk for coronary complications. Deep index S3 implantation (odds ratio, 0.76 [interquartile range, 0.67-0.87]; P<0.001) and selecting Evolut as the second TAV (11% risk reduction in intermediate- or high-risk patients) reduced coronary risk. Estimated moderate or severe patient-prosthesis mismatch risk was 21% for S3-in-S3 and 1% for Evolut-in-S3, assuming optimal expansion of the second TAV. CONCLUSIONS: Redo-TAV replacement with S3-in-S3 and Evolut-in-S3 could be feasible with low risk to coronaries in ≈60% of patients, while the remaining 40% will be at intermediate or high risk. The feasibility of redo-TAV replacement is influenced by sizing strategy, type of second TAV, native annular anatomy, and implant depth.

Importance of imaging-acquisition protocol and post-processing analysis for extracellular volume fraction assessment by computed tomography.

BACKGROUND: Computed tomography angiography (CTA) assessment of myocardial extracellular volume fraction (CT-ECV) is feasible, although the protocols for imaging acquisition and post-processing methodology have varied. We aimed to identify a pragmatic protocol for CT-ECV assessment encompassing both imaging acquisition and post-processing methodologies to facilitate its clinical implementation. METHODS: We evaluated consecutive patients with severe aortic stenosis undergoing evaluation for transcatheter aortic valve replacement (TAVR). Pre-contrast and 3-min-delayed CTA were obtained in systole using either helical prospective-ECG-triggered (high-pitch) or axial sequential-ECG-gated acquisition, adding to standard TAVR CTA protocol. Using a dedicated software for co-registration of CTA datasets, three methodologies for ECV measurement were evaluated: (1) mid-septum region of interest (Septal ECV), (2) averaged-global ECV (Global ECV) encompassing 16-AHA segments, and (3) average of septal and lateral segments (Averaged ECVsep and Averaged ECVlat). RESULTS: Among the 142 patients enrolled (median â€‹= â€‹81 years, 44% females), 8 were excluded due to significant imaging artifacts precluding Global ECV assessment. High-pitch scan mode was performed in 68 patients (48%). Suboptimal image quality for Global ECV assessment was associated with high-pitch scan mode (odds ratio: OR â€‹= â€‹2.26, p â€‹= â€‹0.036), along with the presence of intracardiac leads (OR â€‹= â€‹4.91, p â€‹= â€‹0.002), and BMI≥35 â€‹kg/m2 (OR â€‹= â€‹2.80, p â€‹= â€‹0.026). Septal ECV [median â€‹= â€‹29.4%] and Averaged ECVsep [29.0%] were similar (p â€‹= â€‹0.108), while Averaged ECVlat [27.5%] was lower than Averaged ECVsep (p â€‹< â€‹0.001), resulting in lower Global ECV [28.6%]. CONCLUSIONS: Myocardial CT-ECV assessment is feasible using a systolic sequential acquisition pre-contrast, and similar additional 3-min delayed scan. Septal ECV measurement provides similar values to Global ECV and is equally reproducible.

Association of Left Ventricular Remodeling Assessment by Cardiac Magnetic Resonance With Outcomes in Patients With Chronic Aortic Regurgitation.

Importance: Chronic aortic regurgitation (AR) causes left ventricular (LV) volume overload, which results in progressive LV remodeling negatively affecting outcomes. Whether cardiac magnetic resonance (CMR) volumetric quantification can provide incremental risk stratification over standard clinical and echocardiographic evaluation in patients with chronic moderate or severe AR is unknown. Objective: To compare LV remodeling measurements by CMR and echocardiography between patients with and without heart failure symptoms and to verify the association of remodeling measurements of patients with chronic moderate or severe AR but no or minimal symptoms with clinical outcomes receiving medical management. Design, Setting, and Participants: This multicenter retrospective cohort study included consecutive patients with at least moderate chronic native AR evaluated by 2-dimensional transthoracic echocardiography and CMR examination within 90 days from each other between January 2012 and February 2020 at Allina Health System. Data were analyzed from June 2021 to January 2022. Exposures: Clinical evaluation and risk stratification by CMR. Main Outcomes and Measures: The end point was a composite of death, heart failure hospitalization, or progression of New York Heart Association functional class while receiving medical management, censoring patients at the time of aortic valve replacement (when performed) or at the end of follow-up. Results: Of the 178 included patients, 119 (66.9%) were male, 158 (88.8%) presented with no or minimal symptoms (New York Heart Association class I or II), and the median (IQR) age was 58 (44-69) years. Compared with patients with no or minimal symptoms, symptomatic patients had greater LV end-systolic volume index (LVESVi) by CMR (median [IQR], 66 [46-85] mL/m2 vs 42 [30-58] mL/m2; P < .001), while there were no significant differences by echocardiography (LVESVi: median [IQR], 38 [30-58] mL/m2 vs 27 [20-42] mL/m2; P = .07; LV end-systolic diameter index: median [IQR], 21 [17-25] mm/m2 vs 18 [15-22] mm/m2; P = .17). During the median (IQR) follow-up of 3.3 (1.6-5.8) years, 50 patients with no or minimal symptoms receiving medical management developed the composite end point, which, in multivariate analysis adjusted for age and EuroSCORE II, was independently associated with LVESVi of 45 mL/m2 or greater and aortic regurgitant fraction of 32% or greater, the latter adding incremental prognostic value to CMR volumetric assessment. Conclusions and Relevance: In patients with chronic moderate or severe AR, patients presenting with heart failure symptoms have greater LVESVi by CMR than those with no or minimal symptoms. In patients with no or minimal symptoms, CMR quantification of LVESVi and AR severity may identify those at risk of death or incident heart failure and therefore should be considered in the clinical evaluation and decision-making of these patients.

Nationally Representative Repeat Transcatheter Aortic Valve Replacement Outcomes: Report From the Centers for Medicare and Medicaid Services.

OBJECTIVES: The aim of this study was to examine real-world experience with repeat transcatheter aortic valve replacement (TAVR) in a population-based national database. BACKGROUND: Repeat TAVR is a growing option in patients requiring reintervention for TAVR. However, large-scale studies with longitudinal follow-up are limited. METHODS: All Medicare beneficiaries who underwent TAVR from 2012 to 2017 were included. Outcomes included 30-day and longitudinal mortality and major adverse cardiovascular events, defined as death, stroke, pacemaker insertion, major bleeding, acute kidney injury, or cardiac arrest. Outcomes of repeat TAVR were compared with surgical explantation after TAVR (TAVR explantation) in a matched analysis. RESULTS: Of 133,250 patients who underwent TAVR, 617 (0.46%) underwent subsequent repeat TAVR at a median interval of 154 days (interquartile range: 58-537 days). Mortality at 30 days and 1 year was 6.0% and 22.0%, respectively. Rates of 30-day stroke and pacemaker insertion were 1.8% and 4.2%. Mortality at 30 days was lower in those who underwent their first TAVR during the later era (2015-2017) compared with earlier years (2012-2014) (4.6% vs 8.7%; P = 0.049). Repeat TAVR was associated with lower 30-day mortality compared with a matched group undergoing TAVR explantation (6.2% vs 12.3%; P = 0.05), although 1-year mortality was similar (21.0% vs 20.8%; P = 1.000). The incidence of 30-day major adverse cardiovascular events was higher with TAVR explantation compared with repeat TAVR (risk ratio: 2.92; 95% CI: 1.88-4.99; P ≤ 0.001). CONCLUSIONS: Repeat TAVR was performed with acceptable 30-day mortality in this high-risk population. Short-term outcomes were superior to surgical explantation, but 1-year outcomes were similar. Repeat TAVR will likely be an important option for aortic valve reintervention after TAVR.

Incidence, Characteristics, Predictors, and Outcomes of Surgical Explantation After Transcatheter Aortic Valve Replacement.

BACKGROUND: Currently, there is a paucity of information on surgical explantation after transcatheter aortic valve replacement (TAVR). OBJECTIVES: The purpose of this study was to examine the incidence, patient characteristics, predictors, and outcomes of surgical explantation after TAVR using a population-based, nationally representative database. METHODS: We analyzed the Medicare Provider profile to include all U.S. patients undergoing TAVR from 2012 to 2017. Time to surgical explant was calculated from the index TAVR discharge to surgical explantation. Post-operative survival was assessed using time-dependent Cox proportional hazard regression analysis and landmark analysis. RESULTS: The incidence of surgical explantation was 0.2% (227 of 132,633 patients), and was 0.28% and 0.14% in the early and newer TAVR era, respectively. The median time to surgical explant was 212 days, whereas 8.8% and 70.9% underwent surgical explantation within 30 days and 1 year, respectively. The primary indication for reintervention was bioprosthetic failure (79.3%). Compared with the no-explant cohort, the explant cohort was significantly younger (mean age 73.7 years vs. 81.7 years), with a lower prevalence of heart failure (55.9% vs. 65.8%) but more likely a lower-risk profile cohort (15% vs. 2.4%; all p < 0.05). The 30-day and 1-year mortality rates were 13.2% and 22.9%, respectively, and did not vary by either time to surgical explant or TAVR era, or between patients with versus without endocarditis (all p > 0.05). The time-dependent Cox regression analysis demonstrated a higher mortality in those with surgical explantation (hazard ratio: 4.03 vs. no-explant group; 95% confidence interval: 1.81 to 8.98). Indication, time-to-surgical-explant, and year of surgical explantation were not associated with worse post-explantation survival (all p > 0.05). CONCLUSIONS: The present study provides updated evidence on the incidence, timing, and outcomes of surgical explantation of a TAVR prosthesis. Although the overall incidence was low, short-term mortality was high. These findings stress the importance of future mechanistic studies on TAVR explantation and may have implications on lifetime management of aortic stenosis, particularly in younger patients.

The rapid transformation of cardiac surgery practice in the coronavirus disease 2019 (COVID-19) pandemic: Insights and clinical strategies from a center at the epicenter.

BACKGROUND: The onset of the coronavirus disease 2019 (COVID-19) pandemic has forced our cardiac surgery program and hospital to enact drastic measures that has forced us to change how we care for cardiac surgery patients, assist with COVID-19 care, and enable support for the hospital in terms of physical resources, providers, and resident training. METHODS: In this review, we review the cardiovascular manifestations of COVID-19 and describe our system-wide adaptations to the pandemic, including the use of telemedicine, how a severe reduction in operative volume affected our program, the process of redeployment of staff, repurposing of residents into specific task teams, the creation of operation room intensive care units, and the challenges that we faced in this process. RESULTS: We offer a revised set of definitions of surgical priority during this pandemic and how this was applied to our system, followed by specific considerations in coronary/valve, aortic, heart failure and transplant surgery. Finally, we outline a path forward for cardiac surgery for the near future. CONCLUSIONS: We recognize that individual programs around the world will eventually face COVID-19 with varying levels of infection burden and different resources, and we hope this document can assist programs to plan for the future.

The rapid transformation of cardiac surgery practice in the coronavirus disease 2019 (COVID-19) pandemic: insights and clinical strategies from a centre at the epicentre.

OBJECTIVES: The onset of the coronavirus disease 2019 (COVID-19) pandemic has forced our cardiac surgery programme and hospital to enact drastic measures that has forced us to change how we care for cardiac surgery patients, assist with COVID-19 care and enable support for the hospital in terms of physical resources, providers and resident training. METHODS: In this review, we review the cardiovascular manifestations of COVID-19 and describe our system-wide adaptations to the pandemic, including the use of telemedicine, how a severe reduction in operative volume affected our programme, the process of redeployment of staff, repurposing of residents into specific task teams, the creation of operation room intensive care units, and the challenges that we faced in this process. RESULTS: We offer a revised set of definitions of surgical priority during this pandemic and how this was applied to our system, followed by specific considerations in coronary/valve, aortic, heart failure and transplant surgery. Finally, we outline a path forward for cardiac surgery for the near future. CONCLUSIONS: We recognize that individual programmes around the world will eventually face COVID-19 with varying levels of infection burden and different resources, and we hope this document can assist programmes to plan for the future.

Novel Multiphase Assessment for Predicting Left Ventricular Outflow Tract Obstruction Before Transcatheter Mitral Valve Replacement.

OBJECTIVES: This study proposes a physiologic assessment of left ventricular outflow tract obstruction (LVOTO) that accommodates changes in systolic flow and accounts for the dynamic neo-left ventricular outflow tract (LVOT). BACKGROUND: Patients considered for transcatheter mitral valve replacement trials often screen-fail because of the perceived risk of LVOTO. In the Intrepid Global Pilot Study, assumed risk of LVOTO was based on computed tomography estimates of the neo-LVOT area computed at end-systole. However, this may overestimate actual risk. METHODS: Retrospective analyses were performed for screen-failed patients for potential LVOTO (n = 33) and treated patients (n = 29) with available dynamic computed tomography. A multiphase assessment of the neo-LVOT area was performed and represented as: 1) multiphase average; and 2) early systolic value. Prospective evaluation was performed in 9 patients approved for enrollment with multiphase and early systole methods that would have previously screen-failed with the end-systolic approach. RESULTS: Of 166 patients screened for possible inclusion; 32 were screen-failed for nonanatomical reasons. Screen failure for assumed LVOTO risk occurred in 37 of 134 (27.6%) patients. Retrospective analysis indicated a potential enrollment increase of 11 of 33 (33.3%) and 18 of 33 (54.5%) patients using multiphase and early systolic assessment methods. In the prospective cohort, there were no clinical observations of LVOTO 30 days post-procedure, despite assumed risk based on end-systolic estimates. CONCLUSIONS: Multiphase, and specifically early systolic, assessment of the neo-LVOT may better determine risk of LVOTO with transcatheter mitral valve replacement compared with end-systolic estimates. This novel approach has the potential to significantly increase patient eligibility, with over one-half of patients previously screen-failed now eligible for treatment.

Comparison between Three-Dimensional Echocardiography and Computed Tomography for Comprehensive Tricuspid Annulus and Valve Assessment in Severe Tricuspid Regurgitation: Implications for Tricuspid Regurgitation Grading and Transcatheter Therapies.

BACKGROUND: Tricuspid valve imaging is frequently challenging and requires the use of multiple modalities. Knowledge of limitations and methodologic discrepancies among different imaging techniques is crucial for planning transcatheter valve interventions. METHODS: Thirty-eight patients with severe symptomatic tricuspid regurgitation were included in this retrospective analysis. Tricuspid annulus (TA) measurements were made during mid-diastole using three-dimensional (3D) transthoracic echocardiographic direct planimetry (TTE_direct) and transesophageal echocardiographic direct planimetry (TEE_direct). Moreover, a semiautomated software was used to generate two-dimensional (2D) and 3D perimeter and area on transesophageal echocardiography (TEE) images. Both methods were compared with direct computed tomographic planimetry (CT_direct) and cubic spline interpolation (CT_indirect). The different TA values were used to calculate the effective regurgitant orifice area and compared with 3D Doppler vena contracta area. For tricuspid valve area TEE_direct and CT_direct as well as CT_indirect were measured. RESULTS: Agreement between TEE and computed tomography (CT) for TA sizing was obtained using semiautomated methods (3D TEE_indirect and CT_indirect). TTE_direct was overall less reliable compared with CT. TA area quantified by TEE_direct was 25% (difference 305 ± 238 mm2, P < .001, R = 0.9) and 19% (166 ± 247 mm2, P < .001, R = 0.89) smaller compared with CT_direct and CT_indirect, respectively. TA perimeter measurements by TEE_direct differed by 11% compared with CT_direct (12 ± 11 mm, P < .001, R = 0.87) and 3D CT_indirect (12 ± 11 mm, P < .001, R = 0.88), and 9% compared with 2D CT_indirect (7 ± 11 mm, P = .002, R = 0.87). TEE_direct of the TA allows the most accurate calculation of effective regurgitant orifice area compared with 3D vena contracta area (-8 ± 62 mm2, P = .50, R = 0.85). Tricuspid valve area by CT_indirect best correlated with conventional TEE_direct (80 ± 250 mm2, P = .11, R = 0.80). CONCLUSIONS: In patients with severe tricuspid regurgitation, semiautomated indirect planimetry results in high agreement between TEE and CT for TA sizing and measurement of the tricuspid valve area. TEE_direct of the TA allows the most accurate measurement of diastolic stroke volume for the calculation of regurgitation severity compared with 3D vena contracta area.

Aortic Valve Annular Sizing: Intraoperative Assessment Versus Preoperative Multidetector Computed Tomography.

BACKGROUND: Appropriate valve sizing is critical in aortic valve replacement. We hypothesized that direct intraoperative valve sizing results in smaller aortic annular diameters compared with sizing based on systolic-phase multidetector computerized tomographic (MDCT) imaging. METHODS AND RESULTS: We retrospectively analyzed 78 patients undergoing surgical aortic valve replacement for severe aortic stenosis between 2012 and 2014 at our institution. Preoperative MDCT measurements of the aortic annulus served as basis for assignment to a theoretical surgical valve size, which was then (1) compared to the implanted valve size and (2) to a theoretical transcatheter aortic valve replacement valve size. To quantify the resulting differences, geometric orifice areas (GOA) were calculated. MDCT-based sizing produced the same valve size for n=34 patients (group CT-same), a larger valve with a 25% increased GOA in n=32 patients (group CT-Lg) and a smaller GOA by 22% in n=12 patients (group CT-Sm). On the basis of MDCT measurements, 41% of valves implanted were undersized. The comparison of intraoperative implanted to a theoretical transcatheter aortic valve replacement valve size resulted in GOAs 25% larger for patients in group CT-same, 40.6% larger in group CT-Lg and 14.6% larger in group CT-Sm. CONCLUSIONS: Preoperative MDCT measurements differ substantially from direct intraoperative assessment of the aortic annulus. Implanted surgical aortic valve replacement valves were smaller relative to MDCT-based sizing in 41% of patients, and the potential GOA was between 25% and 40.6% larger if patients had undergone transcatheter aortic valve replacement.

Transcatheter mitral valve replacement: design implications, potential pitfalls and outcomes assessment.

Transcatheter mitral valve replacement (TMVR) is an emerging new treatment option in patients with advanced mitral valve disease deemed a high or prohibitive risk for surgery. Designing an ideal TMVR device requires a detailed understanding of different mitral valve pathologies and the complex, dynamic anatomy and physiology of the mitral apparatus. This review aims to critically evaluate design implications in TMVR in the context of mitral valve disease, imaging prerequisites, procedural approaches, potential complications, and outcomes assessment.