Concomitant anaortic OPCAB and transfemoral TAVR for high-risk patients: A case series.

BACKGROUND: Combined on-pump coronary artery bypass (ONCAB) and surgical aortic valve replacement (SAVR) is the treatment of choice for concomitant severe aortic stenosis and coronary artery disease not amenable to percutaneous coronary intervention. Extensive aortic calcification and atheromatous disease may prohibit cardiopulmonary bypass and aortic cross-clamping. In these cases, anaortic off-pump coronary artery bypass (OPCAB) is a Class I (EACTS 2018) and Class IIA (AHA 2021) indication for surgical coronary revascularization. Transcatheter aortic valve replacement (TAVR) has similar benefits when compared with SAVR for this population (Partner 2 & 3). Herewith we describe a case series of concomitant Anaortic OPCAB and TAVR via the transfemoral approach for patients with coronary artery and valve disease considered too high risk for traditional coronary artery bypass grafting and SAVR due to severe aortic disease. METHODS/RESULTS: Eight patients underwent anaortic OPCAB and transfemoral TAVR during the same anesthetic in a hybrid operating room. Seven patients with multivessel disease had anaortic OPCAB via a sternotomy using composite grafts, one patient with LAD disease had anaortic OPCAB using a Da Vinci-assisted MIDCAB approach. All patients then had an Edwards Sapien 3 TAVR placed percutaneously via the common femoral artery. There was no 30 mortality or CVA in the series and all patients were discharged to home or a rehabilitation facility on Day 4-13. CONCLUSIONS: Combined anaortic OPCAB and transfemoral TAVR is a safe and feasible approach to treating concomitant extensive coronary artery disease and severe aortic stenosis. The aortic no-touch technique provides benefits in the elderly high-risk patients by reducing the risk of postoperative myocardial infarction and cerebrovascular stroke.

Comparison of performance of self-expanding and balloon-expandable transcatheter aortic valves.

Objective: To evaluate the flow dynamics of self-expanding and balloon-expandable transcatheter aortic valves pertaining to turbulence and pressure recovery. Transcatheter aortic valves are characterized by different designs that have different valve performance and outcomes. Methods: Assessment of transcatheter aortic valves was performed using self-expanding devices (26-mm Evolut [Medtronic], 23-mm Allegra [New Valve Technologies], and small Acurate neo [Boston Scientific]) and a balloon-expandable device (23-mm Sapien 3 [Edwards Lifesciences]). Particle image velocimetry assessed the flow downstream. A Millar catheter was used for pressure recovery calculation. Velocity, Reynolds shear stresses, viscous shear stress, and pressure gradients were calculated. Results: The maximal velocity at peak systole obtained with the Evolut R, Sapien 3, Acurate neo, and Allegra was 2.12 ± 0.19 m/sec, 2.41 ± 0.06 m/sec, 2.99 ± 0.10 m/sec, and 2.45 ± 0.08 m/sec, respectively (P < .001). Leaflet oscillations with the flow were clear with the Evolut R and Acurate neo. The Allegra shows the minimal range of Reynolds shear stress magnitudes (up to 320 Pa), and Sapien 3 the maximal (up to 650 Pa). The Evolut had the smallest viscous shear stress magnitude range (up to 3.5 Pa), and the Sapien 3 the largest (up to 6.2 Pa). The largest pressure drop at the vena contracta occurred with the Acurate neo transcatheter aortic valve with a pressure gradient of 13.96 ± 1.35 mm Hg. In the recovery zone, the smallest pressure gradient was obtained with the Allegra (3.32 ± 0.94 mm Hg). Conclusions: Flow dynamics downstream of different transcatheter aortic valves vary significantly depending on the valve type, despite not having a general trend depending on whether or not valves are self-expanding or balloon-expandable. Deployment design did not have an influence on flow dynamics.

Impact of blood pressure on coronary perfusion and valvular hemodynamics after aortic valve replacement.

OBJECTIVE: Our objective was to evaluate the impact of various blood pressures (BPs) on coronary perfusion and valvular hemodynamics following aortic valve replacement (AVR). BACKGROUND: Lower systolic and diastolic (SBP/DBP) pressures from the recommended optimal target range of SBP < 120-130 mmHg and DBP < 80 mmHg after AVR have been independently associated with increased cardiovascular and all-cause mortality. METHODS: The hemodynamic assessment of a 26 mm SAPIEN 3 transcatheter aortic valve (TAV), 29 mm Evolut R TAV, and 25 mm Magna Ease surgical aortic valve (SAV) was performed in a pulsed left heart simulator with varying SBP, DBP, and heart rate (HR) conditions (60 and 120 bpm) at 5 L/min cardiac output (CO). Average coronary flow (CF), effective orifice areas (EOAs), and valvulo-arterial impedance (Zva) were calculated. RESULTS: At HR of 60 bpm, at SBP < 120 mmHg and DBP < 60 mmHg, CF decreased below the physiological lower limit with several different valves. Zva and EOA were found to increase and decrease respectively with increasing SBP and DBP. The same results were found with an HR of 120 bpm. The trends of CF variation with BP were similar in all valves however the drop below the lower physiological CF limit was valve dependent. CONCLUSION: In a controlled in vitro system, with different aortic valve prostheses in place, CF decreased below the physiologic minimum when SBP and DBP were in the range targeted by blood pressure guidelines. Combined with recent observations from patients treated with AVR, these findings underscore the need for additional studies to identify the optimal BP in patients treated with AVR for AS.

Neosinus and Sinus Flow After Self-Expanding and Balloon-Expandable Transcatheter Aortic Valve Replacement.

OBJECTIVES: The aim of this study was to evaluate flow dynamics in the aortic sinus and the neosinus (NS) after transcatheter heart valve (THV) implantation in valve-in-valve (ViV). BACKGROUND: Leaflet thrombosis may occur on THVs and affect performance and durability. Differences in flow dynamics may affect the risk for leaflet thrombosis. METHODS: Hemodynamic assessment following THV implantation in a surgical aortic valve was performed in a left heart simulator under pulsatile physiological conditions. Assessment was performed using a 23-mm polymeric surgical aortic valve (not diseased) and multiple THV platforms, including self-expanding devices (26-mm Evolut, 23-mm Allegra, small ACURATE neo) and a balloon-expandable device (23-mm SAPIEN 3). Particle image velocimetry was performed to assess flow in the sinus and NS. Sinus and NS washout, shear stress, and velocity were calculated. RESULTS: Sinus and NS washout was fastest and approximately 1 cardiac cycle for each with the Evolut, ACURATE neo, and Allegra compared with the SAPIEN 3, with washout in 2 and 3 cardiac cycles, respectively. The Allegra showed the largest shear stress distribution in the sinus, followed by the SAPIEN 3. In the NS, all 4 valves showed equal likelihoods of occurrence of shear stress <1 Pa, but the Allegra showed the highest likelihoods of occurrence for shear stress >1 Pa. The velocities in the sinus and NS were 0.05, 0.078, 0.080, and 0.075 m/s for Evolut, SAPIEN 3, ACURATE neo, and Allegra ViV, respectively. CONCLUSIONS: Sinus and NS flow dynamics differ substantially among THVs after ViV. Self-expanding supra-annular valves seem to have faster washouts compared with an equivalent-size balloon-expandable THV.

Simple 2-dimensional anatomic model to predict the risk of coronary obstruction during transcatheter aortic valve replacement.

OBJECTIVE: In this study, a 2-dimensional (2D) index relying on preprocedural computed tomography (CT) data was developed to evaluate the risk of coronary obstruction during transcatheter aortic valve replacement (TAVR) procedures. METHODS: Anatomic measurements from pre-TAVR CT scans were collected in 28 patients among 600 who were flagged as high risk (defined as meeting coronary artery height, h, <14 mm and/or sinus of Valsalva diameter, SOVd, <30 mm) for coronary obstruction. A geometric model derived from these anatomic measurements was used to predict the post-TAVR native cusp apposition relative to the coronary ostium. The distance from the cusp to the coronary ostium, DLC2D, was measured from the geometric model and indexed with the coronary artery diameter, d, to yield a fractional obstruction measure, DLC2D/d. RESULTS: Twenty-three of 28 high-risk patients successfully underwent TAVR without coronary obstruction, of whom 1 had coronary obstruction and 4 were deemed non-TAVR candidates. DLC2D/d differed significantly between the 2 groups (P < .0018), but neither h nor SOVd did (P > .32). The optimal sensitivity and specificity for DLC2D/d were 85% and occurred at a cutoff of 0.45. The optimal sensitivity and specificity of h and SOVd in this high-risk group were only 60% and 40%, respectively, for cutoffs of h = 10 mm and SOVd = 30.5 mm. CONCLUSIONS: The 2D geometric model derived in this study shows promise for identifying patients with low-lying coronary ostium and/or small SOVd that may be safely treated with TAVR. DLC2D/d is more predictive of obstruction or poor TAVR candidacy compared with h and SOVd.

Interatrial shunt devices for the treatment of heart failure.

Despite ongoing advances in the treatment of heart failure, overall symptom burden remains high. Underlying the primary symptom of dyspnea are often elevations in left atrial pressures, which occur across the spectrum of heart failure subgroups. Current therapies do not directly address improvements in left atrial pressures; however, passive left atrial decompression may offer a new avenue to treat heart failure. New technologies are currently being evaluated in clinical testing and may offer a novel therapeutic approach to heart failure.

2020 ACC Expert Consensus Decision Pathway on Management of Conduction Disturbances in Patients Undergoing Transcatheter Aortic Valve Replacement: A Report of the American College of Cardiology Solution Set Oversight Committee.

Consensus regarding a reasonable strategy to manage cardiac conduction disturbances after transcatheter aortic valve replacement (TAVR) has been elusive. This is due to the absence of adequately powered, randomized controlled trials; the often transient nature of the conduction disturbances; evolving technologies; and the interplay of cardiology subspecialties involved. In the absence of high-quality trials, numerous practice styles have been developed, and prolonged observation, electrophysiological testing, and pre-emptive pacemaker implantation have been described. Although the 2013 European Society of Cardiology guidelines address pacing post-TAVR, they do not provide in-depth discussion of this topic. Furthermore, a summary and proposed strategy for this problem have not been published by cardiovascular societies in the United States, despite an interest in establishing best practices in TAVR, valvular heart disease, and cardiovascular implantable electrical devices. This document reviews existing data and experience regarding the management of conduction disturbances after TAVR and proposes an evidence-based expert consensus decision pathway for their management. Where evidence is lacking or insufficient, the recommendations herein are based on expert opinion.

Modeling risk of coronary obstruction during transcatheter aortic valve replacement.

OBJECTIVE: In this study we aimed to evaluate risk of coronary obstruction during transcatheter aortic valve replacement and develop improved criteria based on computational modeling. METHODS: Patient specific 3-dimensional models were constructed and validated for 28 patients out of 600 patients who were flagged as high risk for coronary obstruction (defined as meeting coronary ostium height < 14 mm and/or sinus of Valsalva diameter [SOVd] < 30 mm). The models consisted finite element analysis to predict the post- transcatheter aortic valve replacement native cusp apposition relative to the coronary ostium and were validated in vitro. The distance from cusp to coronary ostium (DLC) was derived from the 3-dimensional models and indexed with the coronary artery diameter to yield a fractional obstruction measure (DLC/d). RESULTS: Twenty-two out of 28 high-risk patients successfully underwent transcatheter aortic valve replacement without coronary obstruction and 6 did not. DLC/d between the 2 groups was significantly different (P < .00078), whereas neither coronary ostium height nor SOVd were significantly different (P > .32). A cutoff of DLC/d < 0.7 was predictive with 100% sensitivity and 95.7% specificity. The optimal sensitivity and specificity of coronary ostium height and SOVd in this high-risk group was only 60% and 40%, respectively, for cutoff coronary ostium height of 10 mm and SOVd of 30.5 mm. CONCLUSIONS: Three-dimensional modeling has the potential to enable more patients to be safely treated with transcatheter aortic valve replacement who have a low-lying coronary ostium or small SOVd. DLC/d is more predictive of obstruction than coronary ostium height and SOVd.

Managing Mitral Regurgitation in Heart Failure-Perspectives After COAPT.

PURPOSE OF REVIEW: Functional mitral regurgitation (MR) in setting of cardiomyopathy causes significant morbidity and worsened survival. Surgical therapies have failed to demonstrate significant overall benefit for functional MR. More recently, major trials utilizing transcatheter therapies for functional MR have been completed and offer new avenues for intervention. This review evaluates and compares 2 major recent trials designed to test the benefit of edge-to-edge repair using the MitraClip system for severe functional MR. RECENT FINDINGS: The Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) and Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation (MITRA-FR) trials were simultaneous trials evaluating the treatment of effect of MitraClip in the setting of severe functional mitral regurgitation. Results of the trials were quite different with COAPT demonstrating substantial clinical benefit including significantly improved survival compared with MITRA-FR in which no clinical benefit was derived. Key differences in the patient population between the COAPT and MITRA-FR trials help to explain the contrasting results between the 2 trials designed to test the same hypothesis. Patients in COAPT had higher severity of MR with less dilated ventricles compared with MITRA-FR. These results will help shape patient selection for who will most benefit from MitraClip therapy. Further transcather mitral valve therapies continue to evolve and will likely offer alternative therapies for MR as technology improves.

A Prospective, Single-Arm, Multicenter Trial of Catheter-Directed Mechanical Thrombectomy for Intermediate-Risk Acute Pulmonary Embolism: The FLARE Study.

OBJECTIVES: The aim of this study was to evaluate the safety and effectiveness of percutaneous mechanical thrombectomy using the FlowTriever System (Inari Medical, Irvine, California) in a prospective trial of patients with acute intermediate-risk pulmonary embolism (PE). BACKGROUND: Catheter-directed thrombolysis has been shown to improve right ventricular (RV) function in patients with PE. However, catheter-directed thrombolysis increases bleeding risk and many patients with PE have relative and absolute contraindications to thrombolysis. METHODS: Patients with symptomatic, computed tomography-documented PE and RV/left ventricular (LV) ratios ≥0.9 were eligible for enrollment. The primary effectiveness endpoint was core laboratory-assessed change in RV/LV ratio. The primary safety endpoint comprised device-related death, major bleeding, treatment-related clinical deterioration, pulmonary vascular injury, or cardiac injury within 48 h of thrombectomy. RESULTS: From April 2016 to October 2017, 106 patients were treated with the FlowTriever System at 18 U.S. sites. Two patients (1.9%) received adjunctive thrombolytics and were analyzed separately. Mean procedural time was 94 min; mean intensive care unit stay was 1.5 days. Forty-three patients (41.3%) did not require any intensive care unit stay. At 48 h post-procedure, average RV/LV ratio reduction was 0.38 (25.1%; p < 0.0001). Four patients (3.8%) experienced 6 major adverse events, with 1 patient (1.0%) experiencing major bleeding. One patient (1.0%) died, of undiagnosed breast cancer, through 30-day follow-up. CONCLUSIONS: Percutaneous mechanical thrombectomy with the FlowTriever System appears safe and effective in patients with acute intermediate-risk PE, with significant improvement in RV/LV ratio and minimal major bleeding. Potential advantages include immediate thrombus removal, absence of thrombolytic complications, and reduced need for post-procedural critical care.

A case study on implantation strategies to mitigate coronary obstruction in a patient receiving transcatheter aortic valve replacement.

Coronary obstruction is a life threatening complication during and post-transcatheter aortic valve replacement (TAVR). The objective of this preliminary work is to investigate the mechanisms underlying coronary obstruction in a patient after TAVR, in whom coronary obstruction was confirmed in addition to highlighting the importance of pre-procedural planning. The aortic root of an 80-year old male patient with coronary obstruction during TAVR-where a 29 mm SAPIEN 3 was deployed-was segmented from Computed Tomography scans and 3D-printed with compliant material. Flow and pressure data were acquired in this 3D-printed model in-vitro using a pulse duplicator under physiological conditions for the cases: a 29 mm SAPIEN 3, a 26 mm SAPIEN 3 expanded with a 29 mm balloon, and a 31 mm Medtronic-CoreValve deployed annularly, supra and sub-annularly respectively. Only the CoreValve in sub-annular axial position and the 29 mm SAPIEN 3 yielded pressure gradients (PG) lower than 10 mmHg (6.76 ±â€¯0.52 and 5.72 ±â€¯0.13 mmHg respectively) while the 26 mm SAPIEN 3, CoreValve in normal and supra-annular positions yielded higher PGs (15.5 ±â€¯0.48, 12.2 ±â€¯0.15 and 10.8 ±â€¯0.24 mmHg respectively). 29 mm SAPIEN 3 implantation yielded an FFR value of 45.7 ±â€¯0.6%. However, 31 mm CoreValve in any of the three different annular positions yielded FFR values going from 89.6 ±â€¯1.1% in supra-annular position to 98.3 ±â€¯1.1% in sub-annular position. Implantation with a 26 mm SAPIEN 3 expanded with a 29 mm balloon also yielded an FFR of 92.1 ±â€¯1.2%. Coronary obstruction in this patient could have been prevented through usage of different valve types and/or through usage of a different combination of valve size-balloon sizes.

Colonoscopy in Patients With Postmyocardial Infarction Gastrointestinal Bleeding: A Nationwide Analysis.

GOALS: The goal of this study was to evaluate outcomes of colonoscopy in the setting of post myocardial infarction (MI) gastrointestinal bleeding (GIB) in a large population-based data set. BACKGROUND: The literature to substantiate the proposed safety of colonoscopy following an acute MI is limited. STUDY: The Nationwide Inpatient Sample (2007 to 2013) was utilized to identify all adult patients (age, 18 y or above) hospitalized with a primary diagnosis of ST-elevation MI and receiving left heart catheterization (STEMI-C). The outcomes of patients with concomitant diagnosis of GIB receiving endoscopic intervention with esophagogastroduodenoscopy (EGD) or colonoscopy postcatheterization were compared with those who did not. Primary outcomes including mortality, length of stay, and hospital costs were evaluated with univariate and multivariate analysis. RESULTS: There were 131,752 patients with post-STEMI-C GIB (5.35% of all STEMI-C patients) and same admission colonoscopy was performed in 1599 patients (1.21%). Although the prevalence of post-STEMI-C GIB increased from 4.27% in 2007 to 5.87% in 2013 (P<0.001), patients receiving colonoscopy decreased from 1.42% to 1.09% (P<0.001) over the course of the study period. Multivariate analysis revealed that patients receiving no endoscopic intervention [odds ratio, 3.61; 95% confidence interval: 1.57, 8.31] or EGD alone (OR, 2.70; 95% confidence interval: 1.12, 6.49) have higher mortality compared with those receiving colonoscopy. CONCLUSIONS: Same admission colonoscopy performed for post-STEMI-C GIB was associated with lower mortality. However, despite increased incidence of GIB in these patients during the study period, a lower percentage of patients received colonoscopy. These results suggest that colonoscopy is safe but underutilized in this setting.

Impact of patient-specific morphologies on sinus flow stasis in transcatheter aortic valve replacement: An in vitro study.

OBJECTIVE: The goal of this study is to evaluate how sinus flow patterns after transcatheter aortic valve replacement in realistic representative patient roots vary. Sinus flow can affect transcatheter aortic valve operation and likely leaflet thrombosis occurrence due to stasis and poor washout. How the interaction between transcatheter aortic valve and representative patient aortic roots affects sinus hemodynamics is important to establish for future individualization of transcatheter aortic valve replacement therapy. METHODS: Two representative patient aortic roots were selected, segmented and 3-dimensional printed followed by deployment of Medtronic CoreValve (Medtronic Inc, Irvine, Calif) and Edwards SAPIEN (Edwards Lifesciences, Irvine Calif) transcatheter aortic valves. Sinus hemodynamics were assessed in vitro using high spatio-temporal resolution particle-image-velocimetry. Detailed sinus vortex tracking, shear stress probability density functions, and sinus washout were evaluated and assessed as a function of valve type and representative patient morphology as independent case studies. RESULTS: Peak velocity in the sinus with SAPIEN valve was approximately 3 times higher than with CoreValve for both models (0.30 ± 0.02 m/s and 0.34 ± 0.041 m/s vs 0.13 ± 0.01 m/s and 0.10 ± 0.02 m/s) (P < .01). Between representative patient models, vorticity magnitudes were significantly different (75 ± 1.1 s-1, 77 ± 3.2 s-1, 109 ± 2.3 s-1, and 250 ± 4.1 s-1) (P < .01) regardless of valve type. Sinus blood washout characteristic as a function of cardiac cycles was strongly both patient related and valve specific. Fluid dynamics favored shear stresses and washout characteristics due to a smaller sinus and sinotubular junction, further amplified by the SAPIEN valve. CONCLUSIONS: Sinus flow dynamics are highly sensitive to aortic root characteristics and transcatheter aortic valve aortic root interaction. Differences in sinus-flow washout and stasis regions between representative patient models may be reflected in different risks of leaflet thrombosis or valve degeneration.

Sinus Hemodynamics Variation with Tilted Transcatheter Aortic Valve Deployments.

Leaflet thrombosis is a complication associated with transcatheter aortic valve (TAV) replacement (TAVR) correlated with sinus flow stasis. Sinus hemodynamics are important because they dictate shear stress and washout necessary to avoid stasis on TAV leaflets. Sinus flow is controlled by TAV axial deployment position but little is known regarding TAV axis misalignment effect. This study aims to elucidate TAV angular misalignment with respect to aortic root axis effect on sinus flow stasis potentially leading to leaflet thrombosis. Sinus hemodynamics were assessed in vitro using particle-image velocimetry in three different angular misalignments with respect to aorta axis: untilted, tilted away from the sinus and tilted towards sinus. A 26 mm Edwards SAPIEN3 was implanted in a 3D printed model of an anatomically realistic aortic root. TAV hemodynamics, sinus vortex tracking, leaflet shear stress probability density functions, and sinus blood time to washout were calculated. While pressure gradients differed insignificantly, blood velocity and vorticity decreased significantly in both tilted cases sinuses. Shear stress probability near the leaflet decreases with tilt indicating stasis. TAV tilted away from the sinus is the most unfavorable scenario with poor washout. TAV axial misalignment adds to factors list that could influence leaflet thrombosis risk through modifying sinus hemodynamics and washout.

Interventional Heart Failure and Hemodynamic Monitoring.

Convergence of the fields of heart failure (HF) and interventional cardiology has led to the formation of a discipline referred to as interventional HF. Although the term may be applied to essentially any invasive procedure performed in patients with HF (eg, coronary angiography, percutaneous coronary intervention, invasive assessment of hemodynamics), it is more commonly reserved for the application of invasive diagnostic or therapeutic procedures to improve the clinical decision-making, functional status, and outcomes of HF patients. This article reviews developing modalities.

Advanced chronic kidney disease: Relationship to outcomes post-TAVR, a meta-analysis.

Chronic kidney disease (CKD) is associated with worse outcomes in high-surgical-risk patients undergoing transcatheter aortic valve replacement (TAVR). However, it is unclear whether this relationship is apparent in lower-surgical-risk patients. We sought to analyze existing literature to assess whether or not advanced CKD is associated with increased mortality or a greater incidence of adverse events (specifically major stroke, bleeding, and vascular complications). We searched PubMed and Embase (2008-2017) for relevant studies. Studies with <1 year follow-up and those not evaluating advanced CKD or outcomes post-TAVR were excluded. Our co-primary endpoints were the incidence of short-term mortality (defined as in-hospital or 30-day mortality) and long-term mortality (1 year). Our secondary endpoints included incidence of major stroke, life-threatening bleeding, and major vascular complications. Eleven observational studies with a total population of 10709 patients met the selection criteria. Among patients with CKD there was an increased risk of short- and long-term mortality in high-surgical-risk patients who underwent TAVR (hazard ratio [HR]: 1.51, 95% confidence interval [CI]: 1.22-1.88 and HR: 1.56, 95% CI: 1.38-1.77, respectively; P < 0.01). However, there was no association between CKD and mortality in low- to intermediate-risk patients (HR: 1.35, 95% CI: 0.98-1.84, P = 0.06 in short-term and HR: 1.08, 95% CI: 0.92-1.27, P = 0.34 in long-term). In low- to intermediate-risk TAVR patients, advanced CKD is not associated with increased mortality or poorer safety outcomes. These findings should be factored into the clinical decision-making process regarding TAVR candidacy.

Effect of severe bioprosthetic valve tissue ingrowth and inflow calcification on valve-in-valve performance.

While in vivo studies clearly demonstrate that supra-annular Valve-in-Valve (ViV) implantation provides the highest probability for optimal post-ViV pressure gradients (PG), there is still no physical insight into explaining anomalies where some supra-annular ViV implantations yield high pressure gradients while some sub-annular implantations yield low pressure gradients. The aim of this study is to explain how severe tissue ingrowth and calcification (TIC) in a surgical aortic valve (SAV) can be one physical mechanism leading to anomalous ViV performance characteristic. The ViV hemodynamic performance was evaluated as a function of axial positioning -9.8, -6.2, 0, and +6 mm in SAVs with and without TIC. Effective orifice area (EOA) and PG were compared. Leaflet high-speed imaging and particle image velocimetry were performed to elucidate flutter and forward jet characteristics. ViV without TIC showed significantly lower PG and greater EOA (p < 0.01). EOA and PG improve with supra-annular deployment (p < 0.01) while for ViV with TIC, EOA and PG worsen as the deployment varies from -9.8 mm to 0 mm (p < 0.01) only to recover at + 6 mm (p < 0.01). Separated jet flow at the TIC site, and consequently induced stronger TAV leaflet fluttering highlight the dynamic compromising nature of TIC on jet width and performance reduction. We conclude that the inflow TIC greatly influence ViV performance due to dynamic effects that results in a real anomalous performance characteristic different than that seen in most ViV in vivo. Further in vivo studies are needed to evaluate ViV outcomes in the presence of severe TIC in SAVs.

Implantation Depth and Rotational Orientation Effect on Valve-in-Valve Hemodynamics and Sinus Flow.

BACKGROUND: This study evaluated the effect of transcatheter aortic valve implantation depth and rotation on pressure gradient (PG), leakage fractions (LF), leaflet shear stress, and sinus washout in an effort to understand factors that may dictate optimal positioning for valve-in-valve (ViV) procedures. Sinus flow stasis is often associated with prosthetic leaflet thrombosis. Although recent ViV in vitro studies highlighted potential benefits of transcatheter aortic valve supraannular implantation to minimize PGs, the relationship between transcatheter aortic valve depth and other determinates of valve function remains unknown. Among these, LFs, shear stress, and poor sinus washout have been associated with poorer valve outcomes. METHODS: ViV hemodynamic performance was evaluated in vitro vs axial positions -9.8, -6.2, 0, and +6 mm and angular orientations 0, 30, 60, and 90 degrees in a degenerated surgical aortic valve. PGs, LFs, and sinus shear stress and washout were compared. Leaflet high-speed imaging and particle-image velocimetry were performed to elucidate hemodynamic mechanisms. RESULTS: (1) The PG varies as a function of axial position, with supraannular deployments yielding a maximum benefit of 7.85 mm Hg less than PGs for subannular deployments irrespective of commissural alignment (p < 0.01); (2) in contrast, LF decreased in relationship to subannular deployment; and (3) at peak systole, sinus flow shear stress increased with deployment depth as did sinus washout with and without coronary flow. CONCLUSIONS: First, supraannular axial deployment is associated with lower PGs irrespective of commissural alignment. Second, subannular deployment is associated with more favorable sinus hemodynamics and less LF. Further in vivo studies are needed to substantiate these observations and facilitate optimal prosthesis positioning during ViV procedures.