Peak Transvalvular Pressure Gradient Research Articles

Balloon Valvuloplasty in Congenital Critical Aortic Valve Stenosis in Neonates and Infants: A Rescue Procedure for the Left Ventricle.

Congenital critical aortic valve stenosis (CAVS) is a life-threatening disease requiring urgent treatment. First-line therapy is still controversial. The aim of our study was (1) to analyze retrospectively the patients of our institution who underwent balloon aortic valvuloplasty (BAV) due to CAVS and (2) describe the techniques for improved feasibility of intervention using microcatheters and retrieval loops. Twelve patients underwent 23 BAVs: 1 BAV was performed in 3 patients, 2 BAVs were performed in 7 patients, and 3 BAVs were performed in 2 patients. The peak trans-valvular pressure gradient (Δp) and left ventricular shortening fraction (LVSF) improved significantly in the first two interventions. In the first BAV, Δp decreased from 73.7 ± 34.5 mmHg to 39.8 ± 11.9 mmHg (p = 0.003), and the LVSF improved from 22.3 ± 13.5% to 31.6 ± 10.2% (p = 0.001). In the second BAV, Δp decreased from 73.2 ± 33.3 mmHg to 35.0 ± 20.2 mmHg (p < 0.001), and the LVSF increased from 26.7 ± 9.6% to 33.3 ± 7.4% (p = 0.004). Cardiac surgery during the neonatal period was avoided for all children. The median time to valve surgery was 5.75 years. Few complications occurred, namely mild-to-moderate aortic regurgitation, one remediable air embolism, and one intimal injury to the ascending aorta. We conclude that BAV is a successful emergency treatment for CAVS, resulting in left ventricular relief, clinical stabilization, and a time gain until cardiac surgery.

Innovations in Aortic Valve Replacement: A Comprehensive Overview of the Intuity Rapid Deployment Valve

Rapid deployment/sutureless (RDS) valves have recently emerged as an innovative surgical solution, providing an alternative to traditional methods of surgical aortic valve replacement (SAVR) by eliminating the need for suture placement and tying. This innovation leads to a reduction in aortic crossclamp and cardiopulmonary bypass times, enhancing the efficiency of the procedure. Among the 2 available RDS valves, the Edwards Intuity valve in particular has been demonstrated to be a particularly promising substitute in the field of SAVR. The Intuity valve distinguishes itself from other RDS and conventional valves by yielding superior outcomes, such as a significant reduction in mortality, increase in the longevity of the valve, and a marked decrease in both mean and peak transvalvular pressure gradients. These benefits collectively contribute to its appeal as a favorable new solution. However, further investigation is needed to conclusively determine the long-term outcomes and safety of RDS valves. Nevertheless, the utilization of the Intuity valve presents an exciting solution to the existing limitations of conventional and minimally invasive SAVR, especially for patients afflicted with severe aortic stenosis.

AVCAPIR: A Novel Procalcific PIWI-Interacting RNA in Calcific Aortic Valve Disease.

Calcification of the aortic valve leads to increased leaflet stiffness and consequently results in the development of calcific aortic valve disease (CAVD). However, the underlying molecular and cellular mechanisms of calcification remain unclear. Here, we identified a novel aortic valve calcification-associated PIWI-interacting RNA (piRNA; AVCAPIR) that increases valvular calcification and promotes CAVD progression. Using piRNA sequencing, we identified piRNAs contributing to the pathogenesis of CAVD that we termed AVCAPIRs. High-cholesterol diet-fed ApoE-/- mice with AVCAPIR knockout were used to examine the role of AVCAPIR in aortic valve calcification (AVC). Gain- and loss-of-function assays were conducted to determine the role of AVCAPIR in the induced osteogenic differentiation of human valvular interstitial cells. To dissect the mechanisms underlying AVCAPIR-elicited procalcific effects, we performed various analyses, including an RNA pulldown assay followed by liquid chromatography-tandem mass spectrometry, methylated RNA immunoprecipitation sequencing, and RNA sequencing. RNA pulldown and RNA immunoprecipitation assays were used to study piRNA interactions with proteins. We found that AVCAPIR was significantly upregulated during AVC and exhibited potential diagnostic value for CAVD. AVCAPIR deletion markedly ameliorated AVC in high-cholesterol diet-fed ApoE-/- mice, as shown by reduced thickness and calcium deposition in the aortic valve leaflets, improved echocardiographic parameters (decreased peak transvalvular jet velocity and mean transvalvular pressure gradient, as well as increased aortic valve area), and diminished levels of osteogenic markers (Runx2 and Osterix) in aortic valves. These results were confirmed in osteogenic medium-induced human valvular interstitial cells. Using unbiased protein-RNA screening and molecular validation, we found that AVCAPIR directly interacts with FTO (fat mass and obesity-associated protein), subsequently blocking its N6-methyladenosine demethylase activity. Further transcriptomic and N6-methyladenosine modification epitranscriptomic screening followed by molecular validation confirmed that AVCAPIR hindered FTO-mediated demethylation of CD36 mRNA transcripts, thus enhancing CD36 mRNA stability through the N6-methyladenosine reader IGF2BP1 (insulin-like growth factor 2 mRNA binding protein 1). In turn, the AVCAPIR-dependent increase in CD36 stabilizes its binding partner PCSK9 (proprotein convertase subtilisin/kexin type 9), a procalcific gene, at the protein level, which accelerates the progression of AVC. We identified a novel piRNA that induced AVC through an RNA epigenetic mechanism and provide novel insights into piRNA-directed theranostics in CAVD.

Valvular and ascending aortic hemodynamics of the On-X aortic valved conduit by same-day echocardiography and 4D flow MRI.

This study aims to assess whether the On-X aortic valved conduit better restores normal valvular and ascending aortic hemodynamics than other commonly used bileaflet mechanical valved conduit prostheses from St. Jude Medical and Carbomedics by using same-day transthoracic echocardiography (TTE) and 4D flow magnetic resonance imaging (MRI) examinations. TTE and 4D flow MRI were performed back-to-back in 10 patients with On-X, six patients with St. Jude (two) and Carbomedics (four) prostheses, and 36 healthy volunteers. TTE evaluated valvular hemodynamic parameters: transvalvular peak velocity (TPV), mean and peak transvalvular pressure gradient (TPG), and effective orifice area (EOA). 4D flow MRI evaluated the peak systolic 3D viscous energy loss rate (VELR) density and mean vorticity magnitude in the ascending aorta (AAo). While higher TPV and mean and peak TPG were recorded in all patients compared to healthy subjects, the values in On-X patients were closer to those in healthy subjects (TPV 1.9 ± 0.3 vs. 2.2 ± 0.3 vs. 1.2 ± 0.2 m/s, mean TPG 7.4 ± 1.9 vs. 9.2 ± 2.3 vs. 3.1 ± 0.9 mmHg, peak TPG 15.3 ± 5.2 vs. 18.9 ± 5.2 vs. 6.1 ± 1.8 mmHg, p < 0.001). Likewise, while higher VELR density and mean vorticity magnitude were recorded in all patients than in healthy subjects, the values in On-X patients were closer to those in healthy subjects (VELR: 50.6 ± 20.1 vs. 89.8 ± 35.2 vs. 21.4 ± 9.2 W/m3, p < 0.001) and vorticity (147.6 ± 30.0 vs. 191.2 ± 26.0 vs. 84.6 ± 20.5 s-1, p < 0.001). This study demonstrates that the On-X aortic valved conduit may produce less aberrant hemodynamics in the AAo while maintaining similar valvular hemodynamics to St. Jude Medical and Carbomedics alternatives.

Expanded polytetrafluoroethylene conduits with curved and handsewn bileaflet designs for right ventricular outflow tract reconstruction

ObjectiveThis study reviewed the application of curved and bileaflet designs to pulmonary expanded polytetrafluoroethylene conduits with diameters of 10 to 16 mm and characterized this conduit on in vitro experiment, including particle image velocimetry. MethodsAll patients who received this conduit between 2010 and 2022 were evaluated. Three 16-mm conduits were tested in a circulatory simulator at different cardiac outputs (1.5-3.6 L/minute) and bending angles (130°-150°). ResultsFifty consecutive patients were included. The median operative body weight was 8.4 kg (range, 2.6-12 kg); 10-, 12-, 14-, and 16-mm conduits were used in 1, 4, 6, and 39 patients, respectively. In 34 patients, the conduit was implanted in a heterotopic position. The overall survival rate was 89% at 8 years with 3 nonvalve-related deaths. There were 10 conduit replacements; 5 16-mm conduits (after 8 years) and 1 12-mm conduit (after 6 years) due to conduit stenosis, and the remaining 4 for reasons other than conduit failure. Freedom from conduit replacement was 89% and 82% at 5 and 8 years, respectively. Linear mixed-effects models with echocardiographic data implied that 16-mm conduits were durable with a peak velocity <3.5 m/second and without moderate/severe regurgitation until the patient's weight reached 25 kg. In experiments, peak transvalvular pressure gradients were 11.5 to 25.5 mm Hg, regurgitant fractions were 8.0% to 14.4%, and peak Reynolds shear stress in midsystolic phase was 29 to 318 Pa. ConclusionsOur conduits with curved and bileaflet designs have acceptable clinical durability and proven hydrodynamic profiles, which eliminate valve regurgitation and serve as a reliable bridge to subsequent conduit replacement.

Sutureless vs. rapid-deployment valve: a systemic review and meta-analysis for a direct comparison of intraoperative performance and clinical outcomes.

Sutureless and rapid-deployment valves are bioprostheses anchoring within the aortic annulus with few sutures, and they act as a hybrid of conventional surgical and transcatheter valves under aortic valve replacement. Considering that the 3F Enable valve is now off-market, the only two sutureless and rapid-deployment valves available on the world marketplace are the Perceval and Intuity valves. However, a direct comparison of the function of these two valves eludes researchers. Against this background, we performed this systematic review and meta-analysis comparing the intraoperative performance and early clinical outcomes between the Perceval valve and the Intuity valve under sutureless and rapid-deployment aortic valve replacement. We systematically searched electronic databases through PubMed/MEDLINE, OvidWeb, Web of Science, and Cochrane Central Register of Controlled Trials (from the establishment of the database to November 17, 2022, without language restriction) for studies comparing the sutureless valve (the Perceval) and the rapid-deployment valve (the Intuity) under aortic valve replacement. Our primary outcomes were early mortality and postoperative transvalvular pressure gradients. The secondary outcomes were defined to include aortic cross-clamp and cardiopulmonary bypass time, paravalvular leak (any paravalvular leak, moderate-to-severe paravalvular leak) after aortic valve replacement, need for pacemaker implantation, postoperative neurological events (stroke), and intensive care unit stay. This meta-analysis included ten non-randomized trials with 3,526 patients enrolled (sutureless group = 1,772 and rapid-deployment group = 1,754). Quality assessments were performed, with the mean scores of the studies reading 6.90 (SD = 0.99) out of 9 according to the Newcastle-Ottawa Scale. Compared with rapid-deployment aortic valve replacement, sutureless aortic valve replacement was associated with higher mean and peak transvalvular pressure gradients postoperatively. In contrast, aortic cross-clamp and cardiopulmonary time were needed less in sutureless aortic valve replacement vs. rapid-deployment aortic valve replacement. There was no evidence of significant publication bias observed by the funnel plot and Egger's test. For postoperative hemodynamics, sutureless aortic valve replacement was associated with increased mean and peak transvalvular pressure gradients compared with rapid-deployment aortic valve replacement. In sharp contrast, sutureless aortic valve replacement significantly reduced the amount of time needed for fixing the aortic cross-clamp and the cardiopulmonary bypass procedure. https://www.crd.york.ac.uk/prospero/, identifier CRD42022343884.

Left ventricular hypertrophy, diastolic dysfunction and right ventricular load predict outcome in moderate aortic stenosis.

Predictors of progression of moderate aortic valve stenosis (AS) are incompletely understood. The objective of this study was to evaluate the prognostic value of left ventricular hypertrophy (LVH), diastolic dysfunction, and right ventricular (RV) load in moderate AS. Moderate AS was defined by aortic valve area (AVA), peak transvalvular velocity (Vmax) or mean pressure gradient (PGmean). A total of 131 Patients were divided into two groups according to the number of pathophysiological changes (LVH, diastolic dysfunction with increased LV filling pressures and/or RV load): <2 (group 1); ≥2 (group 2). The primary outcome was survival without aortic valve replacement (AVR). After follow-up of 30 months, the reduction of AVA (-0.06 ± 0.16 vs. -0.24 ± 0.19 cm2, P < 0.001), the increase of PGmean (2.89 ± 6.35 vs 6.29 ± 7.13 mmHg, P < 0.001) and the decrease of the global longitudinal strain (0.8 ± 2.56 vs. 1.57 ± 3.42%, P < 0.001) from baseline to follow-up were significantly more pronounced in group 2. Survival without AVR was 82% (group 1) and 56% (group 2) [HR 3.94 (1.74-8.94), P < 0.001]. Survival without AVR or progression of AS was 77% (group 1) and 46% (group 2) [HR 3.80 (1.84-7.86), P < 0.001]. The presence of ≥2 pathophysiological changes predicted outcome whereas age, comorbidities, LDL-cholesterol did not. The presence of ≥2 pathophysiological changes is a strong predictor of outcome in moderate AS and may be useful for risk stratification, particularly for scheduling follow-up time intervals and deciding the timing of AVR.

Two-year outcomes after transcatheter aortic valve-in-valve implantation in degenerated surgical valves.

Transcatheter aortic valve-in-valve implantation (ViV-TAVI) has emerged in recent years as a safe alternative to redo surgery in high-risk patients. Although early results are encouraging, data beyond short-term outcomes are lacking. Herein, we aimed to assess the 2-year outcomes after ViV-TAVI. Patients undergoing ViV-TAVI for degenerated surgical valves between 2013 and 2019 at the Cleveland Clinic were reviewed. The coprimary endpoints were all-cause mortality and congestive heart failure (CHF) hospitalizations. We used time-to-event analyses to assess the primary outcomes. Further, we measured the changes in transvalvular gradients and the incidence of structural valve deterioration (SVD). One hundred and eighty-eight patients were studied (mean age = 76 years; 65% males). At 2 years of follow-up, all-cause mortality and CHF hospitalizations occurred in 15 (8%) and 28 (14.9%) patients, respectively. On multivariable analysis, the postprocedural length of stay was a significant predictor for both all-cause mortality (hazard ratio [HR] = 1.1; 95% confidence interval [CI]: 1.01, 1.19) and CHF hospitalization (HR = 1.16; 95% CI: 1.07, 1.27). However, the internal diameter of the surgical valve was not associated with significant differences in both primary endpoints. For hemodynamic outcomes, nine patients (4.8%) developed SVD. The mean and peak transvalvular pressure gradients remained stable over the follow-up period. ViV-TAVI for degenerated surgical valves was associated with favorable 2-year clinical and hemodynamic outcomes. Further studies are needed to better understand the role of ViV-TAVI as a treatment option in the life management of aortic valve disease.

Hemodynamic performance of INSPIRIS RESILIA aortic bioprosthesis for severe aortic stenosis: 2-year follow-up in Japanese cohort.

The INSPIRIS RESILIA aortic bioprosthesis (Edwards Lifesciences LLC, Irvine, USA) was fixed in novel tissue preservation technology to ensure long-term durability. Hemodynamic performance after aortic valve replacement (AVR) for severe aortic stenosis (AS) has not been published in the Japanese cohort. Twenty-nine patients underwent AVR with INSPIRIS RESILIA bioprosthesis for severe AS between November 1, 2018 and December 31, 2020. The mean age was 75.1 ± 4.5years with 19 female patients. Body surface area was 1.58 ± 0.19 m2 and New York Heart Association functional class was 2.2 ± 0.5. Hemodynamic performance was assessed using follow-up transthoracic echocardiographic data collected at 3-6months, 1year and 2years. The mean follow-up time was 19.2 ± 7.2months, with a 100% follow-up rate. One patient died of postoperative heart failure. The preoperative mean and peak transvalvular pressure gradients (PGs) were 51.9 ± 18.4mmHg and 89.3 ± 34.9mmHg, respectively, and effective orifice area 0.72 ± 0.26 cm2. They improved at 10.2 ± 3.5mmHg (p < 0.0001), 19.3 ± 6.6mmHg (p < 0.0001) and 1.73 ± 0.47cm2 (p < 0.0001) at discharge. The mean transvalvular PG at 3-6months (n = 24), 1year (n = 25) and 2years (n = 15) was 11.2 ± 3.8mmHg (p < 0.0001), 11.1 ± 3.2mmHg (p < 0.0001) and 11.2 ± 3.3mmHg (p < 0.0001), respectively. Left ventricular mass index decreased from 123.0 ± 35.0g/m2 before surgery to 113.4 ± 35.0g/m2 (p = 0.0133) at discharge. It has dropped to 88.0 ± 25.0g/m2 (p = 0.0007) at 2years. Constrictive pericarditis caused heart failure in one patient. INSPIRIS RESILIA bioprosthesis showed improved hemodynamic performance in the early postoperative phase. There were fewer valve-related events observed.

DUSP26 induces aortic valve calcification by antagonizing MDM2-mediated ubiquitination of DPP4 in human valvular interstitial cells.

The morbidity and mortality rates of calcific aortic valve disease (CAVD) remain high while treatment options are limited. Here, we evaluated the role and therapeutic value of dual-specificity phosphatase 26 (DUSP26) in CAVD. Microarray profiling of human calcific aortic valves and normal controls demonstrated that DUSP26 was significantly up-regulated in calcific aortic valves. ApoE-/- mice fed a normal diet or a high cholesterol diet (HCD) were infected with adeno-associated virus serotype 2 carrying DUSP26 short-hairpin RNA to examine the effects of DUSP26 silencing on aortic valve calcification. DUSP26 silencing ameliorated aortic valve calcification in HCD-treated ApoE-/- mice, as evidenced by reduced thickness and calcium deposition in the aortic valve leaflets, improved echocardiographic parameters (decreased peak transvalvular jet velocity and mean transvalvular pressure gradient, as well as increased aortic valve area), and decreased levels of osteogenic markers (Runx2, osterix, and osteocalcin) in the aortic valves. These results were confirmed in osteogenic medium-induced human valvular interstitial cells. Immunoprecipitation, liquid chromatography-tandem mass spectrometry, and functional assays revealed that dipeptidyl peptidase-4 (DPP4) interacted with DUSP26 to mediate the procalcific effects of DUSP26. High N6-methyladenosine levels up-regulated DUSP26 in CAVD; in turn, DUSP26 activated DPP4 by antagonizing mouse double minute 2-mediated ubiquitination and degradation of DPP4, thereby promoting CAVD progression. DUSP26 promotes aortic valve calcification by inhibiting DPP4 degradation. Our findings identify a previously unrecognized mechanism of DPP4 up-regulation in CAVD, suggesting that DUSP26 silencing or inhibition is a viable therapeutic strategy to impede CAVD progression.

Initial experience with the Perceval S sutureless aortic valve.

IntroductionSurgical treatment of the aortic valve represents the gold standard, and thus aortic valve replacement (AVR) is one of the most commonly performed cardiac operations.AimTo evaluate the early outcome of aortic valve replacement with the Perceval S sutureless aortic bioprosthesis.Material and methodsThis was a retrospective analysis of 24 patients (mean age: 71 ±5 years), who underwent aortic valve replacement with a Perceval S valve. Concomitant coronary artery bypass grafting (CABG) was performed in 9 patients. Patients were evaluated preoperatively, at hospital discharge, and once during follow-up.ResultsA total of 15 of 24 patients underwent isolated sutureless aortic valve replacement (mean aortic cross-clamp time: 60 ±14 minutes; mean bypass time: 90 ±23 minutes). Coronary bypass grafting was performed in 9 patients (mean aortic cross-clamp time: 78 ±23 minutes; mean bypass time: 111 ±31 minutes). Hospital mortality was nil. Mean and peak transvalvular pressure gradients were 10 ±2 mm Hg and 21 ±3 mm Hg at follow-up, respectively. Moderate or severe aortic regurgitation did not develop in any patients during the follow-up period. No valve thrombosis, thromboembolic events, or structural valve deterioration were observed.ConclusionsIn our experience with sutureless aortic valve replacement, the surgical procedure is shown to be safe. The early haemodynamic performance seems favourable. By shortening the aortic cross-clamp and bypass times we can notice advantages, especially in high-risk patients. Minimally invasive access seems to be facilitated. Larger studies are needed to confirm our data and determine the long-term durability of the Perceval S sutureless bioprosthesis.

Early clinical outcomes of simple pannus removal for mechanical aortic valve stenosis

BackgroundThis study aimed to confirm the safety and feasibility of simple pannus removal in patients with mechanical aortic valve dysfunction for pannus overgrowth by evaluating its early clinical outcomes.MethodsFrom March 2015 to April 2019, 24 consecutive patients with mechanical aortic valve dysfunction due to subaortic pannus underwent reoperation. In 12 patients the repeat aortic valve replacement (AVR) was performed, and 12 received the simple pannus removal to preserve the previously implanted prosthesis.ResultsThere was only 1 in-hospital death in simple pannus removal group. Significant differences were obtained between procedures in cardiopulmonary bypass (CPB) and aortic cross-clamp time (128.7 vs 179.7 and 74.2 vs 132.7 mins, respectively, P < 0.05). The C-reactive protein (CRP) in simple pannus removal group was lower on the first day (0.13 ± 0.09 vs 0.31 ± 0.22 mg/dl, P < 0.05) and continued to be lower within 1 week after operation. There was no significant difference between procedures in aortic transvalvular peak velocity and transvalvular mean pressure gradient (TMPG) (2.6 ± 0.4 vs 2.5 ± 0.4 m/s and 13.2 ± 3.6 vs 11.6 ± 2.6 mmHg, respectively, P > 0.05) in echocardiography 1 week after operation. In addition, the aortic transvalvular peak velocity and TMPG in echocardiography 1 week after operation in pannus removal group between the repeat and initial surgery were not statistically significant (2.6 ± 0.4 vs. 2.5 ± 0.3 m/s, 13.2 ± 3.6 vs. 13.0 ± 3.5 mmHg, P > 0.05).ConclusionsSimple pannus removal was a safe and effective procedure with satisfied early clinical outcomes for pannus overgrowth in mechanical aortic valve. However, further randomized and long-term follow-up studies were warranted to determine the clinical effects of the simple aortic pannus removal.

In vitro evaluation of a new aortic valved conduit

BackgroundThis study examined whether the presence of a sinus of Valsalva equivalent in the KONECT RESILIA aortic valved conduit (Edwards Lifesciences, Irvine, Calif) improves valve hemodynamics, kinematics, and performance. MethodsA 28-mm KONECT RESILIA aortic valved conduit was used to create an in vitro flow test model, and the same aortic valved conduit model without a sinus section was used as a control. Particle image velocimetry and hydrodynamic characterization experiments were conducted in the vicinity of the valves in a validated left-heart simulator at 3 cardiac output levels. In addition, leaflet kinematics of the valves were determined through en face high-speed imaging. ResultsThe KONECT RESILIA aortic valved conduit model exhibited lower mean and peak transvalvular pressure gradients than the control model at all 3 cardiac outputs. In addition, its leaflets opened more fully than did those of the valved conduit without the sinuses, yielding greater effective and geometric orifice areas. It was found that the presence of the sinuses not only facilitated the development of larger and more stable vortices at the initial stages of the cardiac cycle but also helped to maintain these vortices during the late stages of the cardiac cycle, leading to smoother valve closure. ConclusionsThe KONECT RESILIA aortic valved conduit reproduces the bulged section of the aortic root corresponding to the sinuses of Valsalva. With this Valsalva-type conduit, larger orifice areas were observed, improving valve hemodynamics that may enhance performance.

Modeling of the Instantaneous Transvalvular Pressure Gradient in Aortic Stenosis.

The simplified and modified Bernoulli equations break down in estimating the true pressure gradient across the stenotic aortic valve due to their over simplifying assumptions of steady and inviscid conditions as well as the fundamental nature in which aortic valves are different than idealized orifices. Nevertheless, despite having newer models based on time-dependent momentum balance across an orifice, the simplified and modified Bernoulli continue to be the clinical standard because to date, they remain the only models clinically implementable. The objective of this study is to (1) illustrate the fundamental considerations necessary to accurately model the time-dependent instantaneous pressure gradient across a fixed orifice and (2) propose empirical corrections when applying orifice based models to severely stenotic aortic valves. We introduce a general model to predict the time-dependent instantaneous pressure gradient across an orifice that explicitly model the Reynolds number dependence of both the steady and unsteady terms. The accuracy of this general model is assessed with respect to previous models through pulse duplicator experiments on a round orifice model as well as an explanted stenotic surgical aortic valve both with geometric areas of 0.6cm2 (less than 1cm2 which is the threshold for stenosis determination) over cardiac outputs of 3 and 5L/min and heart rates of 60, 90 and 120bpm. The model and the raw experimental data corresponding to the orifice showed good agreement over a wide range of cardiac outputs and heart rates (R2 exceeding 0.91). The derived average and peak transvalvular pressure gradients also demonstrated good agreement with no significant differences between the respective peaks (p > 0.09). The new model proposed holds promise with its physical and closed form representation of pressure drop, however accurate modeling of the time-variability of the valve area is necessary for the model to be applied on stenotic valves.

Valve Hemodynamics and Clinical Outcomes After Transcatheter Aortic Valve Replacement for a Small Aortic Annulus.

The hemodynamics and outcomes in patients with a small aortic annulus (SAA) after transcatheter aortic valve replacement (TAVR) with a second-generation transcatheter heart valve remain unclear. We investigated whether TAVR with a Sapien XT (Edwards Lifesciences, Irvine, California) influences postprocedural valve hemodynamics and long-term outcome in high-risk SAA patients compared with surgical aortic valve replacement (SAVR).We retrospectively identified 94 SAA patients who underwent aortic valve replacement (TAVR = 35 and SAVR = 59). SAA was defined as an aortic annulus diameter ≤ 20 mm, measured by preprocedural transesophageal echocardiography.The mean age was 80.2 years. The mean Society of Thoracic Surgeons-Predicted Risk of Mortality was 6.8%. The post-procedural peak transvalvular velocity and mean pressure gradient were significantly lower in the TAVR cohort than in the SAVR cohort, whereas the postprocedural aortic valve area was significantly higher in the TAVR cohort. Severe prosthesis-patient mismatch (PPM) occurred less frequently after TAVR than SAVR (TAVR 2.9% versus SAVR 22.0%, P = 0.01). The two-year mortality in SAA patients was similar between the two groups.TAVR with a Sapien XT in SAA patients improved the valve hemodynamics and reduced the incidence of PPM compared with SAVR. TAVR patients had a similar 2-year mortality despite higher risk baseline characteristics. To avoid PPM and the consequent poor outcomes, TAVR can be considered an alternative option to SAVR in high surgical risk patients with SAA.

COMPARATIVE ASSESSMENT OF CLINICAL AND HEMODYNAMIC OUTCOMES AFTER AORTIC HEART VALVE REPLACEMENT WITH XENOAORTIC AND XENOPERICARDIAL BIOLOGICAL PROSTHESES FOR DEGENERATIVE AORTIC VALVULAR DISEASE

Aim. To assess clinical and hemodynamic outcomes of aortic valve replacement with xenoaortic biological prosthesis “Aspire Vascutek” and xenopericardial biological prosthesis “UniLine”. Methods. 130 patients who underwent aortic valve replacement with bioprostheses in the period from October 2012 to March 2016 were included in the study. All patients were enrolled into two groups according to the model of the implanted device. 65 recipients of xenoaortic bioprostheses “Aspire Vascutek” were included in Group 1, whereas patients (n = 65) xenopericardial bioprostheses “UniLine” were assigned in Group 2. Males prevailed in Group 1 (63%, the mean age - 66.4±5.5 years). 85% of Group 1 patients had heart failure Strazhesko-Vasilenko IIA grade and 94% of patients had chronic heart failure NYHA III. Similarly, male patients (58%) prevailed in Group 2. The mean age of Group 2 patients was 66.5±3.65 years. All patients in Group 2 II had heart failure Strazhesko-Vasilenko IIA grade and chronic heart failure NYHA III. Results Two patients in Group 1 died in the early postoperative period (the overall mortality was 1.5%). All patients had chronic heart failure NYHA I-II at discharge. Peak transvalvular pressure gradient significantly decreased in the in-hospital period, particularly in Group 2 patients (82,3±22,7 mm Hg vs. 28.8±7.6 mm Hg). 88% of Group 1 patients underwent the 60-month follow-up, and 96% of Group 2 patients - the 48-month follow-up. Transvalvular pressure gradients decreased progressively in both study groups within 60 months follow-up. This decrease was more pronounced in recipients of xenopericardial biological prostheses. Conclusion. Aortic valve replacement with xenopericardial bioprostheses “UniLine” and xenoaortic bioprostheses “Aspire Vascutek” for aortic valvular disease allows treating intracardiac hemodynamic derangements and achieving good clinical and hemodynamic outcomes.

Determinants of success and hemodynamic impact of balloon postdilatation of self-expanding transcatheter aortic valves.

To explore the rate, the determinants of success, and the hemodynamic impact of balloon postdilatation (BPD) of self-expanding transcatheter heart valves (SE-THVs) BACKGROUND: BPD is commonly used to optimize valve expansion and reduce paravalvular leakage (PVL) after transcatheter aortic valve implantation (TAVI) without clearly knowing its hemodynamic benefits. Patients (n = 307) who received a SE-THV were stratified according to whether a BPD was performed or not. Patients who received BPD were stratified according to the severity of PVL remaining after BPD into two groups: Successful BPD (≤mild PVL + BPD) and Failed BPD (moderate-severe PVL + BPD). BPD was performed in 121 patients (39.4%) and was successful in 106 patients (87.6% of attempts). A ratio of the postdilatation balloon diameter to the annulus diameter ≤0.95 was an independent predictor of BPD failure (OR: 10.72 [2.02-56.76], P = .005). Peak transvalvular pressure gradient (PG) was lower in the Successful BPD group (14[12-22] mm Hg) than in the Failed BPD group (18[16-23] mm Hg, P = .029), and did not rise in either group during follow-up (median [IQR], 364[161-739] days). BPD was performed in 39% of patients who received a SE-THV, and was successful in the majority of attempts. BPD failure was more likely in patients with a small postdilatation balloon-to-annulus diameter ratio. Effective BPD improved THV hemodynamic performance, and this was maintained in the intermediate-term post-TAVI.

Impact of pannus formation on hemodynamic dysfunction of prosthetic aortic valve: pannus extent and its relationship to prosthetic valve motion and degree of stenosis.

Although pannus is an important cause of prosthetic valve dysfunction, the minimum pannus size that can induce hemodynamic dysfunction has not yet been determined. This study investigated the correlation between the limitation of motion (LOM) of the prosthetic valve and pannus extent and determined the pannus extent that could induce severe aortic stenosis. This study included 49 patients who underwent mechanical aortic valve replacement (AVR) and showed pannus on cardiac computed tomography (CT). Pannus width, ratio of pannus width to valve diameter, pannus area, effective orifice area, encroachment ratio by pannus, pannus involvement angle and percent LOM of mechanical valves were evaluated on CT. Transvalvular peak velocity (TPV) and transvalvular pressure gradient (TPG) were measured by transesophageal echocardiography to determine the degree of aortic stenosis. The relationship between percent LOM of the prosthetic valve and pannus extent and the cut-off of pannus extent required to induce severe aortic stenosis were evaluated. The mean interval between AVR and pannus formation was 11years and was longer in patients with than without severe aortic stenosis (14.0 vs. 7.3years). On CT, the percent LOM of the prosthetic valve was significantly associated with the extent of pannus only in patients with pannus involvement angle > 180° (r = 0.55-0.68, P < 0.01). Pannus width, effective orifice area, and encroachment ratio were significantly associated with increased TPV and TPG (r = 0.51-0.62, P < 0.01). Pannus width > 3.5mm, pannus width/valve inner diameter > 0.15, and encroachment ratio > 0.14 were significantly associated with severe aortic stenosis (TPV > 4m/s; mean TPG ≥ 35mmHg), with c-indices of 0.74-079 (P < 0.005). CT-derived pannus extent parameters are good indicators of significant hemodynamic changes with increased TPV and mean TPG.

Reduction of aberrant aortic haemodynamics following aortic root replacement with a mechanical valved conduit.

Previous work suggests that aortic root and valve prostheses alter blood flow patterns in the ascending aorta, creating aberrant haemodynamics compared with those of healthy volunteers. Various valve designs have been proposed to better restore physiological haemodynamics. In this study, magnetic resonance imaging (MRI) was used to non-invasively assess three-dimensional (3D) ascending aortic haemodynamics after aortic root replacement (ARR) with a mechanical valved conduit postulated to create less turbulent blood flow. Ten patients (40 ± 9 years) underwent transthoracic echocardiography and contrast-enhanced multidimensional four-dimensional (4D) flow MRI at 1.5 T after ARR with an On-X mechanical valved conduit. Preoperative 4D flow MRI was available in 7 patients. Ten age- and gender-matched healthy volunteers (42 ± 13 years) were also analysed to characterize physiological flow. The presence of vortex/helix formation was graded by two blinded observers. Peak transvalvular pressure gradients were computed using the simplified Bernoulli equation. Patients' postoperative pressure gradients and helicity/vorticity grades were compared with preoperative gradients and those from healthy volunteers. Intra- and interobserver ratings showed good agreement (κ = 0.93, P < 0.01 and κ = 0.84, P < 0.01, respectively). Highly helical and/or vortical flow was observed in all patients preoperatively, which was significantly reduced postoperatively (P < 0.01 and <0.01, respectively), restoring similar flow patterns similar to those seen in volunteers (P = 0.56 and 0.56). Peak transvalvular pressure gradients (ΔP) were also significantly reduced [43 ± 21 vs 12 ± 7 mmHg, P < 0.05 (Echo); 48 ± 22 vs 16 ± 9 mmHg, P < 0.05 (MRI)], but remained significantly higher than those of volunteers (6 ± 1 mmHg, P < 0.01). Preliminary evidence suggests that ARR with an On-X mechanical valve significantly reduces aberrant aortic haemodynamics, producing flow patterns that resemble those in healthy volunteers.

Time-resolved 3-dimensional magnetic resonance phase contrast imaging (4D Flow MRI) analysis of hemodynamics in valve-sparing aortic root repair with an anatomically shaped sinus prosthesis

ObjectiveThe anatomically shaped sinus prosthesis (Uni-Graft W SINUS; Braun, Melsungen, Germany) used in valve-sparing aortic root replacement promises physiological hemodynamics believed to grant physiologic valve function. Using time-resolved 3-dimensional magnetic resonance phase contrast imaging (4D Flow MRI), we analyzed sinus vortex formation and transvalvular pressure gradients in patients with sinus prosthesis compared with age-matched and young healthy volunteers. MethodsTwelve patients with sinus prosthesis (55 ± 15 years), 12 age-matched and 6 young healthy volunteers (55 ± 6 years, 25 ± 3 years, respectively) were examined at 3T with a 4D flow magnetic resonance imaging sequence. Sinus vortices visualized by streamlines and time-resolved particle paths were graded on a 4-point Likert scale. Time resolved pressure differences of the left ventricular outflow tract and the ascending aorta to a reference point in the aortic bulb as well as the transvalvular pressure gradient were evaluated. Results4D flow visualizations revealed a propensity of the sinus prosthesis toward intermediate (50%) and large (28%) vortices compared with age-matched volunteers with small (61%) and intermediate (36%) vortices. Vortices in sinus prostheses had a similar configuration compared with those in volunteers. The peak transvalvular pressure gradient did not vary significantly between patients and age-matched volunteers (4.0 ± 0.9 mm Hg, 3.8 ± 0.7 mm Hg, P = .373), its temporal evolution resembled that of volunteers with a prolonged positive phase in patients. ConclusionsHemodynamics closely relating to those of volunteers were confirmed in sinus prostheses, believed to grant physiological valve function. Minor differences are presumably attributed to graft compliance and temporal resolution of the acquisition. Nevertheless, long-term deterioration of valve function as it was described for straight grafts could potentially be decelerated using sinus prostheses.