Transprosthetic Pressure Gradient Research Articles

Porcine or Bovine Tissue Valves: Which are Better for Surgical Aortic Valve Replacement?

Summary The choice between mechanical and bioprosthetic aortic valve implants is affected by relatively clear criteria. However, the choice between porcine or pericardial valve is more complex regarding bioprosthetic devices. We aimed to elucidate any hemodynamic and clinical difference between two widely used bioprosthetic valves: the Sorin Mitroflow bovine pericardial valve and the St. Jude Medical Epic Supra porcine valve. We retrospectively studied 71 consecutive patients separated into two groups based on the valve they received. Clinical outcomes included patient survival and hemodynamic performance of the implanted prostheses. Patients were assessed at one and five years postoperatively. Mean transprosthetic pressure gradients were used as a marker of hemodynamic performance. The Mitroflow valve exhibited lesser mean transvalvular gradients than the Epic valve for all labelled sizes at one and five years postoperatively. The 5-year survival was equal between groups. Both prostheses demonstrated a small but significant increase in mean pressure gradients in the fifth year. Most patients enjoyed significant clinical improvement as assessed by NYHA functional class. Both bioprostheses performed very well with excellent hemodynamic parameters. The pericardial valves are a safe and appropriate choice for surgical bioprosthetic aortic valve replacement.

194 THROMBOEMBOLIC ACUTE ST ELEVATION MYOCARDIAL INFARCTION AFTER TRANSCATHETER VALVE IMPLANTATION

Abstract Transcatheter aortic valve implantation (TAVI) is an established treatment of severe symptomatic aortic valve stenosis and is an effective and less invasive treatment option compared with conventional surgical aortic valve replacement (SAVR) for patients considered inoperable or at high surgical risk. Thromboembolic and bleeding complications negatively impact recovery and survival after TAVI. This case describes one of the few reported TAVI-associated myocardial infarction due to thrombosis of the prosthetic aortic valve. A 82-years-old woman, suffering from severe symptomatic aortic stenosis, underwent TAVI. Before the procedure, coronary artery disease was excluded by invasive coronary angiography. Since the time of the discharge the patient didn't assume any therapy with aspirin or other antithrombotic drugs. A month after TAVI she complained persistent epigastric pain and was admitted to our department for anterior ST elevation myocardial infarction. Coronary angiography highlighted a monovascular coronary artery disease with thrombotic occlusion of the first diagonal and of the distal left anterior descending coronary artery. In consideration of the thrombotic load thyrofiban was started and it was performed a chest contrast CT which confirmed the diagnostic suspicion of bioprosthetic valve thrombosis. She was first treated with unfractionated heparin (UFH) and then oral anticoagulant therapy with warfarin was started. Echocardiograms (echo) showed a severely reduced systolic function (EF 25%) and high trans-prosthetic gradients (mean transprosthetic pressure gradient of 30 mmHg). On the 8th day after hospitalization she complained chest pain with evidence of moderate pericardial effusion. Epistenocardica pericarditis was therefore diagnosed and the patient started acetylsalicylic acid therapy with progressive clinical, instrumental and laboratory improvement. After 10 days of anticoagulation therapy, she underwent a transesophageal echocardiogram which turned out negative for bioprosthetic valve thrombosis. The predischarge transthoracic echocardiography showed severely reduced systolic function (EF 30%) with a mean transprothesic gradient of 12 mmHg; the circumferential pericardial effusion was mild-moderate but not haemodynamically significative. Therapy at discharged included warfarin and aspirin. Ten days after an echo showed a reduction of the pericardial effusion, an improved systolic function (EF 42%) and mean transprothesic gradient not changed significantly since discharge. Prosthetic valve thrombosis has been reported in up to 40% of patients after TAVI and this case hightlights the importance of antithrombotic therapy after this procedure. Therapeutic anticoagulation appears to be the only non-invasive treatment for resolving valve thrombosis but it is not clear how long this therapy should last for the prevention of prosthetic valve thrombosis.

The ratio of measured and reference effective orifice areas for discriminating prosthetic aortic valve obstruction.

We aimed to evaluate the efficacy of the measured effective orifice area (EOA)/reference EOA ratio in discriminating mechanical prosthetic aortic valve (PAV) obstruction. This is a retrospective study of 193 mechanical PAV patients with an elevated mean transprosthetic pressure gradient (PG) over 20 mmHg or peak velocity over 3 m/s. Of those, 143 patients were objectively proven PAV obstruction with cardiac computed tomography or surgical inspection. The EOA was measured using the continuity equation, and the reference EOA values were obtained from previous guidelines. The measured/reference EOA ratio was significantly lower in the obstruction group (0.63 ± 0.18 vs. 0.86 ± 0.17; P < 0.001). The EOA ratio added incremental value for discriminating obstruction from the conventional parameters recommended in the guidelines. Receiver operating characteristic curve analysis revealed that the measured/reference EOA ratio discriminated PAV obstruction from those without obstruction [area under the curve (AUC), 0.840; 95% confidence interval, 0.783-0.898; P < 0.001]. A cutoff of 0.71 had 73.4% sensitivity and 82.0% specificity. The novel diagnostic algorithm adding the EOA ratio had similar accuracy to previous guideline algorithms, including reference EOA, and conventional Doppler parameters (AUC, 0.763 vs. 0.731; P = 0.309). In patients with a large PAV (≥23 mm), the novel algorithm had higher accuracy than the previous algorithm (AUC, 0.788 vs. 0.642; P = 0.019). The ratio of measured/reference EOA adds incremental value over conventional Doppler parameters and might be helpful for distinguishing PAV obstruction.

The hemodynamic performance of balloon-expandable aortic bioprostheses in the elderly: a comparison between rapid deployment and transcatheter implantation

BackgroundSurgical aortic valve replacement with a rapid deployment valve (RDV) is a relatively recent treatment option. The aim of this study was to compare the hemodynamic performance of balloon-expandable (BE)-RDVs and BE-transcatheter heart valves (THVs) in a high surgical risk and frail-elderly population. MethodsBE-THVs and BE-RDVs were implanted in 138 and 47 patients, respectively, all older than 75 years and with a Canadian Study of Health and Aging category of 5 or above. Echocardiographic assessment was performed at discharge and six months later. ResultsAt discharge, transprosthetic pressure gradients and indexed effective orifice area (iEOA) were similar in both cohorts. At six-month follow-up, BE-RDVs showed lower peak (14.69 vs. 20.86 mmHg; p < 0.001) and mean (7.82 vs. 11.83 mmHg; p < 0.001) gradients, and larger iEOA (1.05 vs. 0.84 cm2/m2; p < 0.001). Similar findings were also shown considering only small-sized valves. Moderate-to-severe paravalvular leakage was more prevalent in BE-THVs at discharge (14.49 vs. 0.00%; p = 0.032) and, considering exclusively small prostheses, at six months too (57.69 vs. 15.00%; p = 0.014). Nevertheless, BE-THVs determined amelioration in left ventricular ejection fraction (53.79 vs. 60.14%; p < 0.001), pulmonary artery systolic pressure (35.81 vs. 33.15 mmHg; p = 0.042), and tricuspid regurgitation severity (40.58 vs. 19.57%; p = 0.031), from discharge to mid-term follow-up. ConclusionsBE-RDVs showed better hemodynamic performance, especially when implanted in small annuli. Despite their worse baseline conditions, transcatheter patients still exhibited a greater improvement of their echocardiographic profile at mid-term follow-up.

Trifecta versus Perimount Magna Ease aortic valves: Failure mechanisms.

BackgroundThere are increasing reports of early externally mounted pericardial Trifecta bioprosthesis failure. We compared the hemodynamic performance of Trifecta and Carpentier–Edwards Perimount Magna Ease valves to determine the failure mechanism.MethodsWe retrospectively included 270 consecutive patients (age: 73.4 ± 8.2 years; 57.5% male; mean follow-up: 48.0 ± 20.3 months) who underwent aortic valve replacement from 2014 to 2021 at a single center and compared the Trifecta (N = 137) and Carpentier–Edwards Perimount Magna Ease valve (N = 133) patients.ResultsThe prosthetic valve major aortic regurgitation incidence was higher for the Trifecta than that for the Carpentier–Edwards Perimount Magna Ease valve (6.3% vs. 0%, P < 0.009). Among the Trifecta failures, 33% developed structural valve deterioration, but all requiring redo aortic valve replacement developed major prosthetic valve aortic regurgitation. Freedom at 5 years from redo aortic valve replacement due to structural valve deterioration was significantly lower for Trifecta (89.4% vs. 100%, P = 0.003). The reoperation hazards were determined for Trifecta (vs. Carpentier–Edwards Perimount Magna Ease): 11.6 (1.47–90.9; P = 0.02), prosthetic valve aortic regurgitation: 2.38 (1.70–3.32; P < 0.01), structural valve deterioration: 20.82 (4.08–106.2; P < 0.01), 5-year mean transprosthetic pressure gradient: 1.14 per 1-point increase (1.03–1.24; P = 0.007), and urgent surgery: 10.1 (2.59–39.0; P = 0.001). The Cox regression analysis identified that prosthetic valve aortic regurgitation solely contributed to redo aortic valve replacement (hazard ratio: 2.38; confidence intervals: 1.70–3.32).ConclusionsSignificantly, more early failures occurred with the Trifecta valve than the Carpentier–Edwards Perimount Magna Ease valve but the Trifecta showed reasonable mean transprosthetic pressure gradient over time. Prosthetic valve aortic regurgitation and calcific structural valve deterioration synergistically contributed to Trifecta valve failure alternatively.

508 Incidence and determinants of prosthesis-patient mismatch after transcatheter aortic valve replacement using predicted indexed effective orifice area

Abstract Aims A small effective orifice area (EOA) by body surface area (BSA), defined as prosthesis–patient mismatch (PPM), is associated with elevated transprosthetic pressure gradients, less ventricular remodelling, and a worse prognosis. Calculating PPM by dividing the normal reference value of EOA for the model and size of the prosthetic valve (predicted PPM), instead of using the continuity equation has been recently confirmed as more accurate after trans catheter aortic valve intervention (TAVI), providing a stronger association with post-procedural haemodynamic outcomes. However, current evidence using this new definition is still limited, thus impairing generalizability. Accordingly, this analysis aims to extend such evidence providing incidence, and determinants of predicted PPM (PPMp) in an all-comers population undergoing TAVR with a high prevalence of self-expandable devices. Methods 395 patients who underwent TAVI at our Institution from September 2008 to November 2020 were included in this analysis. PPMp was then classified as moderate if ≤ 0.85 cm2/m2 and severe if ≤ 0.65 cm2/m2 as well as moderate if ≤ 0.70 cm2/m2 and severe if ≤ 0.55 cm2/m2 for patients with a body mass index &amp;gt; 30, as recommended by the Valve Academic Research Consortium-3 definition. The independent association between baseline clinical and procedural variables and the presence of moderate or severe PPMp was investigated with cross-sectional logistic regression analysis. Results 11 patients (2.78%) had severe and 33 (8.35%) moderate PPMp. Patients with moderate or severe PPMp (m/s PPMp) were younger, female, with a higher prevalence of hypercholesterolaemia, prior aortic valve implantation and balloon expandable device and lower prevalence of chronic obstructive disease (COPD). Post-procedural mean gradient was higher in patients with m/s PPMp. The independent clinical and procedural correlates associated with higher likelihood of m/s PPMp were valve in valve procedure (ViV) and the use of a balloon-expandable device. Conclusions Moderate or severe PPMp was observed only in a small part of patients underwent TAVI, leading, however, a higher post-procedural mean gradient compared to those without PPMp. Balloon expandable devices and ViV were the strongest determinant of moderate or severe PPM.

Glycoprotein IIb/IIIa receptor targeted PET/CT imaging: a novel diagnostic tool for detecting bioprosthetic valve thrombosis

Abstract Background/Introduction Bioprosthetic valve thrombosis (BPVT) is an important clinical entity eventually following both bioprosthetic surgical and transcatheter aortic valve replacement. Although dynamic contrast-enhanced 4D-MDCT has improved the diagnosis of BPVT, more sensitive and pathology-specific non-invasive imaging tools are lacking. Recently, the glycoprotein IIb/IIIa receptor targeted, elarofiban-derived PET/CT imaging radiotracer [18F]GP1 has been successfully used for visualization of acute venous and arterial thrombi. Purpose We hypothesized that [18F]GP1 PET/CT imaging is suitable to detect BPVT. Methods In this proof-of-concept study, patients after bioprosthetic aortic valve replacement with symptomatic, severe hemodynamic valve dysfunction and confirmed hypoattenuated leaflet thickening (HALT) in dynamic 4D-MDCT were offered to participate in compassionate use examinations to undergo PET/CT imaging with the investigational [18F]GP1 PET tracer at baseline and after a 12-week course of therapeutic oral anticoagulation. Results This case series reports on three patients after aortic valve replacement. Two patients with symptomatic, obstructive BPVT as confirmed by echocardiography and 4D-MDCT fulfilled specified criteria and underwent [18F]GP1 PET/CT imaging. [18F]GP1 PET/CT clearly distinguished between blood pool activity and thrombotic foci. Clot-to-blood ratios at baseline were 8.2 and 4.5, respectively. A 12-week trial of therapeutic oral anticoagulation was associated with a regression of mean transprosthetic pressure gradient and reversal of HALT. Follow-up 4D-MDCT corroborated thrombus resolution in both patients. Correspondingly, [18F]GP1 PET/CT imaging demonstrated decreased tracer uptake in both patients. Clot-to-blood ratio at follow-up visit decreased to 1.2 and 2.9, respectively. While absent tracer uptake was seen in patient #1, residual tracer uptake was observed in patient #2 suggestive of ongoing platelet aggregation. One asymptomatic SAVR patient was examined with [18F]GP1 PET/CT for a different compassionate use and no thrombotic foci were detected on the leaflets. Conclusions [18F]GP1 PET/CT is a novel imaging technique in patients with obstructive BPVT. In a head-to-head comparison we show that [18F]GP1 PET/CT may have incremental diagnostic value over dynamic contrast-enhanced 4D-MDCT alone by detection of sites of ongoing platelet aggregation at the molecular level. [18F]GP1 PET/CT may serve as a novel, highly sensitive tool to overcome some limitations of current diagnostic imaging modalities for detecting BPVT and may prove useful for the monitoring and guidance of therapeutic interventions. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): Life Molecular Imaging provided material for [18F]GP1 radiolabeling free of charge as part of an ongoing research collaboration.

Implantation of a Sutureless Valve Into a Surgically Enlarged Aortic Root: A Bailout Option

Sutureless bioprostheses such as the Sorin Perceval Valve (SPV; Sorin Group, Srl, Saluggia, Italy) have been proposed for replacing stenotic native valves within small aortic roots of geriatric patients with significant comorbidity. Their use seems as safe as that of stented bioprostheses and enables significantly reduced length of surgery. Low transprosthetic pressure gradients have been measured. Because of the radial force of its self-expandable nitinol stent, aortic annulus interruption could be a relative contraindication to SPV use. Off-label implantation of the SPV into a surgically enlarged ascending aorta was first reported in this study, as a bailout option in the presence of a tiny aortic root.

18F-Sodium fluoride PET/CT detects transcatheter aortic valve degeneration

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by the British Heart Foundation, London, United Kingdom Background Early detection of transcatheter aortic valve implantation (TAVI) degeneration is challenging and only feasible when advanced haemodynamic valve dysfunction is apparent. Purpose We tested whether 18F-sodium fluoride (18F-NaF) positron emission tomography and computed tomography (PET/CT) could detect structural TAVI degeneration and haemodynamic valve dysfunction. Methods After TAVI implantation, patients underwent baseline echocardiography, CT angiography and 18F-NaF PET/CT (Figure). We assessed for morphological changes, stenosis or regurgitation on Doppler echocardiography, CT (hypoattenuated leaflet thickening [HALT] or spotty calcification) and PET (18F-NaF uptake; maximum target-to-background ratio, TBRmax). We categorised structural valve degeneration (SVD) according to the standardised definition for surgical and transcatheter bioprosthetic valves, as proposed in a recent consensus statement. Results We recruited 47 patients (81 ± 6 years old, 79% male) 1 month (n = 9), 2 years (n = 22) or 5 years (n = 16) after TAVI: 25 (53%) had received a balloon expanded bioprosthesis and 22 (47%) a self-expanding valve. There was moderate valve dysfunction on Doppler echocardiography in 3 (6%) patients, HALT on CT in 6 (13%) patients, spotty calcification in one patient and 18F-NaF uptake in 7 patients (15%) (TBRmax range: 1.59-5.88); all enrolled 5 years post-TAVI. All patients with increased 18F-NaF uptake (TBRmax ≥1.59) demonstrated either SVD without haemodynamic valve dysfunction (stage 1, n = 4) or structural valve dysfunction with moderate valve dysfunction and mean transprosthetic pressure gradients &amp;gt;20 mmHg (stage 2, n = 3). In patients without increased 18F-NaF uptake there was no evidence of structural valve degeneration (n = 40). Within the increased 18F-NaF uptake (n = 7) group, patients with stage 2 SVD (n = 3) demonstrated higher uptake compared to patients with stage 1 SVD (TBRmax 4.3 [3.02-5.88] versus 1.8 [1.59-2.28]). Patients with stage 2 SVD (n = 3) had over 3 times higher TBRmax than those without SVD (n = 40) (4.30 [3.02, 5.88] versus 1.31 [1.21, 1.46]; p &amp;lt; 0.001); Figure). Conclusion 18F-NaF PET/CT detects patients with SVD and potentially identifies those at risk of valve failure. Abstract Figure.

Determining prosthesis‐patient mismatch after TAVR: Which is the best method?

Determining prosthesis‐patient mismatch after TAVR: Which is the best method?

Early Hemodynamics after Aortic Valve Replacement.

Background and objectives: The aims of this study were to investigate changes in the hemodynamics associated with different types of aortic prostheses and to evaluate patient-prosthesis mismatch (PPM) at rest and after exercise. Materials and Methods: We retrospectively analyzed 150 patients who presented with indications for aortic valve replacement (AVR) with/without concomitant surgery from March 2019 to January 2020. The study population included 90 (60%) men and 60 (40%) women (mean age, 67.33 ± 10.22 years; range, 37–88 years). Echocardiography data such as peak and mean transprosthetic pressure gradients (Gmax, Gmean), velocity (V), effective orifice area (EOA), and indexed EOA (iEOA) were derived at rest and after exercise at baseline and before discharge. The study patients performed the six-minute walk test (6MWT) on the 5th–7th postoperative day. Results: Stented tissue valves showed excellent performance at rest and after exercise in comparison with mechanical valves, which showed favorable hemodynamics at rest only. At the time of discharge, moderate PPM was observed in 7/74 patients (9.5%) at rest and 5/98 (3.3%) patients after exercise. None of the patients showed severe PPM. EOA and iEOA were not significantly different between the groups. However, the stented group showed more pronounced changes in EOA and iEOA after exercise, whereas the changes in the mechanical valve group did not reach significance. Conclusions: In the early postoperative period, mechanical valves and stented valves showed favorable resting hemodynamics. The PPM rate measured after exercise was lower than that at rest.

Abstract 13341: Systolic Time Intervals and Alternative Echocardiographic Parameters to Evaluate Bioprosthetic Aortic Valve Function

Background: Bioprosthesis (BP) used for aortic valve replacement (AVR) in aortic valve disease are subject to structural valve deterioration (SVD) after 20 years or less which leads to reintervention. The diagnostic of SVD can be challenging in the presence of patient-prosthesis mismatch (PPM) which occurs when the effective orifice area (EOA) of the BP is too small for the metabolic needs of a patient. Both SVD and PPM are mainly diagnosed with echocardiography and are characterized by high transprosthetic mean and peak pressure gradients (MG and PG) and maximal velocity (Vmax) as well as reduced EOA. Easily accessible parameters are needed to distinguish SVD from PPM. Acceleration time (AT), ejection time (ET) and AT/ET have been proposed as accurate to identify SVD in presence of PPM. However, these parameters need to be validated. Objectives: The main goal of the present study is to determine the accuracy of AT and AT/ET and to validate new echocardiographic parameters that can distinguish SVD from PPM. New parameters proposed for this study are MG/EOA and PG over mean flow rate (PG/MFR). Methods: In a retrospective study, we analyzed echocardiographic data of 653 patients who underwent AVR. PPM was defined as a projected EOA to body surface area inferior to 0.85 cm 2 /m 2 . SVD was defined using a multiparametric integrative approach including morphological (fibrocalcific remodeling, thickening and stiffening of valve leaflets) criteria and hemodynamic changes according to American Society of Echocardiography/European Association for Cardiovascular Imaging recommendations. Results: EOA was lower and MG higher for patients with SVD compared to those with pure PPM. PG/Q and MG/EOA were significantly higher in patients with SVD compared to patients presenting pure PPM (PG/MFR: 0.22 mm Hg/ml/s ± 0.01 vs 0.15 mm Hg/ml/s ± 0.01; MG/EOA: 31 mm Hg/cm 2 ±2 vs 16 mm Hg/cm 2 ±2, p&lt;0.001) respectively. ROC analysis showed that PG/Q and MG/EOA were the best echocardiographic parameters to distinguish pure PPM from SVD with AUC of 0.872 and 0.876 respectively. AT and AT/ET achieved AUC of 0.682 and 0.663. Conclusion: AT and AT/ET are not accurate parameters to identify SVD in presence of PPM. MG/EOA and PG/MFR represent interesting alternatives to conventional parameters.

Impact of prosthesis-patient mismatch on early and late outcomes after mitral valve replacement: a meta-analysis.

BackgroundPrognostic significance of prosthesis-patient mismatch (PPM) after mitral valve replacement (MVR) remains uncertain because of the limited studies reporting inconsistent or even contrary results. This meta-analysis pooled results of all available studies comparing early and late prognoses between patients with significant mitral PPM and those without.MethodsStudies were identified by searching Pubmed, Excerpta Medica Database, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Impact of PPM on postoperative hemodynamic results, thirty-day mortality, overall mortality, mortality of thirty-day survivors, and primary morbidity after MVR was evaluated via meta-analysis. Robustness of pooled estimates, source of heterogeneity, and publication bias were assessed via sensitivity analyses, meta-regression as well as subgroup analysis stratified according to methodological or clinical heterogeneity, or sequential omission method, and funnel plot or Begg's and Egger's tests, respectively.ResultsNineteen cohort studies involving 9302 individuals (PPM group: n = 5109, Control group: n = 4193) were included for meta-analysis. Total PPM and severe PPM prevalence were 3.8%–85.9% and 1%–27%, with a mean value of 54.9% and 14.1%, respectively. As compared with control group, mitral PPM group demonstrated a poorer postoperative hemodynamic status of higher mean and peak residual transprosthetic pressure gradients (TPG), higher postoperative systolic pulmonary artery pressure (SPAP) and less reduction, higher postoperative pulmonary hypertension (PH) prevalence and less PH regression, smaller net atrioventricular compliance, less NYHA class decrease, higher postoperative functional tricuspid regurgitation prevalence and less regression. The PPM group also revealed a higher thirty-day mortality, long-term overall mortality, mortality of thirty-day survivors, and postoperative congestive heart failure prevalence, which were positively correlated with the severity of PPM if it was classified into tri-level subgroups. Left ventricular end-diastolic diameter, postoperative atrial fibrillation (AF) prevalence, and the AF regression were analogous between groups. Most pooled estimates were robust according to sensitivity analyses. Male patients and bioprosthesis implantation proportion were prominent source of between-study heterogeneity on thirty-day mortality. Publication bias was not significant in tests for all the outcomes, except for SPAP and TPG.ConclusionsMitral PPM would result in poorer postoperative hemodynamics and worse early and late prognosis. Severe PPM must be avoided since deleterious impact of mitral PPM was severity dependent.

Early results of the Resilia Inspiris aortic valve in the old age patients - a retrospective comparison with the Carpentier Edwards Magna Ease.

Introduction: The Inspiris Resilia aortic valve® (INSPIRIS) is a pericardial bio-prosthesis with a new sterilization procedure that shows promising results in terms of reduced calcification. Methods: The 30-day mortality and morbidity were analyzed, comparing the INSPIRIS implanted between May 2017 and the end of January 2019, with its "predecessor", the Carpentier-Edwards Perimound Magna Ease (ME). Echocardiography was performed one-week after surgery. 125consecutively operated patients were included (59 INSPIRIS, 66 ME). Results: One patient in the ME group died and one patient in the INSPIRIS group had a complicated postoperative course due to right heart failure. Two patients (one INSPIRIS, one ME patient) suffered a perioperative stroke. The hemodynamic evaluation shows an effective reduction of mean transvalvular pressure gradients after surgery in both groups. INSPIRIS tended to have lower trans-prosthetic pressure gradients (9 mm Hg, Interquartile range [IQR] 11-7 mm Hg versus 12 mm Hg, IQR 15-9 mmHg; P = 0.001), reduced trans-prosthetic blood flow acceleration (209 cm/s, IQR 220-190 cm/s versus227 cm/s, IQR 263-191 cm/s; P = 0.003) and increased permeability indices (57%, IQR 67%- 47% versus42%, IQR 48%-38%; P8%; P < 0.001). Conclusion: There are only few clinical data available from INSPIRIS, and the present analysis confirms good results initial postoperatively with a tendency towards possibly improved hemodynamics compared to ME.

1643 A challenging diagnosis in prosthetic mitral valve obstruction

Abstract A 53-year-old man was referred to our center for a prosthesic mitral valve obstruction. In December 2017 the patient had a myocardial infarction complicated by papillary muscle rupture and anterior leaflet flail; therefore he underwent a mechanical mitral valve replacement (size 29). A first echocardiographic control in August 2018 was reported as normal. In February 2019 a further echocardiography showed an increase of the trans-prosthetic pressure gradients and a suspected restricted motion of the anterior tilting disk; a cinefluoroscopy view confirmed the tilting disk blockade in the closing position. The patient was referred to our center for further investigations. We performed a 3D TOE that confirmed the prosthesis dysfunction: the anterior tilting disk was blocked (mean gradient 14 mmHg, 3D residual anatomical area 1.4 cm2); the mechanical cause of the obstruction was not identified. A cardiac CT was performed: a clear thrombus or pannus was not visualized, even if a linear hypodensity could be seen along the inner circumferential edge of the blocked disk. Finally the patient underwent the surgical intervention for prosthesis replacement. The visual analysis of the valve revealed a stratified thrombosis in both the atrial and ventricular side of the blocked disk, extending to the prosthetic ring and to the hinges. The patient developed a prosthetic valve dysfunction 9 to 13 months after valve replacement. Thrombus is the most common cause of obstruction of mechanical prostheses (0.3 to 8% per patient-year) while pannus formation usually occur over 5 years after surgery (minimum 12 months later). On the one hand, the patient assured a good anticoagulation regimen in the previous months, thrombosis in mitral valve position usually present with a large formation involving the disk projecting into left atrium, and large prosthesis size is associated with a lower risk of thrombosis. Our TOE confirmed the hemodynamic dysfunction but was not able to detect any cause of the leafleat bloackade. Cardiac CT has a better spatial resolution but only a focused MPR view allowed to identify a linear hypodense formation along the ring surrounding the blocked disk. This thin structure only involved the prostethic ring, apparently not projecting over the disk. These morphologic features are considered more in keeping with pannus, and only the low attenuation values (below the suggested threshold of 200 HU) helped to suspect a thrombotic stratification over the prosthetic ring. The surgical intervention revealed the real nature of the obstruction. In conclusion, thrombus may present with an unconventional appearance as a cause of prosthetic obstruction and, especially when stratified can mimick a pannus. Multimodality imaging is not always able to identify the cause of mechanical valve dysfunction; consequently, when the prosthesis obstruction is evident but imaging is inconclusive cardiac surgery is the only diagnostic and therapeutic resource. Abstract 1643 Figure. Prosthesis valve disfunction

Aortic valve replacement with stentless bioprosthesis «Kemerovo-AB-Neo»

We analyzed 50 aortic valve replacements (AVR) with Kemerovo-AB-Neo stentless bioprostheses. Mean age was 66.75 (54 to78) years, hospital mortality rate accounted for 2%. The peak transprosthetic pressure gradient (PTPG) in patients operated for aortic stenosis came to 19.57 mm Hg. PTPG was shown to be dependent on the implantation technique; it reached 24.57 mm Hg when in order to fix the proximal line, interrupted sutures were used and ran to 175 mm Hg in the case of running sutures (р = 0.03). Helical CT confirmed fine mobility of the cardiac structures after Kemerovo-AB-Neo implantation: the aortic cross-section area varied up to 84% during the cardiac cycle. It should be noted that AVR with Kemerovo-AB-Neo stentless valves gives good clinical and hemodynamic results early after surgery. A free-hand technique of implantation should be preferred. The implantation of stentless bioprostheses retains cardiac structures mobility and natural aortic root dimensions after performing an AVR.

Sutureless prosthesis for failed small Mitroflow valves: the Perceval-after-Mitroflow procedure.

Because of its favourable haemodynamic characteristics and easy implantability, Mitroflow aortic valve bioprosthesis has been the valve of choice for many surgeons in patients with small aortic annulus. Disappointingly, early structural valve deterioration and high transvalvular gradients have been reported mostly in older patients with small prostheses. Reimplanting a new stented prosthesis sutured in a narrow and damaged annulus is technically challenging and demanding mainly in high-risk patients. Valve-in-valve transcatheter aortic valve implantation has been proposed as a viable option; however, it presents significant limitations because of residual high transprosthetic pressure gradients and risk of coronary occlusion. We report a series of 8 patients, with medium-term follow-up, who underwent successful Perceval-S surgical sutureless aortic implant after the removal of a degenerated small Mitroflow valve. No early mortality occurred, but 1 patient died 4 months postoperatively due to gastrointestinal disease. No major complications occurred. Early and mid-term postoperative pressure gradients were low (mean gradients 13.1 ± 3.3 mmHg and 10.2 ± 3.8 mmHg, respectively). In operable patients with a degenerated Mitroflow valve, these favourable clinical and haemodynamic results suggest that the sutureless solution is a simple, valid and safer alternative to conventional redo valve replacement or to valve-in-valve transcatheter aortic valve implantation.

Effective Orifice Area during Exercise in Bileaflet Mechanical Valve Prostheses

The aims of this study were to investigate the evolution of the transprosthetic pressure gradient and effective orifice area (EOA) during dynamic bicycle exercise in bileaflet mechanical heart valves and to explore the relationship with exercise capacity. Patients with bileaflet aortic valve replacement (n=23) and mitral valve replacement (MVR; n=16) prospectively underwent symptom-limited supine bicycle exercise testing with Doppler echocardiography and respiratory gas analysis. Transprosthetic flow rate, peak and mean transprosthetic gradient, EOA, and systolic pulmonary artery pressure were assessed at different stages of exercise. EOA at rest, midexercise, and peak exercise was 1.66±0.23, 1.56±0.30, and 1.61±0.28cm2, respectively (P=.004), in aortic valve replacement patients and 1.40±0.21, 1.46±0.27, and 1.48±0.25cm2, respectively (P=.160), in MVR patients. During exercise, the mean transprosthetic gradient and the square of transprosthetic flow rate were strongly correlated (r=0.65 [P<.001] and r=0.84 [P<.001] for aortic valve replacement and MVR, respectively), conforming to fundamental hydraulic principles for fixed orifices. Indexed EOA at rest was correlated with exercise capacity in MVR patients only (Spearman ρ=0.68, P=.004). In the latter group, systolic pulmonary artery pressures during exercise were strongly correlated with the peak transmitral gradient (ρ=0.72, P<.001). In bileaflet mechanical valve prostheses, there is no clinically relevant increase in EOA during dynamic exercise. Transprosthetic gradients during exercise closely adhere to the fundamental pressure-flow relationship. Indexed EOA at rest is a strong predictor of exercise capacity in MVR patients. This should be taken into account in therapeutic decision making and prosthesis selection in young and dynamic patients.

Treatment of porcine bioprosthetic mitral valve thrombosis with anticoagulation

A 70-year-old man underwent mitral valve replacement using a porcine bioprosthesis for infective endocarditis. Transthoracic echocardiography revealed thickened leaflets with increased transprosthetic pressure gradient and new regurgitation, 6 months after surgery. He was followed up medically with the diagnosis of early valve degeneration. He ultimately presented with worsening orthopnea 13 months after surgery. Transesophageal echocardiography revealed an immobile round mass attached to the ventricular aspect of the leaflets, which hampered valve opening, suggesting bioprosthetic valve thrombosis. Anticoagulation with heparin and warfarin were effective and transthoracic echocardiography showed normal transprosthetic pressure gradient and disappearance of regurgitation 2 months later.

Subprosthetic Pannus after Aortic Valve Replacement Surgery: Cardiac CT Findings and Clinical Features.

To investigate the cardiac computed tomographic (CT) findings and clinical implications of subprosthetic pannus in patients who have undergone aortic valve replacement. The institutional review board approved this retrospective study, and the need to obtain written informed consent was waived. From April 2011 to March 2012, 88 patients (mean age, 63 years; 45 men) with a prosthetic aortic valve who underwent cardiac CT were retrospectively selected. Dynamic cardiac CT images were analyzed by using a multiplanar reformatted technique. The presence or absence of subprosthetic pannus and its extent were evaluated at cardiac CT. The geometric orifice area and the effective orifice area of each prosthetic valve were measured to enable analysis of the pannus encroachment ratio in the systolic phase. Hemodynamic parameters at echocardiography, including mean transprosthetic pressure gradient (MTPG), were compared between patients with and those without pannus. The encroachment ratio and the MTPG were correlated by using the Spearman test to evaluate the relationship between the two variables. Seventeen patients (19%) had subprosthetic pannus at cardiac CT. In patients with subprosthetic pannus, MTPG, peak pressure gradient, transvalvular peak velocity, and left ventricular ejection fraction (LVEF) were significantly higher than in patients without pannus (MTPG: 28.1 mm Hg ± 19.8 [standard deviation] vs 14.0 mm Hg ± 6.5, P = .004; peak pressure gradient: 53.1 mm Hg ± 38.4 vs 26.1 mm Hg ± 11.4, P = .004; transvalvular peak velocity: 3.3 m/sec ± 1.3 vs 2.5 m/sec ± 0.5; and LVEF: 64.7% ± 7.4 vs 56.8% ± 10.5, P = .004). A high MTPG (≥40 mm Hg) was observed in four patients at echocardiography, and subprosthetic panni were identified at CT in all four patients. In patients with increased MTPGs, the encroachment ratio by subprosthetic pannus at CT was significantly higher than that in patients with MTPGs of less than 40 mm Hg (42.7 ± 13.3 vs 7.6 ± 3, P = .012). Cardiac CT revealed subprosthetic pannus to be a cause of the hemodynamic changes in patients who had undergone aortic valve replacement. By helping quantify the encroachment ratio by pannus, cardiac CT may help differentiate which subprosthetic panni might lead to substantial flow limitation over the prosthetic aortic valve.