Aortic Valve Effective Orifice Area Research Articles

Aortic valve hemodynamic characteristics after the Ozaki procedure according to echocardiography: a multicenter retrospective study

Aim. To evaluate the aortic valve (AV) hemodynamic characteristics after the Ozaki procedure according to echocardiography.Material and methods. The retrospective multicenter study included 277 patients with AV defects who were operated on from January 2017 to June 2022 in five centers in Russia. After the Ozaki procedure, the following endpoints were assessed: immediate echocardiographic results (peak AV gradient, mean AV gradient, AV effective orifice area, aortic regurgitation grade), mid-term clinical (three-year survival rate, three-year freedom from reoperation, three-year freedom from grade ≤2 aortic regurgitation) and echocardiographic results (peak and mean AV gradient, AV effective orifice area, aortic regurgitation grade, AV calcification severity). The median follow-up period was 23 (13-32) months. The mean echocardiography follow-up period was 21±10 months.Results. During the treatment, a decrease in the peak AV gradient was observed from 74±30 mm Hg before surgery up to 12 (8-16) mm Hg one week after surgery, which remained in the mid-term period — 12 (9-15) mm Hg. There was also a decrease in the mean gradient from 40 (27-53) mm Hg before surgery up to 6 (4-8) mm Hg one week after surgery. By the mid-term period, the mean gradient was 6 (4-8) mm Hg. The AV effective orifice area increased from 1 (1-1) cm2 to 2 (2-2) cm2 in the mid-term follow-up period. Three-year survival rate was 90,2%, freedom from reoperation was 95%, freedom from grade ³2 aortic regurgitation was 88%, and no patient had AV calcification.Conclusion. The Ozaki procedure in patients with AV defects has good immediate and mid-term hemodynamic parameters according to echocardiography. However, there remains a need for large randomized controlled trials comparing Ozaki procedure with biological AV replacement.

Echocardiographic parameters associated with less reverse left ventricular remodeling after transcatheter aortic valve implant in subjects with prosthesis patient mismatch.

Transaortic valve implant (TAVI) is the treatment of choice for severe aortic stenosis (AS). Some patients develop prosthesis patient mismatch (PPM) after TAVI. It is challenging to determine which patients are at risk for clinical deterioration. We retrospectively measured echocardiographic parameters of left ventricular (LV) morphology and function, prosthetic aortic valve effective orifice area (iEOA) and hemodynamics in 313 patients before and 1year after TAVI. Our objective was to compare the change in echocardiographic parameters associated with left ventricular reverse modeling in subjects with and without PPM. Our secondary objective was to evaluate echo parameters associated with PPM and the relationship to patient functional status and survival post-TAVI. We found that 82 (26.2%) of subjects had moderate and 37 (11.8%) had severe PPM post-TAVI. There was less relative improvement in LVEF with PPM (1.9±21.3% vs. 8.2+30.1%, p=.045). LV GLS also exhibited less relative improvement in those with PPM (13.4+34.1% vs. 30.9+73.3%, p=.012). NYHA functional class improved in 84.3% of subjects by one grade or more. Echocardiographic markers of PPM were worse in those without improvement in NYHA class (mean AT/ET was .29 vs. .27, p=.05; DVI was .46 vs. .51, p=.021; and iEOA was .8cm/m2 vs. .9cm/m2 , p=.025). There was no association with PPM and survival. There was no improvement in LVEF and less improvement in LV GLS in those with PPM post-TAVI. Echocardiographic markers of PPM were present in those with lack of improvement in NYHA functional class.

Influence of moderate prosthesis–patient mismatch on long-term outcomes in patients with severe aortic stenosis with paradoxically reduced gradients against the background of reduced stroke volume after aortic valve replacement with a biological prosthesis: retrospective comparative study

OBJECTIVE: Our aim was to evaluate the impact of moderate prosthesispatient mismatch on long-term results after aortic valve replacement in patients with severe aortic stenosis with paradoxically reduced gradients against the background of a reduced stroke volume of the left ventricle.
 MATERIALS AND METHODS: We analyzed data from 88 patients with symptomatic severe aortic stenosis meeting the criteria: paradoxically reduced gradients against the background of a reduced stroke volume of the left ventricle. Patients were divided into 2 groups: Group 1 (n=42, mean age 674 years) with paradoxically reduced gradients against the background of reduced stroke volume of the left ventricle, with a moderate patientprosthesis mismatch; Group 2 (n=46, mean age 686 years) with paradoxically reduced gradients against the background of reduced stroke volume of the left ventricle, without patientprosthesis discrepancy. All patients underwent transthoracic echocardiographic evaluation.
 RESULTS: The average follow-up period was 84 (quarterly interval 7598) months, during the follow-up period 35 (40%) deaths were registered. There were no significant differences in in-hospital mortality: 2 (4.7%) and 2 (4.3%), respectively (p=0.2). In the long-term follow-up period, there was a significant difference in survival and hospitalization rates for exacerbation of heart failure between patients with and without patientprosthesis mismatch: 46 and 71%, 37 and 72%, respectively (p0.001). In the long-term follow-up period, patients with patientprosthesis mismatch showed a trend towards slower regression of left ventricle mass and left atrial volume, as well as a slower recovery of global longitudinal deformation of the left ventricle and exercise tolerance compared with patients without patientprosthesis mismatch. There were no significant differences in the incidence of stroke (90% and 91%; p=0.7). According to the results of Cox regression, the left ventricular stroke volume index and the aortic valve effective orifice area index were independent predictors of lethal events and the risk of hospitalization for exacerbation of heart failure.
 CONCLUSION: Moderate patientprosthesis mismatch in patients with paradoxically reduced gradients associated with reduced left ventricular stroke volume is independently associated with increased mortality and increased hospitalization for exacerbations of heart failure.

Energy loss index as a predictor of all-cause mortality after transcatheter aortic valve replacement: A long-term follow-up.

As transcatheter aortic valve replacement (TAVR) procedures become more widely available, there is a growing need to monitor and evaluate postoperative outcomes accurately. The energy loss index (ELI) of the ascending aorta has been commonly used to examine the agreement between the echocardiographic and Gorlin measurement of the aortic valve area. This project aims to demonstrate a link between ELI values and mortality following implanted TAVR valves and determine an ELI cutoff value associated with post-TAVR events. We retrospectively reviewed patients undergoing TAVR from 2012 to 2017. We calculated ELI values for patients immediately postoperative after a TAVR procedure. Using Receiver-Operator Characteristic and Cox Regression analyses, we identified a cutoff value to distinguish between "High ELI"(≥1.34) and "Low ELI"(<1.34) patients. This study showed low ELI (hazard ratio, 2.30; 95% confidence interval 1.57-3.36, p<.001) as representative of patients with a high risk of mortality post-TAVR. Additionally, post-TAVR, ejection fraction increased by 3.6% (p<.001), and the aortic valve effective orifice area increased by 1.41cm squared (p<.001) while the mean transvalvular gradient decreased by 32.8mmHg (p<.001) and the peak transvalvular gradient decreased by 49.0mmHg (p<.001). ELI is an additional prognostic factor that should be considered during risk assessment before TAVR. This study shows that patients with Low ELI had decreased cumulative survival post-TAVR. These patients almost had a fivefold increased risk of death following TAVR.

Short-term outcomes of Ozaki procedure: a multicenter study

Aim . To analyze the short-term outcomes of Ozaki procedure. Material and methods . This retro-prospective multicenter study included 724 patients with aortic valve (AV) disease, who underwent AV neo-cuspitization (AVNeo) from 2015 to 2019. The register included 395 (54,5%) men and 329 (45,5%) women. The median age of patients was 63 (57-67) years (minimum age, 10 years; maximum age, 83 years). A total of 496 (68,6%) patients had aortic stenosis, 44 (6%) — aortic regurgitation, 184 (25,4%) — aortic stenosis and regurgitation. Infective endocarditis as a cause of AV disease was diagnosed in 23 (3,2%) patients. NYHA class III-IV heart failure was in 348 (48%) patients. Atrial fibrillation was registered before surgery in 141 (19,5%) patients. Results . In total, 314 (43,4%) patients underwent a single intervention (AVNeo), while the remaining 410 (56,6%) patients underwent combined operations. Access to the heart was performed through a median sternotomy in 687 (95%) patients, and in 37 (5%) patients through a ministernotomy. The median cardiopulmonary bypass time was 130 (110-130) min, while the myocardial ischemic time — 104 (86-122) min. In-hospital mortality was 1,6%. The maximum and mean pressure gradient after surgery were 10,9 (7,4-14,8) mm Hg and 5,3 (3,5-7,3) mm Hg, respectively. The AV effective orifice area (EOA) and indexed EOA after surgery were 3 (2,5-3,9) cm 2 and 1,6 (1,3-2) cm 2 /m 2 , respectively. Thirteen (1,8%) patients received a pacemaker. Acute renal failure was recorded in 4 (0,5%) patients, stroke — in 3 (0,4%), and sternal infection — in 10 (1,4%). Conclusion . The Ozaki procedure is feasible and reproducible, has good shortterm outcomes with excellent hemodynamic parameters. Further research is needed to assess long-term results.

Abstract 17409: Comparison of Post-procedural Echocardiographic Valvular Performance after Transcatheter Aoritc Valve Implantation using Edwards SAPIEN valve versus Medtronic CoreValve for Severe Aortic Stenosis: a Meta-Analysis

Background: In patients with severe aortic stenosis (AS) who are at high risk for surgical aortic valve replacement, transcatheter aortic valve implantation (TAVI) is an emerged alternative procedure. TAVI can be performed using a balloon-expandable Edwards SAPIEN valve (EV) or self-expandable Medtronic CoreValve (CV). The objective of this meta-analysis is to compare post-procedural left ventricular ejection fraction and other echocardiographic valvular performance in patients who underwent TAVI using EV and CV. Methods: PubMed and the Cochrane Center Register of Controlled Trials were searched through May 2014. Eleven studies (n=1513) comparing TAVI procedures that used EV (n=774) and CV (n=739) were included. End points were left ventricular ejection fraction, aortic valve effective orifice area, and mean and peak trans-aortic pressure gradients. The mean difference (MD) with 95% confidence interval (CI) was computed and p&lt;0.05 was considered as a level of significance. Results: There was no significant difference in left ventricular ejection fraction (MD: 1.02, CI: -1.25 to 3.28, p=0.38) and aortic valve effective orifice area (MD: -0.06, CI: -0.17 to 0.06, p=0.04) between EV and CV groups. Mean and peak trans-aortic pressure gradient were significantly higher in CV group compared to EV group (MD: 1.42, CI: 0.4-2.44, p=0.007) (Figure) and (MD: 4.21, CI: 2.33-6.09, p&lt;0.0001) respectively. Conclusion: The results of our meta-analysis suggest that TAVI procedures using CV and EV provide clinically similar valvular performance with possibly clinically insignificant subtle differences in mean and peak trans-aortic pressure gradients in patients with severe aortic stenosis. Further randomized studies are needed for long term echocardiographic outcomes to evaluate valvular performance.

Energy Loss Index in Aortic Stenosis

In the American Heart Association–American College of Cardiology and European Society of Cardiology–European Association for Cardio-Thoracic Surgery guidelines,1,2 aortic valve replacement (AVR) is considered a class I indication in patients with aortic stenosis (AS) if the stenosis is severe and the patient has symptoms or left ventricular ejection fraction <50%. Hence, accurate assessment of the hemodynamic severity of the valvular stenosis is crucial for clinical decision making. The stenosis severity is generally determined by measuring the transvalvular pressure gradient or the aortic valve effective orifice area (AVA); however, these conventional parameters do not account for the extent of pressure recovery that may occur downstream of the stenosis. In an article published in 2000 in Circulation ,3 we proposed a new Doppler echocardiographic parameter based on the energy loss concept to adjust the AVA for pressure recovery, and we postulated that this energy loss index (ELI) would improve assessment of stenosis severity and risk stratification in AS. Thirteen years later, Bahlmann and colleagues4 publish in this issue of Circulation the first prospective study to demonstrate that ELI provides independent and incremental prognostic information to that derived from conventional measures of AS severity. In this elegant substudy of the SEAS (Simvastatin Ezetimibe in Aortic Stenosis) trial, the authors report that a 1 cm2/m2 reduction in baseline ELI predicts a 2-fold increase in the risk of aortic valve events and of the composite of mortality and heart failure hospitalization after adjustment for peak aortic jet velocity or mean gradient. Article see p 1149 The current guidelines1,2 make no distinction between catheterization and Doppler echocardiographic measurements, as though values for gradient and AVA measured by either technique were interchangeable (Figure 1). Yet Doppler estimates the maximum pressure drop through the valve from the …

Validation and Characterization of Transcatheter Aortic Valve Effective Orifice Area Measured by Doppler Echocardiography

The objectives were to compare different Doppler echocardiographic methods for the measurement of prosthetic valve effective orifice area (EOA) following transcatheter aortic valve implantation (TAVI) and to determine the factors influencing the EOA of transcatheter balloon expandable valves. Previous studies have used different methods for the measurement of the valve EOA following TAVI. Factors influencing the EOA of transcatheter valves are unknown. A total of 122 patients underwent TAVI with the use of the Edwards-SAPIEN valve (Edwards Lifesciences, Irvine, California). The EOA was measured by transthoracic echocardiography at hospital discharge, 6 months and 1 year after TAVI with the use of 2 methods as described in previous studies. In Method #1 (EOA(1)), LVOT diameter (LVOTd) entered in the continuity equation was measured at the base of prosthesis cusps whereas, in Method #2 (EOA(2)), LVOTd was measured immediately proximal to the prosthesis stent. The average EOA(2) (1.57 ± 0.41 cm(2)) was larger (p < 0.01) than the EOA(1) (1.21 ± 0.38 cm(2)). Accordingly, incidence of severe PPM (indexed EOA ≤0.65 cm(2)/m(2)) was 3-fold lower with the use of EOA(2) than with EOA(1) (9% vs. 33%; p < 0.001). Mean transprosthetic gradient correlated better (p = 0.03) with indexed EOA(2) (r = -0.70, p < 0.0001) than with indexed EOA(1) (r = -0.58, p < 0.0001). Intraobserver and interobserver variability were lower for EOA(2) compared to EOA(1) (intra: 5% vs. 7%, p = 0.06; inter: 6% vs. 14%; p < 0.001). Aortic annulus size was the sole independent determinant (p = 0.01) of prosthetic valve EOA(2). The average EOA varied from 1.37 ± 0.23 cm(2) for aortic annulus size <19 mm up to 1.90 ± 0.17 cm(2) for size >23 mm. When estimating the EOA of Edwards-SAPIEN valves by Doppler-echocardiography, it is recommended to use the LVOT diameter and velocity measured immediately proximal to the stent. The main determinant of the EOA of transcatheter valves is the patient's annulus size and these valves provide excellent hemodynamics even in patients with a small aortic annulus.

Prosthesis-patient mismatch after transcatheter aortic valve implantation with the Medtronic-Corevalve bioprosthesis

Prosthesis-patient mismatch (P-PM) is an important determinant of morbidity and mortality following open aortic valve replacement. The aims of this study were to report its incidence and determinants following transcatheter aortic valve implantation (TAVI) with the Corevalve bioprosthesis, which have-thus far-not been described. Patients with severe calcific aortic stenosis received TAVI with the Corevalve bioprosthesis via transfemoral route. Following TAVI, moderate P-PM was defined as indexed aortic valve effective orifice area (AVAi) < or =0.85 cm(2)/m(2) and severe P-PM as AVAi < or =0.65 cm(2)/m(2). Clinical, echocardiographic, and procedural factors relating to P-PM were studied. Optimal device position was defined on fluoroscopy as final position of the proximal aspect of the Corevalve stent frame 5-10 mm below the native aortic annulus. Between January 2007 and January 2009, 50 consecutive patients underwent TAVI in a single centre with the Corevalve bioprosthesis. Mean age was 82.8 years (SD 5.9; 70-93) and 48% were male. P-PM occurred in 16 of 50 cases (32%). Optimal position was achieved in 50% of cases. P-PM was unrelated to age, annulus size, LVOT size, Corevalve size, aortic angulation, ejection fraction, and sex. It was inversely correlated to optimal position (Spearman rho r = -0.34, P = 0.015). Those with optimal positioning had a 16% incidence of P-PM relative to 48% of those with suboptimal positioning (Pearson chi(2) P = 0.015). The incidence of P-PM following TAVI with the Corevalve bioprosthesis is compared favourably with that seen after AVR with conventional open stented bioprostheses and its occurrence is influenced by device positioning.

Clinical Implication of Energy Loss Coefficient in Patients With Severe Aortic Stenosis Diagnosed by Doppler Echocardiography

The Doppler-derived energy loss coefficient (ELCo), which can take into account the pressure recovery phenomenon and reconcile discrepancies between the aortic valve effective orifice area (EOA) obtained by the Gorlin formula using a catheter (EOAcath) and the EOA obtained by the Doppler continuity equation (EOADop), is proposed as an equivalent index to represent EOAcath. Therefore, the purpose of this study was to evaluate the clinical impact of ELCo in patients with severe aortic stenosis (AS). Thirty-three patients with severe AS were assessed by Doppler examination [EOA obtained by the continuity equation (EOADop)<or=1.0 cm2], and referred to the cardiac catheterization laboratory for evaluation of EOA obtained by the Gorlin formula (EOAcath). Patients with ELCo<or=1.0 cm2 (n=26) had significantly lower incidence of symptoms related to AS compared with those having ELCo>1.0 cm2 (n=7) (p=0.002). Superior concordance in severity of AS was demonstrated between EOAcath and ELCo compared with EOAcath and EOADop (kappa=0.52, and kappa=0.32, respectively). In 21% of patients with "severe" AS diagnosed by Doppler echocardiography, the ELCo value indicated moderate rather than severe AS. These patients had significantly lower incidence of symptoms compared with patients who had ELCo<or=1.0 cm2.

Flow-Dependent Changes in Doppler-Derived Aortic Valve Effective Orifice Area Are Real and Not Due to Artifact

We sought to determine whether the flow-dependent changes in Doppler-derived valve effective orifice area (EOA) are real or due to artifact. It has frequently been reported that the EOA may vary with transvalvular flow in patients with aortic stenosis. However, the explanation of the flow dependence of EOA remains controversial and some studies have suggested that the EOA estimated by Doppler-echocardiography (EOA(Dop)) may underestimate the actual EOA at low flow rates. One bioprosthetic valve and three rigid orifices were tested in a mock flow circulation model over a wide range of flow rates. The EOA(Dop) was compared with reference values obtained using particle image velocimetry (EOA(PIV)). There was excellent agreement between EOA(Dop) and EOA(PIV) (r2 = 0.94). For rigid orifices of 0.5 and 1.0 cm2, no significant change in the EOA was observed with increasing flow rate. However, substantial increases of both EOA(Dop) and EOA(PIV) were observed when stroke volume increased from 20 to 70 ml both in the 1.5 cm2 rigid orifice (+52% for EOA(Dop) and +54% for EOA(PIV)) and the bioprosthetic valve (+62% for EOA(Dop) and +63% for EOA(PIV)); such changes are explained either by the presence of unsteady effects at low flow rates and/or by an increase in valve leaflet opening. The flow-dependent changes in EOA(Dop) are not artifacts but represent real changes in EOA attributable either to unsteady effects at low flow rates and/or to changes in valve leaflet opening. Such changes in EOA(Dop) can be relied on for clinical judgment making.

Is Prosthesis–Patient Mismatch a Clinically Relevant Entity?

In this issue of Circulation , Koch and associates1 from the Cleveland Clinic published a study on the relationship between prosthetic valve size and the Duke Activity Status Index (DASI) after aortic valve replacement (AVR). The study was conducted with 1014 patients operated on from 1995 through 1998, completed 1 year later, and published now. DASI scores increased from a mean of 29 preoperatively to 46 postoperatively after a mean follow-up of 8.3 months. The investigators could find no obvious relationship between prosthetic valve size and postoperative DASI score. One of the limitations of the study was that prosthetic valve gradients and effective orifice areas were not measured by echocardiography to quantify prosthesis–patient mismatch. It is also interesting to note that more than two thirds of the patients were in New York Heart Association functional classes I and II preoperatively, and yet the DASI mean score before surgery was only 29 out of a maximum of 58.2. For this reason alone, it must be assumed that factors other than the aortic valve disease played a role in the DASI score. Nevertheless, this is not the first study to suggest that valve size plays no role in the clinical outcomes of AVR. See p 3221 Valve prosthesis–patient mismatch (PPM) is a term introduced by Rahimtoola in 1978 to describe a condition in which the in vivo prosthetic valve effective orifice area is smaller than that of the native valve.2 According to this broad definition, every patient with a prosthetic heart valve has PPM because the leaflets of both mechanical and bioprosthetic valves are mounted into frames that occupy …

Estimation of aortic valve effective orifice area by Doppler echocardiography: effects of valve inflow shape and flow rate

Background The effective orifice area (EOA) is the standard parameter for the clinical assessment of aortic stenosis severity. It has been reported that EOA measured by Doppler echocardiography does not necessarily provide an accurate estimate of the cross-sectional area of the flow jet at the vena contracta, especially at low flow rates. The objective of this study was to test the validity of the Doppler-derived EOA. Methods Triangular and circular orifice plates, funnels, and bioprosthetic valves were inserted into an in vitro aortic flow model and were studied under different physiologic flow rates corresponding to cardiac outputs varying from 1.5 to 7 L/min. For each experiment, the EOA was measured by Doppler and compared with the catheter-derived EOA and with the EOA derived from a theoretic formula. In bioprostheses, the geometric orifice area (GOA) was estimated from images acquired by high-speed video recording. Results There was no significant difference between the EOA derived from the 3 methods with the rigid orifices (Doppler vs catheter: y = 0.97x +0.18 mm 2, r 2 = 0.98; Doppler vs theory: y = 1.00x −3.60 mm 2, r 2 = 0.99). Doppler EOA was not significantly influenced by the flow rate in rigid orifices. As predicted by theory, the average contraction coefficient (EOA/GOA) was around 0.6 in the orifice plates and around 1.0 in the funnels. In the bioprosthetic valves, both EOA and GOA increased with increasing flow rate whereas contraction coefficient was almost constant with an average value of 0.99. There was also a very good concordance between EOA and GOA (y = 0.94x +0.05 mm 2, r 2 = 0.88). Conclusions In rigid aortic stenosis, the Doppler EOA is much less flow dependent than generally assumed. Indeed, it depends mainly on the GOA and the inflow shape (flat vs funnel-shaped) of the stenosis. The flow dependence of Doppler EOA observed in clinical studies is likely a result of a variation of the valve GOA or of the valve inflow shape and not an inherent flow dependence of the EOA derived by the continuity equation.