Three-dimensional versus two-dimensional echocardiographic assessment of functional mitral regurgitation proximal isovelocity surface area

Transcatheter mitral valve implantation: Implications of interventional technique and 3D echocardiography for complex valve-in-valve paravalvular leak

Transcatheter mitral valve replacement (TMVR) has emerged as a feasible alternative to surgical reoperation in failed bioprostheses and rings. Residual mitral regurgitation following TMVR can present as a valve-in-valve paravalvular leak (PVL) and is associated with increased morbidity and mortality. Current therapies for valve-in-valve PVL are limited. We present a case of a symptomatic patient with severe valve-in-valve PVL after TMVR for a previous surgical bioprosthesis leak, who then underwent a second TMVR as a valve-in-valve-in-valve implantation with a 29 mm Edwards® SAPIEN 3 valve via transseptal approach using three-dimensional (3D) echocardiography. This unique case highlights the complexity of this clinical entity and recognizes 3D transesophageal echocardiography as a valuable tool to guide valve-in-valve PVL closures.

Benefit of 3D Vena Contracta Area over 2D-Based Echocardiographic Methods in Quantification of Functional Mitral Valve Regurgitation

BACKGROUND

The two-dimensional proximal isovelocity surface area (2D PISA) method in the quantification of an effective regurgitation orifice area (EROA) has limitations in functional mitral valve regurgitation (FMR), particularly in non-circular coaptation defects.

OBJECTIVE

We aimed to validate a three-dimensional vena contracta area (3D VCA) against a conventional EROA using a 2D PISA method and anatomic regurgitation orifice area (AROA) in patients with FMR.

METHODS

Both 2D and 3D full-volume color Doppler data were acquired during consecutive transoesophageal echocardiography (TEE) examinations. The EROA 2D PISA was calculated as recommended by current guidelines. Multiplanar reconstruction was used for offline analysis of the 3D VCA (with a color Doppler) and AROA (without a color Doppler). Receiver operating characteristic (ROC) analysis was used to calculate a cut-off value for the 3D VCA to discriminate between moderate and severe FMR as classified by the EROA 2D PISA.

RESULTS

From 2015 to 2018, 105 consecutive patients with complete and adequate imaging data were included. The 3D VCA correlated strongly with the 2D PISA EROA and AROA (r = 0.93 and 0.94). In the presence of eccentric or multiple regurgitant jets, there was no significant difference in correlations with the 3D VCA. We found a 3D VCA cut-off of 0.43 cm² to discriminate between moderate and severe FMR (area under curve = 0.98). The 3D VCA showed a higher interobserver agreement than the EROA 2D PISA (interclass correlation coefficient: 0.94 vs. 0.81).

CONCLUSIONS

The 3D VCA has excellent validity and lower variability than the conventional 2D PISA in FMR. Compared to the 2D PISA, the 3D VCA was not affected by the presence of eccentric or multiple regurgitation jets or non-circular regurgitation orifices. With a threshold of 0.43 cm² for the 3D VCA, we demonstrated reliable discrimination between moderate and severe FMR.

Impact of assuming a circular orifice on flow error through elliptical regurgitant orifices: computational fluid dynamics and in vitro analysis of proximal flow convergence

Grounded in hydrodynamic theory, proximal isovelocity surface area (PISA) is a simplistic and practical technique widely used to quantify valvular regurgitation flow. PISA provides a relatively reasonable, though slightly underestimated flow rate for circular orifices. However, for elliptical orifices frequently seen in functional mitral regurgitation, PISA underestimates the flow rate. Based on data obtained with computational fluid dynamics (CFD) and in vitro experiments using systematically varied orifice parameters, we hypothesized that flow rate underestimation for elliptical orifices by PISA is predictable and within a clinically acceptable range. We performed 45 CFD simulations with varying orifice areas 0.1, 0.3 and 0.5 cm², orifice aspect ratios 1:1, 2:1, 3:1, 5:1, and 10:1, and peak velocities (V_max) 400, 500 and 600 cm/s. The ratio of computed effective regurgitant orifice area to true effective area (EROA_C/EROA) against the ratio of aliasing velocity to peak velocity (V_A/V_max) was analyzed for orifice shape impact. Validation was conducted with in vitro imaging in round and 3:1 elliptical orifices. Plotting EROA_C/EROA against V_A/V_max revealed marginal flow underestimation with 2:1 and 3:1 elliptical axis ratios against a circular orifice (< 10% for 8% V_A/V_max), rising to ≤ 35% for 10:1 ratio. In vitro modeling confirmed CFD findings; there was a 8.3% elliptical EROA underestimation compared to the circular orifice estimate. PISA quantification for regurgitant flow through elliptical orifices produces predictable, but generally small, underestimation deemed clinically acceptable for most regurgitant orifices.

Spatiotemporal Complexity of Vena Contracta and Mitral Regurgitation Grading Using Three-Dimensional Echocardiographic Analysis

BACKGROUND

Spatiotemporal complexity of the color Doppler vena contracta challenging the assumption of a circular and constant orifice may lead to mitral regurgitation (MR) grading inconsistencies. Using 3D transesophageal echocardiography, we characterized spatiotemporal vena contracta complexity and its impact on MR severity grading.

METHODS

In 192 patients with suspected moderate or severe MR (100 primary MR [PMR]; 92 secondary MR [SMR]), we performed three-dimensional vena contracta area (VCA) quantification using single-frame (midsystolic or VCAmid, maximum or VCAmax) and multiframe (VCAmean) methods, as well as measures of orifice shape (shape index) and systolic variation of VCA. Vena contracta complexity and intermethod discrepancies were analyzed and correlated with functional class and pulmonary vein flow (PVF) patterns and with cardiac magnetic resonance (CMR) in a subset of cases (n = 20).

RESULTS

The vena contracta was noncircular (shape index > 1.5) in 90% of patients. Severe noncircularity (shape index > 3) was more prevalent in SMR than in PMR (32.4% vs 14.6%). Variations of the VCA were more prominent in SMR than in PMR. VCAmid showed a low grading agreement with VCAmax (62%) and high grading agreement with VCAmean (83.3%). Pulmonary vein flow systolic reversal was associated with MR severity by VCA in SMR but not in PMR. VCAmid and VCAmean showed a stronger association with systolic flow reversal than VCAmax (area under the curve, 0.88, 0.86, and 0.79, respectively). In the subset of patients with CMR quantification, severe MR by VCAmax was graded as nonsevere by CMR more frequently compared with VCAmid and VCAmean.

CONCLUSIONS

Highly prevalent spatiotemporal vena contracta complexity features in MR challenge the assumption of a circular and constant orifice. VCAmid seems the best single-frame approximation to multiframe quantification, and VCAmax may lead to severity overestimation.

Joint preoperative transthoracic and intraoperative transoesophageal echocardiographic assessment of functional mitral regurgitation severity provides better association with long-term mortality

OBJECTIVES

Functional mitral regurgitation (MR) is observed with ischaemic heart disease or aortic valve disease. Assessing the value of mitral valve repair or replacement (MVR/P) is complicated by frequent discordance between preoperative transthoracic echocardiographic (pTTE) and intraoperative transoesophageal echocardiographic (iTOE) assessment of MR severity. We examined the association of pTTE and iTOE with postoperative mortality in patients with or without MR, at the time of coronary artery bypass grafting (CABG) and/or aortic valve replacement without MVR/P.

METHODS

Medical records of 6629 patients undergoing CABG and/or aortic valve replacement surgery with or without functional MR and who did not undergo MVR/P were reviewed. MR severity assessed by pTTE and iTOE were examined for association with postoperative mortality using proportional hazards regression while accounting for patient and operative characteristics.

RESULTS

In 72% of 709 patients with clinically significant (moderate or greater) functional MR detected by pTTE, iTOE performed after induction of anaesthesia demonstrated a reduction in MR severity, while 2% of patients had increased severity of MR by iTOE. iTOE assessment of MR was better associated with long-term postoperative mortality than pTTE in patients with moderate MR [hazard ratio (HR) 1.31 (1.11-1.55) vs 1.02 (0.89-1.17), P-value for comparison of HR 0.025] but was not different for more than moderate MR [1.43 (0.96-2.14) vs 1.27 (0.80-2.02)].

CONCLUSIONS

In patients undergoing CABG and/or aortic valve replacement without MVR/P, these findings support intraoperative reassessment of MR severity by iTOE as an adjunct to pTTE in the prediction of mortality. Alone, these findings do not yet provide evidence for an operative strategy.

Computational Analysis of Virtual Echocardiographic Assessment of Functional Mitral Regurgitation for Validation of Proximal Isovelocity Surface Area Methods

BACKGROUND

Mitral regurgitation (MR) quantification by the proximal isovelocity surface area (PISA) method remains challenging. Using computer models, the authors evaluated the accuracy of different PISA methods and quantified their errors.

METHODS

Five functional MR computer models of different geometric and tethering abnormalities were created, validated, and treated as phantom models, from which the reference values were directly obtained. Virtual two-dimensional (2D) PISA and three-dimensional (3D) PISA (both peak and integrated values) were performed on these phantom models. By comparing virtual PISA results with reference values, the accuracy of different PISA methods was evaluated, and their sources of errors were quantified.

RESULTS

Compared with reference values of regurgitant flow rate, excellent correlations were found for true PISA (r = 0.99, bias = 32.3 ± 35.3 mL/sec), 3D PISA (r = 0.97, bias = -24.4 ± 55.5 mL/sec), followed by multiplane 2D hemicylindrical PISA (r = 0.88, bias = -24.1 ± 85.4 mL/sec) and hemiellipsoidal PISA (r = 0.91, bias = -55.7 ± 96.6 mL/sec). Weaker correlations were found for single-plane 2D hemispherical PISA (parasternal long-axis: r = 0.71, bias = -77.6 ± 124.5 mL/sec; apical two-chamber: r = 0.69, bias = -52.0 ± 122.0 mL/sec; apical four-chamber: r = 0.82, bias = -65.5 ± 107.3 mL/sec). For regurgitant volume quantification, integrated PISA was more accurate than peak PISA. The bias of 3D PISA improved from -12.7 ± 7.8 mL (peak PISA) to -2.1 ± 5.3 mL (integrated PISA).

CONCLUSIONS

For functional MR quantification, 2D hemispherical PISA had significant underestimation, multiplane 2D hemiellipsoidal and hemicylindrical PISA showed improved accuracy, and 3D PISA was the most accurate. The PISA method is subject to both systematic underestimation due to the Doppler angle effect and systematic overestimation when regurgitant flow is not perpendicular to PISA contour. Integrated PISA is able to capture dynamic MR and is therefore more accurate than peak PISA. The sum of regurgitant flow rates is the most feasible way to perform integrated PISA.

Intraoperative comparison of 2D versus 3D transesophageal echocardiography for quantitative assessment of mitral regurgitation

Background:

Effective regurgitant orifice area (EROA) can be represented by 3D echocardiographic vena contracta cross-sectional area (3D-VCA) as a reference method for the quantification of mitral regurgitation (MR) without making any geometrical assumptions. EROA can also be derived from 3D PISA technique with a hemispherical (HS) or hemielliptical (HE) assumption of the proximal flow convergence. However, it is not clear whether HS-PISA and HE-PISA has better agreement with 3D-VCA.

Aims:

This study was conducted to compare the EROA and Rvol obtained from 3D-VCA with those obtained from 2D-VC, 2D-HS-PISA, 3D-HS-PISA, and 3D-HE-PISA.

Setting:

Tertiary care hospital.

Design:

Prospective observational study.

Materials and Methods:

After anesthesia induction, 43 consecutive patients were evaluated with RT-3D-TEE after acquiring images from midesophegeal views and performing the offline analysis of volume dataset. 3D-VCA was measured using multiplanar reconstruction mode and EROA and regurgitant volume were estimated using HS-PISA and HE-PISA methods. The HE-PISA was calculated by using the Knud Thomsen formula.

Statistical Analysis:

Agreement between methods to estimate EROA and regurgitant volumes were tested using Bland–Altman analysis. The interobserver variability and intraobserver variability were assessed using an intraclass correlation coefficient.

Results:

The EROA estimated by 3D-VCA was larger than EROA obtained by 2D-HS-PISA and 3D-HS-PISA, which were significantly greater than 3D-HE-PISA. 3D-HS-PISA-EROA showed the best agreement with 3D-VCA (bias: 0.21; limits of agreement: −0.01 to 0.41; SD: 0.1). Correlation between various methods as compared to 3D-VCA was better in the organic MR group than functional MR group.

Conclusion:

3D-HS-PISA showed the best agreement with 3D-VCA compared to other PISA methods. Better correlation between PISA-EROA and 3D-VCA was observed in patients with organic MR than functional MR.

Quantification of regurgitation in mitral valve prolapse with automated real time echocardiographic 3D proximal isovelocity surface area: multimodality consistency and role of eccentricity index

Three-dimensional transthoracic echocardiography (3D-TTE) provides a semi-automated proximal isovelocity surface area method (3D-PISA) to obtain quantitative parameters. Data assessing regurgitation severity in mitral valve prolapse (MVP) are scarce, so we assessed the 3D-PISA method compared with 2D-PISA and cardiovascular magnetic resonance (CMR) and the role of an eccentricity index. We evaluated the 3D-PISA method for assessing MR in 54 patients with MVP (57 ± 14 years; 42 men; 12 mild/mild-moderate; 12 moderate-severe; and 30 severe MR). Role of an asymmetric (i.e. eccentricity index ≥ 1.25) flow convergence region (FCR) and inter-modality consistency were then assessed. 3D-PISA derived regurgitant volume (RVol) showed a good correlation with 2D-PISA and CMR derived parameters (r = 0.86 and r = 0.81, respectively). The small mean differences with 2D-PISA derived RVol did not reach statistical significance in overall population (5.7 ± 23 ml, 95% CI - 0.6 to 12; p = 0.08) but differed in those with asymmetric 3D-FCR (n = 21; 2D-PISA: 72 ± 36 ml vs. 3D-PISA: 93 ± 47 ml; p = 0.001). RVol mean values were higher using PISA methods (CMR 57 ± 33 ml; 2D-PISA 73 ± 39 ml; and 3D-PISA 79 ± 45 ml) and an overestimation was observed when CMR was used as reference (2D-PISA vs. CMR: mean difference: 15.8 ml [95% CI 10-22, p < 0.001]; and 3D-PISA vs. CMR: 21.5 ml [95% CI 14-29, p < 0.001]). Intra- and inter-observer reliability was excellent (ICC 0.91-0.99), but with numerically lower coefficient of variation for 3D-PISA (8%-10% vs. 2D-PISA: 12%-16%). 3D-PISA method for assessing regurgitation in MVP may enable analogous evaluation compared to standard 2D-PISA, but with overestimation in case of asymmetric FCR or when CMR is used as reference method.

A panel of criteria for comprehensive assessment of severity of ultraviolet B radiation-induced non-melanoma skin cancers in SKH-1 mice

The study of causes and cures for ultraviolet B radiation (UVB)-induced non-melanoma skin cancers (NMSC) has been greatly facilitated by use of the albino SKH-1 hairless mice. These mice develop multiple tumors of different sizes and the severity of cancer is often measured by one or more of the four criteria, namely the prevalence, multiplicity, area and volume of tumors. However, there are inherent limitations of each criterion: the prevalence and number do not account for size differences among tumors, area measurement ignores the tumor height, and volume measurement overcompensates for the height at the cost of planar dimensions. Here, using our dataset from an ongoing NMSC study, we discuss the limitations of these four criteria, and suggest refinements in measuring prevalence. We recommend the use of three more criteria, namely the Knud Thomsen tridimensional surface that apportions optimal weightage to three tumor dimensions, weekly occurrence of new tumors and tumor growth-rate to reveal initiation and growth of tumors in early and late phase of NMSC development, respectively. Together, use of this comprehensive panel of seven criteria can provide an accurate assessment of severity of NMSC and lead to a testable hypothesis whether the experimental manipulation of mice has affected the early initiation or growth phase of NMSC tumors.

Comparative quantification of primary mitral regurgitation by computer modeling and simulated echocardiography

Clinical investigations have demonstrated that mitral regurgitation (MR) quantification using echocardiography (echo) may significantly underestimate or overestimate the regurgitant volume, especially for two-dimensional (2D) echo. Computer modeling and simulated echo were conducted to evaluate the fundamental assumptions in the echo quantification of primary MR that is due to posterior mitral leaflet prolapse. The theoretical flaw of the proximal isovelocity surface area (PISA) method originates from the assumption that the MR flow rate is the product of the isovelocity surface area and aliasing velocity, which is only valid when the velocity vectors are perpendicular to the isovelocity surface. Other factors such as the Doppler angle effect, the view planes of 2D echo, and the single time instant of PISA were also analyzed. We find that the hemielliptic PISA method gives the smallest error for moderate and severe MR cases compared with other PISA methods. Compared with the PISA method, the volumetric technique (VT) is theoretically more robust. By considering correction factors that are caused by nonflat velocity profiles and the closing volume of the aortic valve, the accuracy of the VT method can be significantly improved. The corrected volumetric technique provides more accurate results compared with the PISA methods, especially for mild MR.NEW & NOTEWORTHY We evaluate the accuracy of common echocardiography techniques for the quantification of primary mitral regurgitations using computer modeling. The hemielliptic proximal isovelocity surface area (PISA) method gives the smallest error (within 15%) for moderate and severe mitral regurgitation cases compared with other PISA methods. The volumetric method is theoretically more robust than the PISA method. The accuracy of the volumetric method can be improved by a correction factor around 0.7 because of the nonflat velocity profiles and the closing volume of the aortic valve.

Predicting the Number of Edge-to-Edge Repair Devices Needed to Adequately Treat Mitral Regurgitation Using Transesophageal Echocardiography

OBJECTIVES

Increased utilization and highly variable costs seen with percutaneous mitral valve edge-to-edge repair have made cost cutting strategies of significant interest. Mitral regurgitation etiology, the number of devices used, and experience all play a role in variability. Currently a paucity of data exists in predicting the number of devices. Any associations found between echocardiography parameters and the number of devices used could help with pre-procedure planning and device placement strategies, ultimately reducing variability and costs.

DESIGN

In this retrospective analysis the authors evaluated the ability of established and novel three-dimensional (3D) mitral regurgitation measures, namely 3D vena contracta area and vena contracta length, to predict the number of devices used. Other factors evaluated include mitral valve area and ejection fraction. All factors were compared using the Mann Whitney rank sum tests.

PARTICIPANTS

Patients over 18 years old undergoing the MitraClip procedure.

SETTING

Catheterization Laboratory.

MAIN RESULTS

No relationship was found between 3D parameters and the number of devices used, but mitral valve area was strongly associated with the use of multiple devices.

CONCLUSION

The 3D parameters of interest were not associated with the use of multiple devices, but the mitral valve area was associated. Further studies are needed to determine if this relationship is predictive.

Single-center five-year outcomes after interventional edge-to-edge repair of the mitral valve

BACKGROUND

The MitraClip procedure was established as a therapeutic alternative to mitral valve surgery for symptomatic patients with severe mitral regurgitation (MR) at prohibitive surgical risk. In this study, the aim was to evaluate 5-year outcomes after MitraClip.

METHODS

Consecutive patients undergoing the MitraClip system were prospectively included. All patients underwent clinical follow-up and transthoracic echocardiography.

RESULTS

Two hundred sixty-five patients (age: 81.4 ± 8.1 years, 46.7% female, logistic EuroSCORE: 19.7 ± 16.7%) with symptomatic MR (60.5% secondary MR [sMR]). Although high procedural success of 91.3% was found, patients with primary MR (pMR) had a higher rate of procedural failure (sMR: 3.1%, pMR: 8.6%; p = 0.04). Five years after the MitraClip procedure, the majority of patients presented with reduced symptoms and improved functional capacity (functional NYHA class: p = 0.0001; 6 minutes walking test: p = 0.04). Sustained MR reduction (≤ grade 2) was found in 74% of patients, and right ventricular (RV) function was significantly increased (p = 0.03). Systolic pulmonary artery pressure (sPAP) was significantly reduced during follow-up only in sMR patients (p = 0.05, p = 0.3). Despite a pronounced clinical and echocardiographical amelioration and low interventional failure, 5-year mortality was significantly higher in patients with sMR (p = 0.05). The baseline level of creatinine (HR: 0.695), sPAP (HR: 0.96) and mean mitral valve gradient (MVG) (HR: 0.82) were found to be independent predictors for poor functional outcome and mortality.

CONCLUSIONS

Transcatheter mitral valve repair with the MitraClip system showed low complication rates and sustained MR reduction with improved RV function and sPAP 5 years after the procedure was found in all patients, predominantly in patients with sMR. Despite pronounced functional amelioration with low procedure failure, sMR patients had higher 5-year mortality and worse outcomes. Baseline creatinine, MVG, and sPAP were found to be independent predictors of poor functional outcomes and 5-year mortality.

Application of three-dimensional proximal isovelocity surface area method in tricuspid regurgitation quantification

OBJECTIVES

Recently, three-dimensional proximal isovelocity surface area (3D PISA) method has already been widely used in tricuspid regurgitation assessment. This study attempts to demonstrate the feasibility and accuracy of 3D PISA quantifying tricuspid regurgitation and explore the clinical value of 3D PISA in quantifying tricuspid regurgitation.

METHODS

Fifty-four patients with more than mild tricuspid regurgitation (TR) were enrolled. Effective regurgitant orifice area (EROA) and regurgitant volume (Rvol) were assessed by transthoracic 3D PISA method and three-dimensional vena contracta area (3D VCA) method. The 3D VCA was used as reference method. We analyzed the correlation and differences of EROA between 3D PISA method and the reference method.

RESULTS

Both EROA and Rvol assessed by the 3D PISA had good correlations with the reference method, particularly in the assessment of eccentric jets, with the correlation coefficients of r (EROA) = 0.83, P < 0.001, r (Rvol) = 0.90, P < 0.001, respectively. 3D PISA method had good agreement with 3D VCA method in grading TR. Intra-observer and inter-observer agreement were also good.

CONCLUSIONS

Three-dimensional proximal isovelocity surface area method can accurately quantify the degree of tricuspid regurgitation with good repeatability and shorter time-consuming, which is worthy of further study. 3D PISA method is expected to be a new method for evaluating tricuspid regurgitation in clinic practice.

Ischemic Mitral Regurgitation: Repair, Replacement or Nothing

The treatment strategy for ischemic mitral regurgitation (MR) continues to evolve with the completion of multicenter trials and the advancement of surgical and percutaneous interventional techniques. This review defines ischemic MR, outlines key clinical trials that assess surgical and interventional approaches, and reports the main elements of recent national guidelines for decision making in treatment of ischemic MR. New findings in percutaneous mitral valve repair and replacement for ischemic MR will also be described. Effective perioperative care of patients with ischemic MR requires clinicians to be well versed in the most up-to-date recommendations and emerging technological developments.

Echocardiographic Assessment of Mitral Stenosis Orifice Area: A Comparison of a Novel Three-Dimensional Method Versus Conventional Techniques

BACKGROUND

A comprehensive evaluation of mitral stenosis (MS) severity commonly utilizes two-dimensional (2D) echocardiography techniques. However, the complex three-dimensional (3D) structure of the mitral valve (MV) poses challenges to accurate measurements of its orifice area by 2D imaging modalities. We aimed to assess MS severity by comparing measurements of the MV orifice area using conventional echocardiography methods to 3D orifice area (3DOA), a novel echocardiographic technique which minimizes geometric assumptions.

METHODS

Routine 2D and 3D intraoperative transesophageal echocardiographic images from 26 adult cardiac surgery patients with at least moderate rheumatic MS were retrospectively reviewed. Measurements of the MV orifice area obtained by pressure half-time (PHT), proximal isovelocity surface area (PISA), continuity equation, and 3D planimetry were compared to those acquired using 3DOA.

RESULTS

MV areas derived by PHT, PISA, continuity equation, 3D planimetry, and 3DOA (mean value ± standard deviation) were 1.12 ± 0.27, 1.03 ± 0.27, 1.16 ± 0.35, 0.97 ± 0.25, and 0.76 ± 0.21 cm, respectively. Areas obtained from the 3DOA method were significantly smaller than areas derived from PHT (mean difference 0.35 cm, P < .0001), PISA (mean difference: 0.28 cm, P = .0002), continuity equation (mean difference: 0.43 cm, P = .0015), and 3D planimetry (mean difference: 0.19 cm, P < .0001). MV 3DOAs also identified a significantly greater percentage of patients with severe MS (88%) compared to PHT (31%, P = .006), PISA (42%, P = .01), and continuity equation (39%, P = .017) but not in comparison to 3D planimetry (62%, P = .165).

CONCLUSIONS

Novel measures of the stenotic MV 3DOA in patients with rheumatic heart disease are significantly smaller than calculated values obtained by conventional methods and may be consistent with a higher incidence of severe MS compared to 2D techniques. Further investigation is warranted to determine the clinical relevance of 3D echocardiographic techniques used to measure MV area.

Three-dimensional proximal flow convergence automatic calculation for determining mitral valve area in rheumatic mitral stenosis

PURPOSE

Management of patients with mitral stenosis (MS) depends heavily on the accurate quantification of mitral valve area (MVA) using echocardiography. All currently used two-dimensional (2D) methods have limitations. Estimation of MVA using the proximal isovelocity surface area (PISA) method with real time three-dimensional (3D) echocardiography may circumvent those limitations. We aimed to evaluate the accuracy of 3D direct measurement of PISA in the estimation of MVA.

METHODS

Twenty-seven consecutive patients (median age of 63 years; 77.8% females) with rheumatic MS were prospectively studied. Transthoracic and transesophageal echocardiography with 2D and 3D acquisitions were performed on the same day. The reference method for MVA quantification was valve planimetry after 3D-volume multiplanar reconstruction. A semi-automated software was used to calculate the 3D flow convergence volume.

RESULTS

Compared to MVA estimation using 3D planimetry, 3D PISA showed the best correlation (rho=0.78, P<.0001), followed by pressure half-time (PHT: rho=0.66, P<.001), continuity equation (CE: rho=0.61, P=.003), and 2D PISA (rho=0.26, P=.203). Bland-Altman analysis revealed a good agreement for MVA estimation with 3D PISA (mean difference -0.03 cm² ; limits of agreement (LOA) -0.40-0.35), in contrast to wider LOA for 2D methods: CE (mean difference 0.02 cm² , LOA -0.56-0.60); PHT (mean difference 0.31 cm² , LOA -0.32-0.95); 2D PISA (mean difference -0.03 cm² , LOA -0.92-0.86).

CONCLUSIONS

MVA estimation using 3D PISA was feasible and more accurate than 2D methods. Its introduction in daily clinical practice seems possible and may overcome technical limitations of 2D methods.

[Real-time 3D echocardiography for estimation of severity in valvular heart disease : Impact on current guidelines]

Besides providing spatial anatomic information on heart valves, real-time three-dimensional echocardiography (3DE) combined with color Doppler has the potential to overcome the limitations of flow quantification inherent to conventional 2D color Doppler methods. Recent studies validated the application of color Doppler 3DE (cD-3DE) for the quantification of regurgitation flow based on the vena contracta area (VCA) and the proximal isovelocity surface area (PISA) methods. Particularly the assessment of VCA by cD-3DE led to a change of paradigm by understanding of the VCA as being strongly asymmetric in the majority of patients and etiologies. This review provides a comprehensive description of the different concepts of cD-3DE-based flow quantification in the setting of different valvular heart diseases and their presentation in recent guidelines.

Noteworthy Articles in 2015 for the Cardiothoracic Anesthesiologist

Large multicenter, randomized controlled trials published in reputable journals had a large impact on the world of cardiothoracic anesthesia in 2015. We as cardiac anesthesiologists pride ourselves as being experts in applied physiology, physics, ultrasonography, and pharmacology/pharmacotherapy. The selected studies added to our knowledge in the fields of echocardiography, pharmacology, molecular biology, and genetics. Outcome studies shine a light on important topics that are relevant to all cardiac anesthesiologists: does surgical atrial fibrillation ablation during mitral valve surgery reduce the recurrence of atrial fibrillation at 1 year after surgery? Does remote ischemic preconditioning live up to its promise to reduce postoperative major cardiac and cerebral events? Although we still do not have the answer to all the questions, the year 2015 has been a great step toward the goal of understanding molecular mechanisms of ischemic myocardial injury and toward providing evidence-based medicine for improving patient outcome.

Real-Time Three-Dimensional Echocardiographic Assessment of Severity of Mitral Regurgitation Using Proximal Isovelocity Surface Area and Vena Contracta Area Method. Lessons We Learned and Clinical Implications

Mitral regurgitation (MR) is considered the most common valve disease with a prevalence of 2-3 % of significant regurgitation (moderate to severe and severe) in the general population. Accurate assessment of the severity of regurgitation was demonstrated to be of significant importance for patient management and prognosis and consequently has been widely recognized in recent guidelines. However, evaluation of severity of valvular regurgitation can be potentially difficult with the largest challenges presenting in cases of mitral regurgitation. Real-time three-dimensional echocardiography (RT3DE) by the use of color Doppler has the potential to overcome the limitations of conventional flow quantification using 2D color Doppler methods. Recent studies validated the application of color Doppler RT3DE for the assessment of flow based on vena contracta area (VCA) and proximal isovelocity surface area (PISA). Particularly, the assessment of VCA by color Doppler RT3DE led to a change of paradigm by understanding the VCA as being strongly asymmetric in the majority of patients and etiologies. In this review, we provide a discussion of the current state of clinical evaluation, limitations, and future perspectives of the two methods and their presentation in recent literature and guidelines.