Imaging Assessment of Tricuspid Regurgitation Severity.

Assessing the severity of tricuspid regurgitation remains a challenging task, and although echocardiography is the test of choice, significant limitations of the current recommendations exist. Newer methods have been used in current trials of transcatheter devices and may improve our understanding of the disease process. Cardiac magnetic resonance imaging and computed tomography angiography may play significant roles as adjunctive imaging modalities. This paper reviews the imaging modalities currently used to quantify tricuspid regurgitation severity.

Left ventricular geometry predicts optimal response to percutaneous mitral repair via MitraClip: Integrated assessment by two- and three-dimensional echocardiography.

OBJECTIVES: To assess impact of left ventricular (LV) chamber remodeling on MitraClip (MClp) response. BACKGROUND: MitraClip is the sole percutaneous therapy approved for mitral regurgitation (MR) but response varies. LV dilation affects mitral coaptation; determinants of MClp response are uncertain. METHODS: LV and mitral geometry were quantified on pre- and post-procedure two-dimensional (2D) transthoracic echocardiography (TTE) and intra-procedural three-dimensional (3D) transesophageal echocardiography (TEE). Optimal MClp response was defined as ≤mild MR at early (1-6 month) follow-up. RESULTS: Sixty-seven degenerative MR patients underwent MClp: Whereas MR decreased ≥1 grade in 94%, 39% of patients had optimal response (≤mild MR). Responders had smaller pre-procedural LV end-diastolic volume (94 ± 24 vs. 109 ± 25 mL/m2 , p = 0.02), paralleling smaller annular diameter (3.1 ± 0.4 vs. 3.5 ± 0.5 cm, p = 0.002), and inter-papillary distance (2.2 ± 0.7 vs. 2.5 ± 0.6 cm, p = 0.04). 3D TEE-derived annular area correlated with 2D TTE (r = 0.59, p < 0.001) and was smaller among optimal responders (12.8 ± 2.1 cm2 vs. 16.8 ± 4.4 cm2 , p = 0.001). Both 2D and 3D mitral annular size yielded good diagnostic performance for optimal MClp response (AUC 0.73-0.84, p < 0.01). In multivariate analysis, sub-optimal MClp response was associated with LV end-diastolic diameter (OR 3.10 per-cm [1.26-7.62], p = 0.01) independent of LA size (1.10 per-cm2 [1.02-1.19], p = 0.01); substitution of mitral annular diameter for LV size yielded an independent association with MClp response (4.06 per-cm2 [1.03-15.96], p = 0.045). CONCLUSIONS: Among degenerative MR patients undergoing MClp, LV and mitral annular dilation augment risk for residual or recurrent MR, supporting the concept that MClp therapeutic response is linked to sub-valvular remodeling.

Comparison between Three-Dimensional Echocardiography and Computed Tomography for Comprehensive Tricuspid Annulus and Valve Assessment in Severe Tricuspid Regurgitation: Implications for Tricuspid Regurgitation Grading and Transcatheter Therapies.

BACKGROUND: Tricuspid valve imaging is frequently challenging and requires the use of multiple modalities. Knowledge of limitations and methodologic discrepancies among different imaging techniques is crucial for planning transcatheter valve interventions. METHODS: Thirty-eight patients with severe symptomatic tricuspid regurgitation were included in this retrospective analysis. Tricuspid annulus (TA) measurements were made during mid-diastole using three-dimensional (3D) transthoracic echocardiographic direct planimetry (TTE_direct) and transesophageal echocardiographic direct planimetry (TEE_direct). Moreover, a semiautomated software was used to generate two-dimensional (2D) and 3D perimeter and area on transesophageal echocardiography (TEE) images. Both methods were compared with direct computed tomographic planimetry (CT_direct) and cubic spline interpolation (CT_indirect). The different TA values were used to calculate the effective regurgitant orifice area and compared with 3D Doppler vena contracta area. For tricuspid valve area TEE_direct and CT_direct as well as CT_indirect were measured. RESULTS: Agreement between TEE and computed tomography (CT) for TA sizing was obtained using semiautomated methods (3D TEE_indirect and CT_indirect). TTE_direct was overall less reliable compared with CT. TA area quantified by TEE_direct was 25% (difference 305 ± 238 mm2, P < .001, R = 0.9) and 19% (166 ± 247 mm2, P < .001, R = 0.89) smaller compared with CT_direct and CT_indirect, respectively. TA perimeter measurements by TEE_direct differed by 11% compared with CT_direct (12 ± 11 mm, P < .001, R = 0.87) and 3D CT_indirect (12 ± 11 mm, P < .001, R = 0.88), and 9% compared with 2D CT_indirect (7 ± 11 mm, P = .002, R = 0.87). TEE_direct of the TA allows the most accurate calculation of effective regurgitant orifice area compared with 3D vena contracta area (-8 ± 62 mm2, P = .50, R = 0.85). Tricuspid valve area by CT_indirect best correlated with conventional TEE_direct (80 ± 250 mm2, P = .11, R = 0.80). CONCLUSIONS: In patients with severe tricuspid regurgitation, semiautomated indirect planimetry results in high agreement between TEE and CT for TA sizing and measurement of the tricuspid valve area. TEE_direct of the TA allows the most accurate measurement of diastolic stroke volume for the calculation of regurgitation severity compared with 3D vena contracta area.

Mortality risk after transcatheter aortic valve implantation: analysis of the predictive accuracy of the Transcatheter Valve Therapy registry risk assessment model.

AIMS: The risk assessment tools currently used to predict mortality in transcatheter aortic valve implantation (TAVI) were designed for patients undergoing cardiac surgery. We aimed to assess the accuracy of the TAVI dedicated risk score in predicting mortality outcomes. METHODS AND RESULTS: Consecutive patients (n=1,038) undergoing TAVI at a single institution from 2014 to 2016 were included. The ACC/TVT registry mortality risk score, the STS-PROM score and the EuroSCORE II were calculated for all patients. In-hospital and 30-day all-cause mortality rates were 1.3% and 2.9%, respectively. The ACC/TVT risk stratification tool scored higher for patients who died in-hospital than for those who survived the index hospitalisation (6.4±4.6 vs. 3.5±1.6, p=0.03, respectively). The ACC/TVT score showed a high level of discrimination, C-index for in-hospital mortality 0.74, 95% CI: (0.59-0.88). There were no significant differences between the performance of the ACC/TVT registry risk score, the EuroSCORE II and the STS-PROM score for in-hospital and 30-day mortality rates. CONCLUSIONS: The ACC/TVT registry risk model is a dedicated tool to aid in the prediction of in-hospital mortality risk after TAVI.

Aortic Valve Annular Sizing: Intraoperative Assessment Versus Preoperative Multidetector Computed Tomography.

BACKGROUND: Appropriate valve sizing is critical in aortic valve replacement. We hypothesized that direct intraoperative valve sizing results in smaller aortic annular diameters compared with sizing based on systolic-phase multidetector computerized tomographic (MDCT) imaging. METHODS AND RESULTS: We retrospectively analyzed 78 patients undergoing surgical aortic valve replacement for severe aortic stenosis between 2012 and 2014 at our institution. Preoperative MDCT measurements of the aortic annulus served as basis for assignment to a theoretical surgical valve size, which was then (1) compared to the implanted valve size and (2) to a theoretical transcatheter aortic valve replacement valve size. To quantify the resulting differences, geometric orifice areas (GOA) were calculated. MDCT-based sizing produced the same valve size for n=34 patients (group CT-same), a larger valve with a 25% increased GOA in n=32 patients (group CT-Lg) and a smaller GOA by 22% in n=12 patients (group CT-Sm). On the basis of MDCT measurements, 41% of valves implanted were undersized. The comparison of intraoperative implanted to a theoretical transcatheter aortic valve replacement valve size resulted in GOAs 25% larger for patients in group CT-same, 40.6% larger in group CT-Lg and 14.6% larger in group CT-Sm. CONCLUSIONS: Preoperative MDCT measurements differ substantially from direct intraoperative assessment of the aortic annulus. Implanted surgical aortic valve replacement valves were smaller relative to MDCT-based sizing in 41% of patients, and the potential GOA was between 25% and 40.6% larger if patients had undergone transcatheter aortic valve replacement.

Very low intravenous contrast volume protocol for computed tomography angiography providing comprehensive cardiac and vascular assessment prior to transcatheter aortic valve replacement in patients with chronic kidney disease.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is a lifesaving procedure for many patients high risk for surgical aortic valve replacement. The prevalence of chronic kidney disease (CKD) is high in this population, and thus a very low contrast volume (VLCV) computed tomography angiography (CTA) protocol providing comprehensive cardiac and vascular imaging would be valuable. METHODS: 52 patients with severe, symptomatic aortic valve disease, undergoing pre-TAVR CTA assessment from 2013-4 at Columbia University Medical Center were studied, including all 26 patients with CKD (eGFR<30 mL/min) who underwent a novel VLCV protocol (20 mL of iohexol at 2.5 mL/s), and 26 standard-contrast-volume (SCV) protocol patients. Using a 320-slice volumetric scanner, the protocol included ECG-gated volume scanning of the aortic root followed by medium-pitch helical vascular scanning through the femoral arteries. Two experienced cardiologists performed aortic annulus and root measurements. Vascular image quality was assessed by two radiologists using a 4-point scale. RESULTS: VLCV patients had mean (±SD) age 86 ± 6.5, BMI 23.9 ± 3.4 kg/m(2) with 54% men; SCV patients age 83 ± 8.8, BMI 28.7 ± 5.3 kg/m(2), 65% men. There was excellent intra- and inter-observer agreement for annular and root measurements, and excellent agreement with 3D-transesophageal echocardiographic measurements. Both radiologists found diagnostic-quality vascular imaging in 96% of VLCV and 100% of SCV cases, with excellent inter-observer agreement. CONCLUSIONS: This study is the first of its kind to report the feasibility and reproducibility of measurements for a VLCV protocol for comprehensive pre-TAVR CTA. There was excellent agreement of cardiac measurements and almost all studies were diagnostic quality for vascular access assessment.

Improving the accuracy of effective orifice area assessment after transcatheter aortic valve replacement: validation of left ventricular outflow tract diameter and pulsed-wave Doppler location and impact of three-dimensional measurements.

BACKGROUND: Echocardiographic calculation of effective orifice area (EOA) after transcatheter aortic valve replacement is integral to the assessment of transcatheter heart valve (THV) function. The aim of this study was to determine the most accurate method for calculating the EOA of the Edwards SAPIEN and SAPIEN XT THVs. METHODS: One hundred intraprocedural transesophageal echocardiograms were analyzed. To calculate the post-transcatheter aortic valve replacement left ventricular outflow tract (LVOT) stroke volume (SV), four diameters were measured using two-dimensional echocardiography: (1) baseline LVOT diameter (LVOTd_PRE), (2) postimplantation LVOT diameter, (3) native aortic annular diameter, and (4) THV in-stent diameter. Four corresponding areas were planimetered by three-dimensional echocardiography. Two LVOT velocity-time integrals (VTI) were measured with the pulsed-wave Doppler sample volume at (1) the proximal (apical) edge of the valve stent or (2) within the valve stent at the level of the THV cusps. LVOT velocity-time integral with the sample volume at the proximal edge of the valve stent was used with the LVOT and aortic annular measurements above, whereas in-stent VTI was paired with the in-stent THV diameter to yield eight different SVs. Right ventricular outflow tract (RVOT) SV was calculated using RVOT diameter and RVOT VTI and was used as the primary comparator. Transaortic VTI was obtained by continuous-wave Doppler, and EOA calculations using each SV measurement were compared with (1) EOA calculated using RVOTSV and (2) planimetered aortic valve area using three-dimensional echocardiography (AVAplanimetry3D). RESULTS: Post-transcatheter aortic valve replacement EOA calculated using LVOTd_PRE was not significantly different from EOA calculated using RVOTSV (1.88 ± 0.33 vs 1.86 ± 0.39 cm(2), P = .36) or from AVAplanimetry3D (1.85 ± 0.28, P = .38, n = 34). All other two-dimensional EOA calculations were statistically larger than EOA calculated using RVOTSV. All three-dimensional echocardiography-based EOA calculations were statistically different from AVAplanimetry3D. CONCLUSIONS: The most accurate EOA after implantation of a balloon-expandable THV is calculated using preimplantation LVOT diameter and VTI.