Left atrial expansion index measured with cardiovascular magnetic resonance estimates pulmonary capillary wedge pressure in dilated cardiomyopathy.

BACKGROUND: Pulmonary capillary wedge pressure (PCWP) assessment is fundamental for managing dilated cardiomyopathy (DCM) patients. Although cardiovascular magnetic resonance (CMR) has become the gold-standard imaging technique for evaluating cardiac chamber volume and function, PCWP is not routinely assessed with CMR. Therefore, this study aimed to validate the left atrial expansion index (LAEI), a LA reservoir function parameter able to estimate filling pressure with echocardiography, as a novel CMR-measured parameter for non-invasive PCWP estimation in DCM patients. METHODS: We performed a retrospective, single-center, cross-sectional study. We included electively admitted DCM patients referred to our tertiary center for further diagnostic evaluation that underwent a clinically indicated right heart catheterization (RHC) and CMR within 24 h. PCWP invasively measured during RHC was used as the reference. LAEI was calculated from CMR-measured LA maximal and minimal volumes as LAEI = ( (LAVmax-LAVmin)/LAVmin) × 100. RESULTS: We enrolled 126 patients (47 ± 14 years; 68% male; PCWP = 17 ± 9.3 mmHg) randomly divided into derivation (n = 92) and validation (n = 34) cohorts with comparable characteristics. In the derivation cohort, the log-transformed (ln) LAEI showed a strong linear correlation with PCWP (r = 0.81, p < 0.001) and remained a strong independent PCWP determinant over clinical and conventional CMR parameters. Moreover, lnLAEI accurately identified PCWP ≥ 15 mmHg (AUC = 0.939, p < 0.001), and the optimal cut-off identified (lnLAEI ≤ 3.85) in the derivation cohort discriminated PCWP ≥ 15 mmHg with 82.4% sensitivity, 88.2% specificity, and 85.3% accuracy in the validation cohort. Finally, the equation PCWP = 52.33- (9.17xlnLAEI) obtained from the derivation cohort predicted PCWP (-0.1 ± 5.7 mmHg) in the validation cohort. CONCLUSIONS: In this cohort of DCM patients, CMR-measured LAEI resulted in a novel and useful parameter for non-invasive PCWP evaluation.

Myocardial strain analysis of the right ventricle: comparison of different cardiovascular magnetic resonance and echocardiographic techniques.

BACKGROUND: Right ventricular (RV) strain is a useful predictor of prognosis in various cardiovascular diseases, including those traditionally believed to impact only the left ventricle. We aimed to determine inter-modality and inter-technique agreement in RV longitudinal strain (LS) measurements between currently available cardiovascular magnetic resonance (CMR) and echocardiographic techniques, as well as their reproducibility and the impact of layer-specific strain measurements. METHODS: RV-LS was determined in 62 patients using 2D speckle tracking echocardiography (STE, Epsilon) and two CMR techniques: feature tracking (FT) and strain-encoding (SENC), and in 17 healthy subjects using FT and SENC only. Measurements included global and free-wall LS (GLS, FWLS). Inter-technique agreement was assessed using linear regression and Bland-Altman analysis. Reproducibility was quantified using intraclass correlation (ICC) and coefficients of variation (CoV). RESULTS: We found similar moderate agreement between both CMR techniques and STE in patients: r = 0.57-0.63 for SENC; r = 0.50-0.62 for FT. The correlation between SENC and STE was better for GLS (r = 0.63) than for FWLS (r = 0.57). Conversely, the correlation between FT and STE was higher for FWLS (r = 0.60-0.62) than GLS (r = 0.50-0.54). FT-midmyocardial strain correlated better with SENC and STE than FT-subendocardial strain. The agreement between SENC and FT was fair (r = 0.36-0.41, bias: - 6.4 to - 10.4%) in the entire study group. All techniques except FT showed excellent reproducibility (ICC: 0.62-0.96, CoV: 0.04-0.30). CONCLUSIONS: We found only moderate inter-modality agreement with STE in RV-LS for both FT and SENC and poor agreement when comparing between the CMR techniques. Different modalities and techniques should not be used interchangeably to determine and monitor RV strain.

Echocardiography and cardiovascular magnetic resonance based evaluation of myocardial strain and relationship with late gadolinium enhancement.

OBJECTIVES: We sought to: (1) determine the agreement in cardiovascular magnetic resonance (CMR) and speckle tracking echocardiography (STE) derived strain measurements, (2) compare their reproducibility, (3) determine which approach is best related to CMR late gadolinium enhancement (LGE). BACKGROUND: While STE-derived strain is routinely used to assess left ventricular (LV) function, CMR strain measurements are not yet standardized. Strain can be measured using dedicated pulse sequences (strain-encoding, SENC), or post-processing of cine images (feature tracking, FT). It is unclear whether these measurements are interchangeable, and whether strain can be used as an alternative to LGE. METHODS: Fifty patients underwent 2D echocardiography and 1.5 T CMR. Global longitudinal strain (GLS) was measured by STE (Epsilon), FT (NeoSoft) and SENC (Myocardial Solutions) and circumferential strain (GCS) by FT and SENC. RESULTS: GLS showed good inter-modality agreement (r-values: 0.71-0.75), small biases (< 1%) but considerable limits of agreement (- 7 to 8%). The agreement between the CMR techniques was better for GLS than GCS (r = 0.81 vs 0.67; smaller bias). Repeated measurements showed low intra- and inter-observer variability for both GLS and GCS (intraclass correlations 0.86-0.99; coefficients of variation 3-13%). LGE was present in 22 (44%) of patients. Both SENC- and FT-derived GLS and GCS were associated with LGE, while STE-GLS was not. Irrespective of CMR technique, this association was stronger for GCS (AUC 0.77-0.78) than GLS (AUC 0.67-0.72) and STE-GLS (AUC = 0.58). CONCLUSION: There is good inter-technique agreement in strain measurements, which were highly reproducible, irrespective of modality or analysis technique. GCS may better reflect the presence of underlying LGE than GLS.

Non-invasive evaluation of pulmonary capillary wedge pressure using the left atrial expansion index in mitral valve stenosis, prosthesis and repair.

Pulmonary capillary wedge pressure (PCWP) non-invasive evaluation is limited in patients with mitral valve (MV) stenosis, prosthesis, and surgical repair. This study aimed to assess the left atrial expansion index (LAEI) measured through transthoracic echocardiography (TTE) as a novel parameter for estimating PCWP in these challenging cardiac conditions. We performed a retrospective, cross-sectional study, including chronic cardiac patients receiving within 24 h a clinically indicated right heart catheterization (RHC) and transthoracic echocardiographic (TTE) exam. PCWP measured during RHC was used as the reference. TTE measurements were performed offline, blinded to RHC results. LAEI was calculated as LAEI = [(LAmaxVolume-LAminVolume)/LAminVolume] × 100. We included 167 patients (age = 73 ± 11.5 years; PCWP = 18 ± 7.7 mmHg) with rheumatic mitral valve (MV) stenosis (16.2%), degenerative MV stenosis (51.2%), MV prosthesis (18.0%), and MV surgical repair (13.8%). LAEI correlated logarithmically with PCWP, and the log-transformed LAEI (lnLAEI) showed a good linear association with PCWP (r = - 0.616; p < 0.001). lnLAEI was an independent PCWP determinant, providing added predictive value over conventional clinical (age, atrial fibrillation, heart rate, MV subgroups) and echocardiographic variables (LVEF, MV effective orifice area, MV mean gradient, net atrioventricular compliance, and pulmonary arterial systolic pressure). lnLAEI identified PCWP > 12 mmHg with AUC = 0.870, p < 0.001; and PCWP > 15 mmHg with AUC = 0.797, p < 0.001, with an optimal cut-off of lnLAEI < 3.69. The derived equation PCWP = 36.8-5.5xlnLAEI estimated the invasively measured PCWP ± 6.1 mmHg. In this cohort of patients with MV stenosis, prosthesis, and surgical repair, lnLAEI resulted in a helpful echocardiographic parameter for PCWP estimation.

Association of outcome with left ventricular volumes and ejection fraction measured with two- and three-dimensional echocardiography in patients referred for routine, clinically indicated studies.

Objectives: We sought to analyze if left ventricular (LV) volumes and ejection fraction (EF) measured by three-dimensional echocardiography (3DE) have incremental prognostic value over measurements obtained from two-dimensional echocardiography (2DE) in patients referred to a high-volume echocardiography laboratory for routine, clinically-indicated studies. Methods: We measured LV volumes and EF using both 2DE and 3DE in 725 consecutive patients (67% men; 59 ± 18 years) with various clinical indications referred for a routine clinical study. Results: LV volumes were significantly larger, and EF was lower when measured by 3DE than 2DE. During follow-up (3.6 ± 1.2 years), 111 (15.3%) all-cause deaths and 248 (34.2%) cardiac hospitalizations occurred. Larger LV volumes and lower EF were associated with worse outcome independent of age, creatinine, hemoglobin, atrial fibrillation, and ischemic heart diseases). In stepwise Cox regression analyses, the associations of both death and cardiac hospitalization with clinical data (CD: age, creatinine, hemoglobin, atrial fibrillation, and ischemic heart disease) whose Harrel's C-index (HC) was 0.775, were augmented more by the LV volumes and EF obtained by 3DE than by 2DE parameters. The association of CD with death was not affected by LV end-diastolic volume (EDV) either measured by 2DE or 3DE. Conversely, it was incremented by 3DE LVEF (HC = 0.84, p < 0.001) more than 2DE LVEF (HC = 0.814, p < 0.001). The association of CD with the composite endpoint (HC = 0.64, p = 0.002) was augmented more by 3DE LV EDV (HC = 0.786, p < 0.001), end-systolic volume (HC = 0.801, p < 0.001), and EF (HC = 0.84, p < 0.001) than by the correspondent 2DE parameters (HC = 0.786, HC = 0.796, and 0.84, all p < 0.001) In addition, partition values for mild, moderate and severe reduction of the LVEF measured by 3DE showed a higher discriminative power than those measured by 2DE for cardiac death (Log-Rank: χ2 = 98.3 vs. χ2 = 77.1; p < 0.001). Finally, LV dilation defined according to the 3DE threshold values showed higher discriminatory power and prognostic value for death than when using 2DE reference values (3DE LVEDV: χ2 = 15.9, p < 0.001 vs. χ2 = 10.8, p = 0.001; 3DE LVESV: χ2 = 24.4, p < 0.001 vs. χ2 = 17.4, p = 0.001). Conclusion: In patients who underwent routine, clinically-indicated echocardiography, 3DE LVEF and ESV showed stronger association with outcome than the corresponding 2DE parameters.

Left Atrial Expansion Index for Noninvasive Estimation of Pulmonary Capillary Wedge Pressure: A Cardiac Catheterization Validation Study.

BACKGROUND: Pulmonary capillary wedge pressure (PCWP) plays a pivotal role in cardiac disease diagnosis and management. Right heart catheterization (RHC) invasively provides accurate PCWP measurement, but it is impractical for widespread use in all patients. The left atrial expansion index (LAEI), measured on transthoracic echocardiography, describes the relative left atrial volume increase during the left atrial reservoir phase. The aim of this study was to validate LAEI as a noninvasive parameter for PCWP estimation. METHODS: A total of 649 chronic cardiac patients (mean age, 66 ± 14 years; mean PCWP, 14 ± 7.6 mm Hg; mean left ventricular ejection fraction, 50 ± 15%) who underwent both clinically indicated RHC and transthoracic echocardiography within 24 hours were retrospectively enrolled. Patients were randomly divided into derivation (n = 509) and validation (n = 140) cohorts. PCWP was measured during RHC and defined as elevated when >12 mm Hg. Transthoracic echocardiographic parameters and LAEI were measured offline, blinded to RHC results. RESULTS: In the derivation cohort, LAEI correlated logarithmically with PCWP, and the log-transformed LAEI (lnLAEI) correlated linearly with PCWP (r = -0.73, P < .001). lnLAEI showed an independent and additive predictive role for PCWP estimation over clinical and diastolic dysfunction (DD) parameters. The diagnostic accuracy of lnLAEI for elevated PCWP identification (area under the curve = 0.875, P < .001; optimal lnLAEI cutoff < 4.02) was higher than either the single DD parameters or their combination. In the validation cohort, lnLAEI cutoff < 4.02 showed higher accuracy than the 2016 DD algorithm (88% vs 74%) for elevated PCWP identification. Finally, the equation PCWP = 38.3 - 6.2 × lnLAEI, obtained from the derivation cohort, predicted invasively measured PCWP in the validation cohort. CONCLUSIONS: In a cohort of patients with various chronic cardiac diseases, lnLAEI performed better than DD parameters and the 2016 DD algorithm for PCWP estimation. lnLAEI might be a useful echocardiographic parameter for noninvasive PCWP estimation.

Right atrial volume is a major determinant of tricuspid annulus area in functional tricuspid regurgitation: a three-dimensional echocardiographic study.

AIMS: The aim of this study is to explore the relationships of tricuspid annulus area (TAA) with right atrial maximal volume (RAVmax) and right ventricular end-diastolic volume (RVEDV) in healthy subjects and patients with functional tricuspid regurgitation (FTR) of different aetiologies and severities. METHODS AND RESULTS: We enrolled 280 patients (median age 66 years, 59% women) with FTR due to left heart disease (LHD), pulmonary hypertension (PH), corrected tetralogy of Fallot (TOF), chronic atrial fibrillation (AF), and 210 healthy volunteers (45 years, 53% women). We measured TAA at mid-systole and end-diastole, tenting volume of tricuspid leaflets, RAVmax, and RVEDV by 3D echocardiography. Irrespective of TA measurement timing, TAA correlated more closely with RAVmax than with RVEDV in both controls and FTR patients. On multivariable analysis, RAVmax was the most important determinant of TAA, accounting for 41% (normals) and 56% (FTR) of TAA variance. In FTR patients, age, RVEDV, and left ventricular ejection fraction were also independently correlated with TAA. RAVmax (AUC = 0.81) and TAA (AUC = 0.78) had a greater ability than RVEDV (AUC = 0.72) to predict severe FTR (P < 0.05). Among FTR patients, those with AF had the largest RAVmax and smallest RVEDV. RAVmax and TA were significantly dilated in all FTR groups, except in TOF. PH and TOF had largest RVEDV, yet tenting volume was increased only in PH and LHD. CONCLUSION: RA volume is a major determinant of TAA, and RA enlargement is an important mechanism of TA dilation in FTR irrespective of cardiac rhythm and RV loading conditions.

Impact of physiological pacing on functional mitral regurgitation in systolic dysfunction: Initial echocardiographic remodeling findings after His bundle pacing.

BACKGROUND: Although His bundle pacing (HBP) has been shown to improve left ventricular ejection fraction (LVEF), its impact on mitral regurgitation (MR) remains uncertain. OBJECTIVES: The aim of this study was to evaluate change in functional MR after HBP in patients with left ventricular (LV) systolic dysfunction. METHODS: Paired echocardiograms were retrospectively assessed in patients with reduced LVEF (<50%) undergoing HBP for pacing or resynchronization. The primary outcomes assessed were change in MR, LVEF, LV volumes, and valve geometry pre- and post-HBP. MR reduction was characterized as a decline in ≥1 MR grade post-HBP in patients with ≥grade 3 MR at baseline. RESULTS: Thirty patients were analyzed: age 68 ± 15 years, 73% male, LVEF 32% ± 10%, 38% coronary artery disease, 33% history of atrial fibrillation. Baseline QRS was 162 ± 31 ms: 33% left bundle branch block, 37% right bundle branch block, 17% paced, and 13% narrow QRS. Significant reductions in LV end-systolic volume (122 mL [73-152 mL] to 89 mL [71-122 mL], P = .006) and increase in LV ejection fraction (31% [25%-37%] to 39% [30%-49%], P < .001) were observed after HBP. Ten patients had grade 3 or 4 MR at baseline, with reduction in MR observed in 7. In patients with at least grade 3 MR at baseline, reduction in LV volumes, improved mitral valve geometry, and greater LV contractility were associated with MR reduction. Greater reduction in paced QRS width was present in MR responders compared to non-MR responders (-40% vs -25%, P = .04). CONCLUSIONS: In this initial detailed echocardiographic analysis in patients with LV systolic dysfunction, HBP reduced functional MR through favorable ventricular remodeling.

Contrast-enhanced echocardiographic measurement of longitudinal strain: accuracy and its relationship with image quality.

The importance of left ventricular (LV) global longitudinal strain (GLS) is increasingly recognized in multiple clinical scenarios. However, in patients with poor image quality, strain is difficult or impossible to measure without contrast enhancement. The feasibility of contrast-enhanced GLS measurement was recently demonstrated. We sought to determine: (1) whether contrast enhancement improves the accuracy of GLS measurements against cardiac magnetic resonance (CMR) reference, (2) their reproducibility compared to non-enhanced GLS, and (3) the dependence of accuracy and reproducibility on image quality. We prospectively enrolled 25 patients undergoing clinically indicated CMR imaging who subsequently underwent transthoracic echocardiography (TTE) with and without low-dose contrast injection (1-2 mL Optison/3-5 mL saline IV, GE Healthcare). GLS was measured from both non-contrast and contrast-enhanced images using speckle tracking (EchoInsight, Epsilon Imaging). These measurements were compared to each other and to CMR reference values obtained using feature tracking (SuiteHEART, NeoSoft). Inter-technique comparisons included linear regression and Bland-Altman analyses. A random subgroup of 15 patients was used to assess inter- and intra-observer variability using intra-class correlation (ICC). Contrast-enhanced GLS was in close agreement with non-enhanced GLS (r = 0.95; bias: - 0.2 ± 1.5%). Both inter-observer (ICC = 0.88 vs. 0.82) and intra-observer variability (ICC = 0.91 vs. 0.88) were improved by contrast enhancement. The agreement with CMR was better for contrast-enhanced GLS (r = 0.87; bias: 1.1 ± 2.2%) than for non-enhanced GLS (r = 0.80; bias: 1.3 ± 2.7%). In 12/25 patients with suboptimal TTE images that rendered GLS difficult to measure, contrast-enhanced GLS showed better agreement with CMR than non-enhanced GLS (r = 0.88 vs. 0.83) and also improved inter-observer (ICC = 0.83 vs. 0.76) and intra-observer variability (ICC = 0.88 vs. 0.82). In conclusion, contrast enhancement of TTE images improves the accuracy and reproducibility of GLS measurements, resulting in better agreement with CMR, even in patients with suboptimal acoustic windows. This approach may aid in the assessment of LV function in this patient population.

Prognostic value of right ventricular free wall longitudinal strain in a large cohort of outpatients with left-side heart disease.

AIMS: Right ventricular free wall longitudinal strain (RVFWLS) has been proposed as an accurate and sensitive measure of right ventricular function that could integrate other conventional parameters such as tricuspid annulus plane systolic excursion (TAPSE) and fractional area change (FAC%). The aim of the present study was to evaluate the relationship between RVFWLS and outcomes in stable asymptomatic outpatients with left-sided structural heart disease. METHODS AND RESULTS: We enrolled 458 asymptomatic patients with left-side heart diseases and any ejection fraction who were referred for echocardiography to two Italian centres. The composite endpoint of death for any cause and heart failure hospitalization was used as primary outcome of this analysis. After a mean follow-up of 5.4 ± 1.2 years, 145 patients (31%) reached the combined endpoint. Most of echocardiographic parameters were related to outcomes, including right ventricular functional parameters. Mean value of RVFWLS in our cohort was -21 ± 8% and it was significantly related to the combined endpoint and in multivariable Cox-regression model; when tested with other echocardiographic parameters that were significantly related to outcome at univariate analysis, RVFWLS maintained its independent association with outcome (hazard ratio 0.963, 95% confidence interval 0.948-0.978; P = 0.0001). The best cut-off value of RVFWLS to predict outcome was -22% (area under the curve 0.677; P < 0.001; sensitivity 70%; 65% specificity). CONCLUSION: RVFWLS may help clinicians to identify patients with left-sided structural heart disease at higher risk for first heart failure hospitalization and death for any cause.

Validation of non-contrast multiple overlapping thin-slab 4D-flow cardiac magnetic resonance imaging.

BACKGROUND: Cardiac magnetic resonance (CMR) flow quantification is typically performed using 2D phase-contrast (PC) imaging of a plane perpendicular to flow. 3D-PC imaging (4D-flow) allows offline quantification anywhere in a thick slab, but is often limited by suboptimal signal, potentially alleviated by contrast enhancement. We developed a non-contrast 4D-flow sequence, which acquires multiple overlapping thin slabs (MOTS) to minimize signal loss, and hypothesized that it could improve image quality, diagnostic accuracy, and aortic flow measurements compared to non-contrast single-slab approach. METHODS: We prospectively studied 20 patients referred for transesophageal echocardiography (TEE), who underwent CMR (GE, 3 T). 2D-PC images of the aortic valve and three 4D-flow datasets covering the heart were acquired, including single-slab, pre- and post-contrast, and non-contrast MOTS. Each 4D-flow dataset was interpreted blindly for ≥moderate valve disease and compared to TEE. Flow visualization through each valve was scored (0 to 4), and aortic-valve flow measured on each 4D-flow dataset and compared to 2D-PC reference. RESULTS: Diagnostic quality visualization was achieved with the pre- and post-contrast 4D-flow acquisitions in 25% and 100% valves, respectively (scores 0.9 ± 1.1 and 3.8 ± 0.5), and in 58% with the non-contrast MOTS (1.6 ± 1.1). Accuracy of detection of valve disease was 75%, 92% and 82%, respectively. Aortic flow measurements were possible in 53%, 95% and in 89% patients, respectively. The correlation between pre-contrast single-slab measurements and 2D-PC reference was weak (r = 0.21), but improved with both contrast enhancement (r = 0.71) and with MOTS (r = 0.67). CONCLUSIONS: Although non-contrast MOTS 4D-flow improves valve function visualization and diagnostic accuracy, a significant proportion of valves cannot be accurately assessed. However, aortic flow measurements using non-contrast MOTS is feasible and reaches similar accuracy to that of contrast-enhanced 4D-flow.

Development and prognostic validation of partition values to grade right ventricular dysfunction severity using 3D echocardiography.

AIMS: Transthoracic 3D echocardiography (3DE) has been shown to be feasible and accurate to measure right ventricular (RV) ejection fraction (EF) when compared with cardiac magnetic resonance (CMR). However, RV EF, either measured with CMR or 3DE, has always been reported as normal (RV EF > 45%) or abnormal (RV EF ≤ 45%). We therefore sought to identify the partition values of RV EF to stratify RV dysfunction in mildly, moderately, or severely reduced as we are used to do with the left ventricle. METHODS AND RESULTS: We used 3DE to measure RV EF in 412 consecutive patients (55 ± 18 years, 65% men) with various cardiac conditions who were followed for 3.7 ± 1.4 years to obtain the partition values which defined mild, moderate, and severe reduction of RV EF (derivation cohort). Then, the prognostic value of these partition values was tested in an independent population of 446 patients (67 ± 14 years, 58% men) (validation cohort). During follow-up, we recorded 59 cardiac deaths (14%) in the derivation cohort. Using K-Adaptive partitioning for survival data algorithm we identified four groups of patients with significantly different mortality according to RV EF: very low > 46%, 40.9% < low ≤ 46%, 32.1% < moderate ≤ 40.9%, and high ≤ 32.1%. To make the partition values easier to remember, we approximated them to 45%, 40%, and 30%. During 4.1 ± 1.2 year follow-up, 38 cardiac deaths and 88 major adverse cardiac events (MACE) (cardiac death, non-fatal myocardial infarction, ventricular fibrillation, or admission for heart failure) occurred in the validation cohort. The partition values of RV EF identified in the derivation cohort were able to stratify both the risk of cardiac death (log-rank = 100.1; P < 0.0001) and MACEs (log-rank = 117.6; P < 0.0001) in the validation cohort too. CONCLUSION: Our study confirms the independent prognostic value of RV EF in patients with heart diseases, and identifies the partition values of RV EF to stratify the risk of cardiac death and MACE.

Three-dimensional echocardiography investigation of the mechanisms of tricuspid annular dilatation.

Tricuspid annular (TA) size, assessed by 2D transthoracic echocardiography (TTE), has a well-established prognostic value in patients undergoing mitral valve surgery, with TA dilatation triggering simultaneous tricuspid annuloplasty. While TA dilatation is common in patients with dilated atria secondary to atrial fibrillation, little is known about the mechanisms of TA dilatation in patients with sinus rhythm (SR). This study aimed to identify echocardiographic parameters most closely related to the TA size as a potential tool for identification of patients prone to developing TA enlargement. 120 patients with SR underwent clinically indicated TTE, including 30 patients with normal hearts and 90 patients diagnosed with at least one right heart abnormality, defined as: right ventricular (RV) or right atrial (RA) dilatation, ≥ moderate tricuspid regurgitation (TR) and elevated systolic pulmonary artery pressure (sPAP). RA and RV end-diastolic and end-systolic volumes (EDV, ESV) and function were measured using commercial 3D software (TomTec). 3D RV long and short axes were used as surrogate indices of RV shape. Degrees of TR and sPAP were estimated by 2D TTE. 3D TA sizing was performed at end-diastole using 3D custom software. Linear regression analysis was used to identify variables best correlated with TA size, followed by multivariate analysis to identify independent associations. The highest correlations were found between TA area and: RA ESV (r = 0.73; p < 0.01), RV EDV (r = 0.58; p < 0.01), RV end-diastolic long and short axes (r = 0.53, 0.42; both p < 0.01), TR degree (r = 0.40; p < 0.01) and sPAP (r = 0.32; p < 0.01). Multivariate analysis revealed that RA ESV was the only parameter independently associated with TA area (p < 0.05, r = 0.85). In conclusion, RA volume plays an important role in TA dilatation even in patients with normal SR. Understanding of annular remodeling mechanisms could aid in identifying patients at higher risk for TA dilatation, especially those scheduled for mitral valve surgery.

Relative Prognostic Importance of Left and Right Ventricular Ejection Fraction in Patients With Cardiac Diseases.

BACKGROUND: The study aimed (1) to assess the prognostic value of three-dimensional echocardiography (3DE) derived right ventricular (RV) ejection fraction (EF) and (2) to evaluate relative prognostic importance of reduced and preserved left ventricular (LV) EF and RVEF to predict all-cause mortality and cardiac death in a large cohort of patients with cardiac diseases. METHODS: LV and RV volumes and EF were assessed by 3DE in 394 patients with various cardiovascular diseases. Patients were divided into four groups: (1) normal LVEF (≥50%) and normal RVEF (≥45%), n = 183; (2) reduced LVEF (<50%) and normal RVEF (≥45%), n = 75; (3) normal LVEF (≥50%) and reduced RVEF (<45%), n = 61; (4) reduced LVEF (<50%) and reduced RVEF (<45%), n = 75. The patients were followed up for 3.7 ± 1.1 years. RESULTS: Reduced 3DE-derived RVEF was associated with all-cause mortality (P < .0001). The four groups had significantly different survival (P < .0001). Both all-cause mortality and cardiac death in patients with reduced RVEF and normal LVEF were significantly higher than in those with reduced LVEF and normal RVEF (P = .0007 and P = .0091, respectively) and did not differ significantly from patients with reduced EF of both ventricles (P = .2198 and P = .0846, respectively). CONCLUSIONS: Reduced 3DE-derived RVEF was associated with all-cause mortality and cardiac death in patients with various cardiovascular diseases. Impairment of RVEF carried a significantly higher risk of mortality independent of LVEF.

[Current clinical applications of three-dimensional echocardiography]. / Principali applicazioni dell'ecocardiografia tridimensionale nell'attuale pratica clinica.

Three-dimensional echocardiography (3DE) represents one of the most innovative advances in cardiovascular imaging over the last 20 years. Recent technological developments have fueled the full implementation of 3DE in clinical practice and expanded its impact on patient diagnosis, management, and prognosis. One of the most important clinical applications of transthoracic 3DE has been the quantitation of cardiac chamber volumes and function. The main limitations affecting two-dimensional echocardiography calculations of chamber volumes (i.e. geometric assumptions about cardiac chamber shape and view foreshortening) are overcome by 3DE that allows an actual measurement of their volumes. Transesophageal 3DE has been applied mainly to assess the anatomy and function of heart valves, congenital defects and masses in the beating heart. As reparative cardiac surgery and transcatheter procedures have become more and more popular to treat structural heart disease, transesophageal 3DE has become not only one of the main imaging modalities for procedure planning but also for intra-procedural guidance and assessment of procedural results. New image rendering modalities such as 3D printing, holographic display, and fusion of 3DE images with other radiological or nuclear modalities will further expand the clinical applications and indications of 3DE.

Three-dimensional echocardiography to assess left ventricular geometry and function.

Introduction: Quantification of left ventricular (LV) size and function represents the most frequent indication for an echocardiographic study. New echocardiographic techniques have been developed over the last decades in an attempt to provide a more comprehensive, accurate, and reproducible assessment of LV function.Areas covered: Although two-dimensional echocardiography (2DE) is the recommended imaging modality to evaluate the LV, three-dimensional echocardiography (3DE) has proven to be more accurate, by avoiding geometric assumptions about LV geometry, and to have incremental value for outcome prediction in comparison to conventional 2DE. LV shape (sphericity) and mass are actually measured with 3DE. Myocardial deformation analysis using 3DE can early detect subclinical LV dysfunction, before any detectable change in LV ejection fraction.Expert opinion: 3DE eliminates the errors associated with foreshortening and geometric assumptions inherent to 2DE and 3DE measurements approach very closely those obtained by CMR (the current reference modality), while maintaining the unique clinical advantage of a safe, highly cost/effective, portable imaging technique, available to the cardiologist at bedside to translate immediately the echocardiography findings into the clinical decision-making process.

Echocardiographic Assessment of the Tricuspid Annulus: The Effects of the Third Dimension and Measurement Methodology.

BACKGROUND: Evaluation of the tricuspid annulus is crucial for the decision making at the time of left heart surgery. Current recommendations for tricuspid valve repair are based on two-dimensional (2D) transthoracic echocardiography (TTE), despite the known underestimation compared with three-dimensional (3D) echocardiography. However, little is known about the differences in 3D tricuspid annular (TA) sizing using TTE versus transesophageal echocardiography (TEE). The aims of this study were to (1) compare 2D and 3D TA measurements performed with both TTE and TEE and (2) compare two 3D methods for TA measurements: multiplanar reconstruction (MPR) and dedicated software (DS) designed to take into account TA nonplanarity. METHODS: Seventy patients underwent 2D and 3D TTE and TEE. Two-dimensional images were used to measure TA diameter from apical four-chamber, right ventricular-focused (TTE), and midesophageal four-chamber (TEE) views. Three-dimensional full-volume data sets were analyzed using both MPR and DS, to obtain major and minor axes, perimeter, and area. Intertechnique agreement was assessed using Bland-Altman analysis. RESULTS: Measurements on 2D TTE and TEE, which were view dependent, underestimated TA major dimensions in all views compared with 3D values, irrespective of the 3D method. MPR and DS measurements were significantly different, with DS resulting in larger values for all parameters, irrespective of approach. No differences were found between 3D TTE and 3D TEE for both MPR and DS. CONCLUSIONS: Our findings highlight the need for methodology that respects the 3D geometry of the tricuspid annulus, including its nonplanarity, which cannot be accurately assessed from 2D images and is not equally taken into account by different 3D measurement methodologies. Accordingly, a 3D cutoff value for TA enlargement needs to be established and is likely to be larger than the guideline-recommended 2D-based 40-mm cutoff. Importantly, noninvasive 3D TTE can be used instead of 3D TEE because TA measurements are not different.

Comparison Between Four-Chamber and Right Ventricular-Focused Views for the Quantitative Evaluation of Right Ventricular Size and Function.

BACKGROUND: Right ventricular (RV) function plays a pivotal prognostic role in multiple cardiac diseases. Echocardiography guidelines recommend that RV quantification be performed in the RV-focused view, which is theoretically more reproducible than the four-chamber (4Ch) view. However, differences between views in RV size and function measurements have never been systematically studied. Accordingly, the aim of this study was to compare (1) RV size and function parameters obtained from the RV-focused and 4Ch views and (2) test-retest variability between these two views. METHODS: Fifty patients (26 men; mean age, 63 ± 18 years) undergoing clinically indicated transthoracic echocardiography were prospectively enrolled. Each patient underwent three repeated acquisitions of the 4Ch and RV-focused views by two sonographers. The first operator performed two acquisitions at the beginning and the end of the clinical transthoracic echocardiographic study, and the second operator performed the third acquisition afterward. RV size and function measurements were obtained from the two views and compared using paired t-test analysis and Bland-Altman analysis. Intra- and interoperator test-retest and intra- and interreader variability for both views were assessed using intraclass correlations and coefficients of variation. RESULTS: All RV size parameters were significantly larger when measured in the RV-focused view compared with the 4Ch view. Also, all RV function parameters, including RV free wall and global longitudinal strain, were larger in magnitude when measured in the RV-focused view. Measurements variability was consistently better for the RV-focused view. CONCLUSIONS: RV size and function measurements obtained from the RV-focused and 4Ch views are not interchangeable. RV size and function parameters measured from the RV-focused view are more reproducible than from 4Ch acquisitions. Therefore, only the RV-focused view should be used for quantitative assessment of the right ventricle.