Echocardiographic assessment of patient hemodynamics in heart failure.

Heart failure (HF) is a clinical syndrome which is due to cardiac structural and/or functional abnormalities that result in elevated intra-cardiac pressures and/or inadequate cardiac output. Hemodynamic assessment in HF allows the identification and characterization of cardiac dysfunction, systemic and/or pulmonary congestion and the eventual impairment of systemic perfusion which are fundamental to phenotype HF, risk stratify HF patients and to guide their treatment. Patient hemodynamics can be characterized invasively with right heart catheterization but also non-invasively with the use of echocardiography and other non-invasive ultrasound tools. The aim of the present review is to summarize the main echocardiographic and ultrasound parameters to characterize the hemodynamics of patients with HF and help clinicians to make the most of these non-invasive tools to guide HF patient management.

Left Atrial Strain in the Assessment of Diastolic Function in Heart Failure: A Machine Learning Approach.

BACKGROUND: Diastolic dysfunction (DD) assessment in heart failure is still challenging. Peak atrial longitudinal strain (PALS) is strongly related to end-diastolic pressure and prognosis, but it is still not part of standard DD assessment. We tested the hypothesis that a machine learning approach would be useful to include PALS in DD classification and refine prognostic stratification. METHODS: In a derivation cohort of 864 heart failure patients in sinus rhythm (age, 66.6±12 years; heart failure with reduced ejection fraction, n=541; heart failure with mildly reduced ejection fraction, n=129; heart failure with preserved ejection fraction, n=194), machine learning techniques were retrospectively applied to PALS and guideline-recommended diastolic variables. Outcome (death/heart failure rehospitalization) of the identified DD-clusters was compared with that by guidelines-based classification. To identify the best combination of variables able to classify patients in one of the identified DD-clusters, classification and regression tree analysis was applied (with DD-clusters as dependent variable and PALS plus guidelines-recommended diastolic variables as explanatory variables). The algorithm was subsequently validated in a prospective cohort of 189 heart failure outpatients (age, 65±13 years). RESULTS: Three distinct echocardiographic DD-clusters were identified (cluster-1, n=212; cluster-2, n=376; cluster-3 DD, n=276), with modest agreement with guidelines-recommended classification (kappa=0.40; P<0.001). DD-clusters were predicted by a simple algorithm including E/A ratio, left atrial volume index, E/e' ratio, and PALS. After 36.5±29.4 months follow-up, 318 events occurred. Compared to guideline-based classification, DD-clusters showed a better association with events in multivariable models (C-index 0.720 versus 0.733, P=0.033; net reclassification improvement 0.166 [95% CI, 0.035-0.276], P=0.013), without interaction with ejection fraction category. In the validation cohort (median follow-up: 18.5 months), cluster-based classification better predicted outcome than guideline-based classification (C-index 0.80 versus 0.78, P=0.093). CONCLUSIONS: Integrating PALS by machine learning algorithm in DD classification improves risk stratification over recommended current criteria, regardless of ejection fraction status. This proof of concept study needs further validation of the proposed algorithm to assess generalizability to other populations.

Non-invasive assessment of acute heart failure by Stevenson classification: Does echocardiographic examination recognize different phenotypes?

Background: Acute heart failure (AHF) presentation is universally classified in relation to the presence or absence of congestion and the peripheral perfusion condition according to the Stevenson diagram. We sought to evaluate a relationship existing between clinical assessment and echocardiographic evaluation in patients with AHF. Materials and methods: This is a retrospective blinded multicenter analysis assessing both clinical and echocardiographic analyses during the early hospital admission for AHF. Patients were categorized into four groups according to the Stevenson presentation: group A (warm and dry), group B (cold and dry), group C (warm and wet), and group D (cold and wet). Echocardiographic evaluation was executed within 12 h from the first clinical evaluation. The following parameters were measured: left ventricular (LV) volumes, LV ejection fraction (LVEF); pattern Doppler by E/e1 ratio, pulmonary artery systolic pressure (PASP), tricuspid annular plane systolic excursion (TAPSE), and inferior cave vein diameter (ICV). Results: We studied 208 patients, 10 in group A, 16 in group B, 153 in group C, and 29 in group D. Median age of our sample was 81 [69-86] years and the patients enrolled were mainly men (66.8%). Patients in groups C and A showed significant higher levels of systolic arterial pressures with respect to groups B and D (respectively, 130 [115-145] mmHg vs. 122 [119-130] mmHg vs. 92 [90-100] mmHg vs. 95 [90-100] mmHg, p < 0.001). Patients in groups A and C (warm) demonstrated significant higher values of LVEF with respect to patients in groups B and D (43 [34-49] vs. 42 [30-49] vs. 27 [15-31] vs. 30 [22-42]%, p < 0.001). Whereas group B experienced significant lower TAPSE values compared with other group (14 [12-17] mm vs. A: 17 [16-21] mm vs. C: 18 [14-20] mm vs. D: 16 [12-17] mm; p = 0.02). Finally, echocardiographic congestion score including PASP ≥ 40 mmHg, ICV ≥ 21, mm and E/e' > 14 did not differ among groups. Follow-up analysis showed an increased mortality rate in D group (HR 8.2 p < 0.04). Conclusion: The early Stevenson classification remains a simple and universally recognized approach for the detection of congestion and perfusion status. The combined clinical and echocardiographic assessment may be useful to better define the patients' profile.

Prognostic relevance of Doppler echocardiographic re-assessment in HFrEF patients.

BACKGROUND: Current guidelines do not recommend periodically repeating echocardiograms in the follow-up of stable heart failure patients with reduced ejection fraction (HFrEF). The objective of the study was to verify the additional prognostic information provided by a comprehensive re-assessment of their cardiac function and hemodynamic profile at Doppler echocardiography in HFrEF patients. METHODS: Retrospective analysis of 769 stable HFrEF outpatients who underwent two complete echocardiograms, at baseline and at re-assessment. Main candidate predictors of prognosis were: left ventricular (LV) filling pattern, pulmonary artery systolic pressure (PASP) and right ventricular function (TAPSE). Age, LV ejection fraction, mitral regurgitation severity, NYHA class, brain natriuretic peptide plasma levels at baseline, and their changes at 12 months, were used as covariates. Median follow-up was 30 months. All-cause death was the study end-point. RESULTS: At baseline, restrictive filling pattern and low TAPSE were significant predictors of poor prognosis. At re-evaluation, persistently restrictive/worsened filling pattern, persistently-low/worsened TAPSE and worsened PASP, were associated with poorer survival. A significant interaction between changes in TAPSE, PASP and LV filling pattern was observed: in the restrictive pattern subgroup, survival was poorer in worsened/persistently low TAPSE (p < 0.01); in non-restrictive pattern subgroup, survival was poorer in worsened/persistently elevated PASP (p = 0.01). The re-assessment model improved the C-index from 0.69 to 0.74 (P < 0.01) compared to baseline model. CONCLUSIONS: Doppler echocardiographic re-assessment of LV filling pattern, PASP and TAPSE allows a better prognostic stratification of HFrEF outpatients than baseline evaluation and is additional to changes in BNP and NYHA class.

Reproducibility of echocardiographic assessment of 2D-derived longitudinal strain parameters in a population-based study (the STANISLAS Cohort study).

Global peak systolic longitudinal strain (PLS) derived from speckle tracking echocardiography (STE) is a widely used left ventricular deformation parameter. Modern ultrasound systems with improved temporal resolution and new software now allow automated multilayer analysis; however, there is limited evidence regarding its reproducibility. We performed intra- and inter-observer analyses within a population-based cohort study using conventional quantitative strain analysis (GE Healthcare). Fifty patients (49 ± 14 years) were randomly selected among the fourth visit of the STANISLAS Cohort. Multilayer PLS (transmural, subendocardial, and subepicardial), and strain rate (peak systolic, early and late diastolic) were evaluated. Peak systolic shortening (PSS) and early positive systolic strain (EPS) were calculated, as well as post-systolic index (PSI) and pre-stretch index (PST), two additional strain-derived parameters. Intra-observer intraclass correlation coefficients (ICC) were >0.75 for all analyzed parameters. The mean relative intra-observer differences were <5% for all considered parameters, and their 1.96 SDs were <15% for multilayer PLS, strain rate and PSS, but not for EPS, PSI and PST. Inter-observer ICCs were >0.70 (the majority being >0.80). The mean relative inter-observer differences were <7.5% for all considered parameters, with 1.96 SDs of relative differences being <21% for multilayer PLS, strain rate and PSS, but not for EPS, PSI and PST. In this population-based study, in subjects without or with a limited number of cardiovascular risk factors and no previous cardiovascular events, deformation parameters were found to be highly reproducible, except for EPS, PSI and PST, which showed moderately higher variability. Quantitative strain analysis appears to be an effective clinical and research tool, providing insights regarding longitudinal deformation using a simple three-step post-processing procedure.

Echo and BNP serial assessment in ambulatory heart failure care: Data on loop diuretic use and renal function.

We compared the follow-up data on loop diuretic use and renal function, as assessed by serum creatinine levels, and the estimated glomerular filtration rate (eGFR), of two groups of consecutive ambulatory HF patients: 1) the clinically-guided group, in which management was clinically driven based on the institutional protocol of the HF Unit of the Cardiovascular and Thoracic Department of Pisa (standard of care) and 2) the echo and B-type natriuretic peptide (BNP) guided group (patients conforming to the protocol of the Network Labs Ultrasound (NEBULA) in HF Study Group: Pisa, Perugia, Pavia; Verona, Auckland, and Veruno), in which therapy was delivered according to the serial assessment of BNP and echocardiography. Patients whose follow-up was based on standard of care had a significant higher prevalence of worsening renal function, that was likely related to higher diuretic dosages, whilst, a better management of renal function was observed in the echo-BNP-guided group. The data is related to "Echo and natriuretic peptide guided therapy improves outcome and reduces worsening renal function in systolic heart failure: An observational study of 1137 outpatients" (A. Simioniuc, E. Carluccio, S. Ghio, A. Rossi, P. Biagioli, G. Reboldi, G.G. Galeotti, F. Lu, C. Zara, G. Whalley, P.G. Temporelli, F.L. Dini, 2016; K.J. Harjai, H.K. Dinshaw, E. Nunez, M. Shah, H. Thompson, T. Turgut, H.O. Ventura, 1999; A. Ahmed, A. Husain, T.E. Love, G. Gambassi, L.J. Dell׳Italia, G.S. Francis, M. Gheorghiade, R.M. Allman, S. Meleth, R.C. Bourge, 2006) [1], [2], [3].

Echo and natriuretic peptide guided therapy improves outcome and reduces worsening renal function in systolic heart failure: An observational study of 1137 outpatients.

BACKGROUND: B-type natriuretic peptide (BNP) and echocardiography are potentially useful adjunct to guide management of patients with chronic heart failure (HF).Thus, the aim of this retrospective, multicenter study was to compare outcomes and renal function in outpatients with chronic HF with reduced ejection fraction (HFrEF) who underwent an echo and BNP guided or a clinically driven protocol for follow-up. METHODS AND RESULTS: In 1137 consecutive outpatients, management was guided according to echo-Doppler signs of elevated left ventricular filling pressure and BNP levels conforming to the protocol of the Network Labs Ultrasound (NEBULA) in HF Study Group in 570 (mean EF=30%), while management was clinically driven based on the institutional protocol of the HF Unit of the Cardiovascular and Thoracic Department in 567 (mean EF=33%). Propensity score, matching several confounding baseline variables, was used to match pairs based on treatment strategy. The median follow-up was 37.4months. After propensity matching, a lower incidence of death (HR 0.45, 95%CI: 0.30-0.67, p<0.0001), and death or worsening renal function (HR 0.49, 95%CI 0.36-0.67, p<0.0001) was apparent in echo-BNP-guided group compared to clinically-guided group. Worsening of renal function (≥0.3mg/dl increase in serum creatinine) was observed in 9.8% of echo-BNP-guided group and in 21.4% of clinical assessed group (p<0.0001). The daily dose of loop diuretics did not change in echo-BNP-guided group, while it increased in 65% of patients in clinically-guided group (p<0.0001). CONCLUSIONS: Echo and BNP guided management may improve the outcome and reduce worsening of renal function in outpatients with chronic HFrEF.

Fibrosis assessment by integrated backscatter and its relationship with longitudinal deformation and diastolic function in heart failure with preserved ejection fraction.

Myocardial reflectivity, as assessed by calibrated integrated backscatter (cIB) analysis, is a non-invasive surrogate for the amount of left ventricular (LV) fibrosis. The aim of this study was to assess the myocardial reflectivity pattern in patients with heart failure and preserved ejection fraction (HFpEF), and to evaluate its relationship with longitudinal systolic deformation of LV by 2D-speckle tracking echocardiography, and degree of diastolic dysfunction. Transthoracic echocardiography, myocardial Doppler-derived systolic (Sm) and early diastolic velocity (E'), global longitudinal strain (GLS), and tissue characterization by cIB, were obtained in 86 subjects, 46 with HFpEF, and 40 controls. GLS was significantly impaired in HFpEF patients (-15.4 ± 3.5 % vs -21.5 ± 2.9 % in controls; P < 0.0001). Increased myocardial reflectivity, as evidenced by less negative values of cIB, was also found in HFpEF compared to controls (-21.2 ± 4.4 dB vs -25.3 ± 3.9 dB, P < 0.0001). In HFpEF patients, myocardial reflectivity was positively related to GLS (r = 0.68, P < 0.0001), E/E' ratio (r = 0.38, P = 0.009), and Tau (r = 0.43, P = 0.002), and inversely related to E' velocity (r = -0.46, P = 0.0012). These associations remained significant after adjustment for age, preload and afterload indices. Patients with HFpEF show changes of LV structure consistent with enhanced fibrosis-as evidenced by increased myocardial reflectivity- which parallel the degree of diastolic dysfunction, and of longitudinal systolic dysfunction.

The left ventricle as a mechanical engine: from Leonardo da Vinci to the echocardiographic assessment of peak power output-to-left ventricular mass.

The interpretation of the heart as a mechanical engine dates back to the teachings of Leonardo da Vinci, who was the first to apply the laws of mechanics to the function of the heart. Similar to any mechanical engine, whose performance is proportional to the power generated with respect to weight, the left ventricle can be viewed as a power generator whose performance can be related to left ventricular mass. Stress echocardiography may provide valuable information on the relationship between cardiac performance and recruited left ventricular mass that may be used in distinguishing between adaptive and maladaptive left ventricular remodeling. Peak power output-to-mass, obtained during exercise or pharmacological stress echocardiography, is a measure that reflects the number of watts that are developed by 100 g of left ventricular mass under maximal stimulation. Power output-to-mass may be calculated as left ventricular power output per 100 g of left ventricular mass: 100× left ventricular power output divided by left ventricular mass (W/100 g). A simplified formula to calculate power output-to-mass is as follows: 0.222 × cardiac output (l/min) × mean blood pressure (mmHg)/left ventricular mass (g). When the integrity of myocardial structure is compromised, a mismatch becomes apparent between maximal cardiac power output and left ventricular mass; when this occurs, a reduction of the peak power output-to-mass index is observed.

Improvement of myocardial performance (Tei) index closely reflects intrinsic improvement of cardiac function: assessment in revascularized hibernating myocardium.

BACKGROUND: Myocardial performance index (MPI), or Tei index, is an indicator of systolic and diastolic myocardial function. MPI increases in case of cardiac dysfunction; however, whether reversal of left ventricular dysfunction is also reflected by concomitant improvement (i.e., decrease) of MPI is unknown. METHODS: Fifty-two patients with chronic ischemic cardiomyopathy and viable myocardium by dobutamine stress echocardiography were studied by echocardiography before and more than 4 months after cardiac revascularization. Patients were in optimal medical therapy, which remained unchanged following revascularization. RESULTS: At baseline, ejection fraction (EF: 32 ± 6%) and wall motion score index (WMSI: 2.37 ± 0.32) were impaired, and MPI averaged 0.71 ± 0.19. Revascularization markedly improved EF (44 ± 10%, P < 0.0001) and WMSI (1.77 ± 0.44, P < 0.0001). MPI also improved (0.59 ± 0.26, P < 0.0001), and its decrease was significantly correlated with the improvement in EF (r =-0.68, P < 0.0001) and to the extent of viable myocardium (r =-0.45, P = 0.0007). Responders to revascularization (≥5% increase in EF at follow-up, n = 40% and 77%) achieved a significant improvement in MPI at follow-up in contrast with nonresponders (-23 ± 25% vs. 0.02 ± 0.18%, P = 0.001). Improvement in MPI was largely driven by a significant reduction in isovolumic contraction time (P < 0.001) with consequent prolongation of the ejection phase. CONCLUSION: In patients with chronic ischemic cardiomyopathy, MPI improves along with recovery of function, reflecting the intrinsic improvement of viable segments induced by revascularization.

Advantages of deformation indices over systolic velocities in assessment of longitudinal systolic function in patients with heart failure and normal ejection fraction.

AIMS: Tissue Doppler imaging (TDI) systolic velocities have been used to detect impaired systolic function in patients with heart failure and normal ejection fraction (HFnEF). However, many patients do not show alterations by this technique, and furthermore, myocardial systolic velocities can be affected by tethering, translation, and loading conditions. Thus, uncertainties remain about the detection of abnormal systolic function in HFnEF patients. The aim of this study was, therefore, to compare systolic velocities vs. TDI-derived deformation indices for detection of possible abnormalities of systolic function in HFnEF patients, taking into account loading conditions. METHODS AND RESULTS: We studied 40 patients with systolic heart failure (SHF: EF ≤ 40%), 47 HFnEF patients, and 50 controls (C). Systolic velocities of the mitral annulus (pulsed-wave TDI) were measured at four sites and averaged; concomitantly, peak negative TDI-derived strain and strain rate of the four walls were measured in apical, four-, and two-chamber views. Ejection fraction was 65 ± 6% in C, 62 ± 7% in HFnEF, and 29 ± 7% in SHF (P< 0.001 vs. both). In HFnEF patients, systolic velocities and peak negative global longitudinal strain rate and strain were higher than in SHF (P< 0.0001 for all), but lower than in C (P< 0.0001 for all). After controlling for age, left ventricular mass index, end-diastolic volume index, and circumferential end-systolic stress, differences between groups remained significant for deformation indices but not for TDI velocities. By velocity/strain-stress relationship analysis, peak global longitudinal strain was more sensitive than peak systolic motion in detecting systolic dysfunction in HFnEF patients (64 vs. 40%, P< 0.05). CONCLUSION: In patients with HFnEF, TDI-derived deformation indices may more accurately detect abnormal systolic function than myocardial velocities.