New perspectives in the echocardiographic hemodynamics multiparametric assessment of patients with heart failure.

International Guidelines consider left ventricular ejection fraction (LVEF) as an important parameter to categorize patients with heart failure (HF) and to define recommended treatments in clinical practice. However, LVEF has some technical and clinical limitations, being derived from geometric assumptions and is unable to evaluate intrinsic myocardial function and LV filling pressure (LVFP). Moreover, it has been shown to fail to predict clinical outcome in patients with end-stage HF. The analysis of LV antegrade flow derived from pulsed-wave Doppler (stroke volume index, stroke distance, cardiac output, and cardiac index) and non-invasive evaluation of LVFP have demonstrated some advantages and prognostic implications in HF patients. Speckle tracking echocardiography (STE) is able to unmask intrinsic myocardial systolic dysfunction in HF patients, particularly in those with LV preserved EF, hence allowing analysis of LV, right ventricular and left atrial (LA) intrinsic myocardial function (global peak atrial LS, (PALS)). Global PALS has been proven a reliable index of LVFP which could fill the gaps "gray zone" in the previous Guidelines algorithm for the assessment of LV diastolic dysfunction and LVFP, being added to the latest European Association of Cardiovascular Imaging Consensus document for the use of multimodality imaging in evaluating HFpEF. The aim of this review is to highlight the importance of the hemodynamics multiparametric approach of assessing myocardial function (from LVFP to stroke volume) in patients with HF, thus overcoming the limitations of LVEF.

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.

Diastolic function in heart transplant: From physiology to echocardiographic assessment and prognosis.

Heart transplant (HTx) still represents the most effective therapy for end-stage heart failure, with a median survival time of 10 years. The transplanted heart shows peculiar physiology due to the profound alterations induced by the operation, which inevitably influences several echocardiographic parameters assessed during these patients' follow-ups. With these premises, the diastolic function is one of the main aspects to take into consideration. The left atrium (LA) plays a key role in this matter, and that same chamber is significantly impaired with the transplant, with different degrees of altered function based on the surgical technique. Therefore, the traditional echocardiographic evaluation of diastolic function applied to the general population might not properly reflect the physiology of the graft. This review attempts to provide current evidence on diastolic function in HTx starting from defining its different physiology and how the standard echocardiographic parameters might be affected to its prognostic role. Furthermore, based on the experience of our center and the available evidence, we proposed an algorithm that might help clinicians distinguish from actual diastolic dysfunction from a normal diastolic pattern in HTx population.

Strain Echocardiography Is a Promising Tool for the Prognostic Assessment of Sarcoidosis.

Sarcoidosis is a systemic chronic granulomatous disease with significant morbidity and mortality. Although basic transthoracic echocardiography (TTE) is not recommended for the assessment of sarcoidosis, speckle tracking echocardiography (STE) has emerged as more sensitive for the early detection of cardiac sarcoidosis and its outcome. The aim of the study was to assess the utility of left atrial and left ventricular longitudinal STE for the prediction of major adverse cardiac events (MACE) and sarcoidosis relapses. We enrolled 172 consecutive patients with sarcoidosis who underwent TTE and pulmonary function tests (PFTs). All patients were followed for a sarcoidosis relapse and MACE. During a median follow-up of 2217 days, 8 deaths, 23 MACE and 36 sarcoidosis relapses were observed. LV global longitudinal strain (GLS) was significantly lower in patients with MACE (p = 0.025). LV-GLS < 17.13% (absolute value) was identified as a fair predictor of MACE. Concerning the sarcoidosis control, TTE revealed a reduction of the LV ejection fraction (p = 0.0432), tricuspid annular plane systolic excursion (p = 0.0272) and global peak atrial longitudinal strain (PALS, p = 0.0012) in patients with relapses. PALS < 28.5% was the best predictor of a sarcoidosis relapse. Our results highlight a potential role of LV-GLS and PALS as prognostic markers in sarcoidosis, supporting the use of STE in the clinical management of these patients.

Novel Approaches in Cardiac Imaging for Non-invasive Assessment of Left Heart Myocardial Fibrosis.

In the past, the identification of myocardial fibrosis was only possible through invasive histologic assessment. Although endomyocardial biopsy remains the gold standard, recent advances in cardiac imaging techniques have enabled non-invasive tissue characterization of the myocardium, which has also provided valuable insights into specific disease processes. The diagnostic accuracy, incremental yield and prognostic value of speckle tracking echocardiography, late gadolinium enhancement and parametric mapping modules by cardiac magnetic resonance and cardiac computed tomography have been validated against tissue samples and tested in broad patient populations, overall providing relevant clinical information to the cardiologist. This review describes the patterns of left ventricular and left atrial fibrosis, and their characterization by advanced echocardiography, cardiac magnetic resonance and cardiac computed tomography, allowing for clinical applications in sudden cardiac death and management of atrial fibrillation.

Echocardiographic assessment of coronary microvascular dysfunction: Basic concepts, technical aspects, and clinical settings.

Coronary flow reserve is the capacity of the coronary circulation to augment the blood flow in response an increase in myocardial metabolic demands and has a powerful prognostic significance in different clinical situations. It might assess with invasive and noninvasive technique. Transthoracic echocardiography Doppler is an emerging diagnostic technique, noninvasive, highly feasible, safe for patient and physician, without radiation, and able to detect macrovascular and microvascular anomalies in the coronary circulation. This review aims to describe the benefit and limits of echocardiographic assessment of coronary flow reserve.

Systematic Left Ventricular Assist Device Implant Eligibility with Non-Invasive Assessment: The SIENA Protocol.

In patients with end-stage left ventricular (LV) heart failure who receive LV assist device (LVAD) implantation, right ventricular (RV) failure represents a possible critical complication that heavily affects morbidity and mortality. Several clinical, laboratory, hemodynamic, and echocardiographic variables have been found to be associated with RV failure occurrence after surgery. Different models and risk scores have been proposed, with poor results. No accordance has ever been reached about RV pre-operative evaluation, and time has come to introduce a standardized systematic protocol for LVAD suitability assessment according to RV function. We analyzed imaging parameters associated with LVAD implantation-related RV failure, in order to identify the minimum number for pre-operative reliable prediction of post-operative RV failure. A few echocardiographic parameters have been identified as the most reliable, or promising, and reproducible tools in this field: free-wall RV longitudinal strain, RV fractional area change, RV sphericity index, and RV ejection fraction with 3D-echocardiography. We propose the Systematic LVAD Implant Eligibility with Non-invasive Assessment protocol-the SIENA protocol-as a new and simple way of pre-operative evaluation of patients candidates to LVAD implantation.

Left atrial strain: a new parameter for assessment of left ventricular filling pressure.

In order to obtain accurate diagnosis, treatment and prognostication in many cardiac conditions, there is a need for assessment of left ventricular (LV) filling pressure. While systole depends on ejection function of LV, diastole and its disturbances influence filling function and pressures. The commonest condition that represents the latter is heart failure with preserved ejection fraction in which LV ejection is maintained, but diastole is disturbed and hence filling pressures are raised. Significant diastolic dysfunction results in raised LV end-diastolic pressure, mean left atrial (LA) pressure and pulmonary capillary wedge pressure, all referred to as LV filling pressures. Left and right heart catheterization has traditionally been used as the gold standard investigation for assessing these pressures. More recently, Doppler echocardiography has taken over such application because of its noninvasive nature and for being patient friendly. A number of indices are used to achieve accurate assessment of filling pressures including: LV pulsed-wave filling velocities (E/A ratio, E wave deceleration time), pulmonary venous flow (S wave and D wave), tissue Doppler imaging (E' wave and E/E' ratio) and LA volume index. LA longitudinal strain derived from speckle tracking echocardiography (STE) is also sensitive in estimating intracavitary pressures. It is angle-independent, thus overcomes Doppler limitations and provides highly reproducible measures of LA deformation. This review examines the application of various Doppler echocardiographic techniques in assessing LV filling pressures, in particular the emerging role of STE in assessing LA pressures in various conditions, e.g., HF, arterial hypertension and atrial fibrillation.