Contractile reserve assessed by dobutamine test identifies super-responders to cardiac resynchronization therapy

The Utility of Low-Dose-Dobutamine Stress Echocardiography in Patients with Heart Failure with Reduced Ejection Fraction: An Update

Despite significant advancements in medical therapy, heart failure with reduced ejection fraction (HFrEF) continues to be a significant cause of death and disability. Reversible ischaemic left ventricular dysfunction due to viable myocardium is one such contributing factor. In these cases, coronary revascularization has shown promise in improving left ventricular function and prognosis. For patients with HFrEF and wide QRS, cardiac resynchronization therapy (CRT) is an effective option to address electromechanical dyssynchrony. However, approximately 30% of patients do not respond positively to CRT, highlighting the need to refine candidate selection for this treatment. In some patients with reduced HFrEF, there is a condition known as classical low-flow, low-gradient aortic stenosis (AS) that may be observed. This condition is characterized by a low transaortic flow, which leads to reductions in both the transaortic mean gradient and aortic valve area. Decision-making regarding revascularization, CRT, and pharmacological treatment play a crucial role in managing HFrEF. Cardiac imaging can be valuable in guiding decision-making processes and assessing the prognosis of patients with HFrEF. Among the imaging modalities, dobutamine stress echocardiography has come a long way in establishing itself as a feasible, safe, effective, relatively cheap non-invasive technique. The aim of this review is to explore the current literature on the utility of low-dose stress echocardiography in diagnosing and prognosticating patients with HFrEF.

Cardiac remodelling - Part 2: Clinical, imaging and laboratory findings. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

In patients with heart failure, the beneficial effects of drug and device therapies counteract to some extent ongoing cardiac damage. According to the net balance between these two factors, cardiac geometry and function may improve (reverse remodelling, RR) and even completely normalize (remission), or vice versa progressively deteriorate (adverse remodelling, AR). RR or remission predict a better prognosis, while AR has been associated with worsening clinical status and outcomes. The remodelling process ultimately involves all cardiac chambers, but has been traditionally evaluated in terms of left ventricular volumes and ejection fraction. This is the second part of a review paper by the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology dedicated to ventricular remodelling. This document examines the proposed criteria to diagnose RR and AR, their prevalence and prognostic value, and the variables predicting remodelling in patients managed according to current guidelines. Much attention will be devoted to RR in patients with heart failure with reduced ejection fraction because most studies on cardiac remodelling focused on this setting.

Left atrial volume index predicts response to cardiac resynchronisation therapy: a systematic review and meta-analysis

INTRODUCTION

In responders, cardiac resynchronisation therapy (CRT) results in improved left ventricular (LV) function and reduced atrial arrhythmia. The aim of this meta-analysis was to assess the potential relationship between the left atrium (LA) volume and CRT response.

MATERIAL AND METHODS

We systematically searched all electronic databases up to August 2018 in order to select clinical trials and observational studies that assessed the predictive value of LA volume index (LAVI) of CRT response. Left ventricular end-systolic volume (LVESV) reduction ≥ 15 ml and/or LV ejection fraction (EF) increase ≥ 10% were the documented criteria for positive CRT response.

RESULTS

A total of 2191 patients recruited in 10 studies with mean follow-up duration of 10.5 months were included in this meta-analysis. The pooled analysis showed that CRT responders had lower baseline LAVI compared to non-responders, with a weighted mean difference (WMD) of -5.89% (95% CI: -9.47 to -3.22, p < 0.001). At follow-up, LAVI fell in the CRT responders (WMD -4.36%, 95% CI: -3.54 to -5.17, p < 0.001) compared to non-responders (WMD 1.45 %, 95% CI: -0.75 to 3.65, p = 0.20). The mean change of LAVI in the CRT responders was related to the fall in LVESV, β = -1.02 (-1.46 to -0.58), p < 0.001 and the increase in LVEF, β = 2.02 (1.86 to 4.58), p = 0.001. A baseline LAVI < 34 ml/m² predicted CRT response with summary sensitivity 0.80% (0.53-0.95), specificity 0.74% (0.53-0.89), and odds ratio > 11.

CONCLUSIONS

Baseline LAVI predicts CRT response, and its reduction reflects devise-related LA remodelling. These results emphasis the role of LAVI assessment as an integral part of cardiac function response to CRT.

Advances in Cardiac Resynchronization Therapy

The development of cardiac resynchronization therapy (CRT) has been crucial in reducing morbidity and mortality in patients with advanced heart failure. However, a significant proportion of patients who receive CRT fail to derive significant clinical benefits from this therapy. Successful CRT depends on a multitude of factors, including appropriate patient selection, left ventricular lead positioning, and postimplant management. Newer device-based algorithms, multipoint ventricular pacing, and the development of leadless CRT devices constitute important facets of both the present and near-future evolution of this therapy.

Current role of echocardiography in cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is an established treatment for patients with heart failure and left ventricular systolic dysfunction. Patients are usually assessed by echocardiography, which provides a number of anatomical and functional information used for cardiac dyssynchrony assessment, prognostic stratification, identification of the optimal site of pacing in the left ventricle, optimization of the CRT device, and patient follow-up. Compared to other cardiac imaging techniques, echocardiography has the advantage to be non-invasive, repeatable, and safe, without exposure to ionizing radiation or nefrotoxic contrast. In this article, we review current evidence about the role of echocardiography before, during, and after the implantation of a CRT device.

Interleukin-6 signaling in patients with chronic heart failure treated with cardiac resynchronization therapy

INTRODUCTION

Increased expression of interleukin-6 (IL-6) has been described in left ventricular dysfunction in the course of chronic heart failure. Cardiac resynchronization therapy (CRT) is a unique treatment method that may reverse the course of chronic heart failure (CHF) with reduced ejection fraction (HF-REF). We aimed to evaluate the IL-6 system, including soluble IL-6 receptor (sIL-6R) and soluble glycoprotein 130 (sgp130), in HF-REF patients, with particular emphasis on CRT effects.

MATERIAL AND METHODS

The study enrolled 88 stable HF-REF patients (63.6 ±11.1 years, 12 females, EF < 35%) and 35 comorbidity-matched controls (63.5 ±9.8 years, 7 females). Forty-five HF-REF patients underwent CRT device implantation and were followed up after 6 months. Serum concentrations of IL-6, sIL-6R and sgp130 were determined using ELISA kits.

RESULTS

The HF-REF patients had higher IL-6 (median: 2.6, IQR: 1.6-3.8 vs. 2.1, IQR: 1.4-3.1 pg/ml, p = 0.03) and lower sIL-6R concentrations compared to controls (median: 51, IQR: 36-64 vs. 53. IQR 44-76 ng/ml, p = 0.008). There was no significant difference between sgp130 concentrations. In the HF-REF group IL-6 correlated negatively with EF (r = -0.5, p = 0.001) and positively with BNP (r = 0.5, p = 0.008) and CRP concentrations (r = 0.4, p = 0.02). Patients who presented a positive response after CRT showed a smaller change of sIL-6R concentration compared to nonresponders (ΔsIL-6R: -0.2 ±7.1 vs. 7 ±14 ng/ml; p = 0.04).

CONCLUSIONS

HF-REF patients present higher IL-6 and lower sIL-6R levels. IL-6 concentration reflects their clinical status. CRT-related improvement of patients' functional status is associated with a smaller change of sIL-6R concentration in time.

Variability of longitudinal strain in left ventricular segments supplied by non-stenosed coronary artery: insights from speckle tracking analysis of dobutamine stress echocardiograms in patients with high coronary risk profile

INTRODUCTION

Although global deformation parameters have been increasingly used for myocardial function analysis, there are sparse data concerning segmental deformation of the left ventricle (LV). Moreover, some studies suggest heterogeneity of strain among LV segments, which may be especially significant during stress echocardiography. We assessed quantitatively regional LV function in the setting of dobutamine stress echocardiography (DSE), to examine differences of longitudinal strain between basal, mid and apical LV segments and to compare variability of regional deformation between rest and the peak stage of DSE.

MATERIAL AND METHODS

Among 250 patients examined by DSE applied for diagnosis of ischemia, a subset of 111 patients without significant coronary stenoses in angiography was selected (68 females, mean age: 60 ±10 years). Systolic longitudinal strain (SLS) in individual LV segments at baseline and the peak stage of DSE was analyzed with speckle tracking echocardiography.

RESULTS

Inhomogeneity of SLS among the LV segments (p < 0.001) was observed at baseline and the peak stage. Dispersion indices were higher at the peak stage of DSE than at baseline (p < 0.001), and the lowest heterogeneity was observed among mid segments. The analysis of changes in SLS during DSE showed SLS reduction in basal and mid-ventricular segments and an increase in apical segments.

CONCLUSIONS

Significant heterogeneity of strain and the opposite direction of the longitudinal strain changes during DSE between apical and basal LV segments were observed. This variability among non-ischemic LV segments ought to be considered in quantification of LV function during DSE.

What We Can Learn from "Super-responders"

This review discusses the state of the art of knowledge to help decision making in patients who are candidates for cardiac resynchronization therapy (CRT) and to analyze the long-term total and cardiac mortality, sudden death, and CRT with a defibrillator intervention rate, as well as the evolution of echocardiographic parameters in patients with a left ventricular (LV) ejection fraction of greater than 50% after CRT implantation. Owing to normalization of LV function in super-responders, the need for a persistent defibrillator backup is also considered.

Comparison of sublingual isosorbide dinitrate and Valsalva maneuver for detection of obstruction in hypertrophic cardiomyopathy

INTRODUCTION

A left ventricular outflow tract (LVOT) obstruction assessment with a provoking test should be a routine part of the evaluation of patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to compare the utility of the Valsalva maneuver (VM) and sublingual spray application of isosorbide dinitrate (ISDN) for detection of an obstruction.

MATERIAL AND METHODS

We prospectively evaluated 81 consecutive HCM patients without severe rest LVOT obstruction (defined as peak rest pressure gradient (PG) ≥ 50 mm Hg). We measured PG at rest, during the VM, after sublingual ISDN spray, and during the VM after ISDN. An obstruction was defined as a PG ≥ 30 mm Hg.

RESULTS

An obstruction was present in 15 patients (19%) at rest (median and interquartile range of PG 16 (7-26) mm Hg), in 38 patients (47%) during the VM (PG 28 (12-49) mm Hg), in 50 (62%) patients after ISDN (PG 50 (12-79) mm Hg), and in 55 patients (68%) during the VM after ISDN (PG 59 (20-87) mm Hg). The difference in occurrence of obstruction among different provoking tests was statistically significant for all comparisons (p < 0.001, except for the comparison of the ISDN test with the VM during ISDN, p = 0.025).

CONCLUSIONS

The ISDN test and the VM are useful screening methods for the detection of an HCM obstruction. Although ISDN appears to be more precise than the VM, the best option is a combination of both methods, which maximizes inducement of LVOT obstruction in patients with HCM.

Principles of transthoracic echocardiographic evaluation

Transthoracic echocardiography is the most widely used imaging test in cardiology. Although completely noninvasive, transthoracic echocardiography has a well-established role in the diagnosis of numerous cardiovascular diseases, and also provides critical qualitative and quantitative information on their prognosis and pathophysiological processes. The aim of this Review is to outline the broad principles of transthoracic echocardiography, including the traditional techniques of two-dimensional, colour, and spectral Doppler echocardiography, and newly developed advances including tissue Doppler, myocardial deformation imaging, torsion, stress echocardiography, contrast and three-dimensional echocardiography. The advantages and disadvantages, clinical application, prognostic value, and salient research findings of each modality are described. Advances in complex imaging techniques are expected to continue unabated, and this Review highlights technical improvements that will influence the diagnosis and improve our understanding of cardiovascular function and disease.