Global longitudinal strain predicts responders after cardiac resynchronization therapy-a systematic review and meta-analysis

Longitudinal comparison of dyssynchrony correction and 'strain' improvement by conduction system pacing: LEVEL-AT trial secondary findings

AIMS

Longitudinal dyssynchrony correction and 'strain' improvement by comparable cardiac resynchronization therapy (CRT) techniques is unreported. Our purpose was to compare echocardiographic dyssynchrony correction and 'strain' improvement by conduction system pacing (CSP) vs. biventricular pacing (BiVP) as a marker of contractility improvement during 1-year follow-up.

METHODS AND RESULTS

A treatment-received analysis was performed in patients included in the LEVEL-AT trial (NCT04054895), randomized to CSP or BiVP, and evaluated at baseline (ON and OFF programming) and at 6 and 12 months (n = 69, 32% women). Analysis included intraventricular (septal flash), interventricular (difference between left and right ventricular outflow times), and atrioventricular (diastolic filling time) dyssynchrony and 'strain' parameters [septal rebound, global longitudinal 'strain' (GLS), LBBB pattern, and mechanical dispersion). Baseline left ventricular ejection fraction (LVEF) was 27.5 ± 7%, and LV end-systolic volume (LVESV) was 138 ± 77 mL, without differences between groups. Longitudinal analysis showed LVEF and LVESV improvement (P < 0.001), without between-group differences. At 12-month follow-up, adjusted mean LVEF was 46% with CSP (95% CI 42.2 and 49.3%) vs. 43% with BiVP (95% CI 39.6 and 45.8%), (P = 0.31), and LVESV was 80 mL (95% CI 55.3 and 104.5 mL) vs. 100 mL (95% CI 78.7 and 121.6 mL), respectively (P = 0.66). Longitudinal analysis showed a significant improvement of all dyssynchrony parameters and GLS over time (P < 0.001), without differences between groups. Baseline GLS significantly correlated with LVEF and LVESV at 12-month follow-up.

CONCLUSION

CSP and BiVP provided similar dyssynchrony and 'strain' correction over time. Baseline global longitudinal 'strain' predicted ventricular remodelling at 12-month follow-up.

Role of speckle tracking echocardiography beyond current guidelines in cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is a device-based treatment applied to patients with a specific profile of heart failure. According to current guidelines, indication for CRT is given on the basis of QRS morphology and duration, and traditional transthoracic echocardiography is mainly used to estimate left ventricular (LV) ejection fraction. However, the identification of patients who may benefit from CRT remains challenging, since the application of the above-mentioned guidelines is still associated with a high rate of non-responders. The assessment of various aspects of LV mechanics (including contractile synchrony, coordination and propagation, and myocardial work) performed by conventional and novel ultrasound technologies, first of all speckle tracking echocardiography (STE), may provide additional, useful information for CRT patients' selection, in particular among non-LBBB patients, who generally respond less to CRT. A multiparametric approach, based on the combination of ECG criteria and echocardiographic indices of LV dyssynchrony/discoordination would be desirable to improve the prediction of CRT response.

The Prognostic Role of Global Longitudinal Strain and NT-proBNP in Heart Failure Patients Receiving Cardiac Resynchronization Therapy

BACKGROUND

We aimed to evaluate whether baseline GLS (global longitudinal strain), NT-proBNP, and changes in these after cardiac resynchronization therapy (CRT) can predict long-term clinical outcomes and the echocardiographic-based response to CRT (defined by 15% relative reduction in left ventricular end-systolic volume).

METHODS

We enrolled 143 patients with stable ischemic heart failure (HF) undergoing CRT-D implantation. NT-proBNP and echocardiography were obtained before and 6 months after. The patients were followed up (median: 58 months) for HF-related deaths and/or HF hospitalizations (primary endpoint) or HF-related deaths (secondary endpoint).

RESULTS

A total of 84 patients achieved the primary and 53 the secondary endpoint, while 104 patients were considered CRT responders and 39 non-responders. At baseline, event-free patients had higher absolute GLS values (p < 0.001) and lower NT-proBNP serum levels (p < 0001) than those achieving the primary endpoint. A similar pattern was observed in favor of CRT responders vs. non-responders. On Cox regression analysis, baseline absolute GLS value (HR = 0.77; 95% CI, 0.51-1.91; p = 0.002) was beneficially associated with lower primary endpoint incidence, while baseline NT-proBNP levels (HR = 1.55; 95% CI, 1.43-2.01; p = 0.002) and diabetes presence (HR = 1.27; 95% CI, 1.12-1.98; p = 0.003) were related to higher primary endpoint incidence.

CONCLUSIONS

In HF patients undergoing CRT-D, baseline GLS and NT-proBNP concentrations may serve as prognostic factors, while they may predict the echocardiographic-based response to CRT.

Imaging in patients with cardiovascular implantable electronic devices: part 1-imaging before and during device implantation. A clinical consensus statement of the European Association of Cardiovascular Imaging (EACVI) and the European Heart Rhythm Association (EHRA) of the ESC

More than 500 000 cardiovascular implantable electronic devices (CIEDs) are implanted in the European Society of Cardiology countries each year. The role of cardiovascular imaging in patients being considered for CIED is distinctly different from imaging in CIED recipients. In the former group, imaging can help identify specific or potentially reversible causes of heart block, the underlying tissue characteristics associated with malignant arrhythmias, and the mechanical consequences of conduction delays and can also aid challenging lead placements. On the other hand, cardiovascular imaging is required in CIED recipients for standard indications and to assess the response to device implantation, to diagnose immediate and delayed complications after implantation, and to guide device optimization. The present clinical consensus statement (Part 1) from the European Association of Cardiovascular Imaging, in collaboration with the European Heart Rhythm Association, provides comprehensive, up-to-date, and evidence-based guidance to cardiologists, cardiac imagers, and pacing specialists regarding the use of imaging in patients undergoing implantation of conventional pacemakers, cardioverter defibrillators, and resynchronization therapy devices. The document summarizes the existing evidence regarding the use of imaging in patient selection and during the implantation procedure and also underlines gaps in evidence in the field. The role of imaging after CIED implantation is discussed in the second document (Part 2).

The saga of dyssynchrony imaging: Are we getting to the point

Cardiac resynchronisation therapy (CRT) has an established role in the management of patients with heart failure, reduced left ventricular ejection fraction (LVEF &lt; 35%) and widened QRS (&gt;130 msec). Despite the complex pathophysiology of left ventricular (LV) dyssynchrony and the increasing evidence supporting the identification of specific electromechanical substrates that are associated with a higher probability of CRT response, the assessment of LVEF is the only imaging-derived parameter used for the selection of CRT candidates.

This review aims to (1) provide an overview of the evolution of cardiac imaging for the assessment of LV dyssynchrony and its role in the selection of patients undergoing CRT; (2) highlight the main pitfalls and advantages of the application of cardiac imaging for the assessment of LV dyssynchrony; (3) provide some perspectives for clinical application and future research in this field.

Conclusion

the road for a more individualized approach to resynchronization therapy delivery is open and imaging might provide important input beyond the assessment of LVEF.

Assessment of Cardiac Function and Ventricular Mechanical Synchronization in Left Bundle Branch Area Pacing by Speckle Tracking and Three-Dimensional Echocardiography

Real-time 3-dimensional echocardiography combined with speckle tracking was used in this study. A total of 90 patients with normal left ventricular ejection fraction were divided into 3 groups according to the pacing site: left bundle branch area pacing (LBBAP), right ventricular septal pacing (RVSP) or right ventricular apical pacing (RVAP). Procedure duration (90 ± 18 vs 61 ± 6.6 vs 58 ± 5.6 minutes, p = 0.015), Fluoroscopy duration (15.5 ± 5.4 vs 4.8 ± 2.2 vs 4 ± 1.9 minutes, p = 0.004), and ventricular capture threshold at implantation (0.8 ± 0.3 vs 0.6 ± 0.2 vs 0.6 ± 0.1 V, p = 0.002) were significantly increased in patients that received LBBAP compared with RVSP or RVAP. At 4 weeks of follow-up, brain natriuretic peptide levels were significantly lower (22 [12 to 59] vs 135 [86 to 231] vs 235 [147 to 428] pg/ml, p = 0.04), paced QRS duration was significantly shorter (115 ± 26 vs 134 ± 28 vs 157 ± 29 ms, p = 0.012), and global longitudinal strain (-19.4 ± 2.4 vs -19.3 ± 3.4 vs -17.3 ± 3.5%, p = 0.026) and systolic dyssynchrony index (2.5 ± 0.3 vs 5.9 ± 0.9 vs 7.7 ± 1.2, p = 0.001), longitudinal absolute maximum difference of time to peak strain (17 [6 to 68] vs 117 [71 to 173] vs 126 [79 to 178] ms, p <0.0001), and circumferential absolute maximum difference of time to peak strain (76 [32 to 129] vs 148 [117 to 208] vs 161 [118 to 266] ms, p = 0.005) were significantly lower in patients that received LBBAP compared with RVSP or RVAP. In conclusion, LBBAP can provide a more physiological ventricular activation pattern than RVSP or RVAP and results in good left ventricular electrical and mechanical synchronization.