Progress in Cardiac Resynchronisation Therapy and Optimisation

Cardiac resynchronisation therapy (CRT) has become the cornerstone of heart failure (HF) treatment. Despite the obvious benefit from this therapy, an estimated 30% of CRT patients do not respond ("non-responders"). The cause of "non-response" is multi-factorial and includes suboptimal device settings. To optimise CRT settings, echocardiography has been considered the gold standard but has limitations: it is user dependent and consumes time and resources. CRT proprietary algorithms have been developed to perform device optimisation efficiently and with limited resources. In this review, we discuss CRT optimisation including the various adopted proprietary algorithms and conduction system pacing.

Long-Term Performance of Epicardial versus Transvenous Left Ventricular Leads for Cardiac Resynchronization Therapy

Aims: to study the technical performance of epicardial left ventricular (LV) leads placed via video assisted thoracic surgery (VATS), compared to transvenously placed leads for cardiac resynchronization therapy (CRT). Methods: From 2001 until 2013, a total of 644 lead placement procedures were performed for CRT. In the case of unsuccessful transvenous LV lead placement, the patient received an epicardial LV lead. Study groups consist of 578 patients with a transvenous LV lead and 66 with an epicardial LV lead. The primary endpoint was LV-lead failure necessitating a replacement or deactivation. The secondary endpoint was energy consumption. Results: The mean follow up was 5.9 years (epicardial: 5.5 ± 3.1, transvenous: 5.9 ± 3.5). Transvenous leads failed significantly more frequently than epicardial leads with a total of 66 (11%) in the transvenous leads group vs. 2 (3%) in the epicardial lead group (p = 0.037). Lead energy consumption was not significantly different between groups. Conclusions: Epicardial lead placement is feasible, safe and shows excellent long-term performance compared to transvenous leads. Epicardial lead placement should be considered when primary transvenous lead placement fails or as a primary lead placement strategy in challenging cases.

Impact of dapagliflozin on cardiac remodelling in patients with chronic heart failure: The DAPA-MODA study

AIMS

Dapagliflozin improves the prognosis of patients with heart failure (HF), regardless of left ventricular ejection fraction (LVEF). However, its effect on cardiac remodelling parameters, specifically left atrial (LA) remodelling, is not well established.

METHODS AND RESULTS

The DAPA-MODA trial (NCT04707352) is a multicentre, single-arm, open-label, prospective and interventional study that aimed to evaluate the effect of dapagliflozin on cardiac remodelling parameters over 6 months. Patients with stable chronic HF receiving optimized guideline-directed therapy, except for any sodium-glucose cotransporter 2 inhibitor, were included. Echocardiography was performed at baseline, 30 and 180 days, and analysed by a central core-lab in a blinded manner to both patient and time. The primary endpoint was the change in maximal LA volume index (LAVI). A total of 162 patients (64.2% men, 70.5 ± 10.6 years, 52% LVEF >40%) were included in the study. At baseline, LA dilatation was observed (LAVI 48.1 ± 22.6 ml/m2 ) and LA parameters were similar between LVEF-based phenotypes (≤40% vs. >40%). LAVI showed a significant reduction at 180 days (-6.6% [95% confidence interval -11.1, -1.8], p = 0.008), primarily due to a decrease in reservoir volume (-13.8% [95% confidence interval -22.5, -4], p = 0.007). Left ventricular geometry improved with significant reductions in left ventricular mass index (-13.9% [95% confidence interval -18.7, -8.7], p < 0.001), end-diastolic volume (-8.0% [95% confidence interval -11.6, -4.2], p < 0.001) and end-systolic volume (-11.9% [95% confidence interval -16.7, -6.8], p < 0.001) at 180 days. N-terminal pro-B-type natriuretic peptide (NT-proBNP) showed a significant reduction at 180 days (-18.2% [95% confidence interval -27.1, -8.2], p < 0.001), without changes in filling Doppler measures.

CONCLUSION

Dapagliflozin administration in stable out-setting patients with chronic HF and optimized therapy results in global reverse remodelling of cardiac structure, including reductions in LA volumes and improvement in left ventricular geometry and NT-proBNP concentrations.

Clinical Implications of Device-Detected Atrial Fibrillation in Cardiac Resynchronization Therapy

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF) is associated with decreased cardiac resynchronization therapy (CRT) benefits compared to sinus rhythm (SR). Effective biventricular (BiV) pacing is a determinant of CRT success, but AF can interfere with adequate BiV pacing and affect clinical outcomes. We investigated the effect of device-detected AF on clinical outcomes and optimal BiV pacing in patients with heart failure (HF) treated with CRT.

METHODS

We retrospectively analyzed 174 patients who underwent CRT implantation between 2012 and 2019 at a tertiary center. The optimal BiV pacing percentage was defined as ≥98%. Device-detected AF was defined as an atrial high-rate episode ≥180 beats per minute lasting more than 6 minutes during the follow-up period. We stratified the patients without preexisting AF at pre-implantation into device-detected AF and no-AF groups.

RESULTS

A total of 120 patients did not show preexisting AF at pre-implantation, and 54 had AF. Among these 120 patients, 19 (15.8%) showed device-detected AF during a median follow-up of 25.1 months. The proportion of optimal BiV pacing was significantly lower in the device-detected AF group than in the no-AF group (42.1% vs. 75.2%, p=0.009). The device-detected AF group had a higher incidence of HF hospitalization, cardiovascular death, and all-cause death than the no-AF group. The device-detected AF and previous AF groups showed no significant differences regarding the percentage of BiV pacing and clinical outcomes.

CONCLUSIONS

For HF patients implanted with CRT, device-detected AF was associated with lower optimal BiV pacing and worse clinical outcomes than no-AF.

Cardiac Resynchronization Therapy beyond Nominal Settings: An IEGM-Based Approach for Paced and Sensed Atrioventricular Delay Offset Optimization in Daily Clinical Practice

Optimization of the atrioventricular (AV) delay has been performed in several landmark trials in cardiac resynchronization therapy (CRT), although it is often not performed in daily practice. Our aim was to study optimal AV delays and investigate a simple intracardiac electrogram (IEGM)-based optimization approach. 328 CRT patients with paired IEGM and echocardiography optimization data were included in our single-center observational study. Sensed (sAV) and paced (pAV) AV delays were optimized using an iterative echocardiography method. The offset between sAV and pAV delays was calculated using the IEGM method. The mean age of the patients was 69 ± 12 years; 64% were men, 48% had ischemic etiology of heart failure. During echocardiographic optimization, an offset of 73 ± 18 ms was found, differing from nominal AV settings (p < 0.001). Based on the IEGM method, the optimal offset was 75 ± 25 ms. The echocardiographic and IEGM-generated AV offset delays showed good correlation (R2 = 0.62, p < 0.001) and good agreement according to Bland-Altman plot analysis. CRT responders had a near zero offset difference between IEGM and echo optimization (-0.2 ± 17 ms), while non-responders had an offset difference of 6 ± 17 ms, p = 0.006. In conclusion, optimal AV delays are patient-specific and differ from nominal settings. pAV delay can easily be calculated from IEGM after sAV delay optimization.

Special Issue: Latest Advances in Delivery and Outcomes of Cardiac Resynchronization Therapy and Conduction System Pacing

Cardiac Resynchronization Therapy (CRT) is an established technique to improve morbidity and mortality in selected heart failure patients [...].

Left Atrial Reverse Remodeling in Dilated Cardiomyopathy

BACKGROUND

Left atrial (LA) dilation is associated with a worse prognosis in several cardiovascular settings, but therapies can promote LA reverse remodeling. The aim of this study was to characterize and define the prognostic implications of LA volume index (LAVI) reduction in patients with dilated cardiomyopathy (DCM).

METHODS

Consecutive patients with DCM from two tertiary care centers, with available echocardiograms at baseline and at 1-year follow-up, were retrospectively analyzed. LA dilation was defined as LAVI > 34 mL/m², and change in LAVI (ΔLAVI) was defined as the 1-year relative LAVI reduction. The outcome was a composite of death, heart transplantation (HTx), or heart failure hospitalization (HFH).

RESULTS

Five hundred sixty patients were included (mean age, 54 ± 13 years; mean left ventricular ejection fraction, 31 ± 10%; mean LAVI, 45 ± 18 mL/m²). Baseline LAVI had a non-linear association with the risk for death, HTx, or HFH, independent of age, left ventricular ejection fraction, mitral regurgitation, and medical therapy (P < .01). At 1-year follow-up, LAVI decreased in 374 patients (67%; median ΔLAVI, -24%; interquartile range, -37% to -11%). Factors independently associated with ΔLAVI were higher baseline LAVI and lower baseline left ventricular ejection fraction. After multivariable adjustment, ΔLAVI showed a linear association with the risk for death, HTx, or HFH (hazard ratio, 0.96 per 5% decrease; 95% CI, 0.93-0.99; P = .042). At 1-year follow-up, patients with reductions in LAVI of >10% and LAVI normalization (i.e., follow-up LAVI ≤ 34 mL/m²; 31% of the overall cohort) were at lower risk for death, HTx, or HFH (hazard ratio, 0.37; 95% CI, 0.35-0.97; P = .028).

CONCLUSIONS

In a large cohort of patients with DCM, 1-year reduction in LAVI was observed in a number of patients. The association between reduction in LAVI and death, HTx, or HFH suggests that LA structural reverse remodeling might be considered an additional parameter useful in the individualized risk stratification of patients with DCM.

Effect of single ventricular premature contractions on response to cardiac resynchronization therapy

Background

We lack data on the effect of single premature ventricular contractions (PVCs) on the clinical and echocardiographic response after cardiac resynchronization therapy (CRT) device implantation. We aimed to assess the predictive value of PVCs at early, 1 month-follow up on echocardiographic response and all-cause mortality.

Methods

In our prospective, single-center study, 125 heart failure patients underwent CRT implantation based on the current guidelines. Echocardiographic reverse remodeling was defined as a ≥ 15% improvement in left ventricular ejection fraction (LVEF), end-systolic volume (LVESV), or left atrial volume (LAV) measured 6 months after CRT implantation. All-cause mortality was investigated by Wilcoxon analysis.

Results

The median number of PVCs was 11,401 in those 67 patients who attended the 1-month follow-up. Regarding echocardiographic endpoints, patients with less PVCs develop significantly larger LAV reverse remodeling compared to those with high number of PVCs. During the mean follow-up time of 2.1 years, 26 (21%) patients died. Patients with a higher number of PVCs than our median cut-off value showed a higher risk of early all-cause mortality (HR 0.97; 95% CI 0.38–2.48; P = 0.04). However, when patients were followed up to 9 years, its significance diminished (HR 0.78; 95% CI 0.42–1.46; P = 0.15).

Conclusions

In patients undergoing CRT implantation, lower number of PVCs predicted atrial remodeling and showed a trend for a better mortality outcome. Our results suggest the importance of the early assessment of PVCs in cardiac resynchronization therapy and warrant further investigations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02725-3.

Left atrial disease and left atrial reverse remodelling across different stages of heart failure development and progression: a new target for prevention and treatment

The left atrium is a dynamic chamber with peculiar characteristics. Stressors and disease mechanisms may deeply modify its structure and function, leading to left atrial remodelling and disease. Left atrial disease is a predictor of poor outcomes. It may be a consequence of left ventricular systolic and diastolic dysfunction and neurohormonal and inflammatory activation and/or actively contribute to the progression and clinical course of heart failure through multiple mechanisms such as left ventricular filling and development of atrial fibrillation and subsequent embolic events. There is growing evidence that therapy may improve left atrial function and reverse left atrial remodelling. Whether this translates into changes in patient's prognosis is still unknown. In this review we report current data about changes in left atrial size and function across different stages of development and progression of heart failure. At each stage, drug therapies, lifestyle interventions and procedures have been associated with improvement in left atrial structure and function, namely a reduction in left atrial volume and/or an improvement in left atrial strain function, a process that can be defined as left atrial reverse remodelling and, in some cases, this has been associated with improvement in clinical outcomes. Further evidence is still needed mainly with respect of the possible role of left atrial reverse remodelling as an independent mechanism affecting the patient's clinical course and as regards better standardization of clinically meaningful changes in left atrial measurements. Summarizing current evidence, this review may be the basis for further studies.

Predictors of rhythm outcomes after cardiac resynchronization therapy in atrial fibrillation patients: When should we use an atrial lead?

BACKGROUND

Cardiac resynchronization therapy (CRT) is widely used in atrial fibrillation (AF) patients and could impact rhythm stability.

HYPOTHESIS

We aimed to identify predictors of sinus rhythm (SR) stability or AF progression in a real-word cohort of CRT-AF patients.

METHODS

From 330 consecutive implantable cardioverter-defibrillator implantations due to ischemic or dilated cardiomyopathy, 65 (20%) patients with AF history (paroxysmal, n = 32) underwent a CRT implantation with an atrial electrode and were regularly followed every 4-6 months. Rhythm restoration was attempted for most AF patients based on symptoms, biventricular pacing (BP), and lack of thrombi.

RESULTS

After 33 months, 18 (28%) patients progressed to permanent mode switch (MS≥99%) and 20 (31%) patients had stable SR (MS < 1%). Logistic regression showed that history of persistent AF (OR: 8.01, 95%CI: 2.0-31.7, p = .003) is associated with higher risk of permanent MS. In persistent AF patients, a bigger left atrium (OR: 1.2 per mm, 95%CI: 1.03-1.4, p = .025) and older age (OR: 1.15 per life-year, 95%CI: 1.01-1.3, p = .032) were predictors of future permanent MS. Paroxysmal AF at implantation (OR: 5.96, 95%CI: 1.6-21.9, p = .007) and increased BP (OR: 1.4 per 1%, 95%CI: 1.05-1.89, p = .02) were associated with stable SR. In persistent AF patients, stable SR correlated with higher BP (98 ± 2 vs. 92 ± 8%, p < .001).

CONCLUSION

In patients with AF undergoing CRT implantation, persistent AF, LA dilatation and advanced age relate to future permanent MS (AF), whereas high BP promotes SR stability. These findings could facilitate the management of CRT-AF patients and guide therapy in order to maximize its effect on rhythm.

Left ventricular response after cardiac resynchronization therapy is related to early left atrial volume reduction

BACKGROUND/AIMS

The current study aimed to elucidate a time-course change in left atrial volume after cardiac resynchronization therapy (CRT) and to verify factors associated with left atrial volume reduction (LAVR) and its prognostic implications.

METHODS

The records of 97 patients were retrospectively reviewed after CRT. Echocardiographic data were analyzed at baseline before CRT, at early follow-up (FU) (≤ 1 year, median 6 months), and at late FU (median 30 months). Left ventricular volume response (LVVR) was defined as 15% reduction in left ventricular (LV) end-systolic volume (ESV). LAVR was classified into two groups by the median value at early FU: LAVR (≥ 7.5%) and no LAVR (< 7.5%).

RESULTS

LV ESV index continuously decreased from baseline to early FU and from early FU to late FU (106.1 ± 47.4 mL/m2 vs. 87.6 ± 51.6 mL/m2 vs. 72.5 ± 57.1 mL/m2). LA volume index decreased from baseline to early FU, but there were no reductions thereafter (51.8 ± 21.9 mL/m2 vs. 45.1 ± 19.6 mL/m2 vs. 44.9 ± 23.0 mL/m2). The only echocardiographic factor associated with LAVR was change in E velocity (odds ratio [OR], 1.04; p = 0.002). Early LAVR (OR, 10.05; p = 0.002) was an independent predictor for late LVVR.

CONCLUSION

LAVR was related to reduction in E velocity, suggesting its relation with optimization of LV filling pressure. Early LAVR was a predictor for LVVR to CRT in long-term FU.

Early left atrial dysfunction is associated with suboptimal cardiovascular health

AIMS

Two-dimensional speckle-tracking echocardiography can assess left atrial (LA) function by measuring atrial volumes and deformation parameters (strain, strain rate). This cross-sectional analysis explores the association between ideal CV health (CVH), LA function, and systemic biomarkers in healthy individuals from the Chilean MAUCO Cohort.

METHODS

We enrolled 95 MAUCO participants with different levels of CVH (mean age: 51 ± 8 years). We categorized participants into low or high CVH groups: A: 0-2, or B: 3-6 CVH risk factors. 2D echocardiography, glucose, insulin, total cholesterol, triglycerides, proBNP, hsCRP, insulin resistance index (HOMA), and right and left atrial strain (RASs and LASs, respectively) were determined.

RESULTS

LASs was lower in Group A, while systolic and diastolic blood pressure (BP), body mass index (BMI), insulin, HOMA, total cholesterol, triglycerides, and LV and RV end-diastolic volume were significantly higher in Group A than Group B (P < .01). Change in LASs was inversely correlated with insulin (P = .040), HOMA (P = .013), total cholesterol (P = .039), glycemia (P = .018), and BMI (P = .0.037).

CONCLUSION

LASs during the reservoir phase was diminished in subjects with a lower level of CVH. Higher insulin, HOMA, total cholesterol, glycemia, and BMI values were associated with decreased LA deformation during the reservoir phase. Morphofunctional alterations of the LA were also identified in the group with suboptimal CVH, as well as BP values in the range of hypertension. LA dysfunction in an asymptomatic population, along with metabolic syndrome, could be an early event in the continuum of CV damage.

Left Atrial Structure and Function, and Left Ventricular Diastolic Dysfunction: JACC State-of-the-Art Review

Defining left atrial (LA) function has recently emerged as a powerful parameter, particularly in evaluation of left ventricular (LV) diastolic dysfunction (LVDD) and heart failure with preserved ejection fraction. Echocardiographic assessment of LVDD by echocardiography remains a challenging task; recent recommendations provide a simpler approach than previous. However, the shortcomings of the proposed approach (including transmitral flow, tissue velocity, maximum left atrial volume [LAV], and estimated pulmonary artery systolic pressure), lead to the presence and severity of LVDD remaining undetermined in a significant proportion of patients. Maximum LAV is a surrogate measure of the chronicity and severity of LVDD, but LAV alone is an insensitive biomarker of early phases of LVDD, because the LA may take time to remodel. Because the primary function of the LA is to modulate LV filling, it is not surprising that functional LA changes become evident at the earliest stages of LVDD. Moreover, LA function may provide additive value, not only in diagnosing LVDD, but also in grading its severity and in monitoring the effects of treatment. The current review provides a critical appraisal on the existing evidence for the role of LA metrics in evaluation of LVDD and consequent heart failure with preserved ejection fraction.

Effect of epicardial fat and metabolic syndrome on reverse atrial remodeling after ablation for atrial fibrillation

BACKGROUND

Metabolic syndrome/epicardial adipose tissue (EAT) plays an important role in atrial fibrillation (AF). Although reverse atrial remodeling (RAR) often occurs after AF ablation, the effects of EAT on RAR remain unknown.

METHODS

Study subjects were 104 patients in whom transthoracic echocardiography (TTE) was performed before AF ablation and 3, 6, and 12 months afterward. EAT was assessed in terms of its thickness adjacent to the right ventricular anterior wall in the TTE parasternal view. RAR was defined as >10% reduction in the left atrial volume (LAV) index by the 3-month follow-up examination.

RESULTS

Postablation RAR occurred in 57/104 (55%) patients. RAR absence was associated with a relatively thick EAT (4.92 ± 1.65 vs. 3.92 ± 1.17 mm, P = 0.0005), small LAV index (24.6 ± 7.5 vs. 28.8 ± 10.6 mL/m2, P = 0.0233), and metabolic syndrome (62% vs. 28%, P = 0.0006). Metabolic syndrome and EAT were shown to be independent predictors of RAR absence. Thick EAT was significantly associated with AF recurrence after ablation (5.05 ± 2.19 mm vs. 4.17 ± 1.16 mm for no AF recurrence group, P = 0.0116), but metabolic syndrome was not (48% vs. 42%, P = 0.6189). Despite no change in body weight, EAT thickness decreased significantly by 12 months in patients without AF recurrence (4.17 ± 1.16 vs. 3.65 ± 1.16 mm, P < 0.0001).

CONCLUSIONS

EAT and metabolic syndrome appear to be strongly associated with RAR absence, but only the thick EAT was significantly associated with the postablation AF recurrence. Our findings, especially the thinning of EAT, suggest that thick EAT lead to AF vulnerability but that EAT reduction favorably affects ablation outcome.

Mid-regional pro-atrial natriuretic peptide to predict clinical course in heart failure patients undergoing cardiac resynchronization therapy

Aims

Cardiac resynchronization therapy (CRT) induces reverse cardiac remodelling in heart failure (HF), but many patients receiving CRT remain non-responders. This study assessed the role of amino-terminal-pro-B-type natriuretic peptide (NT-proBNP), mid-regional-pro-atrial natriuretic peptide (MR-proANP), and mid-regional-pro-adrenomedullin (MR-proADM) at the time of device implantation to predict favourable clinical course (CRT response and/or risk of MACE) in HF patients receiving CRT.

Methods and results

A total of 137 HF patients were prospectively included. Blood was drawn from the coronary sinus (CS) at CRT implantation, and from a peripheral vein (PV) simultaneously and after 6 months. Clinical CRT response at 6 months and major adverse cardiovascular events (MACE) at 2 years were assessed. Baseline PV-levels of MR-proANP (202 vs. 318 pmol/L, P = 0.009) and MR-proADM (843 vs. 1112 pmol/L, P = 0.02) were lower in CRT responders compared with non-responders. At 6 months, CRT responders showed a decrease in MR-proANP levels, compared with an increase in non-responders (-32 vs. +7 pmol/L, P = 0.02). During the same period, NT-proBNP decreased by a similar way in responders and non-responders, while MR-proADM was unchanged in both groups. High baseline MR-proANP, either in PV (OR 0.41, 95% CI 0.24-0.71, P = 0.002) or CS (OR 0.32, 95% CI 0.15-0.70, P = 0.005) was associated with reduced likelihood of CRT response. Furthermore, PV and CS levels of NT-proBNP, MR-proANP, and MR-proADM were all associated with increased risk of 2-year MACE (all P < 0.01).

Conclusion

Mid-regional-pro-atrial natriuretic peptide may assist prediction of clinical course in HF patients undergoing CRT implantation. Low circulating MR-proANP at the time of device implantation is associated with CRT response and more favourable outcome.

Electrical remodelling and response following cardiac resynchronization therapy: A novel analysis of intracardiac electrogram using a quadripolar lead

BACKGROUND

Cardiac resynchronization therapy (CRT) improves morbidity and mortality in patients with heart failure. Although structural remodelling correlates with improved long-term outcomes, the role of electrical remodelling is poorly understood. This study aimed to evaluate electrical remodelling following CRT using a quadripolar left ventricular (LV) lead and to correlate this with structural remodelling.

METHODS

Consecutive patients undergoing initial CRT implantation using a quadripolar LV lead were enrolled. Patients were followed up for 12 months. Twelve lead ECG, transthoracic echocardiogram, and evaluation of intracardiac electrograms (EGM) were performed. Measures included right and left ventricular lead intrinsic delay, RV-pacing to LV-sensing (RVp-LVs) delay, and LV-pacing to RV-sensing (LVp-RVs) delay. The electrical changes were then correlated with echocardiographic response to CRT, defined by ≥15% relative reduction in LVESV and ≥ 5% absolute improvement in EF on TTE. Activation sequence was determined using the quadripolar lead.

RESULTS

Forty patients were enrolled. Mean intrinsic RV-LV EGM values decreased from 121.9 ± 14.7 ms to 109.1 ± 15.0 ms (P < .01), mean RVp-LVs EGM values from 146.7 ± 16.7 ms to 135.1 ± 13.1 ms, (P < .01), and mean LVp-RVs EGM values from 155.7 ± 18.1 ms to 144.2 ± 17.1 ms (P < .01). The improvement in intrinsic RV-LV EGM was 14.9 ± 8.5 ms in responders vs 8.9 ± 7.9 ms in nonresponders to CRT (P < .05). Changes in activation sequence did not correlate with CRT response.

CONCLUSIONS

This novel study used EGMs from a quadripolar LV lead to demonstrate electrical remodelling occurs following CRT. A nonsignificant trend suggests that electrical remodelling in CRT is greater in responders compared to nonresponders, although further study is needed.