Complications associated with cardiac resynchronization therapy upgrades versus de novo implantations

First-Phase Ejection Fraction Predicts Response to Cardiac Resynchronization Therapy and Adverse Outcomes

OBJECTIVES

The aim of this study was to examine the value of first-phase ejection fraction (EF1), to predict response to cardiac resynchronization therapy (CRT) and clinical outcomes after CRT.

BACKGROUND

CRT is an important treatment for patients with chronic heart failure. However, even in carefully selected cases, up to 40% of patients fail to respond. EF1, the ejection fraction up to the time of maximal ventricular contraction, is a novel sensitive echocardiographic measure of early systolic function and might relate to response to CRT.

METHODS

An initial retrospective study was performed in 197 patients who underwent CRT between 2009 and 2018 and were followed to determine clinical outcomes at King's Health Partners in London. A validation study (n = 100) was performed in patients undergoing CRT at Barts Heart Centre in London.

RESULTS

Volumetric response rate (reduction in end-systolic volume ≥15%) was 92.3% and 12.1% for those with EF1 in the highest and lowest tertiles (P < 0.001). A cutoff value of 11.9% for EF1 had >85% sensitivity and specificity for prediction of response to CRT; on multivariate binary logistic regression analysis incorporating previously defined predictors, EF1 was the strongest predictor of response (odds ratio [OR]: 1.56 per 1% change in EF1; 95% CI: 1.37-1.78; P < 0.001). EF1 was also the strongest predictor of improvement in clinical composite score (OR: 1.11; 95% CI: 1.04-1.19; P = 0.001). Improvement in EF1 at 6 months after CRT implantation (6.5% ± 5.8% vs 1.8% ± 4.3% in responders vs nonresponders; P < 0.001) was the best predictor of heart failure rehospitalization and death after median follow-up period of 20.3 months (HR: 0.81; 95% CI: 0.73-0.90; P < 0.001). In the validation cohort, EF1 was a similarly 1strong predictor of response (OR: 1.45; 95% CI: 1.23-1.70; P < 0.001) as in the original cohort.

CONCLUSIONS

EF1 is a promising marker to identify patients likely to respond to CRT.

Leadless left ventricular endocardial pacing for CRT upgrades in previously failed and high-risk patients in comparison with coronary sinus CRT upgrades

AIMS

Cardiac resynchronization therapy (CRT) upgrades may be less likely to improve following intervention. Leadless left ventricular (LV) endocardial pacing has been used for patients with previously failed CRT or high-risk upgrades. We compared procedural and long-term outcomes in patients undergoing coronary sinus (CS) CRT upgrades with high-risk and previously failed CRT upgrades undergoing LV endocardial upgrades.

METHOD AND RESULTS

Prospective consecutive CS upgrades between 2015 and 2019 were compared with those undergoing WiSE-CRT implantation. Cardiac resynchronization therapy response at 6 months was defined as improvement in clinical composite score (CCS) and a reduction in LV end-systolic volume (LVESV) ≥15%. A total of 225 patients were analysed; 121 CS and 104 endocardial upgrades. Patients receiving WiSE-CRT tended to have more comorbidities and were more likely to have previous cardiac surgery (30.9% vs. 16.5%; P = 0.012), hypertension (59.2% vs. 34.7%; P < 0.001), chronic obstructive airways disease (19.4% vs. 9.9%; P = 0.046), and chronic kidney disease (46.4% vs. 21.5%; P < 0.01) but similar LV ejection fraction (30.0 ± 8.3% vs. 29.5 ± 8.6%; P = 0.678). WiSE-CRT upgrades were successful in 97.1% with procedure-related mortality in 1.9%. Coronary sinus upgrades were successful in 97.5% of cases with a 2.5% rate of CS dissection and 5.6% lead malfunction/displacement. At 6 months, 91 WiSE-CRT upgrades and 107 CS upgrades had similar improvements in CCS (76.3% vs. 68.5%; P = 0.210) and reduction in LVESV ≥15% (54.2% vs. 56.3%; P = 0.835).

CONCLUSION

Despite prior failed upgrades and high-risk patients with more comorbidities, WiSE-CRT upgrades had high rates of procedural success and similar improvements in CCS and LV remodelling with CS upgrades.

Clinical effectiveness of a dedicated cardiac resynchronization therapy pre-assessment clinic incorporating cardiac magnetic resonance imaging and cardiopulmonary exercise testing on patient selection and outcomes

Background

Pre-procedural assessment of patients undergoing cardiac resynchronization therapy (CRT) is heterogenous and patients implanted with unfavorable characteristics may account for non-response. A dedicated CRT pre-assessment clinic (CRT PAC) was developed to standardize the review process and undertake structured pre-procedural evaluation. The aim of this analysis was to determine the effectiveness on patient selection and outcomes.

Methods

A prospective database of consecutive patients attending the CRT PAC between 2013 and 2018 was analyzed. Pre-operative assessment included cardiac magnetic resonance (CMR) and cardiopulmonary exercise testing (CPET). Patients were considered CRT responders based on improvement in clinical composite score (CCS) and/or reduction in left ventricular end-systolic volume (LVESV) ≥ 15% at 6-months follow-up.

Results

Of 252 patients reviewed in the CRT PAC during the analysis period, 192 fulfilled consensus guidelines for implantation. Of the patients receiving CRT, 82% showed improvement in their CCS and 57% had a reduction in LVESV ≥ 15%. The presence of subendocardial scar on CMR and a peak VO₂ ≤ 12 ml/kg/min on CPET predicted CRT non-response. Two patients were unsuitable for CRT as they had end-stage heart failure and died during follow-up. The majority of patients initially deemed unsuitable for CRT did not suffer from unexpected hospitalization for decompensated heart failure or died from cardiovascular disease; only 8 patients (13%) received CRT devices during follow-up because of symptomatic left ventricular systolic impairment.

Conclusion

A dedicated CRT PAC is able to appropriately select patients for CRT. Pre-procedural investigation/imaging can identify patients unlikely to respond to, or may not yet be suitable for CRT.

Leadless Left Ventricular Endocardial Pacing and Left Bundle Branch Area Pacing for Cardiac Resynchronisation Therapy

Cardiac resynchronisation therapy is an important intervention to reduce mortality and morbidity, but even in carefully selected patients approximately 30% fail to improve. This has led to alternative pacing approaches to improve patient outcomes. Left ventricular (LV) endocardial pacing allows pacing at site-specific locations that enable the operator to avoid myocardial scar and target areas of latest activation. Left bundle branch area pacing (LBBAP) provides a more physiological activation pattern and may allow effective cardiac resynchronisation. This article discusses LV endocardial pacing in detail, including the indications, techniques and outcomes. It discusses LBBAP, its potential benefits over His bundle pacing and procedural outcomes. Finally, it concludes with the future role of endocardial pacing and LBBAP in heart failure patients.

Economic evaluation of a dedicated cardiac resynchronisation therapy preassessment clinic

Introduction

Patient evaluation before cardiac resynchronisation therapy (CRT) remains heterogeneous across centres and it is suspected a proportion of patients with unfavourable characteristics proceed to implantation. We developed a unique CRT preassessment clinic (CRT PAC) to act as a final review for patients already considered for CRT. We hypothesised that this clinic would identify some patients unsuitable for CRT through updated investigations and review. The purpose of this analysis was to determine whether the CRT PAC led to savings for the National Health Service (NHS).

Methods

A decision tree model was made to evaluate two clinical pathways; (1) standard of care where all patients initially seen in an outpatient cardiology clinic proceeded directly to CRT and (2) management of patients in CRT PAC.

Results

244 patients were reviewed in the CRT PAC; 184 patients were eligible to proceed directly for implantation and 48 patients did not meet consensus guidelines for CRT so were not implanted. Following CRT, 82.4% of patients had improvement in their clinical composite score and 57.7% had reduction in left ventricular end-systolic volume ≥15%. Using the decision tree model, by reviewing patients in the CRT PAC, the total savings for the NHS was £966 880. Taking into consideration the additional cost of the clinic and by applying this model structure throughout the NHS, the potential savings could be as much as £39 million.

Conclusions

CRT PAC appropriately selects patients and leads to substantial savings for the NHS. Adopting this clinic across the NHS has the potential to save £39 million.