Cardiac resynchronization therapy-heart failure (CRT-HF) clinic: A novel model of care

Multiprofessional heart failure self-development framework

OBJECTIVE

Heart failure remains a key public health priority across the globe. The median age of people with heart failure admitted to hospital in the UK is 81 years old. Many such patients transcend the standard interventions that are well characterised and evidenced in guidelines, into holistic aspects surrounding frailty, rehabilitation and social care. Previous published competency frameworks in heart failure have focused on the value of doctors, nurses and pharmacists. We aimed to provide an expert consensus on the minimum heart failure-specific competencies necessary for multiple different healthcare professionals, including physiotherapists, occupational therapists, dietitians and cardiac physiologists.

METHODS

The document has been developed focussing on four main parts, (1) establishing a project working group of expert professionals, (2) a literature review of previously existing published curricula and competency frameworks, (3) consensus building, which included developing a structure to the framework with ongoing review of the contents to adapt and be inclusive for each specialty and (4) write up and dissemination to widen the impact of the project.

RESULTS

The final competency framework displays competencies across seven sections; knowledge (including subheadings on heart failure syndrome, diagnosis and clinical management); general skills; heart failure-specific skills; clinical autonomy; multidisciplinary team working; teaching and education; and research and development.

CONCLUSION

People with heart failure can be complex and have needs that require input from a broad range of specialties. This publication focuses on the vital impact of wider multidisciplinary groups and should help define the generic core heart failure-specific competencies needed to support future pipelines of professionals, who regularly interact with and deliver care for patients with heart failure.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

Long-term outcomes in nonprogressors to cardiac resynchronization therapy

BACKGROUND

Among patients with heart failure undergoing cardiac resynchronization therapy (CRT), patients with a minimal change in left ventricular ejection fraction (LVEF) have recently been defined as "nonprogressors" rather than as "nonresponders." Little is known regarding long-term outcomes of nonprogressors.

OBJECTIVE

We sought to evaluate outcomes in patients undergoing CRT on the basis of echocardiographically determined response status.

METHODS

We reviewed the medical charts of patients with an LVEF of ≤35% and a QRS duration of ≥120 ms undergoing CRT at the Cleveland Clinic, Johns Hopkins Hospital, and Johns Hopkins Bayview Medical Center between 2003 and 2014. Response to CRT was defined on the basis of LVEF change as follows: super-responders ≥20%, responders 6%-19%, nonprogressors 0%-5%, and progressors <0%. Survival free of left ventricular assist device (LVAD) implantation and heart transplantation was compared on the basis of response classification.

RESULTS

A total of 1058 patients were included and had a mean follow-up 8.7 ± 5.4 years, over which time there were 606 end points (37 LVAD implants, 32 heart transplants, and 537 deaths). Survival free of LVAD and heart transplant differed significantly between response groups after CRT both in the mid-term (4 years) and in the long-term (8.7 ± 5.4 years), with super-responders achieving the best outcomes and progressors the worst (P < .001). In multivariate analysis, nonprogressors had superior outcomes to progressors (P = .02) at 4 years of follow-up. Over the duration of follow-up (8.7 ± 5.4 years), there was no significant difference in survival between those 2 groups (P = .18).

CONCLUSION

Nonprogressors to CRT have superior medium-term outcomes but similar long-term outcomes to progressors and inferior outcomes to responders and super-responders.

The Translation and Commercialisation of Biomarkers for Cardiovascular Disease—A Review

As a leading cause of mortality and morbidity worldwide, cardiovascular disease and its diagnosis, quantification, and stratification remain significant health issues. Increasingly, patients present with cardiovascular disease in the absence of known risk factors, suggesting the presence of yet unrecognized pathological processes and disease predispositions. Fortunately, a host of emerging cardiovascular biomarkers characterizing and quantifying ischaemic heart disease have shown great promise in both laboratory settings and clinical trials. These have demonstrated improved predictive value additional to widely accepted biomarkers as well as providing insight into molecular phenotypes beneath the broad umbrella of cardiovascular disease that may allow for further personalized treatment regimens. However, the process of translation into clinical practice – particularly navigating the legal and commercial landscape – poses a number of challenges. Practical and legal barriers to the biomarker translational pipeline must be further considered to develop strategies to bring novel biomarkers into the clinical sphere and apply these advances at the patient bedside. Here we review the progress of emerging biomarkers in the cardiovascular space, with particular focus on those relevant to the unmet needs in ischaemic heart disease.

What Have We Learned in the Last 20 Years About CRT Non-Responders?

Although cardiac resynchronization therapy (CRT) has become well established in the treatment of heart failure, the management of patients who do not respond after CRT remains a key challenge. This review will summarize what we have learned about non-responders over the last 20 years and discuss methods for optimizing response, including the introduction of novel therapies.

Case Studies of Cardiac Resynchronization Therapy "Nonresponders"

Outcomes following cardiac resynchronization therapy (CRT) vary widely, with some patients experiencing normalization of left ventricular function to some who seem to be harmed by biventricular pacing. The care of CRT patients postoperatively is complex and requires input from physicians specializing in electrophysiology, heart failure, and often cardiac imaging. In this section, cases of apparent CRT suboptimal response from a dedicated CRT optimization clinic are presented.

Female Gender Is Associated with an Increased Left Ventricular Ejection Fraction Recovery in Patients with Heart Failure with Reduced Ejection Fraction

We performed a systematic review and meta-analysis to evaluate the association whether the female gender was associated with an increased chance of left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction (HFrEF). We searched the databases of MEDLINE and EMBASE from inception to 18 January 2022. Included studies were published studies evaluating or reporting characteristics of patients with HF with recovered LVEF. Data from each study were combined using a random-effects model, the generic inverse variance method of DerSimonian and Laird, to calculate odd ratios (OR) and 95% confidence intervals (CI). Eighteen studies were included in the analysis with a total of 12,270 patients (28.2% female). Female gender was associated with an increased chance of LVEF recovery (pooled OR = 1.50, 95% CI = 1.21−1.86, p-value < 0.001, I2 = 74.5%). In our subgroup analysis, female gender was associated with an increased chance of LVEF recovery when defined as LVEF > 50% (pooled OR = 1.78, 95% CI = 1.45−2.18, p-value < 0.001, I2 = 0.0%), and LVEF > 40−45% (pooled OR = 1.45, 95% CI = 1.09−1.91, p-value = 0.009, I2 = 79.2%), but not in LVEF > 35 (OR = 2.18, 95% CI = 0.94−5.05, p-value = 0.06). Our meta-analysis demonstrated that the female gender is associated with an increased chance of LVEF recovery. This association was not statistically significant in the subgroup that defined LVEF recovery as LVEF > 35%.

The Response to Cardiac Resynchronization Therapy in LMNA cardiomyopathy

AIMS

Cardiac implantable electronic device (CIED) therapy is fundamental to the management of LMNA-cardiomyopathy due to the high frequency of atrioventricular block and ventricular tachyarrhythmias. We aim to define the role of cardiac resynchronization therapy (CRT) in impacting heart failure in LMNA-cardiomyopathy.

METHODS AND RESULTS

From 9 referral centers, LMNA-cardiomyopathy patients who underwent CRT with available pre- and post- echocardiograms were identified retrospectively. Factors associated with CRT response were identified [defined as improvement in left ventricular ejection fraction (LVEF) ≥5% 6-months post-implant] and the associated impact on the primary outcome of death, implantation of a left ventricular assist device or cardiac transplantation was assessed. We identified 105 patients (51±10 years) undergoing CRT, including 70 (67%) who underwent CRT as a CIED upgrade. The mean change in LVEF ~6 months post CRT was +4±9%. A CRT response occurred in 40 (38%) patients and was associated with lower baseline LVEF or a high percentage of right ventricular pacing prior to CRT in patients with pre-existing CIED. In patients with an ESC Class I guideline indication for CRT, response rates were 61%. A CRT response was evident at thresholds of LVEF ≤45% or percent pacing ≥50%. There was a 1.3 year estimated median difference in event-free survival in those who responded to CRT (p=0.04).

CONCLUSION

Systolic function improves in patients with LMNA-cardiomyopathy who undergo CRT, especially with strong guideline indications for implantation. Post CRT improvements in LVEF are associated with survival benefits in this population with otherwise limited options.

The importance of early evaluation after cardiac resynchronization therapy to redefine response: Pooled individual patient analysis from 5 prospective studies

BACKGROUND

Cardiac resynchronization therapy (CRT) reduces mortality and improves outcomes in appropriately selected patients with heart failure (HF); however, response may vary.

OBJECTIVE

We sought to correlate 6-month CRT response assessed by clinical composite score (CCS) and left ventricular end-systolic volume index (LVESVi) with longer-term mortality and HF hospitalizations.

METHODS

Individual patient data from 5 prospective CRT studies-MIRACLE, MIRACLE ICD, InSync III Marquis, PROSPECT, and Adaptive CRT-were pooled. Classification of CRT response status using CCS and LVESVi were made at 6 months. Kaplan-Meier analyses were used to assess time to mortality. Cox proportional hazards regression models were used to compute hazard ratios (HRs) for the 3 levels of CRT response: improved, stabilized, and worsened. Adjusted models controlled for baseline factors known to influence both CRT response and mortality. HF-related hospitalization was compared between CRT response categories using incidence rate ratios.

RESULTS

Among a total of 1603 patients, 1426 and 1165 were evaluated in the CCS and LVESVi outcome assessments, respectively. Mortality was significantly lower for patients in the improved (CCS: HR 0.22; 95% confidence interval [CI] 0.15-0.31; LVESVi: HR 0.40; 95% CI 0.27-0.60) and stabilized (CCS: HR 0.38; 95% CI 0.24-0.61; LVESVi: HR 0.41; 95% CI 0.25-0.68) groups than in the worsened group for both measures after adjusting for potential confounders.

CONCLUSION

Patients with a worsened CRT response status have a high mortality rate and HF hospitalizations. Stabilized patients have a more favorable prognosis than do worsened patients and thus should not be considered CRT nonresponders.

Using Machine-Learning for Prediction of the Response to Cardiac Resynchronization Therapy: The SMART-AV Study

OBJECTIVES

This study aimed to apply machine learning (ML) to develop a prediction model for short-term cardiac resynchronization therapy (CRT) response to identifying CRT candidates for early multidisciplinary CRT heart failure (HF) care.

BACKGROUND

Multidisciplinary optimization of cardiac resynchronization therapy (CRT) delivery can improve long-term CRT outcomes but requires substantial staff resources.

METHODS

Participants from the SMART-AV (SmartDelay-Determined AV Optimization: Comparison of AV Optimization Methods Used in Cardiac Resynchronization Therapy [CRT]) trial (n = 741; age: 66 ± 11 years; 33% female; 100% New York Heart Association HF class III-IV; 100% ejection fraction ≤35%) were randomly split into training/testing (80%; n = 593) and validation (20%; n = 148) samples. Baseline clinical, electrocardiographic, echocardiographic, and biomarker characteristics, and left ventricular (LV) lead position (43 variables) were included in 8 ML models (random forests, convolutional neural network, lasso, adaptive lasso, plugin lasso, elastic net, ridge, and logistic regression). A composite of freedom from death and HF hospitalization and a >15% reduction in LV end-systolic volume index at 6 months after CRT was the end point.

RESULTS

The primary end point was met by 337 patients (45.5%). The adaptive lasso model was the most more accurate (area under the receiver operating characteristic curve: 0.759; 95% confidence interval [CI]: 0.678-0.840), well calibrated, and parsimonious (19 predictors; nearly half potentially modifiable). Participants in the 5th quintile compared with those in the 1st quintile of the prediction model had 14-fold higher odds of composite CRT response (odds ratio: 14.0; 95% CI: 8.0-14.4). The model predicted CRT response with 70% accuracy, 70% sensitivity, and 70% specificity, and should be further validated in prospective studies.

CONCLUSIONS

ML predicts short-term CRT response and thus may help with CRT procedure and early post-CRT care planning. (SmartDelay-Determined AV Optimization: A Comparison of AV Optimization Methods Used in Cardiac Resynchronization Therapy [CRT] [SMART-AV]; NCT00677014).

Optimized implementation of cardiac resynchronization therapy: a call for action for referral and optimization of care

Cardiac resynchronization therapy (CRT) is one of the most effective therapies for heart failure with reduced ejection fraction and leads to improved quality of life, reductions in heart failure hospitalization rates and all-cause mortality. Nevertheless, up to two-thirds of eligible patients are not referred for CRT. Furthermore, post-implantation follow-up is often fragmented and suboptimal, hampering the potential maximal treatment effect. This joint position statement from three European Society of Cardiology Associations, Heart Failure Association (HFA), European Heart Rhythm Association (EHRA) and European Association of Cardiovascular Imaging (EACVI), focuses on optimized implementation of CRT. We offer theoretical and practical strategies to achieve more comprehensive CRT referral and post-procedural care by focusing on four actionable domains: (i) overcoming CRT under-utilization, (ii) better understanding of pre-implant characteristics, (iii) abandoning the term 'non-response' and replacing this by the concept of disease modification, and (iv) implementing a dedicated post-implant CRT care pathway.

Optimized implementation of cardiac resynchronization therapy: a call for action for referral and optimization of care: A joint position statement from the Heart Failure Association (HFA), European Heart Rhythm Association (EHRA), and European Association of Cardiovascular Imaging (EACVI) of the European Society of Cardiology

Cardiac resynchronization therapy (CRT) is one of the most effective therapies for heart failure with reduced ejection fraction and leads to improved quality of life, reductions in heart failure hospitalization rates and all-cause mortality. Nevertheless, up to two-thirds of eligible patients are not referred for CRT. Furthermore, post-implantation follow-up is often fragmented and suboptimal, hampering the potential maximal treatment effect. This joint position statement from three European Society of Cardiology Associations, Heart Failure Association (HFA), European Heart Rhythm Association (EHRA) and European Association of Cardiovascular Imaging (EACVI), focuses on optimized implementation of CRT. We offer theoretical and practical strategies to achieve more comprehensive CRT referral and post-procedural care by focusing on four actionable domains: (i) overcoming CRT under-utilization, (ii) better understanding of pre-implant characteristics, (iii) abandoning the term 'non-response' and replacing this by the concept of disease modification, and (iv) implementing a dedicated post-implant CRT care pathway.

Development and implementation of a cardiac resynchronisation therapy care pathway: improved process and reduced resource use

Background

Cardiac resynchronisation therapy (CRT) requires intensive, complex and multidisciplinary care to maximize the clinical benefit. In current practice this is typically a task for highly specialised physicians. We report on a novel multidisciplinary, standardised CRT care pathway (CRT-CPW). Experienced clinicians developed a CPW with simple and broadly applicable aids based on clinical evidence and identified shortcomings in the current CRT care. The resulting CPW was implemented at the Maastricht University Medical Center, aiming at a transfer from heterogeneous physician-led care to standardized nurse-led care.

Methods

Two CRT patient cohorts were compared in this analysis. The benchmarked usual care cohort (2012–2014, 122 patients) was compared with the CRT-CPW cohort (2015–2017, 115 patients). The primary outcomes were process-related: number of physician consultations, nurse consultations, length of stay (LOS) at implantation and total hospitalisation days during 1-year follow-up, and referral-to-treatment time. Clinical outcomes were assessed to adress non-inferiority of quality of care.

Results

Patients in the CRT-CPW cohort consulted nurses and technicians significantly more often than patients in the usual care cohort (2.4±1.5 vs 1.7±2.0, p<0.0001 and 4.3±2.5 vs 3.7±1.5, p=0.063, respectively). Patients with CRT-CPW consulted physicians significantly less often (1.7±1.4 vs 2.6±2.1, p<0.001). Referral to treatment time was significantly reduced in the CRT-CPW group (23.6±18.4 vs 37.0±26.3 days, p=0.002). LOS at implantation and total hospitalisation days were significantly reduced in the CRT-CPW group (1.1±1.2 vs 1.5±0.7 days, p<0.0001 and 2.4±4.8 vs 4.8±9.3, p<0.0001, respectively). Clinical outcome analyses showed no significant difference in 12-month all-cause mortality and heart failure hospitalisations.

Conclusion

The introduction of a novel CRT-CPW resulted in a successful transition of physician-led to nurse-led care, with a significantly reduced resource use and equal clinical outcomes. Future evaluations will focus on impact on outcomes versus costs, to evaluate cost-effectiveness of the CRT-CPW.

Remote Hemodynamic-Guided Therapy of Patients With Recurrent Heart Failure Following Cardiac Resynchronization Therapy

Background

Patients with recurring heart failure (HF) following cardiac resynchronization therapy fare poorly. Their management is undecided. We tested remote hemodynamic‐guided pharmacotherapy.

Methods and Results

We evaluated cardiac resynchronization therapy subjects included in the CHAMPION (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in New York Heart Association Class III Heart Failure Patients) trial, which randomized patients with persistent New York Heart Association Class III symptoms and ≥1 HF hospitalization in the previous 12 months to remotely managed pulmonary artery (PA) pressure‐guided management (treatment) or usual HF care (control). Diuretics and/or vasodilators were adjusted conventionally in control and included remote PA pressure information in treatment. Annualized HF hospitalization rates, changes in PA pressures over time (analyzed by area under the curve), changes in medications, and quality of life (Minnesota Living with Heart Failure Questionnaire scores) were assessed. Patients who had cardiac resynchronization therapy (n=190, median implant duration 755 days) at enrollment had poor hemodynamic function (cardiac index 2.00±0.59 L/min per m²), high comorbidity burden (67% had secondary pulmonary hypertension, 61% had estimated glomerular filtration rate <60 mL/min per 1.73 m²), and poor Minnesota Living with Heart Failure Questionnaire scores (57±24). During 18 months randomized follow‐up, HF hospitalizations were 30% lower in treatment (n=91, 62 events, 0.46 events/patient‐year) versus control patients (n=99, 93 events, 0.68 events/patient‐year) (hazard ratio, 0.70; 95% CI, 0.51–0.96; P=0.028). Treatment patients had more medication up‐/down‐titrations (847 versus 346 in control, P<0.001), mean PA pressure reduction (area under the curve −413.2±123.5 versus 60.1±88.0 in control, P=0.002), and quality of life improvement (Minnesota Living with Heart Failure Questionnaire decreased −13.5±23 versus −4.9±24.8 in control, P=0.006).

Conclusions

Remote hemodynamic‐guided adjustment of medical therapies decreased PA pressures and the burden of HF symptoms and hospitalizations in patients with recurring Class III HF and hospitalizations, beyond the effect of cardiac resynchronization therapy.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00531661.

Machine Learning of 12-Lead QRS Waveforms to Identify Cardiac Resynchronization Therapy Patients With Differential Outcomes

BACKGROUND

Cardiac resynchronization therapy (CRT) improves heart failure outcomes but has significant nonresponse rates, highlighting limitations in ECG selection criteria: QRS duration (QRSd) ≥150 ms and subjective labeling of left bundle branch block (LBBB). We explored unsupervised machine learning of ECG waveforms to identify CRT subgroups that may differentiate outcomes beyond QRSd and LBBB.

METHODS

We retrospectively analyzed 946 CRT patients with conduction delay. Principal component analysis (PCA) dimensionality reduction obtained a 2-dimensional representation of preCRT 12-lead QRS waveforms. k-means clustering of the 2-dimensional PCA representation of 12-lead QRS waveforms identified 2 patient subgroups (QRS PCA groups). Vectorcardiographic QRS area was also calculated. We examined following 2 primary outcomes: (1) composite end point of death, left ventricular assist device, or heart transplant, and (2) degree of echocardiographic left ventricular ejection fraction (LVEF) change after CRT.

RESULTS

Compared with QRS PCA Group 2 (n=425), Group 1 (n=521) had lower risk for reaching the composite end point (HR, 0.44 [95% CI, 0.38-0.53]; P<0.001) and experienced greater mean LVEF improvement (11.1±11.7% versus 4.8±9.7%; P<0.001), even among patients with LBBB with QRSd ≥150 ms (HR, 0.42 [95% CI, 0.30-0.57]; P<0.001; mean LVEF change 12.5±11.8% versus 7.3±8.1%; P=0.001). QRS area also stratified outcomes but had significant differences from QRS PCA groups. A stratification scheme combining QRS area and QRS PCA group identified patients with LBBB with similar outcomes to non-LBBB patients (HR, 1.32 [95% CI, 0.93-1.62]; difference in mean LVEF change: 0.8% [95% CI, -2.1% to 3.7%]). The stratification scheme also identified patients with LBBB with QRSd <150 ms with comparable outcomes to patients with LBBB with QRSd ≥150 ms (HR, 0.93 [95% CI, 0.67-1.29]; difference in mean LVEF change: -0.2% [95% CI, -2.7% to 3.0%]).

CONCLUSIONS

Unsupervised machine learning of ECG waveforms identified CRT subgroups with relevance beyond LBBB and QRSd. This method may assist in objective classification of bundle branch block morphology in CRT.