Response to cardiac resynchronization therapy: is it time to expand the criteria?

Noninvasive Electrical Mapping Compared with the Paced QRS Complex for Optimizing CRT Programmed Settings and Predicting Multidimensional Response

The aim was to test the hypothesis that left ventricular (LV) and right ventricular (RV) activation from body surface electrical mapping (CardioInsight 252-electrode vest, Medtronic) identifies optimal cardiac resynchronization therapy (CRT) pacing strategies and outcomes in 30 patients. The LV80, RV80, and BIV80 were defined as the times to 80% LV, RV, or biventricular electrical activation. Smaller differences in the LV80 and RV80 (|LV80-RV80|) with synchronized LV pacing predicted better LV function post-CRT (p = 0.0004) than the LV-paced QRS duration (p = 0.32). Likewise, a lower RV80 was associated with a better pre-CRT RV ejection fraction by CMR (r =  - 0.40, p = 0.04) and predicted post-CRT improvements in myocardial oxygen uptake (p = 0.01) better than the biventricular-paced QRS (p = 0.38), while a lower LV80 with BIV pacing predicted lower post-CRT B-type natriuretic peptide (BNP) (p = 0.02). RV pacing improved LV function with smaller |LV80-RV80| (p = 0.009). In conclusion, 3-D electrical mapping predicted favorable post-CRT outcomes and informed effective pacing strategies.

The Use of Machine Learning Algorithms in the Evaluation of the Effectiveness of Resynchronization Therapy

Background: Cardiovascular disease remains the leading cause of death in the European Union and worldwide. Constant improvement in cardiac care is leading to an increased number of patients with heart failure, which is a challenging condition in terms of clinical management. Cardiac resynchronization therapy is becoming more popular because of its grounded position in guidelines and clinical practice. However, some patients do not respond to treatment as expected. One way of assessing cardiac resynchronization therapy is with ECG analysis. Artificial intelligence is increasing in terms of everyday usability due to the possibility of everyday workflow improvement and, as a result, shortens the time required for diagnosis. A special area of artificial intelligence is machine learning. AI algorithms learn on their own based on implemented data. The aim of this study was to evaluate using artificial intelligence algorithms for detecting inadequate resynchronization therapy. Methods: A total of 1241 ECG tracings were collected from 547 cardiac department patients. All ECG signals were analyzed by three independent cardiologists. Every signal event (QRS-complex) and rhythm was manually classified by the medical team and fully reviewed by additional cardiologists. The results were divided into two parts: 80% of the results were used to train the algorithm, and 20% were used for the test (Cardiomatics, Cracow, Poland). Results: The required level of detection sensitivity of effective cardiac resynchronization therapy stimulation was achieved: 99.2% with a precision of 92.4%. Conclusions: Artificial intelligence algorithms can be a useful tool in assessing the effectiveness of resynchronization therapy.

Contemporary ICD Use in Patients with Heart Failure

Despite constant breakthroughs in heart failure (HF) therapy, the population of HF patients resume to grow and is linked to increased mortality and morbidity. Ventricular arrhythmias (VA) are one of the leading causes of mortality in HF subjects. Implantable cardioverter-defibrillators (ICDs) are currently the gold standard in treatment, preventing arrhythmic sudden cardiac death (SCD) episodes. However, the death rates related to HF remain elevated, as not all HF subjects benefit equally. Cardiac resynchronization therapy (CRT) has emerged as a novel approach for HF patients. These devices have been thoroughly investigated in major randomized controlled studies but continue to be underutilized in various countries. This review discusses the use of ICD in HF populations on top of treatments.

Machine learning versus conventional clinical methods in guiding management of heart failure patients-a systematic review

Machine learning (ML) algorithms “learn” information directly from data, and their performance improves proportionally with the number of high-quality samples. The aim of our systematic review is to present the state of the art regarding the implementation of ML techniques in the management of heart failure (HF) patients. We manually searched MEDLINE and Cochrane databases as well the reference lists of the relevant review studies and included studies. Our search retrieved 122 relevant studies. These studies mainly refer to (a) the role of ML in the classification of HF patients into distinct categories which may require a different treatment strategy, (b) discrimination of HF patients from the healthy population or other diseases, (c) prediction of HF outcomes, (d) identification of HF patients from electronic records and identification of HF patients with similar characteristics who may benefit form a similar treatment strategy, (e) supporting the extraction of important data from clinical notes, and (f) prediction of outcomes in HF populations with implantable devices (left ventricular assist device, cardiac resynchronization therapy). We concluded that ML techniques may play an important role for the efficient construction of methodologies for diagnosis, management, and prediction of outcomes in HF patients.

Clinical Usefulness of N-terminal Prohormone of Brain Natriuretic Peptide and High Sensitivity Troponin T in Patients with Heart Failure Undergoing Cardiac Resynchronization Therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) is a valuable intracardiac device--based treatment option for a subgroup of patients with advanced heart failure (HF) and QRS prolongation. However, still a significant proportion of patients do not benefit from CRT implantation, labeled as non-responders.

OBJECTIVES

The aim of the present study was to evaluate the N-terminal prohormone of brain natriuretic peptide (NT-pro BNP) and high sensitivity troponin T (cTnThs) value as predictors of CRT response in a 12-month observation.

MATERIALS AND METHODS

The study included 46 patients with HF and implanted CRT-D. Levels of NT-pro BNP and cTnThs were assessed during a 12 month follow up.

RESULTS

46 consecutive patients (76% men) with a mean age of 64±8 were observed for 12 months. The CRT response criteria was met by 26 patients (56,5%). A significant decline in the NT-pro BNP concentrations was documented in responders (p=0.001). Moreover, ΔNT-pro BNP by at least 579 pg/ml had high sensitivity and specificity for identifying the CRT responders. There were no statistically significant differences in the results of cTnThs between the two study groups.

CONCLUSION

The relative change in the level of NT-pro BNP by at least 43,5% allows to identify the responders to CRT after 12 months of follow-up. Serial measurements of NT-pro BNP can be a valuable tool for monitoring the effectiveness of CRT.

Devices in Heart Failure Patients-Who Benefits From ICD and CRT?

Despite advances in heart failure treatment, this condition remains a relevant medical issue and is associated with a high morbidity and mortality. The cause of death in patients suffering from heart failure is not only a result of hemodynamic failure, but can also be due to ventricular arrhythmias. Implantable cardioverter defibrillators (ICDs) are these days the only tool to significantly reduce arrhythmic sudden death; but not all patients benefit to the same extend. In addition, cardiac resynchronization therapy (CRT) is another tool which is used in patients suffering from heart fialure. Even though both devices have been investigated in large randomized trials, both ICD and CRT remain underutilized in many countries. This brief review focuses on various aspects in this regard including a short overview on upcoming device novelties in the near future.

Device Management in Heart Failure

PURPOSE OF REVIEW

Medical devices have become an integral part of comprehensive heart failure management. Not all heart failure patients, however, accrue benefit from every new device, and even with extensive practice guidelines, this remains an evolving field.

RECENT FINDINGS

The addition of implantable devices, like internal cardioverter defibrillators (ICDs), and novel pacing technologies, including cardiac resynchronization therapy (CRT), have helped to compliment goal-directed medical therapy and positively impact prognosis in multiple high-quality clinical trials. This review attempts to summarize the rapidly evolving literature with respect to existing device guidelines for routine implantable devices as well as some available and future technologies that are not yet a part of routine guidelines. ICD, CRT, and other implantable devices continue to save lives, decrease hospitalizations, and evolve the management of patients with heart failure beyond the capabilities of optimal guideline-directed medical therapy alone.

Overview of implantable cardioverter defibrillator and cardiac resynchronisation therapy in heart failure management

Clinical trials have established the benefits of implantable cardioverter defibrillators (ICDs) and cardiac resynchronisation therapy (CRT) in the treatment of heart failure patients. As adjuncts to guideline-directed medical therapy, ICDs confer mortality benefits from sudden cardiac arrest, while CRT reduces mortality, hospitalisation rates and improves functional capacity. This review discusses the use of ICDs and CRT devices in heart failure management, outlining the evidence supporting their use, indications and contraindications.

Fragmented QRS as a Marker of Electrical Dyssynchrony to Predict Inter-Ventricular Conduction Defect by Subsequent Echocardiographic Assessment in Symptomatic Patients of Non-Ischemic Dilated Cardiomyopathy

Background

Left ventricular (LV) dyssynchrony frequently occurs in patients with heart failure (HF). QRS ≥ 120 ms is a surrogate marker of electrical dyssynchrony, which occurs in only 30% of HF patients. In contrary, in those with normal QRS (nQRS) duration, LV dyssynchrony has been reported in 20-50%. This study was carried out to investigate the role of fragmented QRS (fQRS) on the surface electrocardiography (ECG) as a marker of electrical dyssynchrony to predict the presence of significant intraventricular dyssynchrony (IVD) by subsequent echocardiographic assessment.

Methods

A total of 226 consecutive patients with non-ischemic cardiomyopathy were assessed for fQRS on surface ECG as defined by presence of an additional R wave (R prime), notching in nadir of the S wave, notching of R wave, or the presence of more than one R prime (fragmentation) in two contiguous leads corresponding to a major myocardial segment. Tissue Doppler imaging (TDI) was performed in the apical views (four-chamber, two-chamber and long-axis) to analyze all 12 segments at both basal and middle levels. Time-to-peak myocardial sustained systolic (Ts) velocities were calculated. Significant systolic IVD was defined as Ts-SD > 32.6 ms as known as “Yu index”.

Result

Of the total patients, 112 had fQRS (49.5%), while 114 had nQRS (50.5%) with male dominance (M/F = 71:29). Majority of patients were in NYHA class II (n = 122, 54%) followed by class III (n = 83; 37%), and class IV (n = 21; 9%). There were no significant differences among both groups for baseline parameters except higher QRS duration (102.42 ± 14.05 vs. 91.10 ± 13.75 ms; P = 0.001), higher Yu index (35.64 ± 12.79 vs. 20.45 ± 11.17; P = 0.01) and number of patients with positive Yu index (78.6% vs. 21.1%; P = 0.04) in group with fQRS compared with group with nQRS. fQRS complexes had 84.61% sensitivity and 80.32% specificity with positive predictive value of 78.6% and negative predictive value of 85.9% to detect IVD. On detailed segmental analysis for fQRS distribution, inferior segment had maximum (37%), followed by anterior (23%), lateral (19%), inferior and lateral (11%), anterior and inferior (8%), and anterior and lateral (2%). Among 104 patients with significant dyssynchrony, 88 patients (84.6%) had fQRS in the dyssynchronic segment.

Conclusion

Fragmentation of QRS complex is an important predictor of electro-mechanical dyssynchrony. It is also helpful in localizing the dyssynchronous segment. In future, larger studies may be carried out to investigate the role of fQRS as a predictor of response to cardiac resynchronization therapy (CRT) in this subgroup of HF patients with narrow QRS.

Patient-reported health status prior to cardiac resynchronisation therapy identifies patients at risk for poor survival and prolonged hospital stays

Background

Patient-reported factors have largely been neglected in search of predictors of response to cardiac resynchronisation therapy (CRT). The current study aimed to examine the independent value of pre-implantation patient-reported health status in predicting four-year survival and cardiac-related hospitalisation of CRT patients.

Methods

Consecutive patients (N = 139) indicated to receive a first-time CRT-defibrillator at the University Medical Center Utrecht were asked to complete a set of questionnaires prior to implantation. The Kansas City Cardiomyopathy Questionnaire (KCCQ) was used to assess heart failure-specific health status. Data on patients’ demographic, clinical and psychological characteristics at baseline, and on cardiac-related hospitalisations and all-cause deaths during a median follow-up of 3.9 years were obtained from purpose-designed questionnaires and patients’ medical records.

Results

Results of multivariable Cox regression analyses showed that poor patient-reported health status (KCCQ score < 50) prior to implantation was associated with a 2.5-fold increased risk of cardiac hospitalisation or all-cause death, independent of sociodemographic, clinical and psychological risk factors (adjusted hazard ratio 2.46, 95 % confidence interval (CI) 1.30–4.65). Poor health status was not significantly associated with the absolute number of cardiac-related hospital admissions, but with the total number of days spent in hospital during follow-up (adjusted incidence rate ratio 3.20, 95 % CI 1.88–5.44).

Conclusions

Patient-reported health status assessed prior to CRT identifies patients at risk for poor survival and prolonged hospital stays, independent of traditional risk factors. These results emphasise the importance of incorporating health status measures in cardiovascular research and patient management. Heart failure patients reporting poor health status should be identified and offered appropriate additional treatment programs.

Distinct trajectories of disease-specific health status in heart failure patients undergoing cardiac resynchronization therapy

Purpose

It is well known that a significant proportion of heart failure patients (10–44 %) do not show improvement in symptoms or functioning from cardiac resynchronization therapy (CRT), yet no study has examined patient-reported health status trajectories after implantation.

Methods

A cohort of 139 patients with a CRT-defibrillator (70 % men; age 65.7 ± 10.1 years) completed the Kansas City Cardiomyopathy Questionnaire (KCCQ) prior to implantation (baseline) and at 2, 6, and 12–14 months post-implantation. Latent class analyses were used to identify trajectories and associates of disease-specific health status over time.

Results

All health status trajectories showed an initial small to large improvement from baseline to 2-month follow-up, whereafter most trajectories displayed a stable pattern between short- and long-term follow-up. Low educational level, NYHA class III/IV, smoking, no use of beta-blockers, use of psychotropic medication, anxiety, depression, and type D personality were found to be associated with poorer health status in unadjusted analyses. Interestingly, subgroups of patients (12–20 %) who experienced poor health status at baseline improved to stable good health status levels after implantation.

Conclusions

Levels of disease-specific health status vary considerably across subgroups of CRT-D patients. Classification into poorer disease-specific health status trajectories was particularly associated with patients’ psychological profile and NYHA classification. The timely identification of CRT-D patients who present with poor disease-specific health status (i.e., KCCQ score < 50) and a distressed psychological profile (i.e., anxiety, depression, and/or type D personality) is paramount, as they may benefit from cardiac rehabilitation in combination with psychological intervention.

Relationship Between Reverse Remodeling and Cardiopulmonary Exercise Capacity in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

BACKGROUND

Studies on the relationship between left ventricular reverse remodeling and cardiopulmonary exercise capacity in heart failure patients undergoing cardiac resynchronization therapy (CRT) are scarce and inconclusive.

METHODS AND RESULTS

Eighty-four patients with a 1st-time CRT-defibrillator (mean age 65 ± 11; 73% male) underwent echocardiography and cardiopulmonary exercise testing (CPX) before implantation (baseline) and 6 months after implantation. At baseline, patients also completed a set of questionnaires measuring mental and physical health. The association between echocardiographic response (left ventricular end-systolic volume decrease ≥15%) and a comprehensive set of CPX results was examined. Echocardiographic responders (54%) demonstrated higher peak oxygen consumption and better exercise performance than nonresponders at baseline and at 6-month follow-up. Furthermore, only echocardiographic responders showed improvements in ventilatory efficiency during follow-up. Multivariable repeated measures analyses revealed that, besides reverse remodeling, New York Heart Association functional class II and good patient-reported health status before implantation were the most important correlates of higher average oxygen consumption during exercise, and that nonischemic etiology and smaller pre-implantation QRS width were associated with better ventilatory efficiency over time.

CONCLUSIONS

During the first 6 months of CRT there was a significant positive association between reverse remodeling and cardiopulmonary exercise capacity.

Prediction of response to cardiac resynchronization therapy using left ventricular pacing lead position and cardiovascular magnetic resonance derived wall motion patterns: a prospective cohort study

BACKGROUND

Despite marked benefits in many heart failure patients, a considerable proportion of patients treated with cardiac resynchronization therapy (CRT) fail to respond appropriately. Recently, a "U-shaped" (type II) wall motion pattern identified by cardiovascular magnetic resonance (CMR) has been associated with improved CRT response compared to a homogenous (type I) wall motion pattern. There is also evidence that a left ventricular (LV) lead localized to the latest contracting LV site predicts superior response, compared to an LV lead localized remotely from the latest contracting LV site.

METHODS

We prospectively evaluated patients undergoing CRT with pre-procedural CMR to determine the presence of type I and type II wall motion patterns and pre-procedural echocardiography to determine end systolic volume (ESV). We assessed the final LV lead position on post-procedural fluoroscopic images to determine whether the lead was positioned concordant to or remote from the latest contracting LV site. CRT response was defined as a ≥ 15% reduction in ESV on a 6 month follow-up echocardiogram.

RESULTS

The study included 33 patients meeting conventional indications for CRT with a mean New York Heart Association class of 2.8 ± 0.4 and mean LV ejection fraction of 28 ± 9%. Overall, 55% of patients were echocardiographic responders by ESV criteria. Patients with both a type II pattern and an LV lead concordant to the latest contracting site (T2CL) had a response rate of 92%, compared to a response rate of 33% for those without T2CL (p = 0.003). T2CL was the only independent predictor of response on multivariate analysis (odds ratio 18, 95% confidence interval 1.6-206; p = 0.018). T2CL resulted in significant incremental improvement in prediction of echocardiographic response (increase in the area under the receiver operator curve from 0.69 to 0.84; p = 0.038).

CONCLUSIONS

The presence of a type II wall motion pattern on CMR and a concordant LV lead predicts superior CRT response. Improving patient selection by evaluating wall motion pattern and targeting LV lead placement may ultimately improve the response rate to CRT.

The role of the fragmented QRS complexes on a routine 12-lead ECG in predicting non-responsiveness to cardiac resynchronization therapy

Objective:

Cardiac resynchronization therapy (CRT) is introduced as a promising therapeutic option in heart failure (HF) patients with ventricular dyssynchrony. The challenge, however, is identifying the patients who are suitable candidates for this procedure. Fragmented QRS (fQRS) is associated with subendocardial fibrosis and myocardial scars. In this study, we aimed to evaluate the role of fragmented QRS complex on a routine 12-lead ECG as a predictor of response to CRT.

Methods:

Sixty-five consecutive patients with HF who underwent CRT, were studied. Patients’ resting 12-lead ECGs were analyzed to find presence of fQRS by a cardiologist. Echocardiographic response to CRT was defined as ≥15% decrease in left ventricular end-systolic volume (LVESV) after CRT implantation. Response to CRT was compared between patients with and without fQRS.

Results:

The study group included 27 women (41.5%) and 38 men (58.5%) with a mean (±SD) age of 62±12 years. 27 patients (41.5%) had fQRS in their basal ECGs. Totally 46 patients (70.8%) responded to CRT in a way that the mean left ventricular ejection fraction (%) significantly increased, and left ventricular end diastolic volume (LVEDV) significantly decreased after CRT (p<0.001 and p=0.001 respectively). In multivariate logistic analysis, lack of fQRS was found to be a predictor of response to CRT (OR: 4.553, 95% CI: 1.345-15.418, p=0.015).

Conclusion:

We showed that the fQRS complex, as a sign of myocardial scar, predicts non-responsiveness to CRT. Therefore, fQRS may help selecting of CRT candidates.

Discrepancy between echocardiographic and patient-reported health status response to cardiac resynchronization therapy: results of the PSYHEART-CRT study

AIMS

The current study examined the degree of agreement between echocardiographic and patient-reported health status response to CRT 6 months after implantation, and evaluated the differences in pre-implantation characteristics of patients with concordant and discordant echocardiographic and health status responses.

METHODS AND RESULTS

Consecutively implanted CRT-defibrillator patients (n = 109, mean age = 65.4 ± 10.1 years, 74 men) were recruited from the University Medical Center Utrecht, The Netherlands. Prior to implantation and 6 months post-implantation, all patients underwent echocardiography and completed the Kansas City Cardiomyopathy Questionnaire (KCCQ). Echocardiographic response was defined as a relative reduction of ≥15% in LV end-systolic volume; an improvement of ≥10 points in KCCQ score indicated a health status response. In the 54 patients with discordant responses, 25 (22.9%) had an echocardiographic response but no health status response and 29 (26.6%) had a health status response but no echocardiographic response. Patients with concordant and discordant responses differed on various pre-implantation characteristics, including sex, employment status, LV volumes, and pre-implantation KCCQ score. In multivariable analysis, pre-implantation KCCQ score [odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.88-0.95, P < 0.001] and QRS duration (OR = 1.03, 95% CI = 1.01-1.06, P = 0.009) were the only characteristics associated with health status response to CRT.

CONCLUSIONS

Our results show a large discrepancy between echocardiographic and patient-reported health status response to CRT. The most important predictor of health status response was the pre-implantation health status score. These results emphasize that disease-specific health status measures may have additional value over 'objective' measures of CRT response and should be incorporated in clinical practice.

Depression, psychological distress, and quality of life in patients with cardioverter defibrillator with or without cardiac resynchronization therapy

Congestive heart failure is frequent and leads to reduced exercise capacity, reduced quality of life (QoL), and depression in many patients. Cardiac resynchronization therapy (CRT) and implantable cardioverter defibrillators (ICD) offer therapeutic options and may have an impact on QoL and depression. This study was performed to evaluate physical and mental health in patients undergoing ICD or combined CRT/ICD-implantation (CRT-D). Echocardiography, spiroergometry, and psychometric questionnaires [Beck Depression Inventory, General World Health Organization Five Well-being Index (WHO-5), Brief Symptom Inventory and 36-item Short Form (SF-36)] were obtained in 39 patients (ICD: 17, CRT-D: 22) at baseline and 6-month follow-up (FU) after device implantation. CRT-D patients had a higher NYHA class and broader left bundle branch block than ICD patients at baseline. At FU, ejection fraction (EF), peak oxygen uptake, and NYHA class improved significantly in CRT-D patients but remained unchanged in ICD patients. Patients with CRT-D implantation showed higher levels of depressive symptoms, psychological distress, and impairment in QoL at baseline and FU compared to ICD patients. These impairments remained mostly unchanged in all patients after 6 months. Overall, these findings imply that there is a need for careful assessment and treatment of psychological distress and depression in ICD and CRT-D patients in the course of device implantation as psychological burden seems to persist irrespective of physical improvement.