Non-response to Cardiac Resynchronization Therapy

Left bundle branch block-Innocent bystander, silent menace, or both

Left bundle branch block (LBBB) causes immediate electrical and mechanical dyssynchrony of the left ventricle (LV) and gradual structural damages in the Purkinje cells and myocardium. Mechanical dyssynchrony reduces the LV ejection fraction (EF) instantly, but only to ≈55% in an otherwise normal heart. Because of the heart's in-built functional redundancy, a patient with LBBB does not always notice the heart's reduced efficiency straightaway. After a variable period of time (which could be from days to decades), the patient may become symptomatic with heart failure (HF), which classifies as HF with preserved EF ≥50% (HFpEF). The LVEF drops further because of continuous adverse remodeling and inefficient cardiac contraction. The patient transits to HF with moderately reduced EF 35%-50% (HFmrEF) and then reduced EF ≤35% (HFrEF) over 5-21 years. Cardiac resynchronization therapy (CRT) is currently only indicated in guidelines for HFrEF and LBBB. LBBB shortens the median survival of patients with HFmrEF by 5.5 years. Randomized controlled trials have shown that CRT improves echocardiographic indices for HFmrEF with LBBB. CRT in HFpEF with LBBB is a promising but underexplored/underused therapy. There have been anecdotal reports that CRT produced symptom relief in patients debilitated by HFpEF with LBBB, who constitute ≈6% of all patients with HF and an adequate pool of potential randomized controlled trial participants. Conduction system pacing in the form of left bundle branch area pacing is an emerging pacing strategy that might reverse and forestall the deleterious effects of LBBB.

Electrical dyssynchrony mapping and optimization of nonresponders in patients programmed with the adaptive cardiac resynchronization therapy algorithm

BACKGROUND

The adaptive cardiac resynchronization therapy (CRT) (aCRT) algorithm provides an important clinical benefit. However, a significant number of patients are nonresponders.

OBJECTIVES

The goals of this study were to quantify electrical synchrony in patients programmed with aCRT and to assess the echocardiographic effects of optimization in CRT nonresponders and incomplete responders.

METHODS

We studied 125 patients programmed with aCRT and measured electrical synchrony at multiple device settings using novel electrical dyssynchrony mapping (EDM) technology. Electrical synchrony was quantified as cardiac resynchronization index (CRI), a measure that analyzes areas between multiple pairs of anterior and posterior electrograms and calculates synchrony normalized to native rhythm.

RESULTS

CRI improved from baseline aCRT settings to optimal settings on the basis of EDM (56%±29% vs 92%±12%; P<.001). Patients programmed with left ventricle (LV)-only aCRT (group 1, n=68 [54%]) had a higher CRI (62%±25% vs 48%±31%; P=.014) than did patients programmed with biventricular aCRT (group 2, n=57 [46%]). In group 1 and group 2, optimal CRI during sequential biventricular (92%±13% and 93%±9%, respectively) and LV-only (92%±6% and 91%±7%, respectively) pacing was significantly (P<.001) higher than CRI at baseline aCRT setting. In a subset of 53 nonresponders optimized using EDM, there were significant improvements in CRI (37%±25%; P<.0001), LV ejection fraction (6.2%±6.6%; P<.0001), end-diastolic volume (9.5±28.2 mL; P=.015), end-systolic volume (13.4±24.9 mL; P<.001), and transverse (1.5%±4.4%; P=.014), longitudinal (1.0%±2.5%; P=.003), and circumferential (2.6%±8.5%; P=.047) strain.

CONCLUSION

Electrical synchrony improves 56% with CRT using aCRT programming and 92% with EDM optimization. Optimization of aCRT-programmed nonresponders results in significant improvements in LV size and systolic function, offering the possibility of converting CRT nonresponders into responders.

Emerging Cardiac Implantable Electronic Device Technologies

The last several years have witnessed an abundance of new and disruptive cardiac implantable electronic device innovations. These can be categorized in terms of cardiac pacing, noncardiac electrical stimulation, and leadless technology. A working knowledge of these new options for patients on the part of the clinical cardiology community is critical.

Left bundle branch pacing set to outshine biventricular pacing for cardiac resynchronization therapy?

The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacing-induced cardiomyopathy. Until recently, biventricular pacing (BiVP) was the only modality which could mitigate or prevent pacing induced dysfunction. Further, BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes. However, the high non-response rate of around 20%-30% remains a major limitation. This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system. To overcome this limitation, the concept of conduction system pacing (CSP) came up. Despite initial success of the first CSP via His bundle pacing (HBP), certain drawbacks including lead instability and dislodgements, steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy (CRT). Subsequently, CSP via left bundle branch-area pacing (LBBP) was developed in 2018, which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies. Further, its safety has also been well established and is largely free of the pitfalls of the HBP-CRT. In the recent metanalysis by Yasmin et al, comprising of 6 studies with 389 participants, LBBP-CRT was superior to BiVP-CRT in terms of QRS duration, left ventricular ejection fraction, cardiac chamber dimensions, lead thresholds, and functional status amongst heart failure patients with left bundle branch block. However, there are important limitations of the study including the small overall numbers, inclusion of only a single small randomized controlled trial (RCT) and a small follow-up duration. Further, the entire study population analyzed was from China which makes generalizability a concern. Despite the concerns, the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT. At this stage, one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBP-CRT in management of heart failure patients with left bundle branch block.

Add-on Sacubitril/Valsartan Therapy Induces Left Ventricular Remodeling in Non-responders to Cardiac Resynchronization Therapy to a Similar Extent as in Heart Failure Patients Without Resynchronization

INTRODUCTION

Non-responders to cardiac resynchronization therapy (CRT-NR) have poor prognosis. Sacubitril/valsartan (SV) treatment improved the outcome of patients with heart failure with reduced left ventricular (LV) ejection fraction (HFrEF) in randomized trials with no data on the specific cohort of CRT-NRs. The aim of this study was to compare the echocardiographic and biomarker changes in CRT-NR patients treated with versus without SV, and in patients with HFrEF on SV therapy.

METHODS

CRT-NR patients initiated on SV (group I), CRT-NR patients on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARB) (group II), and patients with HFrEF (without CRT) initiated on SV (group III) were identified in our heart failure (HF) registry. CRT-NR was defined as < 10% improvement in left ventricular ejection fraction (LV EF) 6 months after the implantation. Echocardiographic parameters and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels at baseline and at the end of follow-up were compared.

RESULTS

A total of 275 patients (group I, 70; group II, 70; and group III, 135) were included. After a follow-up of 7.54 ± 1.8 months (mean ± standard deviation [SD]), LV EF (%) increased in group I (25.2 ± 5.7 versus 29.4% ± 6.7; p < 0.001) and in group III (26.6 ± 6.4 versus 29.9 ± 6.7; p < 0.001). LV end-systolic diameters (mm) decreased in group I (56.6 ± 9.0 versus 54.3 ± 8.7; p = 0.004) and in group III (55.9 ± 9.9 versus 54.3 ± 11.2; p = 0.021). The levels of NT-proBNP (pg/mL) decreased in group I (2058.86 [1041.07-4502.51] versus 1121.55 [545-2541]; p < 0.001) and in group III (2223.35 [1233.03-4795.96] versus 1123.09 [500.38-2651.27]; p < 0.001). The extent of improvement was similar in groups I and III (p > 0.05). No significant changes were detected in group II.

CONCLUSION

SV therapy induced similar improvements in echocardiographic parameters and in NT-proBNP levels in CRT-NR patients and in patients with HFrEF without resynchronization.

The interventricular conduction delays guide best cardiac resynchronization therapy: A tailored-patient approach to perform a CRT through Conduction System Pacing

Evaluation of conduction intervals to predict success of resynchronization in biventricular pacing(BiVP) or Conduction System Pacing(CSP) is not spread in clinical practice. A right ventricle-to-left ventricle intrinsic conduction interval (RVs-LVs) > 70 ms or prolonged RVpaced - LVs(RVp-LVs)interval can predict Cardiac Resynchronization Therapy (CRT)response.This paper describes a case of cardiac resynchronization guided by spontaneous and paced interventricular conduction delays (IVCD) obtained in BiVP that led to changing intraoperative approach. A strategy for cardiac resynchronization based on the CSP/BiVP approach according to the IVCD could represent a viable and reliable solution to obtain a narrow paced QRS and to improve the CRT response.

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.

Feasibility and safety of left bundle branch area pacing-cardiac resynchronization therapy in elderly patients

BACKGROUND

Left bundle branch area pacing (LBBAP) is an emerging technique to achieve cardiac resynchronization therapy (CRT), but its feasibility and safety in elderly patients with heart failure with reduced ejection fraction and left bundle branch block is hardly investigated.

METHODS

We enrolled consecutive patients with an indication for CRT comparing pacing parameters and complication rates of LBBAP-CRT in elderly patients (≥ 75 years) versus younger patients (< 75 years) over a 6-month follow-up.

RESULTS

LBBAP was successful in 55/60 enrolled patients (92%), among which 25(45%) were elderly. In both groups, LBBAP significantly reduced the QRS duration (elderly group: 168 ± 15 ms to 136 ± 12 ms, p < 0.0001; younger group: 166 ± 14 ms to 134 ± 11 ms, p < 0.0001) and improved LVEF (elderly group: 28 ± 5% to 40 ± 7%, p < 0.0001; younger group: 29 ± 5% to 41 ± 8%, p < 0.0001). The pacing threshold was 0.9 ± 0.8 V in the elderly group vs. 0.7 ± 0.5 V in the younger group (p = 0.350). The R wave was 9.5 ± 3.9 mV in elderly patients vs. 10.7 ± 2.7 mV in younger patients (p = 0.341). The fluoroscopic (elderly: 13 ± 7 min vs. younger: 11 ± 7 min, p = 0.153) and procedural time (elderly: 80 ± 20 min vs. younger: 78 ± 16 min, p = 0.749) were comparable between groups. Lead dislodgement occurred in 2(4%) patients, 1 in each group (p = 1.000). Intraprocedural septal perforation occurred in three patients (5%), 2(8%) in the elderly group (p = 0.585). One patient (2%) in the elderly group had a pocket infection.

CONCLUSIONS

LBBAP is a feasible and safe technique for delivering physiological pacing in elderly patients who are candidates for CRT with suitable pacing parameters and low complication rates.

Success rates, challenges and troubleshooting of left bundle branch area pacing as a cardiac resynchronization therapy for treating patients with heart failure

Cardiac resynchronization therapy (CRT) is an important treatment of heart failure patients with reduced left ventricular ejection fraction (LVEF) and asynchrony of cardiac electromechanical activity. Left bundle branch area pacing (LBBaP) is a novel physiological pacing modality that appears to be an effective method for CRT. LBBaP has several advantages over the traditional biventricular-CRT (BiV-CRT), including a low and stable pacing capture threshold, a high success rate of implantation, a short learning curve, and high economic feasibility. However, LBBaP is not suitable for all heart failure patients needing a CRT and the success rates of LBBaP in heart failure patients is lower because of myocardial fibrosis, non-specific intraventricular conduction disturbance (IVCD), enlargement of the right atrium or right ventricle, etc. In this literature review, we summarize the success rates, challenges, and troubleshooting of LBBaP in heart failure patients needing a CRT.

Cardiac resynchronization therapy optimization in nonresponders and incomplete responders using electrical dyssynchrony mapping

BACKGROUND

Nonresponse to cardiac resynchronization therapy (CRT) occurs in ∼30%-50% of patients. There are no well-accepted clinical approaches for optimizing CRT in nonresponders.

OBJECTIVE

The purpose of this study was to demonstrate the effect of CRT optimization using electrical dyssynchrony mapping on left ventricular (LV) function, size, and dyssynchrony in selected patients with nonresponse/incomplete response to CRT.

METHODS

We studied 39 patients with underlying left bundle branch block or interventricular conduction delay who had an LV ejection fraction of ≤40% after receiving CRT and had significant electrical dyssynchrony. Electrical dyssynchrony was measured at multiple atrioventricular delays and interventricular delays. The QRS area between combinations of 9 anterior and 9 posterior electrograms (QRS area under the curve) was calculated, and cardiac resynchronization index (CRI) was defined as the percent change in QRS area under the curve compared to native conduction. Electrical dyssynchrony maps depicted CRI over the wide range of settings tested. Patients were programmed to an optimal device setting, and echocardiograms were recorded 5.9 ± 3.7 months postoptimization.

RESULTS

CRI increased from 49.4% ± 24.0% to 90.8% ± 10.5%. CRT optimization significantly improved LV ejection fraction from 31.8% ± 4.7% to 36.3% ± 5.9% (P < .001) and LV end-systolic volume from 108.5 ± 37.6 to 98.0 ± 37.5 mL (P = .009). Speckle-tracking measures of LV strain significantly improved by 2.4% ± 4.5% (transverse; P = .002) and 1.0% ± 2.6% (longitudinal; P = .017). Aortic to pulmonic valve opening time, a measure of interventricular dyssynchrony, significantly (P = .040) decreased by 14.9 ± 39.4 ms.

CONCLUSION

CRT optimization of electrical dyssynchrony using a novel electrical dyssynchrony mapping technology significantly improves LV systolic function, LV end-systolic volume, and mechanical dyssynchrony. This methodology offers a noninvasive, practical clinical approach to treating nonresponders and incomplete responders to CRT.

Dyssynchronous Heart Failure: A Clinical Review

PURPOSE OF THE REVIEW

Dyssynchrony occurs when portions of the cardiac chambers contract in an uncoordinated fashion. Ventricular dyssynchrony primarily impacts the left ventricle and may result in heart failure. This entity is recognized as a major contributor to the development and progression of heart failure. A hallmark of dyssynchronous heart failure (HF_d) is left ventricular recovery after dyssynchrony is corrected. This review discusses the current understanding of pathophysiology of HF_d and provides clinical examples and current techniques for treatment.

RECENT FINDINGS

Data show that HF_d responds poorly to medical therapy. Cardiac resynchronization therapy (CRT) in the form of conventional biventricular pacing (BVP) is of proven benefit in HF_d, but is limited by a significant non-responder rate. Recently, conduction system pacing (His bundle or left bundle branch area pacing) has also shown promise in correcting HF_d. HF_d should be recognized as a distinct etiology of heart failure; HF_d responds best to CRT.

Sacubitril/Valsartan in the Management of Heart Failure Patients with Cardiac Implantable Electronic Devices

For heart failure patients with cardiac implantable electronic devices (CIEDs), especially those who remain symptomatic after implantation, the best management strategy is still unclear. Although there are several concerns regarding the clinical utilization of sacubitril/valsartan, it has improved the prognosis of patients with heart failure compared with the use of renin-angiotensin system inhibitors in recent years. Recent real-world observational studies and post hoc analyses demonstrated that sacubitril/valsartan might have effects in patients with CIEDs. Given its potential underlying mechanisms, sacubitril/valsartan could improve outcomes of mortality and sudden cardiac death incidence, as well as clinical and echocardiographic evaluations. The possible antiarrhythmic effect of sacubitril/valsartan is still debated. Moreover, given that hypotension is the critical limitation of uptitration, the rise in systolic blood pressure attributed to cardiac resynchronization therapy might support the use of sacubitril/valsartan, with improved tolerance. The clinical utility of sacubitril/valsartan in heart failure patients with CIEDs requires further investigation to determine the actual effects, optimal target populations, and underlying mechanisms.

Comparing the Modified Frailty Index with conventional scores for prediction of cardiac resynchronization therapy response in patients with heart failure

Objective:

The aim of the study was to compare, Modified Frailty Index (mFI), EAARN (LVEF <22%, Atrial Fibrillation, Age ≥70 years, Renal function (eGFR <60 mL/min/1.73m²), NYHA class IV), and ScREEN (female Sex, Renal function (eGFR ≥60 mL/min/1.73m²), LVEF ≥25%, ECG (QRS duration ≥150 ms) and NYHA class ≤III) score for predicting cardiac resynchronization therapy (CRT) response and all-cause mortality.

Methods:

In this prospective, non-randomized, single-center, observational study we enrolled 93 patients receiving CRT from August 2016 to August 2019. Pre-implant scores were calculated, and patients were followed for six months. Performance of each score for prediction of CRT response (defined as ≥15% reduction in left ventricular end-systolic volume [LVESV]) and all-cause mortality was compared.

Results:

Optimal CRT response was seen in seventy patients with nine deaths. All the three scores exhibited modest performance for prediction of CRT response and all-cause mortality with AUC ranging from 0.608 to 0.701. mFI has an additional benefit for prediction of prolonged post-procedure stay and 30-day rehospitalization events.

Conclusion:

mFI, ScREEN and EAARN score can be used reliably for predicting all-cause mortality and response to CRT.

Improvement in quality of life with sacubitril/ /valsartan in cardiac resynchronization non-responders: The RESINA (RESynchronization plus an Inhibitor of Neprilysin/Angiotensin) registry

BACKGROUND

Clinical management of cardiac resynchronization therapy (CRT) non-responders is difficult, and their prognosis is poor. The aim of the present study was to evaluate whether treatment with sacubitril/valsartan can improve quality of life (QoL) parameters in these patients.

METHODS

Thirty five non-responders to CRT were included (75 ± 7 years, 28% females, mean left ventricular ejection fraction 28 ± 8%, 54% non-ischemic cardiomyopathy) with maximally optimized drug therapy and New York Heart Association class II-III. They were all on angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers and were switched to sacubitril/valsartan. One week before and 6 months after initiation of the therapy they completed both the Minnesota Living with Heart Failure (MLWHF) and the 12-item Kansas City Cardiomyopathy Questionnaires (KCCQ-12). The primary outcome was the effect of sacubitril/valsartan on the physical, clinical, social and emotional QoL parameters and number of hospitalizations.

RESULTS

The mean total scores of both questionnaires improved from baseline to the follow-up visit at 6-months (KCCQ-12 40 ± 10 to 47 ± 10; p < 0.001; MLWHF 40 ± 15 to 29 ± 15; p < 0.001). The best results were seen in the KCCQ-12 total symptom domains (77% improvement), the MLWHF physical domain (81% improvement), and the MLWHF emotional domain (71% improvement). Two patients died during follow-up. The mean number of hospitalizations reduced significantly (1 ± 0.6 vs. 0.5 ± 0.8; p = 0.003) CONCLUSIONS: In CRT non-responders, sacubitril/valsartan significantly improved overall QoL, physical limitations and emotional domains and reduced the number of hospitalizations.

Economic implications of adding a novel algorithm to optimize cardiac resynchronization therapy: rationale and design of economic analysis for the AdaptResponse trial

AIMS

Although cardiac resynchronization therapy (CRT) has proven beneficial in several randomized trials, a subset of patients have limited clinical improvement. The AdaptivCRT algorithm provides automated selection between synchronized left ventricular or biventricular pacing with optimization of atrioventricular delays. The rationale and design of the economic analysis of the AdaptResponse clinical trial are described.

RATIONALE

The costs associated with HF hospitalization are substantial and are compounded by a high rate of readmission. HF hospitalization payments range from $1,001 for Greece to $12,235 for US private insurance. When examining the breakdown of HF-related costs, it is clear that approximately 55% of the hospitalization costs are directly attributable to length of stay. Notably, the mean costs of a CRT patient in need of a HF-related hospitalization are currently estimated to be an average of $10,679.

METHODS

The economic analysis of the AdaptResponse trial has two main objectives. The hospital provider objective seeks to test the hypothesis that AdaptivCRT reduces the incidence of all-cause re-admissions after a heart failure admission within 30 days of the index event. A negative binomial regression model will be used to estimate and compare the number of readmissions after an index HF hospitalization. The payer economic objective will assess cost-effectiveness of CRT devices with the AdaptivCRT algorithm relative to traditional CRT programming. This analysis will be conducted from a U.S. payer perspective. A decision analytic model comprised of a 6-month decision tree and a Markov model for long term extrapolation will be used to evaluate lifetime costs and benefits.

CONCLUSION

AdaptivCRT may offer improvements over traditional device programming in patient outcomes. How the data from AdaptResponse will be used to demonstrate if these clinical benefits translate into substantial economic gains is herein described.

Combination of Left Ventricular End-Diastolic Diameter and QRS Duration Strongly Predicts Good Response to and Prognosis of Cardiac Resynchronization Therapy

Background

Approximately 20–40% of recipients of cardiac resynchronization therapy (CRT) do not respond to it based on the current patient selection criteria. The purpose of this study was to identify baseline parameters that can predict CRT response and to evaluate the effect of those predictive parameters on long-term prognosis.

Methods

This was a retrospective, nonrandomized, noncontrolled cohort study. Patients who received CRT in our centre were divided into responders and nonresponders by the definition of CRT response (an increase in left ventricular ejection fraction (LVEF) of ≥5% and improvement of ≥1 New York Heart Association (NYHA) class from baseline to the 6-month follow-up).

Results

Of the 101 patients, 68 were responders and 33 were nonresponders. Left ventricular end-diastolic diameter (LVEDD; OR: 0.88, 95% CI: 0.81–0.95, P=0.001) and QRS duration (OR: 1.07, 95% CI: 1.04–1.10, P < 0.001) were independent predictors of CRT response. The combination of LVEDD and QRS duration was more valuable for predicting CRT response (AUC 0.836; 95% CI: 0.76–0.91; P < 0.001). Moreover, the combination of LVEDD ≤ 71 mm and QRS duration ≥ 170 ms had a low incidence of all-cause mortality, HF hospitalisation, and the composite endpoint. In addition, baseline LVEDD had a positive correlation with QRS duration (R=0.199, P=0.046). Responders to CRT had better LV reverse remodeling.

Conclusion

The combination of LVEDD and QRS duration provided more robust prediction of CRT response. Moreover, the combination of LVEDD ≤ 71 mm and QRS duration ≥ 170 ms was associated with a low incidence of all-cause mortality, HF hospitalisation, and the composite endpoint. Our results may be useful to provide individualized patient selection for CRT.

Noninvasive cardiac output measurement based optimization in nonresponders of cardiac resynchronization therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) is an important and effective therapy for end-stage heart failure (HF). Nonresponse to CRT is one of the main obstacles to its application in clinical practice. Herein, we investigated the utilization of the optimization technique using noninvasive cardiac output measurement (NICOM) based Mobil-O-Graph device that measures several circulation parameters noninvasively.

METHODS

Seventy-five CRT nonresponder HF patients with an implanted CRT device were included. Patients were randomized equally to 3 groups: NICOM, echocardiographic, and empirical optimization groups. After 3 months of optimization, changes in six minutes walk test (6-MWT), cardiac output (CO), left ventricular ejection fraction (LVEF), and end-systolic volume (LVESV) were measured. New York Heart Association (NYHA) class and hospitalization for HF were also determined.

RESULTS

There were no statistically significant differences among the three groups in terms of demographics, baseline characteristics. In the NICOM group, the 6-MWT, LVEF, CO, and LVESV measurements showed significant improvements compared to baseline values (P < .05). There was no significant improvement in 6-MWT, LVEF, CO, NYHA class, and LVESV in Echo and Empirical groups after 3 months (P > .05). 6-MWT, CO, LVESV percentages, and hospitalization for HF were significantly different between the groups (P < .05). In post hoc analyzes, the percentages of the change in 6-MWT, CO, LVESV, and hospitalization for HF were significantly higher in the NICOM group (P < .017).

CONCLUSIONS

This study suggests that Mobil-O-Graph device optimization according to CO measures does appear to have potential hemodynamic and clinical benefits in nonresponder CRT patients. Use of Mobil-O-Graph device as an option for optimization of CRT devices can be an attractive method of improving CRT outcomes.

Modified frailty as a novel factor in predicting the response to cardiac resynchronization in the elderly population

Background

The response to cardiac resynchronization therapy (CRT) is an important element of the treatment of advanced heart failure, especially in the geriatric population. The aim of the study was to examine the impact of frailty syndrome on the response to treatment with CRT.

Methods

Two hundred and forty-six patients of 60 years or older (aged 73.35±6.95; 22.4% women) with an implanted CRT were included in this single-center prospective study. There was a 12-month follow-up. The Tilburg Frailty Indicator was used to determine frailty (5 or more points). The response to CRT was evaluated based on an analysis of clinical criteria.

Results

One hundred and sixty-nine of 246 (68.9%) patients were found to be clinical CRT responders. Frailty syndrome was recognized in 173 (70.32%). There were 63.0% responders in the frailty-affected group, whereas there were statistically more responders (79.5%) in the robust group (P=0.0116). In the logistic regression, frailty emerged as an independent predictor of the response to CRT (OR=0.81, 95% CI=0.71–0.92; P=0.0008). The area under the curve of the ROC curve for frailty in the responders to CRT was 0.62. The cut-off value for a designation of frailty was 6 (P=0.0014).

Conclusion

Frailty is a novel independent factor that can be used to predict the clinical response to CRT in the elderly population. Modifying the level of recognition in the Tilburg Frailty Indicator can improve the prediction of a response to CRT.