Cardiac Resynchronization Therapy Research Articles

Correction to: Effects of Synchronizing Foot Strike and Cardiac Phase on Exercise Hemodynamics in Patients With Cardiac Resynchronization Therapy: A Within-Subjects Pilot Study to Fine-Tune Cardio-Locomotor Coupling for Heart Failure.

Correction to: Effects of Synchronizing Foot Strike and Cardiac Phase on Exercise Hemodynamics in Patients With Cardiac Resynchronization Therapy: A Within-Subjects Pilot Study to Fine-Tune Cardio-Locomotor Coupling for Heart Failure.

Impact of High-Voltage Device Implantation in Elderly Japanese Patients With Heart Failure as Primary Prevention　- Post Hoc Analysis of HINODE.

Despite an increased incidence of chronic heart failure (HF) and sudden cardiac death (SCD), the use of implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT) is much lower in Japan than in Western countries. The HF Indication and SCD Prevention Trial Japan (HINODE) prospectively assessed the mortality rate, appropriately treated ventricular arrhythmias (VA), and HF in Japanese patients with a higher risk of HF.Methods and Results: HINODE consisted of ICD, CRT-defibrillator (CRT-D), pacing, and non-device treatment cohorts. This subanalysis evaluated the impact of the implantation of high-voltage devices (HVD; ICD and CRT-D) in 171 Japanese patients. We compared all-cause mortality, VA, and HF events between elderly (age >70 years at study enrollment) and non-elderly HVD recipients. The estimated survival rate through 24 months in the HVD cohort was 85.8% (97.5% lower control limit 77.6%). The risk of all-cause mortality was increased for the elderly vs. non-elderly (hazard ratio [HR] 2.82; 95% confidence interval [CI] 1.01-7.91; P=0.039), but did not differ after excluding ICD patients with CRT-D indication (HR 2.32; 95% CI 0.79-6.78; P=0.11). There were no differences in VA and HF event-free rates between elderly and non-elderly HVD recipients (P=0.73 and P=0.55, respectively). Although elderly patients may have a higher risk of mortality in general, the benefit of HVD therapy in this group is comparable to that in non-elderly patients.

Baroreflex activation therapy in patients with heart failure and a reduced ejection fraction: Long-term outcomes.

Carotid baroreflex activation therapy (BAT) restores baroreflex sensitivity and modulates the imbalance in cardiac autonomic function in patients with heart failure with reduced ejection fraction (HFrEF). We tested the hypothesis that treatment with BAT significantly reduces cardiovascular mortality and heart failure morbidity and provides long-term safety and sustainable symptomatic improvement. BeAT-HF was a prospective, multicentre, randomized, two-arm, parallel-group, open-label, non-implanted control trial. New York Heart Association (NYHA) class III subjects, ejection fraction ≤35%, previous heart failure hospitalization or N-terminal pro-B-type natriuretic peptide (NT-proBNP) >400 pg/ml, no class I indication for cardiac resynchronization therapy and NT-proBNP <1600 pg/ml were randomized to BAT plus optimal medical management (BAT group) or optimal medical management alone (control). The primary endpoint was cardiovascular mortality and HF morbidity; additional pre-specified endpoints included durability of safety, quality of life (QOL), exercise capacity (6-min hall walk distance [6MHWD]), functional status (NYHA class), hierarchical composite win ratio, freedom from all-cause death, left ventricular assists device (LVAD) implantation, heart transplant. Overall, 323 patients had 332 primary events, median follow-up was 3.6 years/patient. Both primary endpoint (rate ratio 0.94, 95% confidence interval [CI] 0.57-1.57; p = 0.82) and components of the primary endpoints were not significantly different between BAT and control. The system- and procedure-related major adverse neurological and cardiovascular event-free rate remained 97% throughout the trial. Symptom improvement (QOL, 6MHWD, NYHA class, all nominal p < 0.001) in the BAT group was durable in time, sustainable in extent. Win ratio (1.26, 95% CI 1.02-1.58) and freedom from all-cause death, LVAD implantation, heart transplant (hazard ratio 0.66, 95% CI 0.43-1.01) favoured the BAT group but did not reach statistical significance. The BeAT-HF primary endpoint was neutral; however, BAT provided safe, effective, and sustainable improvements in HFrEF patient's functional status, 6MHWD and QOL.

Blood groups and Rhesus status as potential predictors of outcomes in patients with cardiac resynchronisation therapy

Cardiac resynchronisation therapy (CRT) improves prognosis in patients with heart failure (HF) however the role of ABO blood groups and Rhesus factor are poorly understood. We hypothesise that blood groups may influence clinical and survival outcomes in HF patients undergoing CRT. A total of 499 patients with HF who fulfilled the criteria for CRT implantation were included. Primary outcome of all-cause mortality and/or heart transplant/left ventricular assist device was assessed over a median follow-up of 4.6 years (IQR 2.3–7.5). Online repositories were searched to provide biological context to the identified associations. Patients were divided into blood (O, A, B, and AB) and Rhesus factor (Rh-positive and Rh-negative) groups. Mean patient age was 66.4 ± 12.8 years with a left ventricular ejection fraction of 29 ± 11%. There were no baseline differences in age, gender, and cardioprotective medication. In a Cox proportional hazard multivariate model, only Rh-negative blood group was associated with a significant survival benefit (HR 0.68 [0.47–0.98], p = 0.040). No association was observed for the ABO blood group (HR 0.97 [0.76–1.23], p = 0.778). No significant interaction was observed with prevention, disease aetiology, and presence of defibrillator. Rhesus-related genes were associated with erythrocyte and platelet function, and cholesterol and glycated haemoglobin levels. Four drugs under development targeting RHD were identified (Rozrolimupab, Roledumab, Atorolimumab, and Morolimumab). Rhesus blood type was associated with better survival in HF patients with CRT. Further research into Rhesus-associated pathways and related drugs, namely whether there is a cardiac signal, is required.

Evaluating the predictive value of late gadolinium enhancement assessed by cardiac magnetic resonance on sudden cardiac death in patients selected for implantable cardioverter defibrillator and cardiac resynchronization therapy implantation: a systematic review and meta-analysis.

Late gadolinium enhancement (LGE) assessed by cardiovascular magnetic resonance (CMR) can evaluate myocardial scar associated with a higher risk of sudden cardiac death (SCD), which can guide the selection between cardiac resynchronization therapy with or without a defibrillator (CRT-P/CRT-D). Our aim was to investigate the association between LGE and SCD risk in patients with CRT using the LGE-CMR technique. We performed a systematic literature search using four databases. The target population was CRT candidates. The primary endpoint was SCD. The risk of bias was assessed using the QUIPS tool. Fifteen eligible articles were included with a total of 2494 patients, of whom 27%, 56%, and 19% had an implantable cardioverter defibrillator (ICD), CRT-D, and CRT-P, respectively. Altogether, 54.71% of the cohort was LGE positive, who had a 72% higher risk for SCD (HR 1.72; 95% CI 1.18-2.50) compared to LGE negatives. In non-ischemic patients, the proportion of LGE positivity was 46.6%, with a significantly higher risk for SCD as compared to LGE negatives (HR 2.42; 95% CI 1.99-2.94). The subgroup of CRT-only patients showed no difference between the LGE-positive vs. negative candidates (HR 1.17; 95% CI 0.82-1.68). Comparable SCD risk was observed between articles with short- (OR 7.47; 95% CI 0.54-103.12) vs. long-term (OR 6.15; 95% CI 0.96-39.45) follow-up time. LGE-CMR positivity was associated with an increased SCD risk; however, in CRT candidates, the difference in risk reduction between LGE positive vs. negative patients was statistically not significant, suggesting a role of reverse remodeling. LGE-CMR before device implantation could be crucial in identifying high-risk patients even in non-ischemic etiology.

Interaction of left ventricular size with the outcome of cardiac resynchronization therapy in Japanese patients.

We analyzed the influence of the QRS duration (QRSd) to LV end-diastolic volume (LVEDV) ratio on cardiac resynchronization therapy (CRT) outcomes in heart failure patients classified as III/IV per the New York Heart Association (NYHA) and with small body size. We proposed the hypothesis that the QRSd/LV size ratio is a better index of the CRT substrate. We enrolled 114 patients with advanced heart failure (NYHA class III/IV, and LV ejection fraction >35%) who received a CRT device, including those with left bundle branch block (LBBB) and QRSd ≥120 milliseconds (n = 60), non-LBBB and QRSd ≥150 milliseconds (n = 30) and non-LBBB and QRSd of 120-149 milliseconds (n = 24). Over a mean follow-up period of 65 ± 58 months, the incidence of the primary endpoint, a composite of all-cause death and hospitalization for heart failure, showed no significant intergroup difference (43.3% vs. 50.0% vs. 37.5%, respectively, p = .72). Similarly, among 104 patients with QRSd/LVEDV ≥ 0.67 (n = 54) and QRSd/LVEDV < 0.67 (n = 52), no significant differences were observed in the incidence of the primary endpoint (35.1% vs. 51.9%, p = .49). Nevertheless, patients with QRSd/LVEDV ≥ 0.67 showed better survival than those with QRSd/LVEDV < 0.67 (14.8% vs. 34.6%, p = .0024). Advanced HF patients with a higher QRSd/LVEDV ratio showed better survival in this small-body-size population. Thus, the risk is concentrated among those with a larger QRSd, and patients with a relatively smaller left ventricular size appeared to benefit from CRT.

Atrioventricular optimization improves cardiac resynchronization response in patients with long interventricular electrical delays: A pooled analysis of the SMART-AV and SMART-CRT trials

BackgroundThe utility of atrioventricular (AV) optimization (AVO) algorithms remains in question. A substudy of the SMART-AV trial found that patients with prolonged interventricular delays ≥70 ms were more likely to benefit from cardiac resynchronization therapy (CRT) with AVO. The SMART-CRT trial evaluated AVO on the basis of these results, but the study was underpowered. ObjectiveTo increase statistical power, data from SMART-AV patients meeting the inclusion criterion of interventricular delay ≥70 ms were pooled with data from SMART-CRT to reassess AVO. MethodsSMART-CRT and SMART-AV were prospective, randomized, multicenter clinical trials. Patients in both studies were randomized to be programmed with an AVO algorithm (SmartDelay) or fixed AV delay (120 ms). Paired echocardiograms obtained at baseline and 6 months were compared, with CRT response defined as ≥15% reduction in left ventricular end-systolic volume. ResultsA total of 451 complete patient data sets were pooled and analyzed. The baseline demographics between studies did not differ statistically in terms of age, sex, left ventricular ejection fraction, or left ventricular end-systolic volume. The AVO group had a greater proportion of CRT responders (SmartDelay, 73.9%; fixed, 63.1%; P = .014) and greater changes in measures of reverse remodeling. SmartDelay patients with a recommended sensed AV delay outside the nominal range (100–120 ms) had 2.3 greater odds of CRT response than fixed AV delay patients. ConclusionGreater CRT response and measures of reverse remodeling were observed in patients with SmartDelay enabled vs a fixed AV delay. This study supports the use of SmartDelay in patients with a CRT indication and interventricular delay ≥70 ms. ClinicalTrials.gov registrationNCT00677014 and NCT03089281

Right Atrial Septal Lead Enhances the Favorable Effects of the Adaptive Cardiac Resynchronization Therapy Algorithm

The adaptive cardiac resynchronization therapy (CRT) algorithm provides synchronized left ventricular pacing (sLVP). However, ensuring a high sLVP rate is challenging. We assessed the association between the sLVP rate and pacing sites in the right atrium. We evaluated 71 patients who underwent CRT and in whom the adaptive CRT algorithm was applied (53 men; mean age, 66 ± 14 years; median follow-up period, 301 days; IQR: 212-596 days). The atrial pacing leads were positioned in the right atrial (RA) septum in 17 patients (septal group) and in the RA appendage in 54 patients (RA appendage group), with significantly higher sLVP rates in the septal group compared with the RA appendage group (81% ± 30% vs 63% ± 37%; P = 0.045). In patients with first-degree atrioventricular blocks, the sLVP rates tended to be higher in the septal group. Therefore, RA septal pacing increased sLVP rates in patients undergoing CRT.

Is interventional technique better than the traditional over-the-wire method for the left ventricular lead implantation in cardiac resynchronization therapy?

BackgroundInterventional-cardiac resynchronization therapy (I-CRT) for left ventricular lead (LVL) placement works as a supplement to the traditional over-the-wire-technique (T-CRT). It has been argued that I-CRT is a time-consuming and complicated procedure. ObjectiveTo investigate differences in procedure-related, peri- and post-operative and clinical endpoints between I-CRT and T-CRT. MethodThis single-center retrospective cohort-study included all consecutive patients receiving a CRT-pacemaker/defibrillator between January 1, 2012, and August 31, 2018. Patients underwent T-CRT from January 1, 2012, till June 1, 2015, and I-CRT from January 1, 2016, till August 31, 2018. We obtained data from patient-record-files, fluoroscopies and the Danish Pacemaker and ICD Register. Data were analysed using Wilcoxon-rank-sum/linear regression for continuous variables and Pearson’s Chi-squared/Fisher’s exact for categorical variables. ResultsAn optimal LVL-placement was achieved in 82.7% in the I-CRT and 76.8% in the T-CRT group, respectively (p=0.015). In the I-CRT group 99.0% of LVLs were quadripolar versus 55.3% in the T-CRT group (p<0.001). Two or more leads were used during the procedure in 0.7% and 10.5% of all cases in the I-CRT and T-CRT group, respectively (p<0.001). Total implantation time was 81.0 min in the I-CRT group and 83.0 min in the T-CRT group (p=0.41). Time with catheters in the coronary sinus was 45.0 min versus 37.0 min for the I-CRT and T-CRT group, respectively (p<0.001). ConclusionI-CRT did not prolong total implantation time despite longer time with catheters in the CS. Additionally, I-CRT allowed more optimal LVL-placement, wider usage of quadripolar leads and fewer leads used during the procedure.

Short Registry of Terminal Forms of Chronic Heart Failure in the Samara Region.

To study the clinical characteristics and prognosis of patients with functional class (FC) III-IV chronic heart failure (CHF) who meet the criteria for inclusion in the palliative care program. A short registry of severe CHF forms was conducted at 60 outpatient and inpatient clinics in the Samara region for one month (16.05.2022-15.06.2022). The registry included patients with FC III-IV CHF who sought medical help during that period. Lethal outcomes were assessed at 90 days after the inclusion in the registry using the Mortality Information and Analytics system. 591 patients (median age, 71.0 [64.0; 80.0] years were enrolled, including 339 (57.4%) men, of which 149 (24.1%) were of working age (under 65 years). The main cause of CHF was ischemic heart disease (64.5%). 229 (38.7%) patients had left ventricular ejection fraction &lt;40%. During the past year, 513 (86.8%) patients had at least one hospitalization for decompensated CHF. 45.7% of patients had hydrothorax, and 11.3% of patients had ascites. Low systolic blood pressure was observed in more than 25% of patients; 14.2% required in-hospital inotropic support; and 9.1% received it on the outpatient basis. 4.2% of patients received outpatient oxygen support and 0.8% required the administration of narcotic analgesics. 12 (1.9%) patients were on the waiting list for heart transplantation. In this study, there was an inconsistency in the number of patients with ventricular tachycardia and/or left bundle branch block (LBBB) who were implanted with cardiac resynchronization therapy devices (CRTD) or an implantable cardioverter defibrillator (ICD), a total of 19 patients (11 patients with CRTD and 8 patients with ICD), while 58 (9.8%) patients had indications for CRTD/ICD implantation. Within 90 days from inclusion in the registry, 59 (10.0%) patients died. According to binary logistic regression analysis, the presence of LBBB, hydrothorax, the requirement for outpatient oxygen support, and a history of cardiac surgery were associated with a high risk of death. Patients with severe forms of CHF require not only adequate drug therapy, but also dynamic clinical observation supplemented with palliative care aimed at improving the quality of life, including the ethical principles of shared decision-making and advance care planning to identify the priorities and goals of patients in relation to their care.

Cardiac implantable electronic devices and bloodstream infections: management and outcomes.

Bloodstream infection (BSI) of any cause may lead to device infection in cardiac implantable electronic device (CIED) patients. Aiming for a better understanding of the diagnostic approach, treatment, and outcome, patients with an implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy and defibrillator (CRT-D) hospitalized with BSI were investigated. This is a single-centre, retrospective, cohort analysis including consecutive ICD/CRT-D patients implanted between 2012 and 2021. These patients were screened against a list of all hospitalized patients having positive blood cultures consistent with diagnosed infection in any department of a local public hospital. The total cohort consisted of 515 patients. Over a median follow-up of 59 months (interquartile range 31-87 months), there were 47 BSI episodes in 36 patients. The majority of patients with BSI (92%) was admitted to non-cardiology units, and in 25 episodes (53%), no cardiac imaging was performed. Nearly all patients (85%) were treated with short-term antibiotics, whereas chronic antibiotic suppression therapy (n = 4) and system extraction (n = 3) were less frequent. Patients with BSI had a nearly seven-fold higher rate (hazard ratio 6.7, 95% confidence interval 3.9-11.2; P < .001) of all-cause mortality. Diagnostic workup of defibrillator patients with BSI admitted to a non-cardiology unit is often insufficient to characterize lead-related endocarditis. The high mortality rate in these patients with BSI may relate to underdiagnosis and consequently late/absence of system removal. Efforts to increase an interdisciplinary approach and greater use of cardiac imaging are necessary for timely diagnosis and adequate treatment.

A Revised Definition of Left Bundle Branch Block Using Time to Notch in Lead I

Current left bundle branch block (LBBB) criteria are based on animal experiments or mathematical models of cardiac tissue conduction and may misclassify patients. Improved criteria would impact referral decisions and device type for cardiac resynchronization therapy. To develop a simple new criterion for LBBB based on electrophysiological studies of human patients, and then to validate this criterion in an independent population. In this diagnostic study, the derivation cohort was from a single-center, prospective study of patients undergoing electrophysiological study from March 2016 through November 2019. The validation cohort was assembled by retrospectively reviewing medical records for patients from the same center who underwent transcatheter aortic valve replacement (TAVR) from October 2015 through May 2022. Patients were classified as having LBBB or intraventricular conduction delay (IVCD) as assessed by intracardiac recording. Sensitivity and specificity of the electrocardiography (ECG) criteria assessed in patients with LBBB or IVCD. A total of 75 patients (median [IQR] age, 63 [53-70.5] years; 21 [28.0%] female) with baseline LBBB on 12-lead ECG underwent intracardiac recording of the left ventricular septum: 48 demonstrated complete conduction block (CCB) and 27 demonstrated intact Purkinje activation (IPA). Analysis of surface ECGs revealed that late notches in the QRS complexes of lateral leads were associated with CCB (40 of 48 patients [83.3%] with CCB vs 13 of 27 patients [48.1%] with IPA had a notch or slur in lead I; P = .003). Receiver operating characteristic curves for all septal and lateral leads were constructed, and lead I displayed the best performance with a time to notch longer than 75 milliseconds. Used in conjunction with the criteria for LBBB from the American College of Cardiology/American Heart Association/Heart Rhythm Society, this criterion had a sensitivity of 71% (95% CI, 56%-83%) and specificity of 74% (95% CI, 54%-89%) in the derivation population, contrasting with a sensitivity of 96% (95% CI, 86%-99%) and specificity of 33% (95% CI, 17%-54%) for the Strauss criteria. In an independent validation cohort of 46 patients (median [IQR] age, 78.5 [70-84] years; 21 [45.7%] female) undergoing TAVR with interval development of new LBBB, the time-to-notch criterion demonstrated a sensitivity of 87% (95% CI, 74%-95%). In the subset of 10 patients with preprocedural IVCD, the criterion correctly distinguished IVCD from LBBB in all cases. Application of the Strauss criteria performed similarly in the validation cohort. The findings suggest that time to notch longer than 75 milliseconds in lead I is a simple ECG criterion that, when used in conjunction with standard LBBB criteria, may improve specificity for identifying patients with LBBB from conduction block. This may help inform patient selection for cardiac resynchronization or conduction system pacing.

Incidence, management and prognosis of new-onset sarcoidosis post COVID-19 infection.

SARS-CoV-2 infection has been linked to hyperinflammation in multiple organs with a potential mechanistic link with resulting autoimmunity. There have been reports of many inflammatory complications following COVID-19, including sarcoidosis. A literature review on new-onset sarcoidosis following COVID-19 is lacking. We evaluated potential associations between COVID-19 and development of new-onset sarcoidosis. Articles discussing biopsy-proven sarcoidosis after confirmed COVID-19 infection, published 1956 until April 2023, were included. All article types were deemed eligible except opinion and review articles. A pooled total of 15 patients with new-onset diagnosis of sarcoidosis after COVID-19 infection were included, 45.5% female, mean age 46.1 years (standard deviation 14.7) at onset of sarcoidosis. Patients were from: Europe (n=11); North America (n=2); South America (n=1); Asia (n=1). The mean time between COVID-19 infection and diagnosis of sarcoidosis was 56.3 days, although this ranged from 10 to 140 days. Organ systems predominantly affected by sarcoidosis were: pulmonary (n=11); cutaneous (n=3); cardiac (n=2); ocular (n=1); systemic (n=1) (with overlapping features in certain patients). Sarcoidosis was treated as follows: glucocorticoids (n=8); azathioprine (n=1); cardiac re-synchronisation therapy (n=1); heart transplant (n=1). All patients were reported to have survived, with one requiring intensive care admission. Our result suggests there is a potential link between COVID-19 and new-onset sarcoidosis. The potential mechanism for this is through cytokine mediated immune modulation in COVID-19 infection. Obtaining a tissue sample remains key in confirming the diagnosis of sarcoidosis and this may be delayed during active COVID-19 infection.

Different methods of 3D QRS area calculation from vectorcardiographic X, Y, and Z Leads.

3DQRSarea is a strong marker for cardiac resynchronization therapy and can be obtained by taking the (i) summation or the (ii) difference of the areas subtended by positive and negative deflections in X, Y, Z vectorcardiographic electrocardiogram (ECG) leads. We correlated both methods with the instantaneous-absolute-3D-voltage-time-integral (VTIQRS-3D). 3DQRSarea consistently underestimated the VTIQRS -3D, but the summation method was a closer and more reliable approximation. The dissimilarity was less apparent in left bundle branch block (r2 summation.996vs. difference.972) and biventricular paced ECGs (r2.996vs..957) but was more apparent in normal ECGs (r2.988vs..653).

A three-dimensional left atrial motion estimation from retrospective gated computed tomography: application in heart failure patients with atrial fibrillation.

A reduced left atrial (LA) strain correlates with the presence of atrial fibrillation (AF). Conventional atrial strain analysis uses two-dimensional (2D) imaging, which is, however, limited by atrial foreshortening and an underestimation of through-plane motion. Retrospective gated computed tomography (RGCT) produces high-fidelity three-dimensional (3D) images of the cardiac anatomy throughout the cardiac cycle that can be used for estimating 3D mechanics. Its feasibility for LA strain measurement, however, is understudied. The aim of this study is to develop and apply a novel workflow to estimate 3D LA motion and calculate the strain from RGCT imaging. The utility of global and regional strains to separate heart failure in patients with reduced ejection fraction (HFrEF) with and without AF is investigated. A cohort of 30 HFrEF patients with (n = 9) and without (n = 21) AF underwent RGCT prior to cardiac resynchronisation therapy. The temporal sparse free form deformation image registration method was optimised for LA feature tracking in RGCT images and used to estimate 3D LA endocardial motion. The area and fibre reservoir strains were calculated over the LA body. Universal atrial coordinates and a human atrial fibre atlas enabled the regional strain calculation and the fibre strain calculation along the local myofibre orientation, respectively. It was found that global reservoir strains were significantly reduced in the HFrEF + AF group patients compared with the HFrEF-only group patients (area strain: 11.2 ± 4.8% vs. 25.3 ± 12.6%, P = 0.001; fibre strain: 4.5 ± 2.0% vs. 15.2 ± 8.8%, P = 0.001), with HFrEF + AF patients having a greater regional reservoir strain dyssynchrony. All regional reservoir strains were reduced in the HFrEF + AF patient group, in whom the inferior wall strains exhibited the most significant differences. The global reservoir fibre strain and LA volume + posterior wall reservoir fibre strain exceeded LA volume alone and 2D global longitudinal strain (GLS) for AF classification (area-under-the-curve: global reservoir fibre strain: 0.94 ± 0.02, LA volume + posterior wall reservoir fibre strain: 0.95 ± 0.02, LA volume: 0.89 ± 0.03, 2D GLS: 0.90 ± 0.03). RGCT enables 3D LA motion estimation and strain calculation that outperforms 2D strain metrics and LA enlargement for AF classification. Differences in regional LA strain could reflect regional myocardial properties such as atrial fibrosis burden.

Landmark Evolutions in Time and Indication for Cardiac Resynchronization Therapy: Results from a Multicenter Retrospective Registry.

Background: Cardiac resynchronization therapy (CRT) has evolved into an established therapy for patients with chronic heart failure and a wide QRS complex. Data on long-term outcomes over time are scarce and the criteria for implantation remain a subject of investigation. Methods: An international, multicenter, retrospective registry includes 2275 patients who received CRT between 30 November 2000 and 31 December 2019, with a mean follow-up of 3.6 ± 2.7 years. Four time periods were defined, based on landmark trials and guidelines. The combined endpoint was a composite of all-cause mortality, heart transplantation, or left ventricular assist device implantation. Results: The composite endpoint occurred in 656 patients (29.2%). The mean annual implantation rate tripled from 31.5 ± 17.4/year in the first period to 107.4 ± 62.4/year in the last period. In the adjusted Cox regression analysis, the hazard ratio for the composite endpoint was not statistically different between time periods. When compared to sinus rhythm with left bundle branch block (LBBB), a non-LBBB conduction pattern (sinus rhythm: HR 1.51, 95% CI 1.12-2.03; atrial fibrillation: HR 2.08, 95% CI 1.30-3.33) and a QRS duration below 130 ms (HR 1.64, 95% CI 1.29-2.09) were associated with a higher hazard ratio. Conclusions: Despite innovations, an adjusted regression analysis revealed stable overall survival over time, which can at least partially be explained by a shift in patient characteristics.

Impact of Chronotropic Incompetence and Correlation with Exercise Tolerance in Patients with Implantable Cardiac Devices Undergoing a Phase II Cardiac Rehabilitation Program Article Sidebar

Objective: Since patients with implantable cardiac devices tend to develop chronotropic incompetence (CI) associated with the effect of the device itself or the pharmacological effect of the underlying disease, CI could act as a limiting factor in improving exercise tolerance in patients undergoing cardiac rehabilitation program, since an increase in HR is a crucial part in improving cardiac output as a central component of oxygen consumption (VO2). However, it has been observed that there could be other factors contributing to the improvement in exercise tolerance in these patients regardless of the presence of CI. The aim of this research is to clarify the effect of chronotropic incompetence on the improvement in exercise capacity in patients with implantable cardiac devices after a phase II cardiac rehabilitation program (CRP). Methods: Quasi-experimental study applied to patients with implantable cardiac devices (ICDs, CRT, pacemakers) undergoing a supervised concurrent CRP, lasting 4-6 weeks, at an intensity between 65-80% of heart rate reserve (HRR), associated with kinesiotherapy sessions (with strength and endurance training and other biomotor qualities) and interdisciplinary intervention, education, and counseling. CI was calculated using the chronotropic response index, and METs-load measurement was performed at the beginning and at the end of the intervention. Results: Forty patients with a mean age of 61.4 years were included, mostly male (29) 72.5%, (23) 57.5% diagnosed with heart failure, and regarding the type of device, pacemakers (20) 50%, implantable cardioverter-defibrillator (ICD) (12) 30%, and cardiac resynchronization therapy with defibrillator (CRT-D) (20) 8%, of the total patients (35) 87.5% presented chronotropic incompetence and only (5) 12.5% with normal chronotropic response at the end of the intervention. A significant decrease in the chronotropic response index from 0.70 to 0.47 (p &lt;0.001) and a significant increase in METs-load from 5.47 to 9.35 (p &lt;0.001) were found. The value of the differential between initial and final METs (delta-METs) was obtained for both groups, observing a significant increase between initial and final METs in favor of patients with CI (3.8 Vs 3.5, p&lt;0.012) at the end of the intervention. A significant moderate negative correlation (r=-0.395, Spearman, p&lt;0.012) was determined between the degree of CI and final METs-load. Conclusions: It was observed that patients with implantable cardiac devices undergoing a CRP show an increase in exercise tolerance measured in METs, with an inversely proportional correlation to chronotropic incompetence.

Response predictors to cardiac resynchronization therapy in chronic heart failure: a 10-year-cardiovascular center experience.

Cardiac resynchronization therapy (CRT) has been established as an effective therapy for heart failure with reduced ejection fraction. Randomized clinical trials have shown its impact on mortality and HF hospitalizations, as well as improvement of symptoms and quality of life. Finding clinical, electrocardiographic, and echocardiographic variables that may predict the response to cardiac resynchronization therapy (CRT). We performed a single-center, observational, analytic, and retrospective study that included 102 patients with heart failure (HF) diagnosis who underwent CRT according to guideline-directed therapy from January 2010 to April 2020 in a third-level center. CRT response was defined as an improvement of New York Heart Association functional class in at least 1 category associated with a recovery of ≥ 5% in the left ventricular ejection fraction (LVEF). Our study population was 102 patients of which 61 (59.8%) were men. The mean age at HF diagnosis was 54 ± 18.7 years. Ischemic heart disease was the etiology in 37 (36.3%) cases. Fifty-one (50%) patients were classified as responders. Responders had wider QRS, and lower LVEF and right ventricular fractional area change at baseline. After CRT, responders had a greater reduction of QRS duration, and improvement in LVEF, global longitudinal strain, and echocardiographic dyssynchrony parameters. Multivariate regression analysis showed that left bundle branch block (LBBB), left ventricular end-diastolic volume (LVEDV), tricuspid annular plane systolic excursion (TAPSE), and baseline difference of pre-ejection periods were predictors of a positive response to CRT in this population. LBBB, TAPSE, LVEDV, and pre-ejection time difference are independent variables that can predict adequate response to CRT.

Immediate pharmacotherapy intensification after cardiac resynchronization therapy: incidence, characteristics, and impact.

Cardiac resynchronization therapy (CRT) is an established treatment for drug-refractory heart failure (HF) in patients with left bundle branch block (LBBB). Acute haemodynamic improvement after CRT implantation may enable the intensification of HF medication soon thereafter. Immediate pharmacotherapy intensification (IPI) after CRT implantation achieves a synergetic effect, possibly leading to a better prognosis. This study aimed to explore the incidence, characteristics, and impact of IPI on real-world outcomes among CRT recipients with a history of hospitalization for acute HF. This multicentre retrospective study enrolled CRT recipients with LBBB morphology, a QRS width ≥120ms, a left ventricular ejection fraction ≤35%, and New York Heart Association II-IV HF symptoms. All patients had previous HF hospitalizations within the previous year and received guideline-directed medical therapy before CRT implantation. Patient baseline characteristics, including HF medication, were collected. IPI was defined as the intensification of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists within 30days of CRT implantation. The primary endpoint was all-cause death or first hospitalization for HF; the secondary endpoint was all-cause death. We enrolled 194 patients (75% male; mean age, 65±13years; 78% with non-ischaemic cardiomyopathy). One hundred five (54%) patients received IPI. Patients who received IPI exhibited a significantly shorter QRS duration (159±26 vs. 171±32ms; P=0.004), higher estimated glomerular filtration rate (55.2±20.0 vs. 47.8±24.7mL/min/1.73m2 ; P=0.022), and more dilated cardiomyopathy. During a median follow-up period of 29months, 70 (36%) patients reached the primary endpoint and 42 (22%) patients died. Patients with IPI showed significantly better outcomes for the primary and secondary endpoints than patients without IPI. The volumetric responder ratio at 6months after implantation was not significantly different between patients with and without IPI; however, patients who received IPI had reduced mortality even at 6months after implantation. In the multivariate analysis, IPI was an independent predictor of the primary endpoint (hazard ratio, 0.51; 95% confidence interval, 0.27-0.97; P=0.043). Immediate intensification of HF medication was achieved in 54% of CRT recipients and was significantly higher in patients without excessive QRS prolongation, preserved renal function, and dilated cardiomyopathy than others. In patients with LBBB morphology and QRS≥120ms, IPI was associated with a significantly better prognosis and fewer HF hospitalizations after CRT implantation than others.

Clinical significance of regional constructive and wasted work in patients receiving cardiac resynchronization therapy.

Previous studies have shown that global constructive work (CW) and wasted work (WW) predict response to cardiac resynchronization therapy (CRT). This study evaluated the predictive value of regional CW and WW for reverse remodeling and clinical outcomes after CRT. We performed a prospective study involving 134 CRT candidates with left bundle branch block and left ventricular ejection fraction ≤35%. Global and regional CW and WW were calculated using pressure-strain loop analysis. CRT response was defined by reverse remodeling as a reduction of ≥15% in left ventricular end-systolic volume after six months. At six-month follow-up, 92 (69%) patients responded to CRT. Of the regional CW and WW measures, lateral wall (LW) CW and septal WW were most strongly and significantly correlated with reverse remodeling. At multivariate analysis, LW CW and septal WW were both independent determinants of reverse remodeling. When LW CW and septal WW were included in the model, global CW and WW were not independently associated with reverse remodeling. LW CW and septal WW predicted reverse remodeling with an area under the curve (AUC) of 0.783 (95% CI: 0.700-0.866) and 0.737 (95% CI: 0.644-0.831), respectively. Using both variables increased the AUC to 0.832 (95% CI: 0.755-0.908). Both LW CW ≤878 mmHg% (HR 2.01; 95% CI: 1.07-3.79) and septal WW ≤181 mmHg% (HR 2.60; 95% CI: 1.38-4.90) were significant predictors of combined death and HF hospitalization at two-year follow-up. LW CW and septal WW before CRT are important determinants of reverse remodeling and clinical outcomes.