Cardiac Resynchronization In Patients Research Articles

Short-term cost-utility analysis of biventricular cardiac resynchronization therapy in comparison with left bundle branch area pacing cardiac resynchronization therapy

Abstract Background Cardiac resynchronisation therapy (CRT) is a well-established form of treatment for patients with heart failure and cardiac dyssynchrony. Recently, left bundle branch area pacing (LBBAP) has emerged as a more physiological alternative for biventricular pacing (BiVP) cardiac resynchronization therapy (1,2). Purpose The purpose of this study was to conduct a cost-utility analysis for LBBAP CRT, compared to BiVP CRT in a cohort of patients with heart failure from the Spanish health system perspective. Methods A multicenter prospective quasi-experimental study in which 44 consecutive patients underwent CRT was conducted. According to the study protocol, the four centers would perform their usual clinical practice: two out of them would perform conventional BiVP-CRT while the other half LBBAP-CRT. Intention-to-treat analysis was carried-out. Health outcomes were quality-adjusted life years (QALYs), measured by the EuroQol-5D-5L questionnaire, which the patients were asked to complete at baseline and 12 weeks after the CRT device implantation. The total direct costs include device, leads, guidewires, introducer kits, sheats and operating theater time. The results were expressed as the incremental cost-utility ratio (ICUR). In order to analyze the uncertainty of ICUR results, we performed a non-parametric bootstrapping with 1000 replications. Results The LBBAP procedure was attempted for a total of 26 consecutive patients (1 patient underwent rescue BiVP), while BiVP was attempted for 18 patients (2 patients switched to LBBAP). Mean QALYs over 3 months were 0.1914 ± 0.009 in the LBBAP CRT group and 0.1904 ± 0.0112 in the BiVP CRT. Improvements from baseline were greater in the LBBA CRT group but not statistically significant. The total costs at the end of the intervention were 7546.6 €± 602.15€ in the LBBAP CRT group and 16064.56€ ± 723.7€ in the BiVP CRT group. When excluding from the analysis the cases in which ICD was implanted, the mean difference in QALYs is 0.002; 95% confidence interval [95%CI]: -0.03 to 0.036) and the mean saving is -3.510.38 €. The LBBAP CRT leads to cost savings for the health system and similar QALYs outcomes; 95%CI: -6.660 to -360.71. Based on 1000 bootstrapping replication, the cost savings of using LBBAP vs BiVP occur in 99% of the simulations. Conclusion LBBAP CRT is an efficient alternative to BiVP CRT for cardiac resynchronization in patients with heart failure with similar results in terms of QALYs but with significant average savings per patient.Cost-utility plane for 1000 bootstrappedBaseline characteristics of patients

Effectiveness of left bundle branch area pacing to restore narrow QRS in patients with right bundle branch block

Abstract Background/Introduction Left bundle branch area pacing (LBBaP) is an innovative technique used to capture conduction tissue and maintain ventricular synchrony during pacing. There are few data about the efficacy of LBBaP in right bundle branch block (RBBB). Purpose To compare the response to LBBaP, evaluated by the change in QRS duration (QRSd) after pacing, in patients with RBBB, left bundle branch block (LBBB) or without conduction disorder. Methods A total of 162 patients with pacemaker indication underwent LBBaP with stylet driven lead with dedicated sheaths, between November 2020 and April 2023. ECG characteristics were evaluated. Data are presented in mean ± standard deviation (SD) or n (%). Paired sample t-test was used to compare QRSd before and after pacing. Results Indications for pacing were atrioventricular block (AVB) 48,4 %, sinus node dysfunction (SND) 37,7 %, AVB and SND 10,7 % and cardiac resynchronization therapy 3,1 %. LBBaP was successfully performed in 98 % (159/162) of patients (78 ± 10 years, 62 % male). Overall, baseline QRSd was 113,2 ± 26,7 ms and paced QRSd was 112,3 ± 14,8 ms (p = 0,662), with left ventricular activation time (LVAT) of 69 ± 14 ms (table 1). Baseline ECG showed 18 LBBB, 29 RBBB and 11 undetermined conduction disorder. In every kind of conduction disorder, paced QRSd was reduced to < 120 ms (table 2). Notably, paced QRSd was < 120 ms, regardless of baseline QRSd. In patients with most important pre-existing conduction disorder (QRS ≥ 145 ms), an impressive reduction in QRSd was observed (Delta = -40,8 ms , table 1). Conclusion LBBaP with stylet driven lead is an effective approach to obtain short paced QRS regardless of baseline QRSd and of the nature of the initial conduction disorder. This opens new perspectives for cardiac resynchronization in patients with RBBB.

Changes in medical therapy after cardiac resynchronization in patients with heart failure: insights from the U.S. Veterans Affairs healthcare system

Abstract Background Patients with heart failure with reduced ejection fraction (HFrEF) are often not treated with comprehensive guideline directed medical therapy (GDMT) due to hemodynamic and renal limitations. Cardiac resynchronization therapy (CRT) improves hemodynamics in patients with HFrEF and ventricular dyssynchrony. Whether CRT facilitates intensification of GDMT in patients with HFrEF has not been well-studied. Purpose To assess pre-procedure GDMT (B-blocker, ACEI [angiotensin converting enzyme inhibitor]/ARB [angiotensin receptor blocker], ARNI [angiotensin receptor neprilysin inhibitor], MRA [mineralocorticoid receptor antagonist], SGLT2i [sodium-glucose cotransporter-2 inhibitor]) utilization in HFrEF patients who received CRT and to compare changes in GDMT in patients who received CRT with patients who received implantable cardioverter-defibrillator (ICD). Methods Veterans with left ventricular ejection fraction (LVEF) 35% who received CRT or ICD from Feb 22, 2000 – Jul 28, 2022 were identified. Patients with end-stage renal disease were excluded. Changes in GDMT 12-months following device implant were characterized and compared between CRT and ICD recipients. Mixed effects logistic regression models were generated to evaluate associations between receipt of CRT and the composite of therapy initiation, dose increase, or target dose achievement compared with ICD. Models were adjusted for clinical characteristics and pre-implant GDMT utilization. Similar models were developed to evaluate the adjusted associations between CRT and changes in estimated glomerular filtration rate (eGFR) and blood pressure (BP) compared with ICD. Results A total of 2,082 CRT recipients and 7,263 ICD recipients were identified. Pre-procedure heart rate, BP, serum potassium, and eGFR were within normal ranges and similar between groups. Prior to device implant, ACEI/ARB/ARNI were most frequently prescribed (91%), followed by -blockers (88%), MRA (46%), and SGLT2i (33% in post-SGLT2i era). Pre-procedure GDMT was similar between CRT and ICD recipients. At 12 months follow-up, CRT was independently associated with increased odds of therapy initiation, dose increase, or target dose achievement for ACEI/ARB/ARNI, ARNI, B-blockers, and MRA (Figure 1). ICD was associated with a decline in eGFR while CRT was associated with an increase in eGFR (mean [standard deviation]: -0.95 [0.17] vs. +0.6 [0.29]; p<0.01), while no differences were observed in BP or LVEF at 12 months. Conclusions In a large, contemporary cohort of patients with HFrEF, most patients were not prescribed MRA or SGLT2i prior to receiving CRT or ICD despite no apparent renal or blood pressure-related contraindications. CRT is associated with increased odds of the composite of initiation, dose increase, or target dose achievement for ACEI/ARB/ARNI, ARNI, B-blockers, and MRA compared with ICD. GDMT intensification may be mediated by beneficial changes in kidney function in CRT recipients.Figure 1

Effects of sacubitril/valsartan on cardiac reverse remodeling and cardiac resynchronization in patients with acute myocardial infarction.

In 2014, the PARADIGM-HF trial (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) has shown that sacubitril/valsartan can reduce the risk of hospitalization and death from cardiovascular causes more effectively than enalapril (an ACEI) in heart failure patients with reduced ejection fraction (HFrEF). Similarly, the PARADIGM-HF trial (Comparison of Sacubitril-Valsartan vs. Enalapril on Effect on NT-proBNP in Patients Stabilized from an Acute Heart Failure Episode) came to similar conclusions and extended the PARADIGM-HF trial results in 2019. Since then, numerous new studies have provided further insight in HFrEF, sacubitril/valsartan can reduce N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, increase left ventricular ejection fraction (LVEF), reverse ventricular remodeling, and reduce other non-fatal manifestations of clinical deterioration as compared to ACEI/ARB. However, few trials have compared the effects of these drugs in patients shortly after AMI. Therefore, it is necessary to further explore the clinical efficacy and safety of sacubitril/valsartan vs. valsartan in patients with AMI. We conducted an open-label, prospective, randomized controlled trial to determine the superiority in ameliorating ventricular remodeling and preventing of heart failure in patients with AMI after percutaneous coronary intervention (PCI), 148 patients were randomly assigned (85 to sacubitril/valsartan and 63 to valsartan). LAV, LVDV, and LVSV were all decreased in the sacubitril/valsartan group when compared with before treatment, but there was no difference between the sacubitril/valsartan group and the valsartan group. In addition, compared with before treatment in the sacubitril/valsartan group, the heart global work index (GWI) and the global work efficiency (GWE) increased, while the heart global wasted work (GWW) decreased. Patients in the sacubitril/valsartan group have similar MACE and adverse side effects to those in the valsartan group. Sacubitril/valsartan has the same performance as valsartan in inhibiting ventricular remodeling and preventing heart failure after PCI in patients with AMI, and its clinical application is safe. It provides a clinical foundation for the application of sacubitril/valsartan in patients with AMI.

Dubious effect of the high biventricular paced beats percentage itself on the cardiac resynchronization efficacy in patients with atrial fibrillation. The randomized Pilot-CRAfT Study results

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institute of Cardiology statutory grant Background The presence of atrial fibrillation (AF) in cardiac resynchronization therapy (CRT) recipients is common and AF is a marker of poorer CRT response. The negative influence of AF on CRT efficacy is belived to be mediated mainly by the drop of effectively captured biventricular paced beats percentage (BiVp%). According to observational trials, the minimal BiVp associated with better outcomes is 95-98%, however there is lack of randomized trials to confirm this findings. Purpose The purpose of the study was to assess the influence of BiVp% itself on the clinical outcomes in the population CRT patients with atrial fibrillation in a prospective, randomized cohort. Methods The study included the prospective Pilot-CRAfT study participants that is patients with CRT and permanent or persistent AF lasting for ≥6 months that were randomly assigned to rhythm or rate control strategy. We divided the whole study population according to their BiVp at the 12 month follow-up with two borderline BiVp values (BiVp >98% vs <98% and >95% vs <95%) and analysed the echocardiographic indices, exercise tolerance and quality of life between the prespecified groups. Results The study included 43 CRT patients (97,7% males) aged 68,4 (SD: ±8,3) years with mean BiVp% 82,4% ±9,7% at baseline. The mean baseline left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter (LVEDD) and maximal oxygen uptake (VO2max) were: 30 ±8%, 65 ±8 mm, 14 ±5 mL/(kg*min), respectively. In both of the study arms the BiVp% raised significantly reaching 98,1 ±2,3% and 96,3 ±3,9% in the rhythm control and the rate control arms respectively (P=0,093). As a result the were overall 21 patients with BiVp >98% and 29 patients with BiVp >95% at the end of the study. The BiVp groups >98% vs <98% and >95% vs <95% did not differ as to baseline characteristics and we have not observed any differences in the mean LVEF, mean LVEDD, mean VO2max, and quality of life in the prespecified BiVp% groups at the end of the follow up. Moreover no linear correlations between the BiVp% and LVEF, LVEDD, VO2max values were observed. However, in the rate control group patients with AVNA performed had lower LVEDD at the end of the study (57,7 ±3,0 vs 65,4 ±7,0 p=0,007) and significant decrease in the LVEDD after AVNA was observed (-8,6 95%CI [-14,9; -2,3]). Conclusions The BiVp >98% or >95% alone does not seem to warrant good response to cardiac resynchronization in patients with persistent atrial fibrillation as assessed in the prospective randomized cohort. However, performing AVNA in this group of patients may be beneficial in terms of LVEDD decrease.

Conduction system pacing in cardiac resynchronization: short-mid term follow-up

Abstract Background Conduction system pacing (CSP) includes both His Bundle Pacing (HBP) and left bundle branch pacing (LBBP). It engages the conduction system ensuring synchronous activation of ventricles, potentially acting as cardiac resynchronization. Purpose The aim of the study is to report technical and clinical outcomes of CSP (HBP or LBBP) utilized in patients referred for cardiac resynchronization therapy. Methods CSP was applied in 51 patients (mean age 75±9 years; 47 males) referred for cardiac resynchronization therapy. 41 cases were de-novo implant and 10 were up-grading after PICM. Ischemic aetiology was present in 23 (45%) patients, hypertension in 31 (61%); diabetes in 19 (37%), severe kidney disease in 4 (8%). Devices were checked 48 hours and 1 month after implant and then remotely. Clinical, echocardiographic, electrocardiographic data were also collected. Results Conduction system pacing was successfully obtained in 45 (88.3%) patients. In 28 (62%) cases the lead was implanted in the His Bundle and in 17 (38%) in the left bundle. In 6 (11.7%) patients it was not possible to fix the lead in the His Bundle neither in the Left bundle, in these cases a standard quadripolar lead in the coronary sinus was implanted. In 28 (62%) patients was utilized the 3830 4 Fr lumen-less lead and in the remaining 17 (38%) cases a standard stylet-driven lead. Basal mean EF was 33±9% and improved to 42±9% (P<0.005) after a mean follow-up of 266±212 days. Baseline QRSd narrowed from 168±35 ms to135±12 ms. Four (8.8%) patients were hospitalized due to HF symptoms (in 2 cases fast AF was recorded and treated with AV nodal ablation, in 2 cases significant mitral regurgitation). Conclusions Conduction system pacing can act effectively as cardiac resynchronization in patients with severe cardiac disfunction and bundle branch block with high success rate, significantly narrowed QRS and improved EF at short-medium term follow-up. Funding Acknowledgement Type of funding sources: None. Case report: CRT-D including LB lead

The QR-max index, a novel electrocardiographic index for the determination of left ventricular conduction delay and selection of cardiac resynchronization in patients with non-left bundle branch block.

Non-left bundle branch block (non-LBBB) remains an uncertain indication for cardiac resynchronization therapy (CRT). Non-LBBB includes right bundle branch block (RBBB) and non-specific LV conduction delay (NSCD), two different electrocardiogram (ECG) patterns which are not generally considered to be associated with LV conduction delay as judged by the invasive assessment of the Q-LV interval. We evaluated whether a novel ECG interval (QR-max index) correlated with the degree of LV conduction delay regardless of the type of non-LBBB ECG pattern, and could, therefore, predict CRT response. In 173 non-LBBB patients on CRT (92 NSCD, 81 RBBB), the QR-max index was measured as the maximum interval from QRS onset to R-wave offset in the limb leads. The correlation between QR-max index and Q-LV interval and the impact of the QR-max index on time to first heart failure hospitalization during 3-year follow-up were assessed. Q-LV correlated better with the QR-max index than with QRSd, particularly in the RBBB group (r= 0.91; p< 0.001 vs. r= 0.19; p< 0.089), while the correlations were r= 0.79 (p< 0.01) and r= 0.68 (p< 0.01), respectively, in the NSCD group. In both groups, the QR-max index was significantly more able than QRSd to identify CRT responders (AUC 0.825 vs. 0.576; p= 0.0008 in RBBB; AUC 0.738 vs. 0.701; p= 0.459 in NSCD). A QR-max index exceeding a cutoff value of 120ms was associated with CRT response, with predictive values of 86.8 and 81.4% in RBBB and NSCD, respectively. The QR-max index reflects the degree of LV electrical delay regardless of QRS duration in RBBB and NSCD patients and is a useful indicator of suitability for CRT in non-LBBB patients.

Impact of anticoagulationtherapy on outcomes in patients with cardiac implantable resynchronization devices undergoing transvenous lead extraction: A substudy of the ESC-EHRA EORP ELECTRa (European Lead Extraction ConTRolled) Registry.

Little data are available on anticoagulation (AC) management in patients with cardiac resynchronization (CRT) devices who undergotransvenous lead extraction (TLE) procedure. We investigated the impact of AC on periprocedural complications in CRT patients undergoing TLE, enrolled in the ESC-EHRA European Lead Extraction ConTrolled (ELECTRa) registry. All CRT patients treated with TLE enrolled in the registry were considered. Perioperative AC management was left to the discretion of the Center. Major and minor intraprocedural and postprocedural complications were compared between patients without AC (Gp1) and patients with AC (Gp2). Regression analyses were performed to identify predictors of complications for Gp2. Out of 734 CRT pts, 328 (44.7%) were under AC (Gp2). Patients from Gp2 presented lower LVEF (Gp2 32.5 ± 10.9 vs Gp1 34.5 ± 11.9%; P = 0.03), more advanced heart failure disease (NYHA III/IV: Gp2 42.0 vs Gp1 31.5%; P = 0.02), and renal impairment (Gp2 39.0 vs Gp1 24.3%; P < 0.001). Perioperative regimens included AC interruption (Gp2A: n = 169, 51.5%), "bridging" (Gp2B: n = 135, 41.2%), or continued AC (Gp2C: n = 24, 7.3%). TLE complete success rates (98% in both groups) and major complication rates were comparable for both groups; minor bleeding events were more frequent in Gp2 (5.5%) compared to Gp1 (2.5%; P = 0.051). No independent predictors were identified for Gp2, but minor complications were associated with "bridging" approach (Gp2B: 16 events vs Gp2A/C: 9 events; P = 0.020). CRT patients treated with TLE under AC were more compromised but did not present more major complications compared to patients without AC. More minor complications were associated with "bridging" AC regimen.

ECG Adapted Fastest Route Algorithm to Localize the Ectopic Excitation Origin in CRT Patients.

Although model-based solution strategies for the ECGI were reported to deliver promising clinical results, they strongly rely on some a priori assumptions, which do not hold true for many pathological cases. The fastest route algorithm (FRA) is a well-established method for noninvasive imaging of ectopic activities. It generates test activation sequences on the heart and compares the corresponding test body surface potential maps (BSPMs) to the measured ones. The test excitation propagation patterns are constructed under the assumption of a global conduction velocity in the heart, which is violated in the cardiac resynchronization (CRT) patients suffering from conduction disturbances. In the present work, we propose to apply dynamic time warping (DTW) to the test and measured ECGs before measuring their similarity. The warping step is a non-linear pattern matching that compensates for local delays in the temporal sequences, thus accounting for the inhomogeneous excitation propagation, while aligning them in an optimal way with respect to a distance function. To evaluate benefits of the temporal warping for FRA-based BSPMs, we considered three scenarios. In the first setting, a simplified simulation example was constructed to illustrate the temporal warping and display the resulting distance map. Then, we applied the proposed method to eight BSPMs produced by realistic ectopic activation sequences and compared its performance to FRA. Finally, we assessed localization accuracy of both techniques in ten CRT patients. For each patient, we noninvasively imaged two paced ECGs: from left and right ventricular implanted leads. In all scenarios, FRA-DTW outperformed FRA in terms of LEs. For the clinical cases, the median (25–75% range) distance errors were reduced from 16 (8–23)mm to 5 (2–10)mm for all pacings, from 15 (11–25)mm to 8 (3–13)mm in the left, and from 19 (6–23)mm to 4 (2–8)mm in the right ventricle, respectively. The obtained results suggest the ability of temporal ECG warping to compensate for an inhomogeneous conduction profile, while retaining computational efficiency intrinsic to FRA.

Cardiac Resynchronization Therapy in Preserved to Mildly Reduced Systolic Function.

Cardiac resynchronization therapy has been proven to be clearly beneficial for patients with heart failure, a prolonged QRS duration, and a left ventricular ejection fraction ≤35%. Ejection fraction cutoff, however, is arbitrary and very likely excludes many patients who could benefit from cardiac resynchronization. This article describes the major detrimental effects of left bundle branch block and summarizes the data regarding the potential beneficial effects of cardiac resynchronization in patients with a left ventricular ejection fraction greater than 35%.

A randomized controlled trial of atrioventricular junction ablation and cardiac resynchronization therapy in patients with permanent atrial fibrillation and narrow QRS.

We tested the hypothesis that atrioventricular (AV) junction ablation in conjunction biventricular pacing [cardiac resynchronization (CRT)] pacing is superior to pharmacological rate-control therapy in reducing heart failure (HF) and hospitalization in patients with permanent atrial fibrillation (AF) and narrow QRS. We randomly assigned 102 patients (mean age 72 ± 10 years) with severely symptomatic permanent AF (>6 months), narrow QRS (≤110 ms), and at least one hospitalization for HF in the previous year to AV junction ablation and CRT (plus defibrillator according to guidelines) or to pharmacological rate-control therapy (plus defibrillator according to guidelines). After a median follow-up of 16 months, the primary composite outcome of death due to HF, or hospitalization due to HF, or worsening HF had occurred in 10 patients (20%) in the Ablation+CRT arm and in 20 patients (38%) in the Drug arm [hazard ratio (HR) 0.38; 95% confidence interval (CI) 0.18-0.81; P = 0.013]. Significantly fewer patients in the Ablation+CRT arm died from any cause or underwent hospitalization for HF [6 (12%) vs. 17 (33%); HR 0.28; 95% CI 0.11-0.72; P = 0.008], or were hospitalized for HF [5 (10%) vs. 13 (25%); HR 0.30; 95% CI 0.11-0.78; P = 0.024]. In comparison with the Drug arm, Ablation+CRT patients showed a 36% decrease in the specific symptoms and physical limitations of AF at 1 year follow-up (P = 0.004). Ablation+CRT was superior to pharmacological therapy in reducing HF and hospitalization and improving quality of life in elderly patients with permanent AF and narrow QRS. NCT02137187 (May 2018, date last accessed).

Influence of vitamin D on the percentage time of cardiac resynchronization in patients with heart failure, premature ventricular complexes, and chronic kidney disease

IntroductionRecent studies have shown that in chronic kidney disease (CKD) 25(OH)D deficiency or insufficiency are a significant risk factor for cardiovascular diseases, sudden cardiac death and mortality. The high incidence of premature ventricular complexes (PVCs) have increasingly been recognized as a primary cause for worsening left ventricular systolic function and heart failure in some patients, specialty when these subjects are under optimal treatment and have implantable cardiac defibrillator (ICD) with cardiac resynchronization therapy (CRT), because the great amount of PVCs reduces the percentage of cardiac resynchronization. AimOur aim was to evaluate the influence of reposition of cholecalciferol in patients with deficiency of vitamin D in the changes of the numbers of PVCs, and consequently in the percentage of cardiac resynchronization time, during 6months of follow-up. Methods and resultsWe conducted a prospective, longitudinal study of 56 patients with high incidence of PVCs, heart failure under optimal treatment, ICD+CRT, deficiency of vitamin D (≤20ng/mL) and CKD (estimated glomerular filtration rate measured by MDRD equation, between 16 and 59mL/min/1.73m2). All patients were treated with cholecalciferol. We observed significant ameliorating after cholecalciferol onset in the number of PVCs, CRT % time, renal function, vitamin D levels and plasmatic ions at the 6th month of follow-up vs. baseline. ConclusionsWe suggest that the effectiveness of cholecalciferol reposition for subjects with high incidence of PVCs, heart failure under optimal treatment, ICD+CRT, deficiency of vitamin D and CKD, restoring the function of the CRT, bringing the biventricular pacing to nearby 97%.

Right Ventricular Septal Pacing: In Lieu of Biventricular Pacing for Cardiac Resynchronization in a Patient With Right Bundle Branch Block? *

A 71-year-old male with ischemic cardiomyopathy, severe systolic left ventricular dysfunction and symptomatic heart failure was not considered a good candidate for implantation of a biventricular pacing system to effect cardiac resynchronization due to underlying right bundle branch block (RBBB). He received instead a dual-chamber implantable cardioverter defibrillation with the ventricular lead placed at an alternate site position at the high right ventricular septum. This resulted in significant narrowing of the QRS duration (resynchronization) with a good clinical response over short-term. The case illustrates a possible alternative approach to biventricular pacing for cardiac resynchronization in patients with RBBB.

New Heart Failure Guidelines Improve Prognosis, Quality of Life

New Heart Failure Guidelines Improve Prognosis, Quality of Life

Unexpected and rapid recovery of left ventricular function in patients with peripartum cardiomyopathy: impact of cardiac resynchronization therapy

Aim Peripartum cardiomyopathy (PPCM) is a rare cause of dilated cardiomyopathy responsible for heart failure toward the end of pregnancy, which can lead to chronic heart failure in 50% of cases. In this short report, we assessed the benefit of cardiac resynchronization in patients with PPCM and chronic systolic dysfunction despite optimal medical treatment. For the last 10 years, we managed eight patients diagnosed with PPCM. Two of them presented severe systolic dysfunction, and medical treatment resulted in limited improvement from 10% to 25% and from 25% to 28% despite optimal treatment for 9 and 6 years, respectively. These two patients were porposed to receive an implantatable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT). Six months after ICD-CRT treatment, we observed a significant improvement in systolic function from 25% to 45% and 28% to 50%, respectively, and positive remodelling with reduction of left ventricular end-diastolic volume from 216 to 144 mL and from 354 to 105 mL, which represent a 34% and a 70% reduction, respectively. Physicians in charge of patients with PPCM should offer the opportunity of CRT for patients whose cardiac function has not significantly improved under standard medical treatment.

Managing atrial fibrillation in the CRT patient: Controversy or consensus?

The cumulative incidence of new onset atrial fibrillation (AF) in patients undergoing cardiac resynchronization therapy (CRT) is substantial, exceeding 25% in multiple recent studies. Although AF patients undergoing CRT show improved echocardiographic parameters, functional status, and quality of life in, they benefit to a lesser degree than do patients in normal sinus rhythm. They also exhibit a trend toward increased mortality. Understanding the barriers to response from CRT among AF patients is critical to addressing the needs of growing populations of patients with AF and HF. Foremost among these are suboptimal biventricular pacing, often characterized by fusion or pseudo-fusion complexes, leading to inefficient CRT delivery. Furthermore, AF increases the risk of inappropriate shocks, which lead to substantial psychiatric morbidity, increased risk of heart failure hospitalization, and may also increase mortality. Assiduous rate control is reasonable for all AF patients receiving CRT, but there is a paucity of data regarding specific antiarrhythmic drug therapy recommendations. For patients with permanent AF and severe symptoms, atrioventricular junction ablation appears effective in improving response by ensuring biventricular capture and reducing implantable cardioverter-defibrillator shock burden in selected patients. Catheter-based techniques such as pulmonary vein isolation appear more attractive and in the future may offer further advantages and lower risks, particularly for patients with paroxysmal AF.

Role of AV Nodal Ablation in Cardiac Resynchronization in Patients With Coexistent Atrial Fibrillation and Heart Failure: A Systematic Review

The aim of this study was to systematically review the medical literature to evaluate the impact of AV nodal ablation in patients with heart failure and coexistent atrial fibrillation (AF) receiving cardiac resynchronization therapy (CRT). CRT has a substantial evidence base in patients in sinus rhythm with significant systolic dysfunction, symptomatic heart failure, and prolonged QRS duration. The role of CRT is less well established in AF patients with coexistent heart failure. AV nodal ablation has recently been suggested to improve outcomes in this group. Electronic databases and reference lists through September 15, 2010, were searched. Two reviewers independently evaluated citation titles, abstracts, and articles. Studies reporting the outcomes after AV nodal ablation in patients with AF undergoing CRT for symptomatic heart failure and left ventricular dyssynchrony were selected. Data were extracted from 6 studies, including 768 CRT-AF patients, composed of 339 patients who underwent AV nodal ablation and 429 treated with medical therapy aimed at rate control alone. AV nodal ablation in CRT-AF patients was associated with significant reductions in all-cause mortality (risk ratio: 0.42 [95% confidence interval: 0.26 to 0.68]), cardiovascular mortality (risk ratio: 0.44 [95% confidence interval: 0.24 to 0.81]), and improvement in mean New York Heart Association functional class (risk ratio: –0.52 [95% confidence interval: –0.87 to –0.17]). AV nodal ablation was associated with a substantial reduction in all-cause mortality and cardiovascular mortality and with improvements in New York Heart Association functional class compared with medical therapy in CRT-AF patients. Randomized controlled trials are warranted to confirm the efficacy and safety of AV nodal ablation in this patient population.

ORAL PRESENTATION

ORAL PRESENTATION

504 Does cardiac resynchronization therapy improve outcomes in patients with chronic atrial tachyarrhythmias? results from the resynchronization for ambulatory heart failure trial (raft)

Cardiac resynchronization (CRT) improves survival, prevents heart failure hospitalizations and improves quality of life in patients with systolic heart failure and QRS prolongation. However; the role of CRT in patients with chronic atrial arrhythmias is unclear, as most trials excluded these patients. The RAFT trial randomized patients with NYHA II and III heart failure, a left ventricular ejection fraction of ≤30% and a QRS width of ≥ 120 msec to an implantable defibrillator (ICD) or ICD + CRT. Randomization was stratified based on the presence or absence or chronic atrial tachyarrhythmias. At baseline, 229 patients were identified as having chronic atrial tachyarrhythmias and randomized to ICD (n = 115) or CRT-ICD (n = 114). Patients receiving a CRT-ICD were similar to those receiving an ICD in terms of: age (71.6 ± 7.3 vs. 70.4 ± 7.7 years), left ventricular ejection fraction (22.9 ± 5.3% vs. 22.3 ± 5.1%) and QRS duration (151.0 ± 23.6 vs. 153.4 ± 24.7 msec). Only 1 patient had an AV junction ablation within 6 months of randomization. There was no difference in the primary outcome of death or heart failure hospitalization between those assigned to CRT-ICD vs. ICD (HR = 0.96; 95% CI, 0.65-1.41, P = 0.82). This result was similar among patients with a baseline resting heart rate above (HR = 0.75; 95% CI, 0.42-1.33, P = 0.33) and below (HR = 1.16, 95% CI, 0.67-1.99, P = 0.60) the median value of 68 beats per minute. Cardiovascular death was similar between treatment arms (HR = 0.97; 95% CI, 0.55-1.71, P = 0.91); however, there was a trend for fewer heart failure hospitalizations with CRT-ICD (HR = 0.58; 95% CI, 0.38-1.01, P = 0.052). The change in 6-minute hall walk duration between baseline and 12 months was not different between treatment arms (ICD: 16 ± 76 metres vs. CRT-ICD: 19 ± 84 metres, P = 0.88). Patients treated with CRT showed a trend (P = 0.057) for a greater improvement in Minnesota Living with Heart Failure Score between baseline and 6 months (ICD: 33 ± 20 to 28 ± 20; CRT-ICD: 41 ± 21 to 31 ± 21); however, there were important differences in baseline scores. RAFT is the largest randomized trial of CRT in patients with chronic atrial tachyarrhythmias and shows no clear reduction in clinical events or improvement in surrogate measures.

Kardiale Resynchronisationstherapie bei schmalem QRS-Komplex und gering beeinträchtigtem Leistungsvermögen

Cardiac resynchronization (CRT) through atrio-biventricular pacemaker therapy is now a well established treatment option for severely symptomatic patients with advanced systolic heart failure (HF) and intraventricular conduction delay, especially left bundle branch block. The purpose of this article is to address possible applications of biventricular pacing beyond the classical CRT indication. In particular, a summary is given of available information on CRT in patients with symptomatic systolic HF, but narrow QRS complex, and those with wide QRS, but less pronounced or even absent clinical HF signs.