Age-stratified clinical outcome in patients with known heart failure who receive pacemaker-, resynchronization therapy- or defibrillator implants.

Introduction Patients with heart failure (HF) and bradycardia may be eligible for different types of cardiac implantable electronic devices (CIED), depending on presence of AV conduction disease, age and comorbidities. We aimed to assess prognosis for these patients, after CIED implantation, stratified for type of CIED device. Methods All patients with preexisting HF diagnosis who received a CIED with a right ventricular lead during the period 2005-2018 in Sweden were identified via the Pacemaker-registry. Data was crossmatched with the population registry and national disease registries. Outcome was 5-year risk of HF hospitalization, and mortality. Results 37745 patients were included in the study. Comparing demographics for ICD vs. pacemaker implants, median age was 66 years vs. 83 years, 20% vs. 41% were female, 64% vs. 50% had ischemic heart disease and 35% vs. 67% had atrial fibrillation (all p<0,001). 5-year mortality was highest in single-chamber pacemaker recipients (61% compared to average 40%, p<0.001) but proportion of cardiovascular mortality was highest for CRT recipients (68% vs 63% p<0.001). Adjusted mortality was higher for pacemaker-patients in all age decile groups (ranging from <60 to >90 years old, all p<0.001). HF hospitalization occurred in 28% (dual-chamber pacemaker) to 39% (CRT-P) of patients, and cause of death was HF in 15% (dual-chamber pacemaker) to 25% (CRT-D), all p<0.001. Conclusion In this large real-world cohort of CIED treated patients with prior heart failure, demography- and mortality-data indicate that clinicians chose devices according to the overall status of the patient. Heart failure related events occurred in all groups, but were more common in CRT-treated patients.

Prognostic utility and characterization of left ventricular hypertrophy using global thickness.

Cardiovascular magnetic resonance (CMR) can accurately measure left ventricular (LV) mass, and several measures related to LV wall thickness exist. We hypothesized that prognosis can be used to select an optimal measure of wall thickness for characterizing LV hypertrophy. Subjects having undergone CMR were studied (cardiac patients, n = 2543; healthy volunteers, n = 100). A new measure, global wall thickness (GT, GTI if indexed to body surface area) was accurately calculated from LV mass and end-diastolic volume. Among patients with follow-up (n = 1575, median follow-up 5.4 years), the most predictive measure of death or hospitalization for heart failure was LV mass index (LVMI) (hazard ratio (HR)[95% confidence interval] 1.16[1.12-1.20], p < 0.001), followed by GTI (HR 1.14[1.09-1.19], p < 0.001). Among patients with normal findings (n = 326, median follow-up 5.8 years), the most predictive measure was GT (HR 1.62[1.35-1.94], p < 0.001). GT and LVMI could characterize patients as having a normal LV mass and wall thickness, concentric remodeling, concentric hypertrophy, or eccentric hypertrophy, and the three abnormal groups had worse prognosis than the normal group (p < 0.05 for all). LV mass is highly prognostic when mass is elevated, but GT is easily and accurately calculated, and adds value and discrimination amongst those with normal LV mass (early disease).

Targeted left ventricular lead positioning to the site of latest activation in cardiac resynchronization therapy: a systematic review and meta-analysis.

AIMS: Several studies have evaluated the use of electrically- or imaging-guided left ventricular (LV) lead placement in cardiac resynchronization therapy (CRT) recipients. We aimed to assess evidence for a guided strategy that targets LV lead position to the site of latest LV activation. METHODS AND RESULTS: A systematic review and meta-analysis was performed for randomized controlled trials (RCTs) until March 2023 that evaluated electrically- or imaging-guided LV lead positioning on clinical and echocardiographic outcomes. The primary endpoint was a composite of all-cause mortality and heart failure hospitalization, and secondary endpoints were quality of life, 6-min walk test (6MWT), QRS duration, LV end-systolic volume, and LV ejection fraction. We included eight RCTs that comprised 1323 patients. Six RCTs compared guided strategy (n = 638) to routine (n = 468), and two RCTs compared different guiding strategies head-to-head: electrically- (n = 111) vs. imaging-guided (n = 106). Compared to routine, a guided strategy did not significantly reduce the risk of the primary endpoint after 12-24 (RR 0.83, 95% CI 0.52-1.33) months. A guided strategy was associated with slight improvement in 6MWT distance after 6 months of follow-up of absolute 18 (95% CI 6-30) m between groups, but not in remaining secondary endpoints. None of the secondary endpoints differed between the guided strategies. CONCLUSION: In this study, a CRT implantation strategy that targets the latest LV activation did not improve survival or reduce heart failure hospitalizations.

Hemodynamic forces from 4D flow magnetic resonance imaging predict left ventricular remodeling following cardiac resynchronization therapy.

BACKGROUND: Patients with heart failure and left bundle branch block (LBBB) may receive cardiac resynchronization therapy (CRT), but current selection criteria are imprecise, and many patients have limited treatment response. Hemodynamic forces (HDF) have been suggested as a marker for CRT response. The aim of this study was therefore to investigate left ventricular (LV) HDF as a predictive marker for LV remodeling after CRT. METHODS: Patients with heart failure, EF < 35% and LBBB (n = 22) underwent CMR with 4D flow prior to CRT. LV HDF were computed in three directions using the Navier-Stokes equations, reported in median N [interquartile range], and the ratio of transverse/longitudinal HDF was calculated for systole and diastole. Transthoracic echocardiography was performed before and 6 months after CRT. Patients with end-systolic volume reduction ≥ 15% were defined as responders. RESULTS: Non-responders had smaller HDF than responders in the inferior-anterior direction in systole (0.06 [0.03] vs. 0.07 [0.03], p = 0.04), and in the apex-base direction in diastole (0.09 [0.02] vs. 0.1 [0.05], p = 0.047). Non-responders had larger diastolic HDF ratio compared to responders (0.89 vs. 0.67, p = 0.004). ROC analysis of diastolic HDF ratio for identifying CRT non-responders had AUC of 0.88 (p = 0.005) with sensitivity 57% and specificity 100% for ratio > 0.87. Intragroup comparison found higher HDF ratio in systole compared to diastole for responders (p = 0.003), but not for non-responders (p = 0.8). CONCLUSION: Hemodynamic force ratio is a potential marker for identifying patients with heart failure and LBBB who are unlikely to benefit from CRT. Larger-scale studies are required before implementation of HDF analysis into clinical practice.

Sex-based differences in cardiac resynchronization therapy upgrade and outcome for patients with pacemaker and new-onset heart failure.

BACKGROUND: Patients with chronic right ventricular (RV) pacing are at an increased risk of heart failure. Previous studies have indicated that cardiac resynchronization therapy (CRT) is underused in this setting, and that there may be sex-based differences in both CRT use and clinical outcome. OBJECTIVE: To evaluate sex-based differences in CRT use and clinical outcome for patients with new-onset heart failure post RV pacing. METHODS: Data from the Swedish pacemaker registry was matched with data from the national death and disease registries. Patients with de novo pacemaker implant due to AV block during the period 2005-2020 were included. New-onset heart-failure within two years post-implant was evaluated, primary outcome was all-cause mortality. RESULTS: In all, 30183 patients (37% female) were included. Women were on average 3 years older, but had less comorbidities than men. Median follow-up time was 4.5 [2.0-8.0] years. Women had better age- and comorbidity-adjusted survival (HR 0.78 [0.73-0.84], p < .001). For the 3560 patients (12.4% men and 10.7% women, p < .001) who were diagnosed with new-onset heart failure, 5-year mortality was similar for men and women (50% vs. 48%, p = .29). However, women were less likely to receive CRT-upgrade (3.8% vs. 9.1%, p < .001), and those who did were almost ten years younger than the men. CONCLUSION: Women with pacemaker due to AV block are older but have less comorbidities than men. They are less likely to develop new-onset heart failure, but also less likely to receive a CRT upgrade if they do develop heart failure. Increased awareness of the positive effects of CRT upgrade and potential sex- and age-based discrimination is warranted.

Age-stratified comparison of prognosis in cardiac resynchronization therapy with or without prophylactic defibrillator for nonischemic cardiomyopathy-a nationwide cohort study.

AIMS: Prior studies have suggested that the benefit from primary preventive defibrillator treatment for patients with nonischemic cardiomyopathyy, treated with cardiac resynchronization therapy, may be age-dependent. We aimed to compare age-stratified mortality rates and mode of death in patients with nonischemic cardiomyopathy who are treated with either primary preventive cardiac resynchronization therapy with defibrillator (CRT-D) or CRT with pacemaker (CRT-P). METHODS AND RESULTS: All patients with nonischemic cardiomyopathy and CRT-P or primary preventive CRT-D who were implanted in Sweden during the period 2005-2020 were included. Propensity scoring was used to create a matched cohort. Primary outcome was all-cause mortality within 5 years. In all, 4027 patients were included: 2334 with CRT-P and 1693 with CRT-D. Crude 5-year mortality was 635 (27%) vs. 246 (15%), P < 0.001. In Cox regression analysis, adjusted for clinically relevant covariables, CRT-D was independently associated with higher 5-year survival [0.72 (0.61-0.85), P < 0.001]. Cardiovascular mortality was similar between groups (62 vs. 64%, P = 0.64), but death from heart failure was more common in the CRT-D group (46 vs. 36%, P = 0.007). In the matched cohort (n = 2414), 5-year mortality was 21% (24 vs. 16%, P < 0.001). In age-stratified analyses, CRT-P was associated with higher mortality in age groups <60 years and 70-79 years, but there was no difference in age groups 60-69 years or 80-89 years. CONCLUSION: In this nationwide registry-based study, patients with CRT-D had better 5-year survival compared to patients with CRT-P. The interaction between age and mortality reduction was not consistent, but patients with CRT-D aged <60 years had the largest absolute mortality reduction.

Association between left ventricular lead position and intrinsic QRS morphology with regard to clinical outcome in cardiac resynchronization therapy for heart failure.

BACKGROUND: Left ventricular (LV) lead position may be an important factor for delivering effective cardiac resynchronization therapy (CRT). We therefore aimed to evaluate the effects of LV lead position, stratified by native QRS morphology, regarding the clinical outcome. METHODS: A total of 1295 CRT-implanted patients were retrospectively evaluated. LV lead position was classified as lateral, anterior, inferior, or apical, and was determined using the left and right anterior oblique X-ray views. Kaplan Meier and Cox regression were performed to evaluate the effects on all-cause mortality and heart failure hospitalization, and the potential interaction between LV lead position and native ECG morphologies. RESULTS: A total of 1295 patients were included. Patients were aged 69 ± 7 years, 20% were female, 46% received a CRT-Pacemaker (vs. CRT-Defibrillator), mean LVEF was 25% ± 7%, and median follow-up was 3.3 years [IQR 1.6-5-7 years]. Eight hundred and eighty-two patients (68%) had a lateral LV lead location, 207 (16%) anterior, 155 (12%) apical, and 51 (4%) inferior. Patients with lateral LV lead position had larger QRS reduction (-13 ± 27 ms vs. -3 ± 24 ms, p < .001). Non-lateral lead location was associated with a higher risk for all-cause mortality (HR 1.34 [1.09-1.67], p = .007) and heart failure hospitalization (HR 1.25 [1.03-1.52], p = .03). This association was strongest for patients with native left or right bundle branch block, and not significant for patients with prior paced QRS or nonspecific intraventricular conduction delay. CONCLUSIONS: In patients treated with CRT, non-lateral LV lead positions (including apical, anterior, and inferior positions) were associated with worse clinical outcome and less reduction of QRS duration. This association was strongest for patients with native LBBB or RBBB.

Maximizing QRS duration reduction in contemporary cardiac resynchronization therapy is feasible and shorter QRS duration is associated with better clinical outcome.

BACKGROUND: We aimed to evaluate if optimization by maximizing QRS duration (QRSd) reduction is feasible in an all-comer cardiac resynchronization therapy (CRT) population, and if reduced, QRSd is associated with a better clinical outcome. METHODS: Patients with LBBB receiving CRT implants during the period 2015-2020 were retrospectively evaluated. Implants from 2015-2017 were designated as controls. Starting from 2018, an active 12-lead electrogram-based optimization of QRSd reduction was implemented (intervention group). QRSd reduction was evaluated in a structured way at various device AV and VV settings, aiming to maximize the reduction. The primary endpoint was a composite of heart failure hospitalization or death from any cause. RESULTS: A total of 254 patients were followed for up to 6 years (median 2.9 [1.8-4.1]), during which 82 patients (32%) reached the primary endpoint; 53 deaths (21%) and 58 (23%) heart failure hospitalizations. Median QRS duration pre-implant was 162 ms [150-174] and post-implant 146ms [132-160]. Mean reduction in QRS duration was progressively larger for each year during the intervention period, ranging from - 9.5ms in the control group to - 24 in the year 2020 (p = 0.005). QRS reduction > 14 ms (median value) was associated with a lower risk of death or heart failure hospitalization (adjusted HR 0.54 [0.29-0.98] (p = 0.04). CONCLUSIONS: Implementing a general strategy of CRT device optimization by aiming for shorter QRS duration is feasible in a structured clinical setting and results in larger reductions in QRS duration post-implant. In patients with a larger QRS reduction, compared to those with a smaller QRS reduction, there is an association with a better clinical outcome.

Repositioning and optimization of left ventricular lead position in nonresponders to cardiac resynchronization therapy is associated with improved ejection fraction, lower NT-proBNP values, and fewer heart failure symptoms.

Background: Observational data suggest that an anterior or apical left ventricular (LV) position in cardiac resynchronization therapy (CRT) is associated with worse outcome and higher likelihood of "nonresponse." It is not known whether the benefits of optimizing LV lead position in a second procedure outweighs the procedural risks. Objective: To evaluate the clinical effects of LV lead repositioning. Methods: During the period 2015-2020, we identified all patients in whom the indication for the procedure was LV lead repositioning owing to "nonresponse" in combination with suboptimal LV lead position. All patients were followed with a structured visit 6 months post LV lead revision. Heart failure hospitalization and mortality data were gathered from the medical records and cross-checked with the population registry. Results: A total of 25 patients were identified who fulfilled the inclusion criteria. All procedures were successful in establishing LV lead pacing in a lateral mid or basal location. Median follow-up was 2.5 years [1.1-3.7]. There were improvements in NYHA class (mean -0.5 ± 0.5 class, P < .001), LV ejection fraction (+5 [interquartile range 2-11] absolute %, P = .01), QRS duration (-36 [-44 to -8], P < .001) and N-terminal pro-brain natriuretic peptide (NT-proBNP) (-615 [-2837 to +121] ng/L, P = .03). Clinical outcome was similar to a reference population with CRT (P = ns). Conclusion: In nonresponders to CRT with either an anterior or inferior LV lead position, it was feasible to perform LV lead repositioning in all cases, with a low complication rate. Changing the LV lead position was associated with improved LV ejection fraction, larger QRS reduction, and larger NT-proBNP reduction.

Targeting the latest site of left ventricular mechanical activation is associated with improved long-term outcomes for recipients of cardiac resynchronization therapy.

Background: Previous studies have suggested that targeting the site of latest mechanical activation of the left ventricle (LV) results in improved cardiac resynchronization therapy (CRT) outcomes. It is not known whether these benefits are sustained over medium-term follow-up. Objective: To assess the clinical outcome of imaging-guided LV lead position. Methods: We sought to assess the medium-term clinical outcome by performing a patient-level meta-analysis of 2 previously published randomized controlled trials (the "STARTER" trial and the "CRT Clinic" trial). These 2 trials compared imaging-guided LV lead placement in the latest activated scar-free segment (intervention group) to standard of care (control). Mortality and heart failure hospitalization outcomes over extended follow-up were gathered from the medical records and merged. Results were stratified for native electrocardiogram (ECG) morphology. Results: A total of 289 patients were followed for a median of 6.3 years. Seven years post implant, 47 (28%) in the intervention group had died, vs 47 (38%) in the control group (P = .13); 49 (30%) vs 53 (42%) had been hospitalized for heart failure (P = .035); and 47% vs 59% (P = .057) had reached the combined endpoint. In Kaplan-Meier analysis, patients in the intervention group had better survival free of heart failure hospitalization (P = .045) and lower risk of heart failure hospitalization (P = .019). Conclusion: Targeting the latest mechanically activated segment in CRT results in better medium-term clinical outcome, mainly driven by a reduced risk of hospitalization for heart failure. The effect was seen regardless of native ECG morphology.

Efficacy of the antibacterial envelope to prevent cardiac implantable electronic device infection in a high-risk population.

AIMS: Infection is a serious complication of cardiac implantable electronic device (CIED) therapy. An antibiotic-eluting absorbable envelope has been developed to reduce the infection rate, but studies investigating the efficacy and a reasonable number needed to treat in high-risk populations for infections are limited. METHODS AND RESULTS: One hundred and forty-four patients undergoing CIED implantation who received the antibacterial envelope were compared with a matched cohort of 382 CIED patients from our institution. The primary outcome was the occurrence of local infection, and secondary outcomes were any CIED-related local or systemic infections, including endocarditis, and all-cause mortality. The results were stratified by a risk score for CIED infection, PADIT. The envelope group had a higher PADIT score, 5.9 ± 3.1 vs. 3.9 ± 3.0 (P < 0.0001). For the primary endpoint, no local infections occurred in the envelope group, compared with 2.6% in the control group (P = 0.04), with a more pronounced difference in the stratum with a high (>7 points) PADIT score, 0 vs. 9.9% (P = 0.01). The total CIED-related infections were similar between groups, 6.3% compared with 5.0% (P = 0.567). Mortality after 1600 days of follow-up did not differ between groups, 22.9 vs. 26.4%, P = 0.475. CONCLUSION: Our study confirms the clinical efficacy of an antibacterial envelope in the prevention of local CIED infection in patients with a higher risk according to the PADIT score. In an effort to improve cost-benefit ratios, ration of use guided by the PADIT score is advocated. Further prospective randomized studies in high-risk populations are called for.

Diagnosis and treatment of the rare procedural complication of malpositioned pacing leads in the left heart: a single center experience.

Objectives. This study assessed the management approach and outcome of the pacemaker or implantable cardioverter-defibrillator (ICD) leads malpositioned in the left heart. Malpositioned leads (MPLs) may have deleterious consequences, and appropriate management remains uncertain. Methods. The study population included all patients referred to a single institution for MPL in the left side of the heart after pacemaker or ICD implantation during the period from 2015 to 2021. The approach and outcome of lead management were retrospectively assessed. Results. During the study period, 6887 patients underwent device implantation. MPL was diagnosed in five patients (0.07%). In four cases, the pacing lead was placed in a coronary sinus (CS) branch, while the pacing lead was inside the left ventricle (LV) in one case. Symptoms suggestive of lead malposition were reported by 2 patients (40%). One of the patients presented with recurrent TIAs. Another presented with inappropriate ICD shocks. In one asymptomatic case, an ICD lead changed position from the right ventricle to the CS, suggesting idiopathic lead migration. In 4/5 patients, the leads were removed or repositioned by percutaneous approach, with no major periprocedural complications. Conclusions. In this series of MPL in the left heart, two patients presented with thromboembolic events or inappropriate ICD shocks. These serious complications highlight the critical need for early correct diagnosis and proper management of MPL.

Anatomy of the coronary sinus with regard to cardiac resynchronization therapy implantation.

Knowledge of the coronary sinus (CS) anatomy is crucial for implantation of cardiac resynchronization therapy (CRT). Obstacles to CS entry, such as the Eustachian ridge and Thebesian valve, as well as within the CS, such as Vieussen's valve and the vein of Marshall, are important to understand and differentiate during implantation or to identify earlier by imaging. Anatomic knowledge is mandatory to select the most suitable side branch for lead implantation. Modern tools and techniques almost always enable other anatomic problems, such as tortuous, small, short, or overly straight side branches, to also be overcome.

Ventricular longitudinal function by cardiovascular magnetic resonance predicts cardiovascular morbidity in HFrEF patients.

AIMS: Ventricular longitudinal function measured as basal-apical atrioventricular plane displacement (AVPD) or global longitudinal strain (GLS) is a potent predictor of mortality and could potentially be a predictor of heart failure-associated morbidity. We hypothesized that low AVPD and GLS are associated with the combined endpoint of cardiovascular mortality and heart failure-associated morbidity. METHODS AND RESULTS: Two hundred eighty-seven patients (age 62 ± 12 years, 78% male) with heart failure with reduced (≤40%) ejection fraction (HFrEF) referred to a cardiovascular magnetic resonance exam were included. Ventricular longitudinal function, ventricular volume, and myocardial fibrosis or infarction were analysed from cine and late gadolinium enhancement images. National registries provided data on causes of cardiovascular hospitalizations and cardiovascular mortality for the combined endpoint. Time-to-event analysis capable of including reoccurring events was employed with a 5-year follow-up. HFrEF patients had EF 26.5 ± 8.0%, AVPD 7.8 ± 2.4 mm, and GLS -7.5 ± 3.0%. In contrast, ventricular longitudinal function was approximately twice as large in an age-matched control group (AVPD 15.3 ± 1.6 mm; GLS -20.6 ± 2.0%; P < 0.001 for both). There were 578 events in total, and the majority were HF hospitalizations (n = 418). Other major events were revascularizations (n = 64), cardiovascular deaths (n = 40), and myocardial infarctions (n = 21). One hundred fifty-five (54%) patients experienced at least one event (mean 2.0, range 0-64). Of these patients, 119 (71%) had three events or fewer, and the first three events comprised 51% of all events (295 events). Patients in the bottom AVPD or GLS tertile (<6.8 mm or >-6.1%) overall experienced more than 3 times as many events as the top tertile (>8.8 mm or <-8.4%; P < 0.001). Patients in this tertile also faced more cardiovascular deaths (P < 0.05), HF hospitalizations (P = 0.001), myocardial infarctions (only GLS: P = 0.032), and accumulated longer in-hospital length-of-stay overall (AVPD 20.9 vs. 9.1 days; GLS 22.4 vs. 6.5 days; P = 0.001 for both), and from HF hospitalizations (AVPD 19.3 vs. 8.3 days; GLS 19.3 vs. 5.4 days; P = 0.001 for both). In multivariate analysis adjusted for significant covariates, AVPD and GLS remained independent predictors of events (hazard ratio 1.12 per-mm-decrease and 1.13 per-%-increase) alongside hyponatremia (<135 mmol/L), aetiology of HF, and LV end-diastolic volume index. CONCLUSIONS: Low ventricular longitudinal function is associated with an increase in number of events as well as longer in-hospital stay from cardiovascular causes. In addition, AVPD and GLS have independent prognostic value for cardiovascular mortality and morbidity in HFrEF patients.

Successful percutaneous extraction of malpositioned pacemaker lead in the left ventricle after proper dabigatran treatment.

Malpositioned pacemaker lead in the left ventricle (LV) is a rare procedural complication, which causes a special risk of thromboembolic events. Hence, prompt identification and early management of misplaced leads inside the LV is critical. Herein, we present a case of malpositioned pacemaker lead with transient ischemic attacks after the pacemaker implantation. The misplaced ventricular lead was discovered during regular echocardiography. Both leads were extracted percutaneously after dabigatran treatment. To our knowledge, this is the first report of uncomplicated percutaneous extraction of an inadvertently placed LV lead after dabigatran treatment. No neurologic events during a follow-up of 4 years.

Baseline QRS Area and Reduction in QRS Area Are Associated with Lower Mortality and Risk of Heart Failure Hospitalization after Cardiac Resynchronization Therapy.

INTRODUCTION: Cardiac resynchronization therapy (CRT) is an established treatment for heart failure in selected patients. However, current guideline indications do not accurately predict individual prognosis with CRT, and up to 30% are nonresponders. Previous studies have shown that QRS area reduction following CRT is associated with improved survival. This study evaluates the incremental value of using QRS area derived from digital electrocardiogram (ECG) recordings, preoperatively and during CRT pacing. METHODS: Medical records of 445 patients receiving CRT implants at a large-volume tertiary care center in Sweden were retrospectively evaluated. Digital ECG before and after CRT implantation were collected, and ECG parameters were analyzed in relation to a primary composite endpoint of heart failure hospitalization or death from any cause. RESULTS: 147 patients (33%) reached the primary endpoint (93 deaths and 103 heart failure hospitalizations) over a median follow-up time of 2.7 years. A larger preimplant QRS area (HR, 0.89; [0.85-0.93]; p = <0.0001; adjusted HR, 0.93; [0.88-0.98]; p = 0.011) and a larger QRS area reduction (HR, 0.92; [0.88-0.96]; p = <0.0001; adjusted HR, 0.95; [0.90-0.99]; p = 0.042) postimplant correlated with a reduced risk of reaching the primary endpoint. This association was seen in patients with native left bundle branch block morphology, nonspecific intraventricular conduction delay, or paced ECG morphology but not in patients with right bundle branch block. CONCLUSION: Larger preimplant QRS area and QRS area reduction were associated with better clinical outcome following CRT in this retrospective material. This knowledge could help optimize patient selection and postoperative management.

Pulmonary perfusion and NYHA classification improve after cardiac resynchronization therapy.

BACKGROUND: Evaluation of cardiac resynchronization therapy (CRT) often includes New York Heart Association (NYHA) classification, and echocardiography. However, these measures have limitations. Perfusion gradients from ventilation/perfusion single-photon emission computed tomography (V/P SPECT) are related to left-heart filling pressures and have been validated against invasive right-heart catheterization. The aim was to assess if changes in perfusion gradients are associated with improvements in heart failure (HF) symptoms after CRT, and if they correlate with currently used diagnostic methods in the follow-up of patients with HF after receiving CRT. METHODS AND RESULTS: Nineteen patients underwent V/P SPECT, echocardiography, NYHA classification, and the quality-of-life scoring system "Minnesota living with HF" (MLWHF), before and after CRT. CRT caused improvement in perfusion gradients from V/P SPECT which were associated with improvements in NYHA classification (P = .0456), whereas improvements in end-systolic volume (LVESV) from echocardiography were not. After receiving CRT, the proportion of patients who improved was lower using LVESV (n = 7/19, 37%) than perfusion gradients (n = 13/19, 68%). Neither change in perfusion gradients nor LVESV was associated with changes in MLWHF (P = 1.0, respectively). CONCLUSIONS: Measurement of perfusion gradients from V/P SPECT is a promising quantitative user-independent surrogate measure of left-sided filling pressure in the assessment of CRT response in patients with HF.

Regional contributions to left ventricular stroke volume determined by cardiac magnetic resonance imaging in cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) restores ventricular synchrony and induces left ventricular (LV) reverse remodeling in patients with heart failure (HF) and dyssynchrony. However, 30% of treated patients are non-responders despite all efforts. Cardiac magnetic resonance imaging (CMR) can be used to quantify regional contributions to stroke volume (SV) as potential CRT predictors. The aim of this study was to determine if LV longitudinal (SVlong%), lateral (SVlat%), and septal (SVsept%) contributions to SV differ from healthy controls and investigate if these parameters can predict CRT response. METHODS: Sixty-five patients (19 women, 67 ± 9 years) with symptomatic HF (LVEF ≤ 35%) and broadened QRS (≥ 120 ms) underwent CMR. SVlong% was calculated as the volume encompassed by the atrioventricular plane displacement (AVPD) from end diastole (ED) to end systole (ES) divided by total SV. SVlat%, and SVsept% were calculated as the volume encompassed by radial contraction from ED to ES. Twenty age- and sex-matched healthy volunteers were used as controls. The regional measures were compared to outcome response defined as ≥ 15% decrease in echocardiographic LV end-systolic volume (LVESV) from pre- to 6-months post CRT (delta, Δ). RESULTS: AVPD and SVlong% were lower in patients compared to controls (8.3 ± 3.2 mm vs 15.3 ± 1.6 mm, P < 0.001; and 53 ± 18% vs 64 ± 8%, P < 0.01). SVsept% was lower (0 ± 15% vs 10 ± 4%, P < 0.01) with a higher SVlat% in the patient group (42 ± 16% vs 29 ± 7%, P < 0.01). There were no differences between responders and non-responders in neither SVlong% (P = 0.87), SVlat% (P = 0.09), nor SVsept% (P = 0.65). In patients with septal net motion towards the right ventricle (n = 28) ΔLVESV was - 18 ± 22% and with septal net motion towards the LV (n = 37) ΔLVESV was - 19 ± 23% (P = 0.96). CONCLUSIONS: Longitudinal function, expressed as AVPD and longitudinal contribution to SV, is decreased in patients with HF scheduled for CRT. A larger lateral contribution to SV compensates for the abnormal septal systolic net movement. However, LV reverse remodeling could not be predicted by these regional contributors to SV.

The CHA2DS2-VASc Score and Its Association with Long-Term Outcome in a Cardiac Resynchronization Therapy Population.

BACKGROUND: Cardiac resynchronization therapy (CRT) is commonly used in patients with heart failure and left ventricular dyssynchrony. Several scoring systems have been tested in order to predict long-term outcome. Although intended for use in patients with atrial fibrillation, we sought to assess the performance of the CHA2DS2-VASc score in a CRT population. METHODS: Data on 796 consecutive CRT patients were retrospectively gathered from hospital records and healthcare registries. CHA2DS2-VASc scores were calculated, as well as other stratification scores for comparison. The outcomes were crude mortality, time to first heart failure hospitalization, and a composite of the 2. CHA2DS2-VASc score was evaluated against the end points with survival analyses and compared to other risk stratification scores. RESULTS: The CHA2DS2-VASc score was significantly correlated with both outcomes in univariable and multivariable analysis adjusting for other known predictors of CRT outcome (unadjusted HR 1.28, 95% CI 1.21-1.36 and HR 1.19, 95% CI 1.13-1.25 for the mortality and heart failure hospitalization end points, respectively). Its performance compared well to other validated scores for the mortality end point (Harrell's C: 0.61, range for other scoring systems: 0.57-0.65), as well as the heart failure hospitalization end point (Harrell's C: 0.57, range of other scoring systems: 0.58-0.62). It correlated to 5- and 10-year survival with an area under the curve of 0.63 and 0.73, respectively. CONCLUSION: When tested for association with outcome in a CRT population, the CHA2DS2-VASc score correlates to increased mortality and risk of heart failure hospitalization. It performs similarly to CRT-specific scores. However, the results of this study indicate that all tested scores should be used with caution in CRT patients.

Interatrial Block Predicts Atrial Fibrillation and Total Mortality in Patients with Cardiac Resynchronization Therapy.

BACKGROUND: Interatrial block (IAB) and abnormal P-wave terminal force in lead V1 (PTFV1) are electrocardiographic (ECG) abnormalities that have been shown to be associated with new-onset atrial fibrillation (AF) and death. However, their prognostic importance has not been proven in cardiac resynchronization therapy (CRT) recipients. OBJECTIVE: To assess if IAB and abnormal PTFV1 are associated with new-onset AF or death in CRT recipients. METHODS: CRT recipients with sinus rhythm ECG at CRT implantation and no AF history were included (n = 210). Automated analysis of P-wave duration (PWD) and morphology classified patients as having either no IAB (PWD <120 ms), partial IAB (pIAB: PWD ≥120 ms, positive P waves in leads II and aVF), or advanced IAB (aIAB: PWD ≥120 ms and biphasic or negative P wave in leads II or aVF). PTFV1 >0.04 mm•s was considered abnormal. Adjusted Cox regression analyses were performed to assess the impact of IAB and abnormal PTFV1 on the primary endpoint new-onset AF, death, or heart transplant (HTx) and the secondary endpoint death or HTx at 5 years of follow-up. RESULTS: IAB was found in 45% of all patients and independently predicted the primary endpoint with HR 1.9 (95% CI 1.2-2.9, p = 0.004) and the secondary endpoint with HR 2.1 (95% CI 1.2-3.4, p = 0.006). Abnormal PTFV1 was not associated with the endpoints. CONCLUSIONS: IAB is associated with new-onset AF and death in CRT recipients and may be helpful in the risk stratification in the context of heart failure management. Abnormal PTFV1 did not demonstrate any prognostic value.