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 the presence of atrioventricular conduction disease, age, and comorbidities. We aimed to assess the prognosis for these patients, after CIED implantation, stratified for the 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 were crossmatched with the population registry and national disease registries. The outcome was 5-year risk of HF hospitalization and mortality. RESULTS: A total of 37,745 patients were included in the study. Comparing demographics for implantable cardioverter defibrillator versus pacemaker implants, median age was 66 years versus 83 years, 20% versus 41% were female, 64% versus 50% had ischemic heart disease, and 35% versus 67% had atrial fibrillation (all p < 0.001). Five-year mortality was highest in single-chamber pacemaker recipients (61% compared to average 40%, p < 0.001), but the proportion of cardiovascular mortality was highest for cardiac resynchronization therapy (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 HF, demography and mortality data indicate that clinicians chose devices according to the overall status of the patient. HF-related events occurred in all groups but were more common in CRT-treated patients.

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.

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.

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.

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.

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.

Risk factors and incidence of new-onset heart failure with conventional pacemaker implant: A nationwide study.

Background: Studies have shown that the risk of new-onset heart failure (HF) is higher postimplantation for patients receiving right ventricular pacing. Objective: This study aimed to investigate incidence, risk factors, and implications for long-term prognosis of new-onset HF in patients after pacemaker implantation. Methods: Patients without pre-existing HF who received a pacemaker in Sweden during the period of 2005 to 2020 were identified via the nationwide Pacemaker Registry. Data were crossmatched with the population registry and national disease registries. The primary outcome was new-onset HF within 5 years, and a risk score for this was developed and validated. Results: In all, 65,579 patients met the inclusion criteria (10,351 single-chamber ventricular and 55,228 dual-chamber pacemakers). A total of 13,792 (21.0%) patients were diagnosed with HF within 5 years postimplantation. Of these, 6244 (45.3%) were hospitalized for HF. Patients with new-onset HF were more likely to die within 5 years (41.2% vs 19.7%, P < .0001). Risk factors for new-onset HF included increasing age, male sex, hypertension, diabetes, atrial fibrillation, chronic lung and kidney disease, ischemic heart disease, and atrioventricular block. In a combined score using these variables, patients in the highest risk-score quartile had a hazard ratio of 5.36 (95% CI 4.91-5.86, P < .001) and an absolute risk of 32% for developing HF. Conclusion: Pacemaker therapy is associated with >20% risk of new-onset HF within 5 years, and we identified 9 risk factors associated with the diagnosis of new-onset HF. The proposed score based on these variables can be used to identify patients at high risk for new-onset HF.

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.