Non-infective left ventricular lead complications requiring re-intervention following cardiac resynchronization therapy: prevalence, causes and outcomes.

PURPOSE: Left ventricular (LV) lead complications in cardiac resynchronization therapy are challenging and poorly reported. We aimed to establish prevalence, causes and outcomes of LV lead complications requiring re-intervention. METHODS: We analysed the rate of complications in 2551 consecutive patients who received a transvenous de novo LV lead as part of a cardiac resynchronization therapy device between 2000 and 2018. LV lead complications requiring re-intervention were identified; those due to infection were excluded. Patient, procedural and device characteristics, and outcomes were examined for non-infective LV lead complications requiring re-intervention. RESULTS: During a median of 4.7 years, 142 (5.6%) patients required re-intervention for non-infective LV lead complications with a decrease from 10.7% between 2000 and 2004, 8.7% between 2005 and 2009, 3.2% between 2010 and 2014 to 3.2% after 2014. The most common complications were LV lead displacement (50%), high pacing threshold (28%) and phrenic nerve stimulation (15%). Of the complications, 79 (56%) occurred within 90 days post-implant and 63 (44%) later. At the end of the study period, 132/142 patients (93%) had a functional LV lead. Lead re-intervention was associated with higher risk of complications (20%), but no increase in mortality (P = 0.19). Quadripolar leads had longer longevity and lower risk of complications compared with unipolar and bipolar LV leads. CONCLUSIONS: A small but significant proportion of patients required LV lead re-intervention for complications following de novo implant. Lead displacement accounted for half of the re-interventions. Re-intervention was associated with a higher complication rate, but 92% of these patients had functional LV leads at the end of follow-up.

Syncope in paced patients with sick sinus syndrome from the DANPACE trial: incidence, predictors and prognostic implication.

OBJECTIVES: Syncope is a cause of significant morbidity in sick sinus syndrome (SSS) which may not be resolved with permanent pacemaker therapy. We aimed to determine the incidence, predictors and prognostic implication of syncope in paced patients with SSS. METHODS: We studied 1415 patients (mean age 72.9 years, SD 11.1) with SSS who were randomised in the DANPACE study to either rate-responsive single chamber pacing (n=707) or rate-responsive dual chamber pacing (n=708). Main outcome measures were patient-reported syncope after pacemaker implantation and mortality. RESULTS: Mean follow-up was 5.4 years (SD 2.6). A total of 247 (17.5%) patients experienced syncope after pacemaker implantation (135 (19%) from the rate-responsive single chamber pacing group, and 112 (15.8%) from the rate-responsive dual chamber pacing group. Predictors of syncope post pacemaker implantation included: age 0-39 years (HR 2.9, 95% CI 1.4 to 6.3, p=0.01; reference range 60-79 years), age ≥80 years (HR 1.4, 95% CI 1.0 to 1.8, p=0.03), syncope prior to pacemaker implant (HR 1.8, 95% CI 1.4 to 2.3, p<0.001), previous myocardial infarction (HR 1.5, 95% CI 1.1 to 2.1, p=0.03), heart failure (HR 1.4, 95% CI 1.0 to 1.9, p=0.046), and high Charlson comorbidity index (HR 1.6, 95% CI 1.1 to 2.2, p=0.01). Patients who experienced syncope post pacemaker implant had higher mortality compared with patients who did not (adjusted HR 1.6, 95% CI 1.3 to 2.1, p<0.001). CONCLUSIONS: Syncope in paced patients with SSS is common, and is associated with higher mortality. The predictors identified in this study suggest a multifactorial aetiology of syncope.