Differences in the yield of the implantable loop recorder between secondary and tertiary centers.

BACKGROUND: The implantable loop recorder (ILR) is a useful tool for diagnosis of syncope or palpitations. Its easy use and safety have extended its use to secondary hospitals (those without an Electrophysiology Lab). The aim of the study was to compare results between secondary and tertiary hospitals. METHODS: National prospective and multicenter registry of patients with an ILR inserted for clinical reasons. Data were collected in an online database. The follow-up ended when the first diagnostic clinical event occurred, or 1 year after implantation. Data were analyzed according to the center of reference; hospitals with Electrophysiology Lab were considered Tertiary Hospitals, while those hospitals without a lab were considered Secondary Hospitals. RESULTS: Seven hundred and forty-three patients (413 [55.6%] men; 65 ± 16 year-old): 655 (88.2%) from Tertiary Centers (TC) and 88 (11.8%) from Secondary Centers (SC). No differences in clinical characteristics between both groups were found. The electrophysiologic study and the tilt table test were conducted more frequently in Tertiary Centers. Follow-up was conducted for 680 (91.5%) patients: 91% in TC and 94% in SC. There was a higher rate of final diagnosis among SC patients (55.4% vs. 30.8%; p < 0.001). Tertiary Hospital patients showed a trend towards a higher rate of neurally mediated events (20% vs. 4%), while bradyarrhythmias were more frequent in SC (74% vs. 60%; p = 0.055). The rate of deaths and adverse events was similar in both populations. CONCLUSIONS: Patients with an ILR in SC and TC have differences in terms of the use of complementary tests, but not in clinical characteristics. There was a higher rate of diagnosis in Secondary Hospital patients.

Implantable loop recorder allows an etiologic diagnosis in one-third of patients. Results of the Spanish reveal registry.

BACKGROUND: The implantable loop recorder (ILR) is a useful tool for diagnosing paroxysmal conditions potentially related to arrhythmias. Most investigations have focused on selected clinical studies or high-volume centers. The aim of this study was to evaluate the indications and outcomes of the ILR in real clinical practice. METHODS AND RESULTS: This was a prospective, multicenter registry of patients undergoing ILR implantation for clinical indications (April 2006-December 2008). Clinical characteristics (symptoms, arrhythmias, treatments) were recorded in a database. Follow-up data at 1 year or after the occurrence of the first episode were also recorded. Total enrollment: 743 patients (male, 413, 55.6%; 64.9 ± 16 years); 228 (30.7%) had structural heart disease (SHD), and 183 (24.6%), bundle branch block (BBB). Recurrent syncope (76.4%) was the most common indication for implantation. Complete follow-up was obtained for 680 patients (91.5%). Three hundred and twenty-five patients (48%) presented 414 events, with a final diagnosis in 230 patients (70.8% of patients with events; 33.1% of patients with follow-up). Syncope secondary to bradyarrhythmia was the most frequent diagnosis. Similar rates of final diagnoses were noted in subgroups of SHD, BBB and normal heart. Regarding the cause of implantation, higher event rates were registered among patients with recurrent syncope. CONCLUSIONS: One-third of patients obtained a final diagnosis with the ILR, independent of the baseline characteristics. Only the cause of implantation provided different rates of final diagnosis.