Early versus delayed implantation of a loop recorder in patients with unexplained syncope--effects on care pathway...

This study looked to assess the care pathway and diagnostic yield in patients who received an implantable loop recorder (ILR) after an "initial phase of the diagnostic work-up" (initial work-up) or after a "full evaluation" of unexplained syncope.

Physicians classified the timing of an ILR implant in 514 patients as either following an "initial work-up" (n=128; 25%) or "full evaluation" (n=386; 75%). Patients with an "initial work-up" underwent a median (IQ range) of 8 (6-14) tests prior to ILR implant compared to 14 (10-21) tests after "full evaluation" (p<0.0001). Hospitalization and injury before implant were less common in patients with an "initial work-up": 53 vs. 75%, p<0001, and 23% vs. 39%, p<0.001, as were visits to specialists, e.g. neurologist, 32% vs. 50%, p<0.001. At one year after implant, the syncope recurrence rate was 32% in the initial work-up group and 36% in the full evaluation group, and the incidence of recurrences with an ILR-guided diagnosis was 52% and 75% respectively. Diagnoses were cardiac in 90% after "initial work-up" vs. 79% after "full evaluation".

Patients who only underwent an "initial work-up" had fewer investigations and a lower incidence of injury or hospitalization. The diagnostic yield from the ILR was high in both groups. Patients in both groups underwent more investigations than suggested in the ESC guidelines and could have benefitted from limiting the initial evaluation before an ILR is implanted.