Presence of Sub-Clinical Atrial Fibrillation using an implantable cardiac monitor in patients with cardiovascular risk factors (ASSERT II)

In a quarter of cases of ischemic stroke the cause is unknown. Sub-clinical AF
might possibly play an important role in the origin of these strokes. The
ASSERT study has shown that 85% of atrial tachyarrhythmias in pacemaker
patients are without symptoms, and 10 - 40% of these patients have sub-clinical
AF depending on the follow up period after implantation of the pacemaker.
The question is how often patients without a pacemaker but with risk factors
for cadiovascular events such as hypertension and diabetes have sub-clinical
AF. Using an implantable cardiac monitor the heart rythm of patients can be
monitored continuosly in a relatively minimal invasive way, and the incidence
of sub-clinical AF can be determined in patients with cardiovascular risk
factors. This makes it possible to treat patients with sub-clinical AF
prophylactic if necessary.

To determine the rate of detection of sub-clinical atrial AF (* 5 minutes)
within an average of 12 months following implant of the Confirm® Implantable
Cardiac Monitor in patients with known cardiovascular risk factors and left
atrial enlargement, but without prior AF.

International, multicenter, observational cohort study.

Implantation of the cardiac monitor is an extra burden for the patient, but it
is a relatively minimal invasive procedure. Prophylactic antibiotics will be
administered, but there is always an infection risk. If this happens the device
will have to be explanted.

At all follow up visits 1, 3, 6, 9 and 18 months after implantation the device
will be read out. This does not give a physical burden for the patient but the
patient will have to come to the out patient clinic.