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SILENT - Subclinical AtrIal FibrilLation and StrokE PreveNtion Trial (SILENT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT02004509
Recruitment Status : Not yet recruiting
First Posted : December 9, 2013
Last Update Posted : September 9, 2014
Information provided by (Responsible Party):
Martino Martinelli Filho, InCor Heart Institute

Brief Summary:
Introduction: Patients with atrial fibrillation (AF) have a substantial risk of stroke and systemic embolism. Subclinical AF is often suspected to be the cause of stroke in these patients. The detection of asymptomatic AF episodes is a challenge and the real rate of occurrence of these episodes remains unknown. The rate of stroke is high among patients who have received a pacemaker and this device can detect subclinical episodes of rapid atrial rate, which correlate with electrocardiographically documented AF. The net benefit of anticoagulant treatment is well established in patients with clinical AF but data about anticoagulation in subclinical AF setting is unknown. The aim of this study is to assess the impact of anticoagulant therapy on subclinical AF, directed by cardiac implantable electronic device (CIED) intensive monitoring, on the incidence of stroke and systemic embolism and correlate the AF episodes detected by CIED with thromboembolic events. Methods: This is a prospective, randomized, unicentric, parallel clinical study in patients with atrioventricular pacemaker, defibrillator or cardiac resynchronization therapy devices in sinus rhythm and CHADS2 score (an index of the risk of stroke in patients with atrial fibrillation, range from 0 to 6) ≥ 2 . Patients will be randomized to the intervention group - intensive monitoring arm (Group I) or control group - routine schedule arm (Group II) in a 1:1 ratio. Time to inclusion will be 24 months and all patients will be followed up for a period of 36 months. Group I patients will be submitted to device data collection every 2 months, while the Group II patients will be managed conventionally. Patients from Group I with episodes of subclinical AF will receive anticoagulant therapy, as well as patients with clinical AF of both arms. Device data from Group II patients will not be analyzed until they achieve the primary endpoint. Primary endpoint: stroke or systemic embolism. Secondary endpoints: subclinical AF rate, total mortality, cardiovascular mortality, myocardial infarction, cardiovascular hospitalization and bleeding rates. Expected outcome: It is expected that anticoagulation therapy of subclinical AF directed by CIED intensive monitoring will reduce the incidence of stroke and systemic embolism comparing to patients with non-diagnosed subclinical AF.

Condition or disease Intervention/treatment Phase
Atrial Fibrillation Drug: anticoagulant by physician criteria Phase 4

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 2054 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Study Start Date : February 2015
Estimated Primary Completion Date : October 2020
Estimated Study Completion Date : October 2020

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: anticoagulant by physician criteria Drug: anticoagulant by physician criteria
Anticoagulant treatment will be started in case of subclinical atrial fibrillation (>5,5 hours per day) be diagnosed by cardiac implantable electronic device at intervention group, or clinical atrial fibrillation in both groups.

No Intervention: Control

Primary Outcome Measures :
  1. Stroke [ Time Frame: 36 months ]
  2. Systemic embolism [ Time Frame: 36 months ]

Secondary Outcome Measures :
  1. Subclinical AF rate [ Time Frame: 36 months ]
  2. Total mortality [ Time Frame: 36 months ]
  3. Cardiovascular mortality [ Time Frame: 36 months ]
  4. Myocardial infarction [ Time Frame: 36 months ]
  5. Cardiovascular hospitalization [ Time Frame: 36 months ]
  6. Bleeding rates [ Time Frame: 36 months ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age >= 18 years
  • CHADS2 score >=2
  • Sinus rhythm
  • Cardiac Implantable Electronic Device

Exclusion Criteria:

  • Atrial fibrillation
  • Severe heart valve disease
  • Anticoagulation therapy
  • Pregnancy

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Responsible Party: Martino Martinelli Filho, Prof., MD, InCor Heart Institute Identifier: NCT02004509    
Other Study ID Numbers: SILENT
First Posted: December 9, 2013    Key Record Dates
Last Update Posted: September 9, 2014
Last Verified: September 2014
Keywords provided by Martino Martinelli Filho, InCor Heart Institute:
atrial fibrillation
Additional relevant MeSH terms:
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Atrial Fibrillation
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes