Theophylline for Low Adenosine Syncope (THEO-USA)
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|ClinicalTrials.gov Identifier: NCT03803215|
Recruitment Status : Recruiting
First Posted : January 14, 2019
Last Update Posted : January 22, 2020
|Condition or disease||Intervention/treatment|
Theophylline has been used for 3 decades in ordinary medical practice to tentatively prevent syncopal recurrences in patients affected by neurally-mediated syncope. Observational studies report a recurrence rate with this drug ranging between 12% and 22%. Theophylline was much more effective in selected patients with syncope without prodromes and normal heart who had ECG documentation of long pauses at the time of syncopal attack and low values of baseline plasmatic adenosine. Since theophylline is a non-selective antagonist of purinergic receptors, it has been hypothesized that purinergic receptors are involved in the mechanism of syncope in such patients. Conversely, theophylline was suspected to be ineffective (or less effective) in patients affected by other forms of neurally-mediated syncope.
The present study aims at assessing that theophylline is effective in patients with no prodromes, normal heart and with low values of plasmatic adenosine compared with a propensity-score matched untreated control population.
This will be a multicenter, non interventional study, verified by ICM, with 2 predefined subgroups:
- Low adenosine group: Patients with Low Adenosine values (<0.40 μmol/L)
- Normal/high adenosine (≥0.40 μmol/L) group: any other patient Subgroup #2
- Patients with no prodromes or very short prodromes (≤5 sec), normal heart and normal ECG (No prodrome group)
- Any other form of atypical neurally-mediated syncope with prodromes >5 sec. Remote or in-hospital periodic follow-up will be done according to centre's clinical practice for ICM monitoring.
Patients will be followed up until the first primary endpoint event with a maximum follow-up of 24 months since start of theophylline treatment.
|Study Type :||Observational|
|Estimated Enrollment :||100 participants|
|Official Title:||Theophylline in Patients With Unexplained Syncope and Low Adenosine. Study Verified by ICM, Controlled by Propensity-score Matching|
|Actual Study Start Date :||May 11, 2016|
|Estimated Primary Completion Date :||June 30, 2020|
|Estimated Study Completion Date :||June 30, 2020|
Patients who have electrocardiographic documentation of asystolic syncope will be treated with oral theophylline at tailored dosage
Oral theophylline initially 600 mg bid and then titrated at the maximum tolerated dose
Control untreated group
A propensity-score matched control group is generated from the large database of patients who had received an implantable loop recorder
- Asystolic syncope [ Time Frame: 24 months ]Number of patients. The primary objective aims to test the hypothesis that theophylline is able to reduce asystolic events in the Low-Adenosine subgroup compared with the propensity-score matched control group
- Time to first syncope recurrence [ Time Frame: 24 months ]Months from enrolment to the first recurrence of syncope
- Asystolic syncope in the subgroup with low adenosine plasmatic values [ Time Frame: 24 months ]Number of patients with asystolic syncope during follow-up
- Asystolic syncope in patients without prodrome, normal heart and normal ECG [ Time Frame: 24 months ]Number of patients with asystolic syncope during follow-up
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03803215
|Contact: Michele Brignole, MD||+390185329567||mbrignole@ASL4.liguria.it|
|Department of Cardiology, Ospedali del Tigullio||Recruiting|
|Lavagna, Italy, 16033|
|Contact: Michele Brignole, MD 0185329567 email@example.com|
|Principal Investigator:||Michele Brignole, MD||Department of Cardiology, Ospedali del Tigullio|