Who is sponsoring NCT03775512?

NCT03775512 is sponsored by Biosense Webster, Inc..

What drugs are being tested in NCT03775512?

Interventions in NCT03775512: RF Ablation with QDOT Micro.

What condition does NCT03775512 study?

NCT03775512 studies Paroxysmal Atrial Fibrillation.

Is NCT03775512 still recruiting?

NCT03775512 is currently completed. Last updated 16 March 2023.

Are results published for NCT03775512?

Yes — primary outcome results have been posted to ClinicalTrials.gov. See the outcomes section above for details.

Last reviewed 2023-03-16 · How we verify

NCT03775512: Q-FFICIENCY

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

Evaluation of QDOT MICRO™ Catheter for Pulmonary Vein Isolation in Subjects With Paroxysmal Atrial Fibrillation

Completed NA Results posted Last updated 16 March 2023

What this trial tests

NA trial testing RF Ablation with QDOT Micro in Paroxysmal Atrial Fibrillation in 283 participants. Completed in 17 February 2022.

Timeline

30 January 2019

Primary endpoint
17 February 2022

17 February 2022

Quick facts

Lead sponsor	Biosense Webster, Inc.
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	non randomized
Design	sequential
Masking	none
Primary purpose	treatment
Enrollment	283
Start date	30 January 2019
Primary completion	17 February 2022
Estimated completion	17 February 2022
Sites	22 locations across United States

Drugs / interventions tested

RF Ablation with QDOT Micro

Conditions studied

Paroxysmal Atrial Fibrillation — all drugs for Paroxysmal Atrial Fibrillation →

Sponsor

Biosense Webster, Inc. — full company profile →

Who can join

18 and older, any sex, with Paroxysmal Atrial Fibrillation. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Percentage of Participants With Early Onset Primary Adverse Events (PAEs): Atrio-esophageal Fistula and Pulmonary Vein (PV) Stenosis Primary · Up to 90 days (post initial and repeated ablation procedure)

An adverse event (AE) is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. A Primary AEs is an event which occurred within 90 days following initial and repeated ablation procedure using the QDOT MICRO. Primary AEs included: atrio-esophageal fistula and pulmonary vein stenosis.

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	0
Variable Flow Arm: QDOT Micro Catheter	0

Percentage of Participants With Early Onset PAEs: Death, Myocardial Infraction, Cardiac Tamponade/Perforation, Thromboembolism, Stroke/Cardiovascular Accident , TIA, PNP, Heart Block, Pulmonary Edema, Vagal Nerve Injury, Pericarditis, and MVAC/Bleeding Primary · Up to 7 days (post initial and repeated ablation procedure)

A Primary AEs is an event which occurred within the first week (7 days of the initial and repeated ablation procedure) which included death, myocardial infraction (MI), cardiac tamponade (CT)/perforation, thromboembolism, stroke/cardiovascular accident (CVA), transient ischemic attack (TIA), phrenic nerve paralysis (PNP), heart block, pulmonary edema, vagal nerve injury, pericarditis, and major vascular access complication/bleeding (MVAC).

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	3.6
Variable Flow Arm: QDOT Micro Catheter	2.4

Percentage of Participants With Freedom From Documented Atrial Fibrillation (AF), Atrial Tachycardia (AT), or Atrial Flutter (AFL) Episodes or Other Failure Modes Primary · Day 91 to Day 365

Percentage of participants with freedom from documented AF, AT, or AFL episodes or following failure modes: a) Acute procedural: Failure to confirm entrance block in all pulmonary veins post-procedure and use of a non-study catheter to treat left atrial ablation targets and Cavo-tricuspid isthmus; b) Repeat ablation: \>2 repeat ablation procedures with the study catheter during the 3-Month blanking period (Day 0-90) after the index ablation procedure, use of a non-study catheter to treat study arrhythmia ablation targets during the blanking period, and any repeat ablation procedure during the

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	76.3
Variable Flow Arm: QDOT Micro Catheter	67.5

Number of Participants With Unanticipated Adverse Device Effects (UADEs) Secondary · Up to 20 months

Number of participants with UADEs were reported.

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	0
Variable Flow Arm: QDOT Micro Catheter	0

Number of Participants With Serious Non-Primary Adverse Events (SAEs) Within 7 Days (Early Onset), 8-30 Days (Peri-procedural) and Greater Than or Equal to (>=) 31 Days (Late Onset) of Initial Ablation Procedure Secondary · Within 7 days (early onset), 8-30 days (peri-procedural) and >=31 days (late onset) of initial ablation procedure (up to 20 months)

Number of participants with serious non-primary AEs within 7 days (early onset), 8-30 days (peri-procedural) and \>=31 days (late onset) of initial ablation were reported.

0 - 7 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	8
Variable Flow Arm: QDOT Micro Catheter	4

8 - 30 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	4
Variable Flow Arm: QDOT Micro Catheter	3

>= 31 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	25
Variable Flow Arm: QDOT Micro Catheter	12

Number of Participants With Bleeding Complication by International Society on Thrombosis and Haemostasis (ISTH) Class and Timing of Onset Secondary · Within 7 days (early onset), 8-30 days (peri-procedural) and >=31 days (late onset) of initial ablation procedure (up to 20 months)

Number of participants with bleeding complication (ISTH definitions): a) major, b) clinically relevant non-major and c) minor bleeding were reported. The ISTH classification of major bleeding event is a hemoglobin drop of greater than or equal to (\>=) 2 grams per deciliter (g/dL), transfusion of \>= 2 units (U) packed red blood cells, symptomatic bleed in a critical area, or fatal bleed. Clinically relevant non-major (CRNM) events require prolong hospitalization or result in laboratory testing, imaging, compression, procedure, interruption of the study medication or a change in concomitant th

Major: 0 - 7 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	3
Variable Flow Arm: QDOT Micro Catheter	0

Major: 8 - 30 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	0
Variable Flow Arm: QDOT Micro Catheter	0

Major: >= 31 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	0
Variable Flow Arm: QDOT Micro Catheter	0

CRNM: 0-7 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	3
Variable Flow Arm: QDOT Micro Catheter	0

CRNM: 8-30 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	0
Variable Flow Arm: QDOT Micro Catheter	0

CRNM: >= 31 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	2
Variable Flow Arm: QDOT Micro Catheter	0

Minor: 0-7 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	5
Variable Flow Arm: QDOT Micro Catheter	0

Minor: 8-30 Days

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	1
Variable Flow Arm: QDOT Micro Catheter	0

Percentage of Participants With Electrical Isolation of Pulmonary Veins (PVs) (Entrance Block) at the End of the Procedure Secondary · End of the Procedure (up to 20 months)

Percentage of participants with electrical isolation of PVs (entrance block) at the end of the procedure were reported

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	100
Variable Flow Arm: QDOT Micro Catheter	100

Percentage of Participants With Electrical Isolation of PV After First Encirclement With Acute Reconnection Secondary · Up to 20 months

Percentage of participants with electrical isolation of PV after first encirclement with acute reconnection were reported.

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	42.7
Variable Flow Arm: QDOT Micro Catheter	31.7

Percentage of Participants With Electrical Isolation of PV After First Encirclement Without Acute Reconnection Secondary · Up to 20 months

Percentage of participants with electrical isolation of PV after first encirclement without acute reconnection were reported.

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	57.3
Variable Flow Arm: QDOT Micro Catheter	68.3

Percentage of Participants With Pulmonary Veins (PV) Touch-up Secondary · Up to 20 months

Percentage of participants with PV touch-up were reported. PV touch-up was defined as additional ablations being performed after first encirclement for targeted veins with acute reconnection.

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	42.7
Variable Flow Arm: QDOT Micro Catheter	31.7

Percentage of Targeted Veins With Touch-up (Ablation of Acute Reconnection) Among All Targeted Veins Secondary · Up to 20 months

Percentage of targeted veins with touch-up (ablation of acute reconnection) among all targeted veins were reported.

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	27.4
Variable Flow Arm: QDOT Micro Catheter	20.7

Percentage of Participants With Touch-up at Anatomical Location of Acute PV Reconnection After First Encirclement Secondary · Up to 20 months

Percentage of participants with touch-up at anatomical location of acute PV reconnection after first encirclement was reported. The location included anterior, superior, ridge, posterior, and inferior region of the left pulmonary veins (LPV) and right pulmonary veins (RPV). The review of all ablation targets for the 1 participant with RPV ridge entered by site resulted in reclassification to RPV superior. This outcome measure was planned to be analyzed for specified arm (main arm) only.

LPV: Anterior

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	31.1

LPV: Inferior

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	28.9

LPV: Posterior

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	53.3

LPV: Ridge

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	42.2

LPV: Superior

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	44.4

RPV: Anterior

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	53.5

RPV: Inferior

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	37.2

RPV: Posterior

Group	Value	95% CI
Main Arm: QDOT Micro Catheter	58.1

Adverse events — posted to ClinicalTrials.gov

Time frame: Up to 20 months. Reporting threshold: 0%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Main Arm: QDOT Micro Catheter

Serious: 32/177 (18%)

Deaths: 1/177

Variable Flow Arm: QDOT Micro Catheter

Serious: 14/87 (16%)

Deaths: 1/87

Serious adverse events (47 terms)

Reaction	System	Main Arm: QDOT Micro Cathe…	Variable Flow Arm: QDOT Mi…
Atrial fibrillation	Cardiac disorders	—	—
Atrial flutter	Cardiac disorders	—	—
Chest pain	General disorders	—	—
Headache	Nervous system disorders	—	—
Atrial tachycardia	Cardiac disorders	—	—
Tachycardia	Cardiac disorders	—	—
Pneumonia	Infections and infestations	—	—
Migraine	Nervous system disorders	—	—
Cardiac failure congestive	Cardiac disorders	—	—
Cardiac tamponade	Cardiac disorders	—	—
Pyrexia	General disorders	—	—
Arteriovenous fistula	Vascular disorders	—	—
Pleuritic pain	Respiratory, thoracic and mediastinal disorders	—	—
Sinus node dysfunction	Cardiac disorders	—	—
Cardiac valve fibroelastoma	Neoplasms benign, malignant and unspecified (incl cysts and polyps)	—	—
Pericardial effusion	Cardiac disorders	—	—
Pulmonary embolism	Respiratory, thoracic and mediastinal disorders	—	—
Cardiac failure	Cardiac disorders	—	—
Thrombocytopenia	Blood and lymphatic system disorders	—	—
Angina unstable	Cardiac disorders	—	—
Atrioventricular block	Cardiac disorders	—	—
Cardiac arrest	Cardiac disorders	—	—
Ventricular extrasystoles	Cardiac disorders	—	—
Cyst	General disorders	—	—
Prostate cancer	Neoplasms benign, malignant and unspecified (incl cysts and polyps)	—	—

Other adverse events (62 terms — click to expand)

Reaction	System	Main Arm: QDOT Micro Cathe…	Variable Flow Arm: QDOT Mi…
Hypotension	Vascular disorders	—	—
Dyspnea	Respiratory, thoracic and mediastinal disorders	—	—
Hypertension	Vascular disorders	—	—
Ventricular extrasystoles	Cardiac disorders	—	—
Pulmonary vein stenosis	Respiratory, thoracic and mediastinal disorders	—	—
Supraventricular tachycardia	Cardiac disorders	—	—
Headache	Nervous system disorders	—	—
Pericardial effusion	Cardiac disorders	—	—
Atrial flutter	Cardiac disorders	—	—
Pericarditis	Cardiac disorders	—	—
Non-Cardiac Chest pain	General disorders	—	—
Hematoma	Vascular disorders	—	—
Atrial tachycardia	Cardiac disorders	—	—
Supraventricular extrasystoles	Cardiac disorders	—	—
Ventricular tachycardia	Cardiac disorders	—	—
Chronic obstructive pulmonary disease	Respiratory, thoracic and mediastinal disorders	—	—
Major Vascular Access Complication / Bleeding	Vascular disorders	—	—
Hematuria	Renal and urinary disorders	—	—
Oropharyngeal pain	Respiratory, thoracic and mediastinal disorders	—	—
Cardiac Tamponade/Perforation	Cardiac disorders	—	—
Angina pectoris	Cardiac disorders	—	—
Vomiting	Gastrointestinal disorders	—	—
Chest pain	General disorders	—	—
Urinary tract infection	Infections and infestations	—	—
Incision site hemorrhage	Injury, poisoning and procedural complications	—	—
Urinary tract injury	Injury, poisoning and procedural complications	—	—
Laboratory test abnormal	Investigations	—	—
Weight increased	Investigations	—	—
Groin pain	Musculoskeletal and connective tissue disorders	—	—
Joint swelling	Musculoskeletal and connective tissue disorders	—	—
Musculoskeletal chest pain	Musculoskeletal and connective tissue disorders	—	—
Neck Pain	Musculoskeletal and connective tissue disorders	—	—
Hypoesthesia	Nervous system disorders	—	—
Migraine	Nervous system disorders	—	—
Presyncope	Nervous system disorders	—	—
Prostatitis	Reproductive system and breast disorders	—	—
Pleuritic pain	Respiratory, thoracic and mediastinal disorders	—	—
Fluid overload	Metabolism and nutrition disorders	—	—
Vaginal hemorrhage	Reproductive system and breast disorders	—	—
Coronary artery disease	Cardiac disorders	—	—

Most-reported serious reactions: Atrial fibrillation, Atrial flutter, Chest pain, Headache, Atrial tachycardia, Tachycardia, Pneumonia, Migraine.

Data from ClinicalTrials.gov NCT03775512 adverse events section.

Sponsor's own description

Prospective, non-randomized, pre-market clinical evaluation of the QDOT MICRO™ Catheter to demonstrate the safety and effectiveness when compared to an historical control performance goal.

Publications & conference data

4 peer-reviewed publications reference this trial (live from Europe PMC):

Very High-Power Short-Duration, Temperature-Controlled Radiofrequency Ablation in Paroxysmal Atrial Fibrillation: The Prospective Multicenter Q-FFICIENCY Trial.
Osorio J, Hussein AA, Delaughter MC, Monir G, et al · · 2023 · cited 60× · PMID 36752484 · DOI 10.1016/j.jacep.2022.10.019
High-power, Short-duration Radiofrequency Ablation for the Treatment of AF.
Kotadia ID, Williams SE, O'Neill M. · · 2020 · cited 35× · PMID 32685157 · DOI 10.15420/aer.2019.09
QDOT MICRO™ versus THERMOCOOL<sup>®</sup> SMARTTOUCH™ and THERMOCOOL SMARTTOUCH<sup>®</sup> Surround Flow in radiofrequency ablation of paroxysmal atrial fibrillation.
Osorio J, Maccioni S, Sharma R, Patel L, et al · · 2023 · PMID 37584396 · DOI 10.57264/cer-2023-0005
Rapid Point-by-Point Pulmonary Vein Isolation.
Michaud GF, Narayan SM. · · 2019 · PMID 31320007 · DOI 10.1016/j.jacep.2019.05.007

Verify or expand the search:

Other recruiting trials for Paroxysmal Atrial Fibrillation

Currently open trials in the same condition.

NCT07535268 — REPRESENT-PF Registry · recruiting
NCT07344961 — Determinates of Atrial Tracking and Prevalence of Atrial Fibrillation in the Micra AV2 (DANCE AFIB) · recruiting
NCT07281898 — Burst Stimulation for Paroxysmal Atrial Fibrillation · NA · recruiting
NCT07116525 — A Study Assessing Arrhythmia Mapping With a Multi-Electrode Mapping Catheter · NA · recruiting
NCT06765356 — Pragmatic Evaluation of a Pentaspline Pulsed Field Ablation System to Treat Atrial Fibrillation and Related Arrhythmias · Phase 4 · active not recruiting

Other Biosense Webster, Inc. trials

Trials by the same sponsor.

NCT07527299 — A Study of VARIPULSE Catheter in Participants With Persistent Atrial Fibrillation Undergoing Pulmonary Vein and Superior · NA · not yet recruiting
NCT07523750 — A Study of VARIPULSE Pulsed Field Ablation (PFA) Catheter and FARAWAVE PFA Catheter in the Treatment of Participants Wit · NA · not yet recruiting
NCT07429214 — A Study of VARIPULSE Catheter and TRUPULSE Generator With VARIPULSE Pro Software in Participants With PAF or PsAF · NA · recruiting
NCT07428564 — A Study of VARIPULSE Catheter and TRUPULSE Generator With VARIPULSE PRO Software in Participants With PsAF · NA · not yet recruiting
NCT07227532 — A Study Assessing Long-Term Safety and Effectiveness in Treatment Management of Atrial Fibrillation With VARIPULSE Cathe · NA · recruiting

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT03775512 (US National Library of Medicine, public domain)
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Biosense Webster, Inc.
Last refreshed: 16 March 2023

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03775512.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing