The PRECEPT Clinical Study1,2

was the first prospective, multicenter, nonrandomized clinical study designed to determine the safety and effectiveness of contact force–guided radiofrequency ablation of persistent AF using the THERMOCOOL SMARTTOUCH® SF Catheter.


The study included 27 centers across the United States and Canada.

Patient impact​

381 patients with drug-refractory symptomatic persistent AF participated in the study.

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Clinical Success

80% of persistent AF patients experienced clinical success at 15 months following radiofrequency catheter ablation with the THERMOCOOL SMARTTOUCH® SF Catheter.

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Primary Effectiveness

61% of patients met the primary effectiveness endpoint of freedom from documented recurrence and prespecified failure modes.

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Freedom from Repeat Ablation

The estimated freedom from repeat ablation was 86%.

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Rate of Primary Adverse Events

The 4.7% adverse event rate is similar to that reported in paroxysmal AF studies.3,4


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Quality of Life Outcomes5

Persistent AF patients experienced improvement in quality of life and reduced healthcare utilization rates at 15 months post ablation:

  • 81% of patients self-classified as asymptomatic with respect to AF
  • 29 point increase on quality of life questionnaire (5 point increase considered clinically significant)6
  • 83% decrease in cardioversion
  • 75% reduction in Class I/III AAD use
  • 84% freedom from cardiovascular hospitalization

A Tailored Approach to Ablation1


PVI-only or PVI+ Ablation

RF ablation with the THERMOCOOL SMARTTOUCH® SF Catheter for isolation of all pulmonary veins was required for all patients (PVI only). Additional ablations were allowed (PVI+) per operator’s discretion.

Patient Inclusion and Exclusion Criteria1

Key Inclusion Criteria

  • Documented symptomatic persistent AF, defined as sustained episodes lasting longer than 7 days but less than 1 year
  • Nonresponse or intolerance to at least one Class I or III AAD

Key Exclusion Criteria

  • Left ventricular ejection fraction <40%
  • Left atrial diameter ≥50 mm
  • Previous AF ablation or cardiac surgery
  • NYHA class III or IV
  • Documented left atrial thrombus within 48 hours of procedure
  • Myocardial infarction within the previous 2 months
  • Thromboembolic event in the previous 12 months

Patient Follow Up1

The blanking period consisted of a 3-month medication adjustment period followed by a 3-month therapy consolidation period. All symptomatic cardiac episodes were recorded and transmitted via transtelephonic monitoring at the time of the event.

Patients were followed-up for 15 months using stringent and standard-of-care monitoring.
A quality of life questionnaire was administered at baseline, 6, 9, 12, and 15 months to assess changes in quality of life.

BWI Precept - Patient Follow Up Graph


Primary Endpoints1,c

•    Primary effectiveness defined as freedom from documented AF/AT/AFL ≥30 sec and prespecified failure modes at 15 months (40% performance goal). 
•    Incidence of primary adverse events occurring within 7 days of the initial and repeat ablation procedures (16% performance goal). 

The THERMOCOOL SMARTTOUCH® SF Catheter is indicated for drug refractory recurrent symptomatic persistent atrial fibrillation (AF) (continuous AF >7 days but <1 year), refractory or intolerant to at least 1 Class I or III AAD, when used with the CARTO® 3 System.


1. Mansour M, Calkins H, Osorio J, et al. Persistent atrial fibrillation ablation with contact force sensing catheter: The prospective multicenter PRECEPT trial. JACC Clin Electrophysiol. 2020;6(8):958-969.
2. PRECEPT IDE G140102
3. Natale A, Reddy VY, Monir G, et al. Paroxysmal AF catheter ablation with a contact force sensing catheter: results of the prospective, multicenter SMART-AF trial. J Am Coll Cardiol. 2014;64(7):647-656. 
4. Chinitz LA, Melby DP, Marchlinski FE, et al. Safety and efficiency of porous-tip contact-force catheter for drug-refractory symptomatic paroxysmal atrial fibrillation ablation: results from the SMART SF trial. Europace. 2018;20(FI_3):f392-f400. 
5. Natale A, Calkins H, Osorio J, et al. Positive clinical benefit on patient care, quality of life, and symptoms after contact force-guided radiofrequency ablation in persistent atrial fibrillation: Analyses from the PRECEPT prospective multicenter study. Circ Arrhythm Electrophysiol. 2021;14(1):e008867.
6. Holmes DN, Piccini JP, Allen LA, et al. Defining Clinically Important Difference in the Atrial Fibrillation Effect on Quality-of-Life Score. Circ Cardiovasc Qual Outcomes. 2019;12(5):e005358.

Abbreviations and Footnotes

AAD, antiarrhythmic drug; AF, atrial fibrillation; AFL, atrial flutter; AT, atrial tachycardia; CTI, cavotricuspid isthmus; ECG, electrocardiogram; HM, Holter monitoring; NYHA, New York Heart Association; PVI, pulmonary vein isolation; PVI+, PVI with additional left atrial ablation per operator's discretion; RF, radiofrequency; TTM, transtelephonic monitoring.

a CTI ablation with documented atrial flutter.
b The Atrial Fibrillation on Quality of Life Questionnaire Tool (AFEQT) and the Canadian Cardiovascular Society Severity in Atrial Fibrillation scale were used to assess changes in quality of life and symptom severity, respectively. A 5-point increase on the AFEQT is considered a clinically important difference. 
c Primary effectiveness failure modes included: acute procedural failure, use of nonstudy catheter, repeat procedures, use of new/higher dose AAD, and surgical ablation. Primary adverse events included: death, atrioesophageal fistula, cardiac tamponade/perforation, myocardial infarction, stroke/cerebrovascular accident, thromboembolism, transient ischemic attack, diaphragmatic paralysis, pneumothorax, heart block, PV stenosis, pulmonary edema, pericarditis, and major vascular access complication or bleeding. PV stenosis and atrioesophageal fistulas occurring more than 7 days after the index procedure were also considered primary adverse events.


Important information: Prior to use, refer to the instructions for use supplied with this device for indications, contraindications, side effects, warnings and precautions. Caution: US law restricts this device to sale by or on the order of a physician.