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Physician Clinical Data

CONVERGE IDE Study Design

The CONVERGE IDE trial enrolled 153 patients (88 persistent and 65 long-standing persistent patients) at 27 locations (25 in the United States and 2 in the United Kingdom). Patients were randomized at a rate of 2:1 and received either Hybrid AF Convergent therapy or endocardial RF catheter ablation alone. David DeLurgio, MD, of Emory St. Joseph’s Hospital in Atlanta, Georgia, was the trial’s national principal investigator.

CONVERGE IDE Trial Findings

The Hybrid AF Convergent procedure is the only proven therapy to treat patients who have been in AF for more than one year.1,2 Both 12-month (Table 1) and 18-month (Table 2) data from the CONVERGE IDE trial show that the Hybrid AF Convergent procedure provides durable, long-lasting efficacy.

Table 1: Effectiveness Endpoints for Long-Standing Persistent AF Sub-group—12-Month Follow-Up2

Parameter Hybrid AF Convergent Ablation Arm
(N=38)
Endocardial RF Catheter Ablation Arm
(N=27)
Difference
(Hybrid – Endocardial catheter ablation)
Freedom from AF/AFL/AT from 3-month blanking period through 12 months*
n%, (95% Confidence Interval)
65.8%
(50.7%, 80.9%)
37.0%
(18.8%, 55.3%)
28.8%
in favor of Hybrid
≥90% burden reduction at 12 months*
n%, (95% Confidence Interval)
78.9%
(66.0%, 91.9%)
46.2%
(27.0%, 65.3%)
32.7%
in favor of Hybrid
Freedom from AF through 12 months *
n%, (95% Confidence Interval)
71.1%
(56.6%, 85.5%)
37.0%
(18.8%, 55.3%)
34.1%
in favor of Hybrid

*Without new/ increased dosage of previously failed class I/III AADs
AADs: anti-arrhythmic drugs; AF: atrial fibrillation; AFL: atrial flutter; AT: atrial tachycardia

Table 2: Effectiveness Endpoints for Long-Standing Persistent AF Sub-group—18-Month Follow-Up2

Parameter Hybrid AF Convergent Ablation Arm
(N=38)
Endocardial RF Catheter Ablation Arm
(N=27)
Difference
(Hybrid – Endocardial catheter ablation)
Freedom from AF/AFL/AT from 3-month blanking period through 18 months*
n%, (95% Confidence Interval)
60.5%
(45.0%, 76.1%)
25.9%
(9.4%, 42.5%)
34.6%
in favor of Hybrid
≥90% burden reduction at 18 months*
n%, (95% Confidence Interval)
73.0%
(58.7%, 87.3%)
36.0%
(17.2%, 54.8%)
37.0%
in favor of Hybrid
Freedom from AF through 18 months *
n%, (95% Confidence Interval)
68.4%
(53.6%, 83.2%)
29.6%
(12.4%, 46.9%)
38.8%
in favor of Hybrid

*Without new/ increased dosage of previously failed class I/III AADs
AADs: anti-arrhythmic drugs; AF: atrial fibrillation; AFL: atrial flutter; AT: atrial tachycardia


Hybrid AF Convergent Procedure in Electroanatomic Heterogeneous Cohort3

In this challenging cohort of patients with refractory, long-standing persistent atrial fibrillation (LSPAF), the probability of long-term arrhythmia-free survival was significantly higher with Hybrid AF Convergent ablation (p=0.003).

The study by Maclean, et al., enrolled 43 consecutive patients with LSPAF, who were treated with the Hybrid AF Therapy. Outcomes were compared with a matched group of 43 patients who had catheter ablation alone. Both groups underwent multiple catheter ablations as needed.

Parameter Hybrid AF Convergent Arm Catheter Ablation Arm
AF-Free Survival with AADs at 12 months
P = 0.002
60.5% 25.6%
AF-Free Survival with AADs at 30.5 months
P = 0.016
58.1% 30.2%
AF-Free Survival without AADs at 30.5 months
P = 0.036
32.5% 11.6%
Although the survival data are lower than those reported in other studies, the authors suggest this may be due to electroanatomic heterogeneity of the study cohort, which included patients with:
  • Severe left ventricular systolic dysfunction
  • Cardiomyopathy
  • Pacemakers
  • Prior unsuccessful rhythm control in over one-third of cases

While the Hybrid AF Convergent group had an increased incidence of atrial tachycardia (AT, 32.6%) none of these arrhythmias originated from the posterior wall. Instead, the origin of the AT prompted the authors to suggest consideration of empirical cavotricuspid isthmus (CTI) lines.

This study reveals that in patients with LSPAF, the Hybrid AF Convergent procedure is associated with increased freedom from AF at one year—and improved arrhythmia-free survival long term—versus endocardial catheter ablation alone.

AADs: anti-arrhythmic drugs


Hybrid AF CryoConvergent Therapy4

This study by Makati, et al., showed that using endocardial cryothermy in Hybrid AF Convergent procedures achieved marked reductions in AF burden, even in long-standing persistent AF (LSPAF). Most Hybrid AF Convergent studies use radiofrequency as the endocardial and epicardial energy. This study reports the safety and efficacy of the Hybrid AF Convergent procedure using endocardial cryothermy.

Method: Retrospective analysis of 226 TRAC-AF Registry patients (2011-2018) who underwent epicardial RF ablation and endocardial cryothermy.

Parameter All patients
(mean 15.4 ± 6.5 months)
Persistent AF
(mean 14.7 ± 6.1 months)
LSPAF
(mean 16.8 ± 6.3 months)
Free of AF/AFL/AT: on or off previously failed AADs 75% 85% 70%
Free of AF/AFL/AT: off amiodarone 70% 84% 64%
Free of AF/AFL/AT: off AADs 53%    
AF Burden Reduction (3-12 months) 98.9% 99.3% 98.5%
AF Burden Reduction (12-24 months) 91.5% 89.3% 92.5%

Results indicate Hybrid AF Convergent using cryo energy provides a promising solution for treatment of persistent AF and LSPAF, evidenced by relatively low AF recurrence rates and marked AF burden reduction after treatment—even in LSPAF patients.

AF: atrial fibrillation; AFL: atrial flutter; AT: atrial tachycardia; AADs: anti-arrhythmic drugs


Outcomes of Convergent Atrial Fibrillation Ablation with Continuous Rhythm Monitoring5

The study involved 113 consecutive patients at one institution who underwent the Hybrid AF Convergent procedure. Among the patient characteristics: 88% had either persistent AF or long-standing persistent (LSP) AF; mean duration of AF before the procedure was 5.1 ± 4.6 years; 45% had undergone at least one prior catheter ablation; 31% had impaired LVEF; 62% had moderate or severe LA enlargement.

During follow-up, most patients (n = 92) had continuous rhythm monitoring. During the mean follow-up of 501 days, results were as follows.

Parameter Finding  
AF/AT-Free Survival 53% For any episode >30 sec at 12 months (after the 90-day blanking period) in all patients
AF/AT Mean Burden <5% Among patients (n=92) with continuous rhythm monitoring who had recurrences—with those very low rates remaining stable throughout follow-up
Off AADs 64% At last follow-up

Procedural complications decreased significantly following the transition from transdiaphragmatic to subxiphoid surgical access: 23% vs 3.8% (p = 0.005). Other results included: 9% of patients had elective cardioversion outside the blanking period, and 9.7% of patients underwent repeat ablation at a mean of 229 ± 178 days post procedure.

As noted in the Discussion, the data “highlight the potential shortcomings of conventional definitions of AF ablation success which have utilized a definition of recurrence including any AF/AT episode lasting >30 seconds ... [with most study results therefore showing] very modest success rates at approximately 50% to 60% at 1 year.”

The authors noted that recent study results, such as those from CASTLE-AF, suggest AF burden may be more reflective of ablation efficacy than conventional freedom from recurrence. In the current study, the authors found nearly 95% of their continuously monitored patients with recurrences remained free from an arrhythmia burden >5%.

In summary, more than half of the patients were AF/AT-free, and among patients who did experience an AF recurrence, the Hybrid AF Convergent procedure was able to reduce AF burden to very low mean levels of <5%, a level which appeared consistent over time.

At time of study completion, it was noted that future trials will be necessary to best define which patients are most likely to benefit from the Convergent approach.


Convergent Ablation for Persistent Atrial Fibrillation: Single Center Experience6

This retrospective study examined 31 symptomatic patients—with persistent AF (n =16) or long-standing persistent (LSP, n = 15) AF—who were treated with the Convergent procedure. All patients underwent surgical epicardial ablation via subxiphoid approach, followed by radiofrequency endocardial ablations on the same day. Median LA size was 4.3 cm. All but 4 patients, who were lost to follow-up, completed 2-year follow-up.

Arrhythmia Recurrence with or without AADs
Type of Arrhythmia At 1 Year At 2 Years
AF Only 13% 29%
AF/AFL 29% 48%
Freedom from Arrhythmias
Type of Arrhythmia At 2 Years
AF Only 71%
Atrial Tachyarrhythmias 52%

Interestingly, there was no statistical significance in AF/AFL recurrence in patients with or without AADs. Perioperatively, there was a 12.9% (4/31 patients) complication rate, but “some of these complications occurred early in our experience and steps were taken to avoid” these complications in the future. Of the 3 mortalities, 2 were from noncardiac causes within 18 months, and one was from cardiac arrest due to unknown causes at 4 months post intervention.

It is important to point out that 16.1% of this patient cohort had hypertrophic cardiomyopathy, and these patients are known to have much higher AF recurrence rates.

The Convergent procedure emphasizes the importance of silencing the posterior LA, which is an important area of arrhythmogenicity. This study demonstrates that the Convergent approach can be a reasonable alternative for treating patients with advanced stages of AF and severely dilated LA.

The authors concluded the hybrid procedure is a relatively safe and effective option for patients with PAF. Further studies are needed to better determine its long-term outcomes.

AF: atrial fibrillation; AT: atrial tachycardia;
LVEF: left ventricular ejection fraction;
LA: left atrial; AADs: anti-arrhythmic drugs

  1. DeLurgio, D.B., et al. (2021). Hybrid epicardial-endocardial RF ablation vs. endocardial catheter ablation for long-standing persistent atrial fibrillation treatment: Results from CONVERGE randomized controlled trial. International AF Symposium.
  2. IFU for EPi-Sense® Guided Coagulation System Data: PMA# P200002
  3. Maclean, E., et al. (2020). The CONVERGENT procedure versus catheter ablation alone in long-standing persistent atrial fibrillation: a single center, propensity-matched cohort study. International Journal of Cardiology, 303,49-53.
  4. Makati, K. J., et al. (2020). Safety and efficacy of Convergent Hybrid procedure using cryo as endocardial energy source for the treatment of atrial fibrillation. Circulation: Arrhythmia and Electrophysiology. 13, e008556.
  5. Larson, J., et al. (2020). Outcomes of convergent atrial fibrillation ablation with continuous rhythm monitoring. Journal of Cardiovascular Electrophysiology, 31(6): 1270-6.
  6. Gulkarov, I. et al. (2019). Convergent ablation for persistent atrial fibrillation: single center experience. Journal of Cardiac Surgery, 34(10):1037-43.

    This material is intended to provide objective information about the use of AtriCure's Technology, including where and how the device can be used within the continuum of care. The enclosed publication includes information regarding patients with persistent or long-standing persistent atrial fibrillation treated with the EPi-sense technology in a hybrid procedure. This material is being provided to demonstrate use of the EPi-Sense system in the treatment of long-standing atrial fibrillation and its clinical outcomes. This publication was chosen for this purpose because the study summarized herein utilized a trial design similar to that used in the CONVERGE IDE study which supported FDA approval of the EPi-Sense System for the indication stated above.
PM-US-1642A-0423-G