ELECTROPHYSIOLOGY
Sequential Hybrid Surgical CryoMaze and Transvenous Catheter Ablation of Atrial Fibrillation MARTIN EISENBERGER, M.D., PH.D.,*,† ALAN BULAVA, M.D., PH.D.,*,† ALES MOKRACEK, M.D., PH.D,* JIRI HANIS, M.D.,* VOJTECH KURFIRST, M.D., PH.D.,* and LADISLAV DUSEK, PH.D.‡ From the *South Bohemia Cardiac Centre, Budweis Hospital, Budweis, Czech Republic; †Faculty of Health and Social Studies, South Bohemia University, Budweis, Czech Republic; and ‡Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic
Background: The aim of the study was to evaluate whether the sequential hybrid approach combining surgical CryoMaze followed by the radiofrequency (RF) catheter ablation can improve freedom from atrial arrhythmias. Methods: Thirty-five patients with persistent atrial fibrillation underwent a CryoMaze procedure in conjunction with cardiac surgery for structural heart disease. Three months after surgery, all patients underwent a 7-day electrocardiogram Holter followed by an electrophysiological study and mapping of the left and right atria. All pulmonary veins were reisolated and all ablation lines were completed, if necessary, using RF energy. Patients were followed-up at 3 months, 6 months, and 12 months after the catheter ablation. Results: Before the mapping study and RF ablation, nine patients (26%) had ongoing atrial fibrillation or atrial tachycardia, 10 patients (28%) had paroxysmal atrial tachyarrhythmia, and 16 patients (46%) had sinus rhythm on the 7-day Holter monitoring. During the electrophysiological procedure, complete cryoablation lines around the left pulmonary veins were found in 29 patients (83%), around the right pulmonary veins in 25 patients (71%), between the superior veins in 20 patients (57%), between the inferior veins in 27 patients (77%), across the mitral isthmus in 12 patients (34%), and across the cavotricuspid isthmus in one patient (3%). Arrhythmia-free survival rate of antiarrhythmic drugs after reisolation of the veins and completion of the lines was 86% at 12 months. Conclusion: Ablation lines created using surgical CryoMaze are often incomplete. Sequential surgical CryoMaze procedures followed by catheter ablation significantly increase freedom from arrhythmia in patients with persistent atrial fibrillation. (PACE 2015; 38:1379–1385) CryoMaze, surgical ablation, catheter ablation, atrial fibrillation, hybrid approach, incomplete lines Introduction The CryoMaze procedure was developed as a surgical alternative to incisional treatment for atrial fibrillation. The procedure is usually done in conjunction with coronary artery bypasses or valve surgery.1 However, incomplete lines can decrease the efficacy of the ablation procedure and can be proarrhythmic.2–4 There is no information in the literature about the incidence and location of conduction gaps after CryoMaze surgery. Equally unknown is whether Funding source: This research has been supported by BOV2012_001 grant from the South Bohemia University. Address for reprints: Martin Eisenberger, M.D., Ph.D., South Bohemia Cardiac Centre, Budweis Hospital, B. Nemcove 585/54, 370 01 Budweis, Czech Republic. Fax: 420 386 461 941; e-mail: [email protected] Received April 25, 2015; revised June 29, 2015; accepted July 5, 2015. doi: 10.1111/pace.12686
subsequent radiofrequency (RF) catheter ablation and completion of ablation lines in all patients can increase freedom from arrhythmia. Based on the research of Pison et al.,5 Gehi et al.,6 Bulava et al.,7 and Kurfirst et al.,8 using hybrid approaches to the management of atrial fibrillation by surgeons and electrophysiologists, we pioneered a staged hybrid approach combining surgical CryoMaze followed, in 3 months, by RF catheter ablation. There are ongoing clinical trials, such as DEEP and CONVERGE, that are currently assessing the efficacy and safety of hybrid techniques, but none of the studies were designed to assess the use of cryoenergy for the surgical part of the hybrid procedure. The primary end point of our study was arrhythmia-free survival of Class I or III antiarrhythmic drugs following the combined surgical plus subsequent catheter ablation approach. The secondary end points included the percent of patients free of atrial tachyarrhythmias regardless of antiarrhythmic drug status and redo ablations,
©2015 Wiley Periodicals, Inc. PACE, Vol. 38
December 2015
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EISENBERGER, ET AL.
Table I. Baseline Characteristics All Patients (N = 35) Age (years) Male BMI Atrial fibrillation duration (months) Atrial fibrillation type Persistent Longstanding persistent Previous cardioversions Hypertension Diabetes LVEF (%) LA diameter (mm) Cardiac surgery type Valve operation CABG operation Combined CABG and valve operation Other operation
71 ± 6 23 (66%) 29.0 ± 4.9 52 ± 11
9 (26%) 26 (74%) 20 (57%) 29 (83%) 8 (23%) 63 ± 7 49.8 ± 4.9 19 (54%) 7 (20%) 8 (23%) 1 (3%)
BMI = body mass index; CABG = coronary artery bypass grafting; LA = left atrium; LVEF = left ventricular ejection fraction.
incidence of conduction gaps after the standard CryoMaze procedure, and frequency of procedure-related complications including death, myocardial infarction, stroke, transient ischemic attack, pulmonary embolism, peripheral arterial embolism, tamponade, and severe vascular injury, at 30 days or hospital discharge, whichever was longer. Methods Patients Thirty-five consecutive patients who required cardiac surgery between November 2013 and August 2014 and additionally underwent cryothermic ablation for a diagnosis of persistent or longstanding persistent atrial fibrillation were enrolled in the study. Definitions of persistent and longstanding persistent atrial fibrillation were based on expert consensus statement.9 All patients underwent echocardiography and coronary angiography before surgery. Patient demographics, operative information, and outcome data were recorded (Table I). The protocol was approved by the institutional ethics committee. All patients provided a written informed consent before participation in the study. CryoMaze Procedure CryoMaze ablations were performed using the standard sternotomy approach and a Cardioblate
1380
CryoFlex Surgical Ablation Probe (Medtronic Inc., Minneapolis, MN, USA). The procedures were carried out by five different, experienced cardiac surgeons. Each lesion was created by one application of cryothermia at a temperature of approximately −140°C for 2 minutes. The standard protocol of biatrial CryoMaze consisted of a left-sided lesion set with continuous lesions surrounding each group of right and left pulmonary veins with connecting lesions between the superior and inferior pulmonary veins and to the posterior segment of the mitral annulus. The ligament of Marshall was dissected and the left atrial appendage was excluded in patients with a previous history of stroke or a CHA2 DS2 VASc score ࣙ 3. The right atrial lesion consisted of an isthmus line connecting the inferior vena cava with the tricuspid annulus. All patients who remained in atrial fibrillation once the surgical procedure was completed underwent attempted cardioversion before chest closure and again before hospital discharge if arrhythmia persisted. Patients were discharged without any antiarrhythmic medication unless required for recurrent symptomatic arrhythmias. A 7-day electrocardiogram (ECG) Holter monitor was scheduled at 3 months after the CryoMaze procedure just before admission for the catheter ablation. Catheter Ablation Patients were brought to the electrophysiological laboratory 3 months after the CryoMaze procedure. A 3-month period was elected to allow time for tissue healing. Electroanatomical mapping of the left and right atria was performed using a 3.5-mm irrigated-tip catheter (ThermoCool SmartTouch, Biosense Webster, Inc., Diamond Bar, CA, USA) using a CARTO3 navigation system (Biosense Webster, Inc.) and intracardiac echocardiography. Intravenous heparin was administered after the first transseptal puncture to achieve and maintain activated clotting time of 300– 400 seconds. Contrast-enhanced computerized tomography (CT) of the heart was performed in all patients before the procedure and CT images were integrated with detailed CARTO3 bipolar voltage maps. The low-voltage regions and scarred areas (
Sequential Hybrid Surgical CryoMaze and Transvenous Catheter Ablation of Atrial Fibrillation MARTIN EISENBERGER, M.D., PH.D.,*,† ALAN BULAVA, M.D., PH.D.,*,† ALES MOKRACEK, M.D., PH.D,* JIRI HANIS, M.D.,* VOJTECH KURFIRST, M.D., PH.D.,* and LADISLAV DUSEK, PH.D.‡ From the *South Bohemia Cardiac Centre, Budweis Hospital, Budweis, Czech Republic; †Faculty of Health and Social Studies, South Bohemia University, Budweis, Czech Republic; and ‡Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic
Background: The aim of the study was to evaluate whether the sequential hybrid approach combining surgical CryoMaze followed by the radiofrequency (RF) catheter ablation can improve freedom from atrial arrhythmias. Methods: Thirty-five patients with persistent atrial fibrillation underwent a CryoMaze procedure in conjunction with cardiac surgery for structural heart disease. Three months after surgery, all patients underwent a 7-day electrocardiogram Holter followed by an electrophysiological study and mapping of the left and right atria. All pulmonary veins were reisolated and all ablation lines were completed, if necessary, using RF energy. Patients were followed-up at 3 months, 6 months, and 12 months after the catheter ablation. Results: Before the mapping study and RF ablation, nine patients (26%) had ongoing atrial fibrillation or atrial tachycardia, 10 patients (28%) had paroxysmal atrial tachyarrhythmia, and 16 patients (46%) had sinus rhythm on the 7-day Holter monitoring. During the electrophysiological procedure, complete cryoablation lines around the left pulmonary veins were found in 29 patients (83%), around the right pulmonary veins in 25 patients (71%), between the superior veins in 20 patients (57%), between the inferior veins in 27 patients (77%), across the mitral isthmus in 12 patients (34%), and across the cavotricuspid isthmus in one patient (3%). Arrhythmia-free survival rate of antiarrhythmic drugs after reisolation of the veins and completion of the lines was 86% at 12 months. Conclusion: Ablation lines created using surgical CryoMaze are often incomplete. Sequential surgical CryoMaze procedures followed by catheter ablation significantly increase freedom from arrhythmia in patients with persistent atrial fibrillation. (PACE 2015; 38:1379–1385) CryoMaze, surgical ablation, catheter ablation, atrial fibrillation, hybrid approach, incomplete lines Introduction The CryoMaze procedure was developed as a surgical alternative to incisional treatment for atrial fibrillation. The procedure is usually done in conjunction with coronary artery bypasses or valve surgery.1 However, incomplete lines can decrease the efficacy of the ablation procedure and can be proarrhythmic.2–4 There is no information in the literature about the incidence and location of conduction gaps after CryoMaze surgery. Equally unknown is whether Funding source: This research has been supported by BOV2012_001 grant from the South Bohemia University. Address for reprints: Martin Eisenberger, M.D., Ph.D., South Bohemia Cardiac Centre, Budweis Hospital, B. Nemcove 585/54, 370 01 Budweis, Czech Republic. Fax: 420 386 461 941; e-mail: [email protected] Received April 25, 2015; revised June 29, 2015; accepted July 5, 2015. doi: 10.1111/pace.12686
subsequent radiofrequency (RF) catheter ablation and completion of ablation lines in all patients can increase freedom from arrhythmia. Based on the research of Pison et al.,5 Gehi et al.,6 Bulava et al.,7 and Kurfirst et al.,8 using hybrid approaches to the management of atrial fibrillation by surgeons and electrophysiologists, we pioneered a staged hybrid approach combining surgical CryoMaze followed, in 3 months, by RF catheter ablation. There are ongoing clinical trials, such as DEEP and CONVERGE, that are currently assessing the efficacy and safety of hybrid techniques, but none of the studies were designed to assess the use of cryoenergy for the surgical part of the hybrid procedure. The primary end point of our study was arrhythmia-free survival of Class I or III antiarrhythmic drugs following the combined surgical plus subsequent catheter ablation approach. The secondary end points included the percent of patients free of atrial tachyarrhythmias regardless of antiarrhythmic drug status and redo ablations,
©2015 Wiley Periodicals, Inc. PACE, Vol. 38
December 2015
1379
EISENBERGER, ET AL.
Table I. Baseline Characteristics All Patients (N = 35) Age (years) Male BMI Atrial fibrillation duration (months) Atrial fibrillation type Persistent Longstanding persistent Previous cardioversions Hypertension Diabetes LVEF (%) LA diameter (mm) Cardiac surgery type Valve operation CABG operation Combined CABG and valve operation Other operation
71 ± 6 23 (66%) 29.0 ± 4.9 52 ± 11
9 (26%) 26 (74%) 20 (57%) 29 (83%) 8 (23%) 63 ± 7 49.8 ± 4.9 19 (54%) 7 (20%) 8 (23%) 1 (3%)
BMI = body mass index; CABG = coronary artery bypass grafting; LA = left atrium; LVEF = left ventricular ejection fraction.
incidence of conduction gaps after the standard CryoMaze procedure, and frequency of procedure-related complications including death, myocardial infarction, stroke, transient ischemic attack, pulmonary embolism, peripheral arterial embolism, tamponade, and severe vascular injury, at 30 days or hospital discharge, whichever was longer. Methods Patients Thirty-five consecutive patients who required cardiac surgery between November 2013 and August 2014 and additionally underwent cryothermic ablation for a diagnosis of persistent or longstanding persistent atrial fibrillation were enrolled in the study. Definitions of persistent and longstanding persistent atrial fibrillation were based on expert consensus statement.9 All patients underwent echocardiography and coronary angiography before surgery. Patient demographics, operative information, and outcome data were recorded (Table I). The protocol was approved by the institutional ethics committee. All patients provided a written informed consent before participation in the study. CryoMaze Procedure CryoMaze ablations were performed using the standard sternotomy approach and a Cardioblate
1380
CryoFlex Surgical Ablation Probe (Medtronic Inc., Minneapolis, MN, USA). The procedures were carried out by five different, experienced cardiac surgeons. Each lesion was created by one application of cryothermia at a temperature of approximately −140°C for 2 minutes. The standard protocol of biatrial CryoMaze consisted of a left-sided lesion set with continuous lesions surrounding each group of right and left pulmonary veins with connecting lesions between the superior and inferior pulmonary veins and to the posterior segment of the mitral annulus. The ligament of Marshall was dissected and the left atrial appendage was excluded in patients with a previous history of stroke or a CHA2 DS2 VASc score ࣙ 3. The right atrial lesion consisted of an isthmus line connecting the inferior vena cava with the tricuspid annulus. All patients who remained in atrial fibrillation once the surgical procedure was completed underwent attempted cardioversion before chest closure and again before hospital discharge if arrhythmia persisted. Patients were discharged without any antiarrhythmic medication unless required for recurrent symptomatic arrhythmias. A 7-day electrocardiogram (ECG) Holter monitor was scheduled at 3 months after the CryoMaze procedure just before admission for the catheter ablation. Catheter Ablation Patients were brought to the electrophysiological laboratory 3 months after the CryoMaze procedure. A 3-month period was elected to allow time for tissue healing. Electroanatomical mapping of the left and right atria was performed using a 3.5-mm irrigated-tip catheter (ThermoCool SmartTouch, Biosense Webster, Inc., Diamond Bar, CA, USA) using a CARTO3 navigation system (Biosense Webster, Inc.) and intracardiac echocardiography. Intravenous heparin was administered after the first transseptal puncture to achieve and maintain activated clotting time of 300– 400 seconds. Contrast-enhanced computerized tomography (CT) of the heart was performed in all patients before the procedure and CT images were integrated with detailed CARTO3 bipolar voltage maps. The low-voltage regions and scarred areas (
