Impact of Uncontrolled Hypertension on Atrial Fibrillation Ablation Outcome.

OBJECTIVES: The goal of this study was to evaluate the impact of hypertension on the outcome of atrial fibrillation (AF) ablation. BACKGROUND: Hypertension is a well-known independent risk factor for incident AF. METHODS: A total of 531 consecutive patients undergoing AF ablation were enrolled in this study and divided into 3 groups: patients with uncontrolled hypertension despite medical treatment (group I, n = 160), patients with controlled hypertension (group II, n = 192), and patients without hypertension (group III, n = 179). Pulmonary vein (PV) antrum and posterior wall isolation was always performed, and non-PV triggers were identified during isoproterenol infusion. All patients underwent extensive follow-up. RESULTS: Three groups differed in terms of left atrial (LA) size, non-PV triggers, and moderate/severe LA scar. Non-PV triggers were present in 94 (58.8%), 64 (33.3%), and 50 (27.9%) patients in groups I, II, and III, respectively (p < 0.001). After 19 ± 7.7 months of follow-up, 65 (40.6%), 54 (28.1%), and 46 (25.7%) patients in groups I, II, and III had recurrences (log-rank test, p = 0.003). Among patients in group I who underwent additional non-PV trigger ablation, freedom from AF/atrial tachycardia was 69.8%, which was similar to groups II and III procedural success (log-rank p = 0.7). After adjusting for confounders, uncontrolled hypertension (group I) (hazard ratio [HR]: 1.52, p = 0.045), non-PV triggers (HR: 1.85, p < 0.001), and nonparoxysmal AF (HR: 1.64, p = 0.002) demonstrated significant association with arrhythmia recurrence. CONCLUSIONS: Controlled hypertension does not affect the AF ablation outcome when compared with patients without hypertension. By contrast, uncontrolled hypertension confers higher AF recurrence risk and requires more extensive ablation.

Effect of periprocedural amiodarone on procedure outcome in patients with longstanding persistent atrial fibrillation undergoing extended pulmonary vein antrum isolation: results from a randomized study (SPECULATE).

BACKGROUND: The impact of amiodarone on ablation outcome in longstanding persistent atrial fibrillation (LSPAF) patients is not known yet. OBJECTIVE: The purpose of this study was to assess the effect of amiodarone on procedural-outcomes in LSPAF patients undergoing catheter ablation. METHODS: We enrolled 112 LSPAF patients on amiodarone and scheduled to undergo atrial fibrillation (AF) ablation. Patients were randomized to amiodarone discontinuation 4 months before ablation (group 1, n = 56) and a control group (group 2, n = 56) in which ablation was performed without amiodarone discontinuation. All patients underwent pulmonary vein (PV) antrum and posterior wall isolation, defragmentation and extra PV triggers ablation. Patients were followed up for recurrence for 32 ± 8 months post-ablation. Repeat procedures in all recurrent patients were performed off amiodarone. RESULTS: During ablation, AF termination was more frequent in group 2 compared to group 1 [44 (79%) vs 32 (57%), P = .015]. After high-dosage isoproterenol, more non-PV triggers were disclosed in group 1 compared to group 2 (42 [75%] vs 24 [43%] respectively, P <.001). Group 2 had lower procedure, radiofrequency and fluoroscopy times compared to group 1 (2.7 ± 1 vs 3.1 ± 1 h, 69 ± 13 min vs 87 ± 11 min and 64 ± 14 min vs 85 ± 18 min respectively, p < .05). At 32 ± 8 month follow-up, on or off antiarrhythmic drug success rate was 37 (66%) in group 1 and 27 (48%) in group 2 (P = .04). During redo, new non-PV trigger sites were identified in group 2 patients. CONCLUSION: Periprocedural continuous amiodarone was associated with higher organization rate and lower radiofrequency ablation rate. However, masking non-PV triggers increased the late recurrence rate.

Effects of smoking in patients treated with cardiac resynchronization therapy.

Smoking is associated with increased morbidity and mortality in cardiac patients. However, data on the prognostic impact of smoking in heart failure (HF) patients on cardiac resynchronization therapy with defibrillator (CRT-D) are absent. We investigated the effects of smoking on all-cause mortality and on a composite endpoint (all-cause death/appropriate device therapy), appropriate and inappropriate device therapy, in 649 patients with HF who underwent CRT-D between January 2003 and October 2011 in 6 Centers (4 in Italy and 2 in USA). 68 patients were current smokers, 396 previous-smokers (patients who had smoked in the past but who had quit before the CRT-D implant), and 185 had never smoked. The risk of each endpoint by smoking status was evaluated with both Kaplan-Meier and Cox proportional-hazard analysis. After adjusting for age, left ventricular ejection fraction, QRS width and ischemic etiology, both current and previous smoking were independent predictors of all-cause death [HR = 5.07 (95 % CI 2.68-9.58), p < 0.001 and HR = 2.43 (95 % CI 1.38-4.29), p = 0.002, respectively) and of composite endpoint [HR = 1.63 (1.04-2.56); p = 0.033 and HR = 1.46 (1.04-2.04) p = 0.027]. In addition, current smokers had a significantly higher rate of inappropriate device therapy compared to never smokers [HR = 21.74 (4.53-104.25), p = 0.005]. Our study indicates that in patients with HF who received a CRT-D device, current and previous smoking increase the event rate per person-time of death and of appropriate and inappropriate ICD therapy more than other known negative prognostic factors such as age, left ventricular dysfunction, prolonged QRS duration and ischemic etiology.

Endo-epicardial homogenization of the scar versus limited substrate ablation for the treatment of electrical storms in patients with ischemic cardiomyopathy.

OBJECTIVES: This study investigated the impact on recurrences of 2 different substrate approaches for the treatment of these arrhythmias. BACKGROUND: Catheter ablation of electrical storms (ES) for ventricular arrhythmias (VAs) has shown moderate long-term efficacy in patients with ischemic cardiomyopathy. METHODS: Ninety-two consecutive patients (81% male, age 62 ± 13 years) with ischemic cardiomyopathy and ES underwent catheter ablation. Patients were treated either by confining the radiofrequency lesions to the endocardial surface with limited substrate ablation (Group 1, n = 49) or underwent endocardial and epicardial ablation of abnormal potentials within the scar (homogenization of the scar, Group 2, n = 43). Epicardial access was obtained in all Group 2 patients, whereas epicardial ablation was performed in 33% (14) of these patients. RESULTS: Mean ejection fraction was 27 ± 5. During a mean follow-up of 25 ± 10 months, the VAs recurrence rate of any ventricular tachycardia (VTs) was 47% (23 of 49 patients) in Group 1 and 19% (8 of 43 patients) in Group 2 (log-rank p = 0.006). One patient in Group 1 and 1 patient in Group 2 died at follow-up for noncardiac reasons. CONCLUSIONS: Our study demonstrates that ablation using endo-epicardial homogenization of the scar significantly increases freedom from VAs in ischemic cardiomyopathy patients.

Safety and outcomes of cryoablation for ventricular tachyarrhythmias: results from a multicenter experience.

BACKGROUND: Catheter ablation of ventricular arrhythmias (VAs) with cryoenergy has not been widely reported. OBJECTIVE: The purpose of this study was to assess the feasibility and safety of cryoablation for VA. METHODS: Cases where cryoablation of VA was attempted as the initial strategy or was considered to prevent potential damage to other structures such as the coronary arteries, phrenic nerve, and His bundle were collected. Thirty-three patients with either normal heart or structural heart disease undergoing VA ablation using cryoenergy at six different institutions were enrolled in the study. Epicardial access was obtained when appropriate. RESULTS: Fifteen patients (7 men) underwent endocardial ablation, 13 (9 men) epicardial ablation (from the coronary sinus in 7), and 5 (2 men) aortic cusp ablation. Mean age was 54 ± 8 years, and ejection fraction was 45% ± 5%. In 15 (45%) patients, VAs were successfully ablated, whereas cryoablation was unsuccessful in the remaining 18 (55%) patients. Cryoablation was successful in all parahisian cases (100%). In three patients, epicardial cryoablation was successful after several failed attempts with open irrigated catheter. An aortic dissection occurred during catheter placement in the aortic cusp. At follow-up of 24 ± 5 months, all patients with acute success were free from clinical VA. CONCLUSION: Use of cryoenergy for ablation of VA has excellent success for arrhythmias near the His bundle; however, success rates at other sites appear less favorable. Cryoablation may be considered as an alternative approach for reducing complications during ablation of VAs originating from sites close to other relevant cardiac structures (conduction system, coronary arteries, phrenic nerve) and, in rare cases, could be used epicardially when radiofrequency energy applications have failed.

Periprocedural stroke and management of major bleeding complications in patients undergoing catheter ablation of atrial fibrillation: the impact of periprocedural therapeutic international normalized ratio.

BACKGROUND: Catheter ablation of atrial fibrillation is associated with the potential risk of periprocedural stroke, which can range between 1% and 5%. We developed a prospective database to evaluate the prevalence of stroke over time and to assess whether the periprocedural anticoagulation strategy and use of open irrigation ablation catheter have resulted in a reduction of this complication. METHODS AND RESULTS: We collected data from 9 centers performing the same ablation procedure with the same anticoagulation protocol. We divided the patients into 3 groups: ablation with an 8-mm catheter off warfarin (group 1), ablation with an open irrigated catheter off warfarin (group 2), and ablation with an open irrigated catheter on warfarin (group 3). Outcome data on stroke/transient ischemic attack and bleeding complications during and early after the procedures were collected. Of 6454 consecutive patients in the study, 2488 were in group 1, 1348 were in group 2, and 2618 were in group 3. Periprocedural stroke/transient ischemic attack occurred in 27 patients (1.1%) in group 1 and 12 patients (0.9%) in group 2. Despite a higher prevalence of nonparoxysmal atrial fibrillation and more patients with CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score >2, no stroke/transient ischemic attack was reported in group 3. Complications among groups 1, 2, and 3, including major bleeding (10 [0.4%], 11 [0.8%], and 10 [0.4%], respectively; P>0.05) and pericardial effusion (11 [0.4%], 11 [0.8%], and 12 [0.5%]; P>0.05), were equally distributed. CONCLUSIONS: The combination of an open irrigation ablation catheter and periprocedural therapeutic anticoagulation with warfarin may reduce the risk of periprocedural stroke without increasing the risk of pericardial effusion or other bleeding complications.

Radiofrequency catheter ablation of ventricular arrhythmias in patients with hypertrophic cardiomyopathy: safety and feasibility.

BACKGROUND: Management of ventricular tachycardia (VT) in patients with hypertrophic cardiomyopathy (HCM) is challenging. OBJECTIVE: The purpose of this study is to assess the value of radiofrequency catheter ablation (RFCA) for the treatment of the VTs in the setting of HCM. METHODS: Twenty-two patients (18 with ICD) with HCM and multiple episodes of VTs resistant to medical therapy underwent RFCA with an open irrigation catheter. Epicardial access was obtained if required. All patients were followed for at least 1 year after RFCA. RESULTS: Mean age was 50.4 +/- 15.3, and mean ejection fraction was 34.3% +/- 9.8%. RFCA was performed endocardially in all patients, while epicardial radiofrequency applications were needed in 13 patients. A previous endocardial ablation was unsuccessful in six patients. At 20 +/- 9 months of follow-up, elimination of VTs reached 73%. No major complication was observed during and after the procedures in all patients. CONCLUSION: Catheter ablation of VTs in patients with hypertrophic cardiomyopathy refractory to medical therapy is safe, feasible, and successful in eliminating VT. Epicardial VT mapping and ablation should be considered as an important access option for the treatment of these patients to increase the success rate.

Thromboembolism in patients with atrial fibrillation with and without left atrial thrombus documented by transesophageal echocardiography.

The incidence of cerebrovascular events (CVEs) was investigated in 95 consecutive patients with atrial fibrillation (AF) with left atrial thrombus (LAT) diagnosed by transesophageal echocardiography (TEE) and in 131 age- and sex-matched AF patients without LAT. Compared with patients without LAT, patients with LAT had a larger left atrial diameter (49 versus 44 mm, P < 0.0001), a lower left ventricular ejection fraction (40% versus 50%, P < 0.0001), a higher prevalence of spontaneous echocardiographic contrast (88% versus 25%, P < 0.001), a reduced left atrial appendage emptying velocity (0.25 versus 0.41 cm/s, P < 0.0001), and less use of antiarrhythmic drugs (61% versus 76%, P = 0.03). Before TEE, the prevalence of prior CVE was higher in LAT patients (20%) compared with patients without LAT (8%) (P = 0.01). Fifty-four of 95 LAT patients (57%) and 81 of 131 non-LAT patients (62%) were on warfarin before TEE. The incidence of prior CVE in LAT patients without warfarin (32%) was higher than that in non-LAT patients without warfarin (10%) (P = 0.02). The mortality rate in LAT patients with an international normalized ratio (INR) >or= 2.0 (42%) was higher than that in patients without LAT and an INR >or= 2.0 (11%) (P < 0.001). Fifty-one of 95 LAT patients (54%) underwent repeat TEE before cardioversion (48 patients received warfarin therapy). The thrombus resolved in 40 of 51 patients (78%) after the first TEE. There was no significant difference in INR between the patients with persistent and resolved LAT. AF patients with persistent LAT had a higher incidence of CVE (45%) than the patients with resolved LAT (5%) (P = 0.003). We suggest that patients with LAT be treated with warfarin to maintain an INR between 2.5 and 3.5 rather than between 2.0 and 3.0 because they are at a high risk for new thromboembolism.

Warfarin therapy initiated before is more beneficial than after transesophageal echocardiography detected left atrial thrombus.

OBJECTIVE: Warfarin anticoagulation significantly reduces the risk of thromboembolism in patients with atrial fibrillation (AF). However, there are many patients with AF who begin anticoagulation only after left atrial thrombus (LAT) is detected by transesophageal echocardiography (TEE). The impact of anticoagulation in these patients has not been clearly described. The purpose of this study was to investigate the incidence of cerebrovascular accident (CVA) among AF patients who began warfarin before LAT was detected by TEE compared to those who began warfarin only after TEE demonstrated LAT and those did not receive warfarin at any point. METHOD: Of the 90 consecutive AF patients with LAT (male 48, female 42, age 71.5 +/- 10.1 years), 49 began warfarin more than 3 weeks before TEE (Group I); 29 began warfarin after TEE (Group II); and 12 did not receive warfarin at all (Group III). RESULTS: The incidence of CVA in Group I (14%, 7/49, prior CVA 5, new CVA after TEE 2) was significantly lower than Group II (45%, 13/29, prior CVA 10, new CVA after TEE 3, P = 0.006) and III (42%, 5/12, prior CVA 3, new CVA after TEE 2, P = 0.047). Patients with persistent LAT had significantly higher incidence (64% vs 23%, P = 0.024) of CVA and lower CVA free survival than those with resolved LAT. CONCLUSION: The incidence of CVA among AF patients, who began warfarin before LAT detection, is significantly lower than those who began warfarin after LAT detection as well as those who did not receive warfarin at all.