A randomized comparison of manual pressure versus figure-of-eight suture for hemostasis after cryoballoon ablation for atrial fibrillation.

INTRODUCTION: Cryoballoon ablation is commonly used to treat atrial fibrillation (AF). Femoral vein hemostasis after cryoballoon ablation for AF is routinely achieved with manual pressure (MP) after reversal of heparin and reassessment of the activated clotting time, or with a figure-of-eight suture (F8). The purpose of this randomized trial was to compare these two techniques for femoral vein hemostasis after cryoballoon ablation for AF in a patient population predominantly on novel anticoagulants (NOAC). METHODS AND RESULTS: Seventy consecutive patients who underwent cryoballoon ablation were randomized to either the MP or F8 for femoral vein hemostasis. Clinical and procedural characteristics were similar between the groups with the majority of patients treated with a NOAC. The total time in the electrophysiology laboratory for the MP group and the F8 group (197 ± 37 minutes vs 167 ± 36 minutes, respectively; P = .02), and the time from sheath removal until the patient left the laboratory (28 ± 9 minutes vs 20 ± 5 minutes, respectively; P < .0001) were significantly less in the F8 group. Additional pressure for hemostasis in the recovery suite was required more often in the MP Group, as opposed to the F8 group (29% vs 3%; P = .003). No major bleeding occurred and the rate of minor hematomas was statistically similar. CONCLUSIONS: Hemostasis obtained with a F8 suture after cryoballoon ablation for AF is associated with significantly less patient time in the electrophysiology laboratory, and an improved safety profile, compared with manual hemostasis, even amongst patients treated with a NOAC.

A randomized controlled trial evaluating the safety and efficacy of cardiac contractility modulation in advanced heart failure.

BACKGROUND: Cardiac contractility modulation (CCM) delivers nonexcitatory electrical signals to the heart during the absolute refractory period intended to improve contraction. METHODS: We tested CCM in 428 New York Heart Association class III or IV, narrow QRS heart failure patients with ejection fraction (EF) ≤ 35% randomized to optimal medical therapy (OMT) plus CCM (n = 215) versus OMT alone (n = 213). Efficacy was assessed by ventilatory anaerobic threshold (VAT), primary end point, peak Vo2 (pVo2), and Minnesota Living with Heart Failure Questionnaire (MLWFQ) at 6 months. The primary safety end point was a test of noninferiority between groups at 12 months for the composite of all-cause mortality and hospitalizations (12.5% allowable delta). RESULTS: The groups were comparable for age (58 ± 13 vs 59 ± 12 years), EF (26% ± 7% vs 26% ± 7%), pVo2 (14.7 ± 2.9 vs 14.8 ± 3.2 mL kg⁻¹ min⁻¹), and other characteristics. While VAT did not improve at 6 months, CCM significantly improved pVo2 and MLWHFQ (by 0.65 mL kg⁻¹ min⁻¹ [P = .024] and -9.7 points [P < .0001], respectively) over OMT. Forty-eight percent of OMT and 52% of CCM patients experienced a safety end point, which satisfied the noniferiority criterion (P = .03). Post hoc, hypothesis-generating analysis identified a subgroup (characterized by baseline EF ≥ 25% and New York Heart Association class III symptoms) in which all parameters were improved by CCM. CONCLUSIONS: In the overall target population, CCM did not improve VAT (the primary end point) but did improve pVo2 and MLWHFQ. Cardiac contractility modulation did not have an adverse affect on hospitalizations or mortality within the prespecified boundaries. Further study is required to clarify the role of CCM as a treatment for medically refractory heart failure.

Subgroup analysis of a randomized controlled trial evaluating the safety and efficacy of cardiac contractility modulation in advanced heart failure.

BACKGROUND: Cardiac contractility modulation (CCM) signals are nonexcitatory electrical signals delivered during the absolute refractory period intended to improve contraction. We previously tested the safety and efficacy of CCM in 428 NYHA functional class III/IV heart failure patients with EF ≤35% and narrow QRS randomized to optimal medical treatment (OMT) plus CCM (n = 215) versus OMT alone (n = 213) and found no significant effect on ventilatory anaerobic threshold (VAT), the study's primary end point. In the present analysis, we sought to identify if there was a subgroup of patients who showed a response to CCM. METHODS AND RESULTS: The protocol specified that multiregression analysis would be used to determine if baseline EF, NYHA functional class, pVO(2), or etiology of heart failure influenced the impact of CCM on AT. Etiology and baseline pVO(2) did not affect efficacy. However, baseline NYHA functional class III and EF ≥25% were significant predictors of increased efficacy. In this subgroup (comprising 97 OMT and 109 CCM patients, ∼48% of the entire population) VAT increased by 0.10 ± 2.36 in CCM versus -0.54 ± 1.83 mL kg(-1) min(-1) in OMT (P = .03) and pVO(2) increased by 0.34 ± 3.11 in CCM versus -0.97 ± 2.31 (P = .001) at 24 weeks compared with baseline; 44% of CCM versus 23% of OMT subjects showed improvement of ≥1 class in NYHA functional class (P = .002), and 59% of CCM versus 42% of OMT subjects showed a ≥10-point reduction in Minnesota Living with Heart Failure Questionnaire (P = .01). All of these findings were similar to those seen at 50 weeks. CONCLUSIONS: The results of this retrospective hypothesis-generating analysis indicate that CCM significantly improves objective parameters of exercise tolerance in a subgroup of patients characterized by normal QRS duration, NYHA functional class III symptoms, and EF >25%.

Nonexcitatory, cardiac contractility modulation electrical impulses: feasibility study for advanced heart failure in patients with normal QRS duration.

BACKGROUND: Cardiac contractility modulation signals are associated with acutely improved hemodynamics, but chronic clinical impact is not defined. OBJECTIVES: The purpose of this randomized, double-blind, pilot study was to determine the feasibility of safely and effectively delivering cardiac contractility modulation signals in patients with heart failure. METHODS: Forty-nine subjects with ejection fraction <35%, normal QRS duration (105 +/- 15 ms), and New York Heart Association (NYHA) class III or IV heart failure despite medical therapy received a cardiac contractility modulation pulse generator. Patients were randomized to have their devices programmed to deliver cardiac contractility modulation signals (n = 25, treatment group) or to remain off (n = 24, control group) for 6 months. Evaluations included NYHA class, 6-minute walk, cardiopulmonary stress test, Minnesota Living with Heart Failure Questionnaire, and Holter monitoring. RESULTS: Although most baseline features were balanced between groups, ejection fraction (31.4% +/- 7.4% vs 24.9% +/- 6.5%, P = .003), end-diastolic dimension (52.1 +/- 21.4 mm vs 62.5 +/- 6.2 mm, P = .01), peak VO(2) (16.0 +/- 2.9 mL O(2)/kg/min vs 14.3 +/- 2.8 mL O(2)/kg/min, P = .02), and anaerobic threshold (12.3 +/- 2.5 mL O(2)/kg/min vs 10.6 +/- 2.4 mL O(2)/kg/min, P = .01) were worse in the treatment group than in the control group. Nevertheless, one death occurred in the control group, and more patients in the treatment group were free of hospitalization for any cause at 6 months (84% vs 62%). No change in ectopy was observed. Compared with baseline, 6-minute walk (13.4 m), peak VO(2) (0.2 mL O(2)/kg/min), and anaerobic threshold (0.8 mL O(2)/kg/min) increased more in the treatment group than in control. None of these differences were statistically significant (small sample size). NYHA and Minnesota Living with Heart Failure Questionnaire changed similarly in the two groups. CONCLUSION: Despite a sicker population in the treatment group, no specific safety concerns emerged with chronic cardiac contractility modulation signal administration. Further study is required to definitively define the safety and efficacy of cardiac contractility modulation signals.

Right Ventricular Pacing for Assessment of Cavo-Tricuspid Isthmus Block.

Background: Cavo-tricuspid isthmus (CTI) dependent atrial flutter is typically treated with cardiac ablation. Standard techniques to assess CTI block after ablation can be technically challenging. Right ventricular (RV) pacing may allow for another technique to assess CTI block after ablation. Objective: The purpose of this study was to evaluate RV pacing as a method to assess CTI block after ablation of CTI dependent atrial flutter, and define endpoints of ablation using this technique. Methods: 28 patients undergoing ablation of CTI dependent atrial flutter with intact ventriculoatrial (VA) conduction were prospectively enrolled in this study and underwent the RV pacing protocol, as well as standard coronary sinus (CS) pacing techniques to assess CTI block. Results: The mean trans-isthmus conduction interval during CS pacing (TICICS) at 600 and 400ms after CTI ablation was 168 +/- 9ms and 175 +/- 18ms, respectively. The mean trans-isthmus conduction interval during RV pacing (TICIRV) at 600ms and 400ms after CTI ablation was 109 +/- 5ms and 111 +/- 5ms, respectively. A TICIRV >100ms was associated with a successful outcome after CTI ablation. Conclusions: RV pacing may add incremental value in the assessment of CTI block in patients undergoing ablation of CTI dependent atrial flutter.

Minimally invasive stand-alone Cox-maze procedure for patients with nonparoxysmal atrial fibrillation.

BACKGROUND: Catheter-based ablation for atrial fibrillation (AF) performed percutaneously is shown to be limited in patients with nonparoxysmal AF (non-PAF). The full Cox-Maze surgical procedure demonstrated good success with non-PAF, but concerns were raised regarding increased morbidity eliminating the effect of the success rate. This study assessed the safety and efficacy of a stand-alone on-pump Cox-Maze procedure for non-PAF. METHODS: Since 2005, 104 stand-alone Cox-Maze procedures for non-PAF were performed through a right minithoracotomy (6 cm) with femoral cannulation. Patients were monitored prospectively through our AF registry. Rhythm was verified by electrocardiogram and 24-hour Holter monitoring. Health-related quality of life (SF-12 Health Survey, Quality Metric, Lincoln, RI) and AF symptoms were assessed. RESULTS: Patients were a mean age of 55.9±9.0 years, and 78% had long-standing persistent AF. Patient outcomes included no operative (30 days) deaths or renal failure, 1 pacemaker, and 1 transient ischemic attack. The return to sinus rhythm at 6, 12, 24, 36 months was 94%, 94%, 92%, 92%, and off antiarrhythmic drugs was 87%, 87%, 79%, 80%, respectively. The success rate at 6 months after the initial 20 patients improved from 89% to 94%. Multivariate analysis found duration of AF predicted rhythm at 6 months (odds ratio, 1.15; 95% confidence interval, 1.01 to 1.31; p=0.04). Significant improvement was noted for health-related quality of life and decreased AF symptoms at 1 year. CONCLUSIONS: The long-term success rate after the Cox-Maze III procedure in a challenging group of non-PAF patients is acceptable. Our experience suggests the development of educational strategies to overcome the initial learning curve and patient selection criteria for AF surgical ablation.

Percutaneous catheter ablation treatment of recurring atrial arrhythmias after surgical ablation.

BACKGROUND: Surgical ablation for atrial fibrillation is associated with early and late recurrence of atrial arrhythmias. Although early arrhythmias may be controlled with conventional treatment, late arrhythmias are often highly symptomatic and relatively hard to manage with antiarrhythmic drugs and electrical cardioversion. This study explores a single-center experience with catheter ablation to treat late failures (>3 months) after surgery. METHODS: This is a prospective longitudinally designed study assessing all patients who underwent surgical treatment for atrial fibrillation as a standalone or concomitant with other procedures by multiple surgeons. All patients were monitored according to the Heart Rhythm Society guidelines. RESULTS: From January 2005 to present, 400 consecutive patients operated on by multiple surgeons were enrolled. The overall success rate per the Heart Rhythm Society guidelines was 87% and 84% (off antiarrhythmic drugs, 78% and 73%) at 12 and 24 months, respectively. Sixteen patients (4%) were referred for electrophysiology study after the surgical procedure (15 Cox-maze III or IV, 1 pulmonary vein isolation). The average age was 61.1+/-15.2 years; the mean left atrium size was 5.1+/-0.7 cm; and the mean time to ablation was 16.9+/-10 months. In 16 patients radiofrequency ablation was applied to treat the following atrial arrhythmias: 7 right atrial flutter or tachycardia, 3 left atrial flutter, 1 biatrial flutter, and 5 left atrial tachycardia. Six patients required a subsequent radiofrequency ablation intervention including 4 patients who required atrioventricular nodal ablations. The long-term success rate for the subsequent catheter ablation in these 16 patients (follow-up of 42.9+/-9.8 months) determined by the rate of sinus rhythm as captured by electrocardiography was 94%. Fifty-three percent of the patients (n=8) in sinus rhythm were still taking antiarrhythmic drugs; 8 patients remained on warfarin. There was 1 late noncardiac death and no late strokes. CONCLUSIONS: In a certain subset of patients, unsuccessful surgical ablation of atrial fibrillation may result in symptomatic atrial arrhythmia. If indicated, catheter ablation is a safe and effective intervention with a relatively high success rate. The combination of the two treatment modalities, catheter and surgical ablation, can improve the outcome even in complex patients.