The Year in Cardiology 2013: arrhythmias.

The Year in Cardiology 'arrhythmias' presents an update on the latest studies and innovations published in the field within the last 12 months. Recent advances in the management of atrial fibrillation and novel treatment strategies and technologies are presented. New consensus documents to improve the diagnosis and treatment of patients with inherited cardiac arrhythmias and for paediatric patients with cardiac arrhythmias are summarized. Great progress has also been made in the field of cardiac implantable electronic devices: improvements in implantation techniques and novel technologies have been introduced and successfully applied. In addition, novel data on prevention of implantable cardioverter defibrillator-shocks and cardiac resynchronization therapy will certainly help to improve the quality of care for patients with cardiac arrhythmias and heart failure.

Differences of two cryoballoon generations: insights from the prospective multicentre, multinational FREEZE Cohort Substudy.

AIMS: Cryoballoon (CB) ablation with the second-generation cryoballoon (CBG2) seems to be more effective than its predecessor [first-generation cryoballoon (CBG1)], but phrenic nerve palsies were observed more frequently. The aim of this study was to compare the safety and efficacy of CBG1 and CBG2 in a substudy of the prospective multicentre, multinational FREEZE Cohort Study. METHODS AND RESULTS: Periprocedural data were analysed, and a total of 532 patients with paroxysmal atrial fibrillation (AF) were examined (n = 224 for CBG1 and n = 308 for CBG2). Procedure time decreased significantly from 149 to 130 min when comparing CBG1 with CBG2 (P < 0.0001), and pulmonary vein isolation (PVI) was achieved in 97.8 and 97.6% of PVs with CBG1 and CBG2 (P = 0.77), respectively. The need for dual-balloon usage within a procedure dropped (20.1 vs. 9.0%, P < 0.001), and the fluoroscopy time was reduced when operating the CBG2. Atrial fibrillation recurrence rates until discharge were similar (5.0 vs. 5.8%, P = 0.69). Comparable low rates of major complications were observed with both CBs, and there was a non-significant trend for more phrenic nerve palsies. CONCLUSION: Second-generation cryoballoon demonstrated a high rate of acute PVI in a significant faster procedure, which also utilized less radiation exposure and less dual-balloon usage during an average procedure. The safety profile remains favourable with a non-significant trend for more phrenic nerve palsies. If the enhancements lead to a higher clinical benefit has to be determined. The 1-year outcome data from the ongoing FREEZE Cohort Study comparing radiofrequency and CB ablation will shed some light on that issue. CLINICAL TRIALS GOV IDENTIFIER: NCT01360008.

Cardiac contractility modulation treatment in patients with symptomatic heart failure despite optimal medical therapy and cardiac resynchronization therapy (CRT).

BACKGROUND: A significant proportion of patients receiving CRT are non-responders. We evaluated the efficacy of Cardiac Contractility Modulation in subjects with reduced LVEF who, despite cardiac resynchronization therapy (CRT), continued to experience clinically significant symptoms. METHODS: This was a multi-center, open label, treatment-only, feasibility study of 17 CRT non-responders who received CCM therapy. Changes in NYHA class, ejection fraction (EF), Minnesota Living with Heart Failure Questionnaire (MLWHFQ) score, and exercise tolerance (6 minute walk test; 6MWT and peak VO2) were analyzed over 6 months. Mortality and hospitalization rates were determined. RESULTS: Patients (82% male) were 69.4 ±â€¯9.6 years of age with baseline EF = 22.8 ±â€¯6.5%. Among primary endpoints, peak VO2 increased 1.1 ±â€¯1.6 ml/kg/min (p = 0.03) and MLWHFQ improved (-16 ±â€¯16 points; p < 0.01). Mean NYHA class improved (-0.33 ±â€¯0.49; p = 0.02), 6MWT increased (52 ±â€¯60 m; p < 0.01), while EF trended up (2.9 ±â€¯5.8%; p = 0.08) at 6 months. During the 6-month follow-up period, there were 18 hospitalizations in 9 subjects and 2 patients died. CONCLUSIONS: Patients with heart failure and reduced ejection fraction who remain moderately to severely symptomatic despite use of CRT, may benefit from CCM therapy with improvement in quality of life and exercise tolerance. A larger prospective study in this population is warranted.

Implantation and 30-Day Follow-Up on All 4 Valve Sizes Within the Portico Transcatheter Aortic Bioprosthetic Family.

OBJECTIVES: The aim of this study was to evaluate the short-term safety and performance of the full range of valve sizes offered within the Portico transcatheter aortic valve replacement system. BACKGROUND: The Portico transcatheter aortic heart valve is a fully resheathable, repositionable, and self-expanding bioprosthesis designed to achieve optimal valve position and hemodynamic performance and limit conduction disturbances. METHODS: Patients (n = 222) with symptomatic (New York Heart Association functional class ≥II) severe aortic stenosis considered by a multidisciplinary heart team to be at high surgical risk were recruited between December 2011 and September 2015 in this prospective, nonrandomized, multicenter study. Patients were implanted with the full range of Portico heart valves (23, 25, 27, and 29 mm) using the transfemoral approach. The primary endpoint was all-cause mortality at 30 days. Secondary endpoints included valve performance, improvement in functional class, and procedural outcomes as defined by Valve Academic Research Consortium criteria. RESULTS: A total of 220 patients (mean age 83.0 ± 4.6 years, 74.3% women, mean Society of Thoracic Surgeons score 5.8%) had valves implanted. All resheathing and repositioning attempts (n = 72) were successful. At 30 days, all-cause mortality was 3.6%. Procedural outcomes included disabling (major) stroke (3.2%), major vascular complications (7.2%), and permanent pacemaker implantation (13.5%). Compared with baseline, 75.8% of patients improved by ≥1 New York Heart Association functional class at 30 days. The rate of moderate paravalvular leak was 5.7%, with no severe paravalvular leak reported. No differences in paravalvular leak incidence and severity were observed among valve sizes (p = 0.24). CONCLUSIONS: Across all valve sizes, use of the repositionable Portico transcatheter aortic valve replacement system resulted in safe and effective treatment of aortic stenosis in high-risk patients.

Comparing Antiarrhythmic Drugs and Catheter Ablation for Treatment of Atrial Fibrillation.

In the past years, catheter ablation has evolved into an effective treatment option for symptomatic, drug-resistant atrial fibrillation (AF) and it has recently been implemented as a primary treatment strategy for patients with paroxysmal AF. Although a significant number of studies have evaluated the potential benefits of catheter ablation compared with anti-arrhythmic drug (AAD)-therapy, to date, there are only a small number of randomised controlled trials in the literature, and several issues remain unsolved. The aim of this review is to analyze the current literature regarding this important issue and further discuss the question, whether catheter ablation may be more beneficial when compared to AAD therapy.