Ignacio Fernández Lozano

Primary Results From the SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV) Trial A Randomized Trial Comparing Empirical, Echocardiography-Guided, and Algorithmic Atrioventricular Delay Programming in Cardiac Resynchronization Therapy

Background— One variable that may influence cardiac resynchronization therapy response is the programmed atrioventricular (AV) delay. The SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV) Trial prospectively randomized patients to a fixed empirical AV delay (120 milliseconds), echocardiographically optimized AV delay, or AV delay optimized with SmartDelay, an electrogram-based algorithm. Methods and Results— A total of 1014 patients (68% men; mean age, 66±11 years; mean left ventricular ejection fraction, 25±7%) who met enrollment criteria received a cardiac resynchronization therapy defibrillator, and 980 patients were randomized in a 1:1:1 ratio. All patients were programmed (DDD-60 or DDDR-60) and evaluated after implantation and 3 and 6 months later. The primary end point was left ventricular end-systolic volume. Secondary end points included New York Heart Association class, quality-of-life score, 6-minute walk distance, left ventricular end-diastolic volume, and left ventricular ejection fraction. The medians (quartiles 1 and 3) for change in left ventricular end-systolic volume at 6 months for the SmartDelay, echocardiography, and fixed arms were −21 mL (−45 and 6 mL), −19 mL (−45 and 6 mL), and −15 mL (−41 and 6 mL), respectively. No difference in improvement in left ventricular end-systolic volume at 6 months was observed between the SmartDelay and echocardiography arms (P=0.52) or the SmartDelay and fixed arms (P=0.66). Secondary end points, including structural (left ventricular end-diastolic volume and left ventricular ejection fraction) and functional (6-minute walk, quality of life, and New York Heart Association classification) measures, were not significantly different between arms. Conclusions— Neither SmartDelay nor echocardiography was superior to a fixed AV delay of 120 milliseconds. The routine use of AV optimization techniques assessed in this trial is not warranted. However, these data do not exclude possible utility in selected patients who do not respond to cardiac resynchronization therapy. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00677014.

Primary Results From the SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV) Trial

Background— One variable that may influence cardiac resynchronization therapy response is the programmed atrioventricular (AV) delay. The SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV) Trial prospectively randomized patients to a fixed empirical AV delay (120 milliseconds), echocardiographically optimized AV delay, or AV delay optimized with SmartDelay, an electrogram-based algorithm. Methods and Results— A total of 1014 patients (68% men; mean age, 66±11 years; mean left ventricular ejection fraction, 25±7%) who met enrollment criteria received a cardiac resynchronization therapy defibrillator, and 980 patients were randomized in a 1:1:1 ratio. All patients were programmed (DDD-60 or DDDR-60) and evaluated after implantation and 3 and 6 months later. The primary end point was left ventricular end-systolic volume. Secondary end points included New York Heart Association class, quality-of-life score, 6-minute walk distance, left ventricular end-diastolic volume, and left ventricular ejection fraction. The medians (quartiles 1 and 3) for change in left ventricular end-systolic volume at 6 months for the SmartDelay, echocardiography, and fixed arms were −21 mL (−45 and 6 mL), −19 mL (−45 and 6 mL), and −15 mL (−41 and 6 mL), respectively. No difference in improvement in left ventricular end-systolic volume at 6 months was observed between the SmartDelay and echocardiography arms (P=0.52) or the SmartDelay and fixed arms (P=0.66). Secondary end points, including structural (left ventricular end-diastolic volume and left ventricular ejection fraction) and functional (6-minute walk, quality of life, and New York Heart Association classification) measures, were not significantly different between arms. Conclusions— Neither SmartDelay nor echocardiography was superior to a fixed AV delay of 120 milliseconds. The routine use of AV optimization techniques assessed in this trial is not warranted. However, these data do not exclude possible utility in selected patients who do not respond to cardiac resynchronization therapy. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00677014.

Impact of Biventricular Pacing on Mortality in a Randomized Crossover Study of Patients with Heart Failure and Ventricular Arrhythmias

Biventricular (BV) pacing is under clinical investigation for the treatment of heart failure. Its impact on mortality is unknown. Patients with heart failure and ventricular tachyarrhythmias received an implantable cardioverter defibrillator with BV pacing capability. Patients were randomized 1:1 to BV pacing or no pacing, then crossed over to the alternate mode after 3 months. All‐cause mortality was measured in each arm up to the point of crossover. Fifteen of 222 patients died between implant and crossover. Five patients died while programmed to BV pacing and 19 died while programmed to no pacing. Survival in the BV pacing arm was 93 ± 4% versus 86 ± 6% in the no pacing arm (P = 0.18). In a patient population with symptomatic heart failure and ventricular arrhythmias, BV pacing does not appear to be associated with excess mortality. Larger and longer studies will be needed to determine if BV pacing confers a survival benefit.

Comentarios a la guía de práctica clínica de la ESC para el manejo del infarto agudo de miocardio en pacientes con elevación del segmento ST

The European Society of Cardiology (ESC) guidelines are endorsed by the Spanish Society of Cardiology (SEC) and translated into Spanish for their publication in the Revista Española de Cardiología. Under the policy introduced in 2011, each new guideline is accompanied by an article that formulates comments in accordance with the objectives and methodology recommended in the article that established the Guidelines Committee of the SEC.1 In the present article, we discuss the new European guidelines for ST-segment elevation acute myocardial infarction (STEMI).2 The Guidelines Committee established a work group composed of members proposed by the Ischemic Heart Disease, Hemodynamics, Clinical Cardiology, Heart Failure, and Geriatric Cardiology work groups. As a general comment, we consider that the present guidelines introduce highly interesting developments and that the topics are dealt with clearly and in detail. However, we should also point out that it contains 157 recommendations, 69 (44%) of which are accompanied by level C evidence (expert consensus), predominantly in the sections on in-hospital management, heart failure, and complications, fields in which there thus remains ample room for individualization and progress in clinical research. In applying them, we should not forget that the guidelines themselves remind us that the level A and B recommendations are based on clinical trials, and that even these results are open to interpretation. The different therapeutic options could be influenced by the available resources. Thus, it will be increasingly necessary to perform cost-efficiency studies that aid us in choosing among the different strategies. For the purpose of making the article more readable and to highlight the most relevant or novel aspects, as well as those that are not made clear or are not addressed, we have summarized them in Tables 1 and 2, respectively.

Performance of a new steroid-eluting coronary sinus lead designed for left ventricular pacing.

The Ventak CHF/CONTAK CD Biventricular Pacing Study is a prospective randomized trial to examine the safety and efficacy of biventricular (BV) pacing in patients with standard indications for an ICD, symptomatic heart failure, a LVEF ≤ 0.35, and a QRS ≥ 120 ms. Patients underwent implantation of a BV pacing and sensing system with backup defibrillation capability, which includes a steroideluting coronary venous lead that is advanced into the coronary venous vasculature by over‐the‐wire techniques. LV pacing threshold, BV impedance, and BV R wave amplitude were measured in 58 consecutive patients. Using a percutaneous over‐the‐wire insertion technique, steroid‐eluting coronary venous leads were associated with satisfactory mean LV pacing threshold, BV impedance, and BV R wave amplitude acutely up to 4 months after implantation. Pacing threshold stabilized 2 weeks after lead implantation and sensing threshold remained stable from the time of implant.

Morphology discrimination criterion wavelet improves rhythm discrimination in single-chamber implantable cardioverter-defibrillators: Spanish Register of morphology discrimination criterion wavelet (REMEDIO).

AIMS Implantable cardioverter defibrillators (ICDs) are increasingly being used for treatment of ventricular tachycardia (VT)/fibrillation. Inappropriate therapy delivery remains the most frequent complication in patients with ICDs, resulting in psychological distress, proarrhythmia, and battery life reduction. We aim to determine if inappropriate therapies could be reduced by using a morphology discrimination criterion. METHODS AND RESULTS We evaluated the performance of the Wavelet morphology discrimination algorithm (Medtronic, Inc.) independently from other discrimination enhancements (rate onset and interval stability). A non-randomized, prospective, multicenter, and observational study was designed to determine the sensitivity and specificity of the new morphology criterion. Sensitivity and specificity in slow tachycardia with cycle length (CL) between 340 and 500 ms were analysed as a pre-specified secondary endpoint. A total of 771 spontaneous episodes in 106 patients were analysed. Five hundred and twenty-two episodes corresponded to true supraventricular tachycardia (SVT) with ventricular CL in the VT or FVT zone, of which 473 had therapy appropriately withheld. Of the 249 episodes of true VT/FVT, 21 were classified according to the Wavelet criteria as SVT (specificity: 90.6%; sensitivity: 91.6%). All of them were spontaneously terminated with no adverse clinical consequences. No syncopal episodes occurred. For VTs in the slowest analysed range (CL: 340-500 ms), a total of 235 episodes were studied, yielding a specificity of 95.9% and sensitivity of 83.2%. CONCLUSION Wavelet discrimination criteria in single-chamber ICDs as the sole discriminator can significantly reduce inappropriate therapy for SVT, not only in the range of VTs in the slowest analysed range (340-500 ms for this study) but also for faster VTs. No significant clinical consequences were found when the algorithm was used, but final data should prompt the use of the algorithm in combination with a high rate time-out feature.

SmartDelay Determined AV Optimization: A Comparison of AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV): Rationale and Design

Background: The clinical benefit of cardiac resynchronization therapy (CRT) for patients with moderate‐to‐severely symptomatic heart failure, left ventricular systolic dysfunction, and ventricular conduction delay is established. However, some patients do not demonstrate clinical improvement following CRT. It is unclear whether systematic optimization of the programmed atrioventricular (AV) delay improves the rate of clinical response.

Cardiac resynchronization therapy in patients with permanent atrial fibrillation. Is it mandatory to ablate the atrioventricular junction to obtain a good response

Current guidelines recommend atrioventricular junction (AVJ) ablation in patients with atrial fibrillation (AF) treated with cardiac resynchronization therapy (CRT). Our study compared the CRT response of patients in sinus rhythm (SR) vs. AF.

Cardioverter-defibrillators: a cost or an investment?

Implantable cardioverter-defibrillator (ICD) therapy has emerged as the most effective treatment for life-threatening ventricular arrhythmias. Most studies indicate that ICD therapy in appropriately selected patients at high risk of sudden cardiac death (SCD) is associated with cost-effectiveness ratios similar to, or better than, other accepted treatments, including renal dialysis. The up-front costs of ICD therapy are admittedly high and as such, ICD implantation is more akin to an operation than a drug. As would be the case for a life-saving operation, the adoption of short time horizons is apt to lead to underestimations of cost effectiveness. As well as the time horizon, the underlying aetiology of the arrhythmic substrate, implantation technique, ICD battery life, and the presence of co-morbidities are important issues in maximizing cost effectiveness. Above all, we should consider that ICD therapy is the only available option for prolonging survival in patients who are at risk of SCD.

Should We Anticoagulate Patients at High Risk of Atrial Fibrillation

Manuel Martinez-Selles*, Ignacio Fernandez Lozano, Adrian Baranchuk, Antoni Bayes-Genis y Antonio Bayes de Luna a Servicio de Cardiologia, Hospital General Universitario Gregorio Maranon, Universidad Europea y Universidad Complutense, Madrid, Espana b Servicio de Cardiologia, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Espana Division of Cardiology, Queen’s University, Kingston, Ontario, Canada d Servicio de Cardiologia, Hospital Universitari Germans Trias i Pujol, Universitat Autonoma de Barcelona, Badalona, Barcelona, Espana e Fundacio Investigacio Cardiovascular, ICCC, Barcelona, Espana