Multi-scale Entropy Evaluates the Proarrhythmic Condition of Persistent Atrial Fibrillation Patients Predicting Early Failure of Electrical Cardioversion.

Atrial fibrillation (AF) is nowadays the most common cardiac arrhythmia, being associated with an increase in cardiovascular mortality and morbidity. When AF lasts for more than seven days, it is classified as persistent AF and external interventions are required for its termination. A well-established alternative for that purpose is electrical cardioversion (ECV). While ECV is able to initially restore sinus rhythm (SR) in more than 90% of patients, rates of AF recurrence as high as 20-30% have been found after only a few weeks of follow-up. Hence, new methods for evaluating the proarrhythmic condition of a patient before the intervention can serve as efficient predictors about the high risk of early failure of ECV, thus facilitating optimal management of AF patients. Among the wide variety of predictors that have been proposed to date, those based on estimating organization of the fibrillatory (f-) waves from the surface electrocardiogram (ECG) have reported very promising results. However, the existing methods are based on traditional entropy measures, which only assess a single time scale and often are unable to fully characterize the dynamics generated by highly complex systems, such as the heart during AF. The present work then explores whether a multi-scale entropy (MSE) analysis of the f-waves may provide early prediction of AF recurrence after ECV. In addition to the common MSE, two improved versions have also been analyzed, composite MSE (CMSE) and refined MSE (RMSE). When analyzing 70 patients under ECV, of which 31 maintained SR and 39 relapsed to AF after a four week follow-up, the three methods provided similar performance. However, RMSE reported a slightly better discriminant ability of 86%, thus improving the other multi-scale-based outcomes by 3-9% and other previously proposed predictors of ECV by 15-30%. This outcome suggests that investigation of dynamics at large time scales yields novel insights about the underlying complex processes generating f-waves, which could provide individual proarrhythmic condition estimation, thus improving preoperative predictions of ECV early failure.

Spanish Results of the Second European Cardiac Resynchronization Therapy Survey (CRT-Survey II).

INTRODUCTION AND OBJECTIVES: We describe the results for Spain of the Second European Cardiac Resynchronization Therapy Survey (CRT-Survey II) and compare them with those of the other participating countries. METHODS: We included patients undergoing CRT device implantation between October 2015 and December 2016 in 36 participating Spanish centers. We registered the patients' baseline characteristics, implant procedure data, and short-term follow-up information until hospital discharge. RESULTS: Implant success was achieved in 95.9%. The median [interquartile range] annual implantation rate by center was significantly lower in Spain than in the other participating countries: 30 implants/y [21-50] vs 55 implants/y [33-100]; P=.00003. In Spanish centers, there was a lower proportion of patients ≥ 75 years (27.9% vs 32.4%; P=.0071), a higher proportion in New York Heart Association functional class II (46.9% vs 36.9%; P <.00001), and a higher percentage with electrocardiographic criteria of left bundle branch block (82.9% vs 74.6%; P <.00001). The mean length of hospital stay was significantly lower in Spanish centers (5.8±8.5 days vs 6.4±11.6; P <.00001). Spanish patients were more likely to receive a quadripolar LV lead (74% vs 56%; P <.00001) and to be followed up by remote monitoring (55.8% vs 27.7%; P <.00001). CONCLUSIONS: The CRT-Survey II shows that, compared with other participating countries, fewer patients in Spain aged ≥ 75 years received a CRT device, while more patients were in New York Heart Association functional class II and had left bundle branch block. In addition, the length of hospital stay was shorter, and there was greater use of quadripolar LV leads and remote CRT monitoring.

[Reduction in acute myocardial infarction mortality over a five-year period]. / Reducción de la mortalidad por infarto agudo de miocardio en un período de 5 años.

INTRODUCTION AND OBJECTIVES: To assess recent changes in the management of patients with acute myocardial infarction (AMI) and their impact on mortality using data from the PRIAMHO I and II registries (1995 and 2000). PATIENTS AND METHOD: Of the 168 public hospitals in Spain, 24 and 58 contributed to the 1995 and 2000 PRIAMHO registries, respectively. RESULTS: Patients in the PRIAMHO II registry (n=6221) were significantly older, more often female, and proportionally more likely to have coronary risk factors or a previous myocardial infarction, or to have undergone revascularization than those in PRIAMHO I (n=5242). Reperfusion therapy was administered more often (46.9% vs 41.9%, P<.001) and earlier (48 min vs 60 min, P<.001). Antiplatelet drugs were given to 96.1% vs 89.1% of patients, beta-blockers to 51.1% vs 30.1%, and ACE inhibitors to 41.6% vs 24.9% (P<.001 for all comparisons). In addition, 28-day mortality was 11.3% and 14.2% (P<.001), respectively, and one-year mortality, 16.4% and 18.5% (P<.001), respectively. The adjusted hazard ratio for mortality at one year in PRIAMHO II compared with PRIAMHO I was 0.78 (95% CI, 0.70-0.86, P<.001; adjusted for age, sex, diabetes, smoking, dyslipemia, hypertension, previous MI and CABG, ST-elevation status and Killip class at admission, and hospital characteristics). CONCLUSIONS: Even though patients registered in 2000 formed a higher risk group than those registered in 1995, one-year mortality after AMI decreased by 22% over the five-year period. This improvement was due to more frequent and earlier reperfusion therapy and better use of antithrombotics, beta-blockers and ACE inhibitors.