Introduction: Cardiac biomarkers have been proposed as a new tool to improve risk stratification of serious arrhythmic events in patients with heart failure (HF) beyond estimates of left ventricular ejection fraction. Growth differentiation factor (GDF)-15, a stress-induced cytokine, has been found to correlate with markers of myocardial fibrosis and adverse clinical outcomes, but its role as a predictor of arrhythmic events in patients with nonischemic HF is uncertain. Methods and Results: A prospective observational study was conducted in 148 nonischemic patients with HF who underwent comprehensive clinical and laboratory evaluation, including measurement of serum GDF-15. The study endpoints were serious arrhythmic events (which included appropriate implantable cardioverter-defibrillator therapy and sudden cardiac death) and all-cause mortality. Mean age of the cohort was 54.8±12.7 years, and mean left ventricular ejection fraction (LVEF) was 27.4±7.5. During a mean follow-up time of 42 months, arrhythmic events occurred in 28 patients (19%), and 40 patients (27%) died. An increase in serum GDF-15 (log-transformed) correlated linearly with a higher risk of serious arrhythmic events (HR 1.14, 95% CI 1.01-1.28, p=0.03) even after adjustment for other potential clinical predictors (HR 1.16, 95% CI 1.02-1.32, p=0.02). GDF-15 was also strongly and independently associated with all-cause mortality (HR 1.17, 1.05-1.31, p=0.004). Conclusion: In this cohort of nonischemic HF patients on optimized medical treatment, serum GDF-15 levels were independently associated with major arrhythmic events and overall mortality. This biomarker may add prognostic information beyond LVEF to better stratify the risk of sudden death in this particular population.

Advances in human reproductive science are allowing women to get pregnant even at advanced ages. Thus, the incidence of arrhythmic events in pregnancy is rising and represents a significant cause of hospitalization and morbidity for mother and fetus. The most common arrhythmias in this context are atrial fibrillation and supraventricular tachycardia, which acutely can be managed, as usual, with adenosine or cardioversion, and beta blockers in the long-term. For recurrent cases, sodium blockers, such as propafenone, or even fluoroless cardiac ablation can be used. In the context of maternal congenital heart disease, ventricular tachycardia can occur, demanding a specific approach including cardiac defibrillator implant. Unfortunately, the medical evidence in this context is scarce, and most available reviews don't have the objectivity needed to guide daily's practice. This review aims to be a straightforward guide to the approach to tachyarrhythmias in pregnancy.