Endothelin in neurohormonal activation in heart failure

Could Endothelin-1 Be a Promising Neurohormonal Biomarker in Acute Heart Failure?

Acute heart failure (AHF) is a life-threatening condition with high morbidity and mortality. Even though this pathology has been extensively researched, there are still challenges in establishing an accurate and early diagnosis, determining the long- and short-term prognosis and choosing a targeted therapeutic strategy. The use of reliable biomarkers to support clinical judgment has been shown to improve the management of AHF patients. Despite a large pool of interesting candidate biomarkers, endothelin-1 (ET-1) appears to be involved in multiple aspects of AHF pathogenesis that include neurohormonal activation, cardiac remodeling, endothelial dysfunction, inflammation, atherosclerosis and alteration of the renal function. Since its discovery, numerous studies have shown that the level of ET-1 is associated with the severity of symptoms and cardiac dysfunction in this pathology. The purpose of this paper is to review the existing information on ET-1 and answer the question of whether this neurohormone could be a promising biomarker in AHF.

Differential effects of carvedilol and metoprolol succinate on plasma norepinephrine release and peak exercise heart rate in subjects with chronic heart failure

Dosing equivalency of carvedilol and metoprolol remains a debate. Degree of beta 1-blockade is best assessed by blunting of the exercise-induced heart rate. Accordingly, the authors have investigated dosing equivalency by examining baseline and peak exercise heart rates and norepinephrine levels in subjects with chronic heart failure treated with carvedilol or metoprolol. Thirty-seven subjects treated with carvedilol (32.9 +/- 3.5 mg; n = 23) or metoprolol succinate (XL) (96.4 +/- 15.9 mg; n = 14) referred for cardiopulmonary exercise testing were studied prospectively. Carvedilol versus metoprolol XL subjects did not differ with respect to baseline heart rate (73 +/- 2 vs 70 +/- 3 bpm), or baseline plasma norepinephrine levels (597.5 +/- 78.3 vs 602.1 +/- 69.6 pg/mL), P = NS. However, despite similar peak exercise norepinephrine levels (2735.8 +/- 320.1 vs 2403.1 +/- 371.6 pg/mL), heart rate at peak exercise was higher in subjects receiving carvedilol (135 +/- 4 bpm) than those receiving metoprolol XL (117 +/- 6 bpm), P = 0.02. Similar norepinephrine release and more complete beta 1-blockade is observed in well-matched subjects with chronic heart failure treated with a mean daily dose of metoprolol XL 96.4 mg compared with carvedilol 32.9 mg.