Effect of levosimendan on ventriculo-arterial coupling in patients with ischemic cardiomyopathy.

Levosimendan, a novel calcium sensitizer, enhances myocardial contractility without affecting intracellular calcium concentration. It also dilates peripheral arterial vessels by acting on ATP-dependent K(+) channels. Ventriculo-arterial coupling, the relationship between myocardial contractility and the arterial system, describes the efficiency of the cardiovascular system by analysing the relationship between myocardial contractility expressed by ventricular elastance (E(es)) and arterial elastance (E(a)). The aim of this prospective clinical investigation was to evaluate the effects of levosimendan on ventriculo-arterial coupling in patients with ischemic cardiomyopathy. Fifteen patients with stable angina and left ventricular dysfunction underwent elective coronary surgery. Before surgery started, ventriculo-arterial coupling and several variables of cardiovascular performance were assessed by invasive monitoring and transoesophageal echocardiography before and after administration of levosimendan (12 mug/kg bolus) in coronary patients under general anesthesia. The cardiac index and ejection fraction increased significantly [from 1.92 +/- 0.4 to 2.1 +/- 0.4 l/min/m(2) (P = 0.0004) and from 31% +/- 6 to 40% +/- 9 (P = 0.001), respectively], while mean arterial pressure and systemic vascular resistances decreased significantly [from 83 +/- 10 to 72 +/- 5 mmHg (P = 0.0016) and from 997 +/- 341 to 855 +/- 324 dyne s/cm(5) (P = 0.0002), respectively]. After administration of levosimendan, E(a) decreased significantly (from 4.3 +/- 1.8 to 3.2 +/- 1.3 mmHg/ml/m(2), P= 0.005), while E(es) significantly increased (from 2.8 +/- 1.6 to 4.4 +/- 2.3 mmHg/ml/m(2), P= 0.05); as a result, E(a)/E(es) decreased significantly (from 1.76 +/- 1 to 0.83 +/- 0.2, P= 0.002). Levosimendan improves ventriculo-arterial coupling and cardiovascular performance in coronary patients with left ventricular dysfunction by enhancing myocardial contractility and reducing arterial elastance.