Impact of levosimendan treatment on chronic heart failure

Effects of Levosimendan on Left Ventricular Diastolic Function After Primary Angioplasty for Acute Anterior Myocardial Infarction: A Doppler Echocardiographic Study

BACKGROUND

Levosimendan is a new Ca-sensitizing drug with combined positive inotropic and vasodilatory effects that offers new therapeutic possibilities in patients with severe heart failure. Compared with other inotropic agents, animal studies demonstrated that levosimendan does not impair left ventricular diastolic function.

OBJECTIVE

We sought to evaluate the effects of levosimendan on left ventricular diastolic function, using conventional transmitral Doppler and Doppler tissue imaging parameters, in patients with anterior acute myocardial infarction undergoing primary angioplasty.

METHODS

After a successful primary angioplasty, we randomized 52 consecutive patients with anterior acute myocardial infarction to levosimendan or placebo infusion and analyzed the diastolic function using conventional transmitral Doppler flow and Doppler tissue imaging at mitral annulus.

RESULTS

At 24 hours after the index intervention, patients treated with levosimendan (n = 26) showed a significant reduction of the isovolumetric relaxation time (114.6 +/- 15.1-69.2 +/- 5.6 milliseconds; P = .001) and the ratio between the early diastolic flow and early tissue velocity (E/E') (21.4 +/- 10.7-12.8 +/- 7.3; P = .04), and a significant increase of the ratio between the early and late diastolic flow (E/A) (0.86 +/- 0.33-1.52 +/- 0.88; P = .03) and E' (6.4-7.9 cm/s; P = .001). On the other hand, only a significant increase in E/A ratio (0.97 +/- 0.32-1.64 +/- 0.51; P = .002) was observed in the placebo group (n = 26).

CONCLUSIONS

Levosimendan, after primary angioplasty in patients with anterior acute myocardial infarction, appears to improve the Doppler echocardiographic parameters of left ventricular diastolic function.

Protein kinase C epsilon induces systolic cardiac failure marked by exhausted inotropic reserve and intact Frank-Starling mechanism

Myofilament dysfunction is a common point of convergence for many forms of heart failure. Recently, we showed that cardiac overexpression of PKC epsilon initially depresses myofilament activity and then leads to a progression of changes characteristic of human heart failure. Here, we examined the effects of PKC epsilon on contractile reserve, Starling mechanism, and myofilament activation in this model of end-stage dilated cardiomyopathy. Pressure-volume loop analysis and echocardiography showed that the PKC epsilon mice have markedly compromised systolic function and increased end-diastolic volumes. Dobutamine challenge resulted in a small increase in contractility in PKC epsilon mice but failed to enhance cardiac output. The PKC epsilon mice showed a normal length-dependent tension development in skinned cardiac muscle preparations, although Frank-Starling mechanism appeared to be compromised in the intact animal. Simultaneous measurement of tension and ATPase demonstrated that the maximum tension and ATPase were markedly lower in the PKC epsilon mice at any length or Ca2+ concentration. However, the tension cost was also lower indicating less energy expenditure. We conclude 1) that prolonged overexpression of PKC epsilon ultimately leads to a dilated cardiomyopathy marked by exhausted contractile reserve, 2) that PKC epsilon does not compromise the Frank-Starling mechanism at the myofilament level, and 3) that the Starling curve excursion is limited by the inotropic state of the heart. These results reflect the significance of the primary myofilament contractilopathy induced by phosphorylation and imply a role for PKC epsilon-mediated phosphorylation in myofilament physiology and the pathophysiology of decompensated cardiac failure.