The inhibitory in-vitro effect of high-dose levosimendan on platelet function may be mediated through its action as a phosphodiesterase inhibitor

Impact of Levosimendan and Its Metabolites on Platelet Activation Mechanisms in Patients during Antiplatelet Therapy-Pilot Study

Levosimendan is used for the short-term treatment of severe heart failure or other cardiac conditions. The area of existing clinical applications for levosimendan has increased significantly. This study aimed to assess whether levosimendan and its metabolites impact the mechanisms related to platelet activation. In this study, we included patients with coronary artery disease receiving antiplatelet therapy. We analyzed the pharmacodynamic profile using three independent methods to assess platelet activity. The results of the conducted studies indicate a mechanism of levosimendan that affects the function of platelets, causing higher inhibition of platelet receptors and, thus, their aggregation. It is essential to clarify whether levosimendan may affect platelets due to the need to maintain a balance between bleeding and thrombosis in patients treated with levosimendan. This is especially important in the case of perioperative bleeding. This study was conducted in vitro; the research should be continued and carried out in patients to check the complete pharmacokinetic and pharmacodynamic profile.

Levosimendan administration is not associated with increased risk of bleeding and blood transfusion requirement in patients undergoing off-pump coronary artery bypass grafting: a retrospective study from single center

BACKGROUND

Levosimendan (LEVO) is a positive inotropic drug which could increase myocardial contractility and reduce the mortality rate in cardiac surgical patients. However, Whether LEVO is associated with postoperative bleeding and blood transfusion in cardiac surgical patients is controversial. Therefore, the current study was designed to investigate the impact of LEVO administration on bleeding and blood transfusion requirement in off-pump coronary artery bypass grafting (OPCAB) patients.

METHODS

In a retrospective analysis, a total of 292 patients, aged 40-87 years, undergoing elective OPCAB between January 2019 and July 2019, were divided into LEVO group (n = 151) and Control group (n = 141). Patients in LEVO group continuously received LEVO at a rate of 0.1-0.2 μg kg^-1 min^-1 after anesthesia induction until 24 hours after OPCAB or patients in Control group received no LEVO. The primary outcome was postoperative chest drainage volume. The secondary outcomes were reoperation for postoperative bleeding, transfusion requirement of red blood cells (RBCs), fresh frozen plasma (FFP) and platelet concentrate (PC), etc. Comparisons of two groups were performed with the Student's t-test or Wilcoxon-Mann-Whitney test.

RESULTS

There was no significant difference with respect to chest drainage volume ((956.29 ± 555.45) ml vs (1003.19 ± 572.25) ml, p = 0.478) and the incidence of reoperation for postoperative bleeding (1.32% vs 1.42%, p = 0.945) between LEVO group and Control group. The transfusion incidence and volume of allogeneic RBCs, FFP, and PC were comparable between two groups.

CONCLUSIONS

LEVO administration was neither associated with more postoperative blood loss nor increased allogeneic blood transfusion requirement in OPCAB patients.

The effect of levosimendan on postoperative bleeding and blood transfusion in cardiac surgical patients: a PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Levosimendan (LEVO), is an inotropic agent which has been shown to be associated with better myocardial performance, and higher survival rate in cardiac surgical patients. However, preliminary clinical evidence suggested that LEVO increased the risk of post-operative bleeding in patients undergoing valve surgery. Currently, there has been no randomized controlled trials (RCTs) designed specifically on this issue. Therefore, we performed present systemic review and meta-analysis.

METHODS

Electronic databases were searched to identify all RCTs comparing LEVO with Control (placebo, blank, dobutamine, milrinone, etc). Primary outcomes include post-operative blood loss and re-operation for bleeding. Secondary outcomes included post-operative transfusion of red blood cells (RBC), fresh frozen plasma (FFP) and platelet concentrates (PC). For continuous variables, treatment effects were calculated as weighted mean difference (WMD) and 95% confidential interval (CI). For dichotomous data, treatment effects were calculated as odds ratio (OR) and 95% CI.

RESULTS

Search yielded 15 studies including 1,528 patients. Meta-analysis suggested that, LEVO administration was not associated with increased risk of reoperation for bleeding post-operatively (OR = 1.01; 95%CI: 0.57 to 1.79; p = 0.97) and more blood loss volume (WMD = 28.25; 95%CI: -19.21 to 75.72; p = 0.24). Meta-analysis also demonstrated that, LEVO administration did not increase post-operative transfusion requirement for RBC (rate: OR = 0.97; 95%CI: 0.72 to 1.30; p = 0.83 and volume: WMD = 0.34; 95%CI: -0.55 to 1.22; p = 0.46), FFP (volume: WMD = 0.00; 95%CI: -0.10 to 0.10; p = 1.00) and PC (rate: OR = 1.01; 95%CI: 0.41 to 2.50; p = 0.98 and volume: WMD = 0.00; 95%CI: -0.05 to 0.04; p = 0.95).

CONCLUSION

This meta-analysis suggested that, peri-operative administration of LEVO was not associated with increased risks of post-operative bleeding and blood transfusion requirement in cardiac surgical patients.

Impact of Perioperative Levosimendan Administration on Risk of Bleeding After Cardiac Surgery: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Levosimendan, a calcium sensitizer and potassium channel opener, has been demonstrated to improve myocardial function without increasing oxygen consumption and to show protective effects in other organs. Recently, a prospective, randomized controlled trial (RCT) revealed an association between levosimendan use and a possible increased risk of bleeding postoperatively. Levosimendan's anti-platelet effects have been shown in in vitro studies. Current studies do not provide sufficient data to support a relation between perioperative levosimendan administration and increased bleeding risk.

PURPOSE

Our goal was to investigate the relation between perioperative levosimendan administration and increased bleeding risk using a meta-analysis study design.

METHODS

The PubMed, Ovid, EMBASE and Cochrane Library databases were searched for relevant RCTs before July 1, 2019. The outcome parameters included reoperation secondary to increased bleeding in the postoperative period, the amount of postoperative recorded blood loss, and the need for transfusion of packed red blood cells (RBCs) and other blood products.

RESULTS

A total of 1160 patients in nine RCTs (576 in the levosimendan group and 584 in the control group) were included according to our inclusion criteria. Analysis showed that perioperative levosimendan administration neither increased the rate of reoperation secondary to bleeding nor increased the amount of postoperative chest tube drainage when compared with the control group. In terms of blood product transfusion, levosimendan did not influence the requirement for RBC transfusion, platelet transfusion nor fresh frozen plasma (FFP) transfusion. Levosimendan also did not shorten or prolong the aortic cross-clamp time or the cardiopulmonary bypass time.

CONCLUSION

The analyzed parameters, including reoperations due to bleeding, postoperative chest drainage and the requirement for blood products, revealed that levosimendan did not increase postoperative bleeding risk. More studies with a larger sample size are needed to address a more reliable conclusion due to study limitations.

Cardioprotective and Anti-Aggregatory Effects of Levosimendan on Isoproterenol-Induced Myocardial Injury in High-Fat-Fed Rats Involves Modulation of PI3K/Akt/mTOR Signaling Pathway and Inhibition of Apoptosis

Hyperlipidemia and hypercoagulability states are linked with the increased risks of myocardial infarction (MI). Levosimendan has vasorelaxant and anti-aggregatory properties. The present study evaluated the anti-aggregatory and cardioprotective effects of levosimendan versus cilostazol in high-fat diet (HFD)-fed rats subjected to isoproterenol-induced MI. Rats were assigned to normal, HFD, HFD + isoproterenol, HFD + isoproterenol + cilostazol, and HFD + isoproterenol + levosimendan. The present study investigated the anti-aggregatory effect of both levosimendan and cilostazol and revealed that both drugs attenuated the severity of platelet aggregation. Moreover, both levosimendan and cilostazol revealed effectiveness in attenuating the severity of HFD/isoproterenol-induced myocardial injury as revealed by electrocardiogram signs, apoptotic markers, and histopathological score via counteracting the oxidative stress burden, increments in the expression of inflammatory mediators, and modulating nuclear factor kappa-B (NF-κB) and phosphatidylinositide 3-kinases (PI3K)/protein kinase B (Akt)/ mechanistic target of rapamycin (mTOR) pathway. It was obvious that levosimendan offered more cardioprotective properties than cilostazol. The study showed the relations between hyperlipedemia, hyperaggregability state, and myocardial injury with the modulation of NF-κB and PI3K/Akt/mTOR pathway.

Impact of levosimendan on platelet function

Levosimendan has been developed for treatment of severe heart failure. The favorable hemodynamic effect of levosimendan is related to its unique dual mechanism of action - increase of the contractile force of the myocardium caused by enhanced sensitivity of myofilaments to calcium combined with vasodilatation caused by the opening of adenosine triphosphate - dependent potassium channels. Due to the structural similarities to phosphodiesterase inhibitors it may partly exert its action via inhibition of phosphodiesterase inhibitors III. Inhibition of the phosphodiesterase inhibitors III leads to an increase of intracellular concentration of cyclic adenosine monophosphate causing an anti-aggregatory effect. There are some contradictory or indirect and inconclusive reports related to the impact of levosimendan on platelet function. The aim of this systematic review was to critically discuss the impact of levosimendan on platelet function according to currently available knowledge based on the findings of experimental as well as observational and randomized clinical studies.

Peri-operative Levosimendan in Patients Undergoing Cardiac Surgery: An Overview of the Evidence

Levosimendan, a calcium sensitiser, has recently emerged as a valuable agent in the peri-operative management of cardiac surgery patients. Levosimendan is a calcium-sensitising ionodilator. By binding to cardiac troponin C and reducing its calcium-binding co-efficient, it enhances myofilament responsiveness to calcium and thus enhances myocardial contractility without increasing oxygen demand. Current evidence suggests that levosimendan enhances cardiac function after cardiopulmonary bypass in patients with both normal and reduced left ventricular function. In addition to being used as post-operative rescue therapy for low cardiac output syndrome, a pre-operative levosimendan infusion in high risk patients with poor cardiac function may reduce inotropic requirements, the need for mechanical support, the duration of intensive care admissions as well as post-operative mortality. Indeed, it is these higher-risk patients who may experience a greater degree of benefit. Larger, multicentre randomised trials in cardiac surgery will help to elucidate the full potential of this agent.

Levosimendan alone and in combination with valsartan prevents stroke in Dahl salt-sensitive rats

The effects of levosimendan on cerebrovascular lesions and mortality were investigated in models of primary and secondary stroke. We aimed to determine whether the effects of levosimendan are comparable to and/or cumulative with those of valsartan, and to investigate whether levosimendan-induced vasodilation has a role in its effects on stroke. In a primary stroke Dahl/Rapp rat model, mortality rates were 70% and 5% for vehicle and levosimendan, respectively. Both stroke incidence (85% vs. 10%, P<0.001) and stroke-associated behavioral deficits (7-point neuroscore: 4.59 vs. 5.96, P<0.001) were worse for vehicle compared to levosimendan. In a secondary stroke model in which levosimendan treatment was started after cerebrovascular incidences were already detected, mean survival times were 15 days with vehicle, 20 days with levosimendan (P=0.025, vs. vehicle), 22 days with valsartan (P=0.001, vs. vehicle), and 31 days with levosimendan plus valsartan (P<0.001, vs. vehicle). The respective survivals were 0%, 16%, 20% and 59%, and the respective incidences of severe lesions were 50%, 67%, 50% and 11%. In this rat model, levosimendan increased blood volume of the cerebral vessels, with significant effects in the microvessels of the cortex (∆R=3.5±0.15 vs. 2.7±0.17ml for vehicle; P=0.001) and hemisphere (∆R=3.2±0.23 vs. 2.6±0.14ml for vehicle; P=0.018). Overall, levosimendan significantly reduced stroke-induced mortality and morbidity, both alone and with valsartan, with apparent cumulative effects, an activity in which the vasodilatory effects of levosimendan have a role.

Levosimendan's effect on platelet function in a rat sepsis model

Although studies have evaluated the efficacy of levosimendan in heart failure during sepsis, it still is a subject of controversy whether levosimendan produces an effect on platelets. In this study, the short- and long-term effects of levosimendan on platelet aggregation were investigated in untreated animals and in a rat model of sepsis. Therefore, adult rats (n = 40) were randomly divided into four groups with n = 10 per group: (I) sham, (II) levosimendan (bolus 53 µg/kg + 285 µg/kg/hour, intravenously (i.v.) injected), (III) LPS (lipopolysaccharide, 8 mg/kg body weight intraperitoneally injected), and (IV) LPS + levosimendan. Levosimendan was given 24 hours after LPS injections. The number of platelets was determined. Platelet aggregation was measured using venous blood from rats 10 minutes and 5 days after levosimendan application with Dynabyte Multiplate system. Aggregation responses were evaluated with adenosine diphosphate (10 µM) and collagen (5 µg/ml). In addition to clinical dosage, the in vitro effect of high-dosage levosimendan on platelet function was investigated. The results clearly showed that LPS significantly reduced the platelet aggregation 1 day after injection compared to controls; 6 days after LPS, a marked increase (p < 0.01) was noted. This result is associated with numbers of platelets. Levosimendan (bolus 53 µg/kg + 285 µg/kg/hour i.v.) had no significant effect on the platelets of rats in contrast to the high-dosage in vitro findings. Thus, the in vivo use of levosimendan does not affect blood coagulation significantly in this rat model. This also applies under the conditions of decreased and increased numbers of platelets during mild sepsis.