Safety and efficacy of levosimendan in patients with cardiac amyloidosis.

BACKGROUND: Patients with cardiac amyloidosis (CA) often experience heart failure (HF) episodes. No evidence is available on inotropic therapy. This study aims to fill this gap by examining the safety and efficacy of levosimendan. METHODS: We retrieved all HF patients receiving ≥1 levosimendan infusion from 2013 to 2023. CA patients were matched with HF patients without CA (controls) based on sex, age, and left ventricular ejection fraction (LVEF). The response to levosimendan was measured as changes in daily urinary output, body weight, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and estimated glomerular filtration rate (eGFR). RESULTS: CA patients (median age 77 years, 73% men, 59% with ATTR-CA) and controls were compared. Levosimendan infusion was stopped because of hypotension in 2 cases with CA and (in 1 case) worsening renal function, and in 2 controls because of ventricular tachycardia episodes and (in 1 case) hypotension. CA patients showed a trend toward increased daily urinary output (p = 0.078) and a significant decrease in body weight (p < 0.001), without significant changes in NT-proBNP (p = 0.497) and eGFR (p = 0.732). Both CA patients and controls displayed similar changes in urinary output, weight, and eGFR, but NT-proBNP decreased more significantly among controls (p < 0.001). No differences were noted in rehospitalization rates, but CA patients experienced higher mortality at 6 and 12 months (p = 0.003 and p = 0.001, respectively). CONCLUSIONS: Levosimendan appears safe for CA patients needing inotropic support. The diuretic response and weight decrease during hospitalization were comparable between CA patients and matched HF patients, despite the greater mortality of CA patients after discharge.

In silico study of the mechanisms of hypoxia and contractile dysfunction during ischemia and reperfusion of hiPSC cardiomyocytes.

Interconnected mechanisms of ischemia and reperfusion (IR) has increased the interest in IR in vitro experiments using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). We developed a whole-cell computational model of hiPSC-CMs including the electromechanics, a metabolite-sensitive sarcoplasmic reticulum Ca2+-ATPase (SERCA) and an oxygen dynamics formulation to investigate IR mechanisms. Moreover, we simulated the effect and action mechanism of levosimendan, which recently showed promising anti-arrhythmic effects in hiPSC-CMs in hypoxia. The model was validated using hiPSC-CM and in vitro animal data. The role of SERCA in causing relaxation dysfunction in IR was anticipated to be comparable to its function in sepsis-induced heart failure. Drug simulations showed that levosimendan counteracts the relaxation dysfunction by utilizing a particular Ca2+-sensitizing mechanism involving Ca2+-bound troponin C and Ca2+ flux to the myofilament, rather than inhibiting SERCA phosphorylation. The model demonstrates extensive characterization and promise for drug development, making it suitable for evaluating IR therapy strategies based on the changing levels of cardiac metabolites, oxygen and molecular pathways.

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.

Effect of levosimendan on ventricular remodelling in patients with left ventricular systolic dysfunction: a meta-analysis.

Heart failure is the final stage of several cardiovascular diseases, and the key to effectively treating heart failure is to reverse or delay ventricular remodelling. Levosimendan is a novel inotropic and vasodilator agent used in heart failure, whereas the impact of levosimendan on ventricular remodelling is still unclear. This study aims to investigate the impact of levosimendan on ventricular remodelling in patients with left ventricular systolic dysfunction. Electronic databases were searched to identify eligible studies. A total of 66 randomized controlled trials involving 7968 patients were included. Meta-analysis results showed that levosimendan increased left ventricular ejection fraction [mean difference (MD) = 3.62, 95% confidence interval (CI) (2.88, 4.35), P < 0.00001] and stroke volume [MD = 6.59, 95% CI (3.22, 9.96), P = 0.0001] and significantly reduced left ventricular end-systolic volume [standard mean difference (SMD) = -0.52, 95% CI (-0.67, -0.37), P < 0.00001], left ventricular end-diastolic volume index [SMD = -1.24, 95% CI (-1.61, -0.86), P < 0.00001], and left ventricular end-systolic volume index [SMD = -1.06, 95% CI (-1.43, -0.70), P < 0.00001]. In terms of biomarkers, levosimendan significantly reduced the level of brain natriuretic peptide [SMD = -1.08, 95% CI (-1.60, -0.56), P < 0.0001], N-terminal pro-brain natriuretic peptide [SMD = -0.99, 95% CI (-1.41, -0.56), P < 0.00001], and interleukin-6 [SMD = -0.61, 95% CI (-0.86, -0.35), P < 0.00001]. Meanwhile, levosimendan may increase the incidence of hypotension [risk ratio (RR) = 1.24, 95% CI (1.12, 1.39), P < 0.0001], hypokalaemia [RR = 1.57, 95% CI (1.08, 2.28), P = 0.02], headache [RR = 1.89, 95% CI (1.50, 2.39), P < 0.00001], atrial fibrillation [RR = 1.31, 95% CI (1.12, 1.52), P = 0.0005], and premature ventricular complexes [RR = 1.86, 95% CI (1.27, 2.72), P = 0.001]. In addition, levosimendan reduced all-cause mortality [RR = 0.83, 95% CI (0.74, 0.94), P = 0.002]. In conclusion, our study found that levosimendan might reverse ventricular remodelling when applied in patients with left ventricular systolic dysfunction, especially in patients undergoing cardiac surgery, decompensated heart failure, and septic shock.

Preoperative Levosimendan in Patients With Severe Left Ventricular Dysfunction Undergoing Isolated Coronary Artery Bypass Grafting: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: To verify the impact of preoperative levosimendan on patients with severe left ventricular dysfunction (ejection fraction <35%) undergoing isolated coronary artery bypass grafting. DESIGN: A meta-analysis. SETTING: Hospitals. PARTICIPANTS: The authors included 1,225 patients from 6 randomized controlled trials. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The authors performed a meta-analysis of trials that compared preoperative levosimendan with placebo or no therapy, reporting efficacy and safety endpoints. Statistical analyses used mean differences and risk ratios (RR), with a random effects model. Six studies were included, comprising 1,225 patients, of whom 615 (50.2%) received preoperative levosimendan, and 610 (49.8%) received placebo/no therapy. Preoperative levosimendan showed a lower risk of all-cause mortality (RR 0.31; 95% CI 0.16-0.60; p < 0.01; I2 = 0%), postoperative acute kidney injury (RR 0.44; 95% CI 0.25-0.77; p < 0.01; I2 = 0%), low-cardiac-output syndrome (RR 0.45; 95% CI 0.30-0.66; p < 0.001; I2 = 0%), and postoperative atrial fibrillation (RR 0.49; 95% CI 0.25-0.98; p = 0.04; I2 = 85%) compared to control. Moreover, levosimendan significantly reduced the need for postoperative inotropes and increased the cardiac index at 24 hours postoperatively. There were no differences between groups for perioperative myocardial infarction, hypotension, or any adverse events. CONCLUSION: Preoperative levosimendan in patients with severe left ventricular dysfunction undergoing isolated coronary artery bypass grafting was associated with reduced all-cause mortality, low-cardiac-output syndrome, acute kidney injury, postoperative atrial fibrillation, and the need for circulatory support without compromising safety.

Acute and chronic effects of levosimendan in the ZSF1 obese rat model of heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction (HFpEF) is a syndrome characterized by impaired cardiovascular reserve in which therapeutic options are scarce. Our aim was to evaluate the inodilator levosimendan in the ZSF1 obese rat model of HFpEF. Twenty-week-old male Wistar-Kyoto (WKY), ZSF1 lean (ZSF1 Ln) and ZSF1 obese rats chronically treated for 6-weeks with either levosimendan (1 mg/kg/day, ZSF1 Ob + Levo) or vehicle (ZSF1 Ob + Veh) underwent peak-effort testing, pressure-volume (PV) haemodynamic evaluation and echocardiography (n = 7 each). Samples were collected for histology and western blotting. In obese rats, skinned and intact left ventricular (LV) cardiomyocytes underwent in vitro functional evaluation. Seven additional ZSF1 obese rats underwent PV evaluation to assess acute levosimendan effects (10 µg/kg + 0.1 µg/kg/min). ZSF1 Ob + Veh presented all hallmarks of HFpEF, namely effort intolerance, elevated end-diastolic pressures and reduced diastolic compliance as well as increased LV mass and left atrial area, cardiomyocyte hypertrophy and increased interstitial fibrosis. Levosimendan decreased systemic arterial pressures, raised cardiac index, and enhanced LV relaxation and diastolic compliance in both acute and chronic experiments. ZSF1 Ob + Levo showed pronounced attenuation of hypertrophy and interstitial fibrosis alongside increased effort tolerance (endured workload raised 38 %) and maximum O2 consumption. Skinned cardiomyocytes from ZSF 1 Ob + Levo showed a downward shift in sarcomere length-passive tension relationship and intact cardiomyocytes showed decreased diastolic Ca2+ levels and enhanced Ca2+ sensitivity. On molecular grounds, levosimendan enhanced phosphorylation of phospholamban and mammalian target of rapamycin. The observed effects encourage future clinical trials with levosimendan in a broad population of HFpEF patients.

Repetitive ambulatory levosimendan as a bridge to heart transplantation.

INTRODUCTION AND OBJECTIVES: Repetitive ambulatory doses of levosimendan are an option as a bridge to heart transplantation (HT), but evidence regarding the safety and efficacy of this treatment is scarce. The objective of the LEVO-T Registry is to describe the profile of patients on the HT list receiving levosimendan, prescription patterns, and clinical outcomes compared with patients not on levosimendan. METHODS: We retrospectively reviewed all patients listed for elective HT from 2015 to 2020 from 14 centers in Spain. RESULTS: A total of 1015 consecutive patients were included, of whom 238 patients (23.4%) received levosimendan. Patients treated with levosimendan had more heart failure (HF) admissions in the previous year and a worse clinical profile. The most frequent prescription pattern were fixed doses triggered by the patients' clinical needs. Nonfatal ventricular arrhythmias occurred in 2 patients (0.8%). No differences in HF hospitalizations were found between patients who started levosimendan in the first 30 days after listing and those who did not (33.6% vs 34.5%; P=.848). Among those who did not, 102 patients (32.9%) crossed over to levosimendan after an HF admission. These patients had a rate of 0.57 HF admissions per month before starting levosimendan and 0.21 afterwards. Propensity score matching analysis showed no differences in survival at 1 year after listing between patients receiving levosimendan and those who did not (HR, 1.03; 95%CI, 0.36-2.97; P=.958) or in survival after HT (HR, 0.97; 95%CI, 0.60-1.56; P=.958). CONCLUSIONS: Repetitive levosimendan in an ambulatory setting as a bridge to heart transplantation is commonly used, is safe, and may reduce HF hospitalizations.

Effects of levosimendan on the outcome of veno-arterial extracorporeal membrane oxygenation: a systematic review and meta-analysis.

OBJECTIVES: For patients with severe cardiopulmonary failure, such as cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is primarily utilized to preserve their life by providing continuous extracorporeal respiration and circulation. However, because of the complexity of patients' underlying diseases and serious complications, successful weaning from ECMO is often difficult. At present, there have been limited studies on ECMO weaning strategies, so the principal purpose of this meta-analysis is to examine how levosimendan contributes to the weaning of extracorporeal membrane oxygenation. METHODS: The Cochrane Library, Embase, Web of Science, and PubMed were browsed for all potentially related research about clinical benefits of levosimendan in weaning patients receiving VA-ECMO and included 15 of them. The main outcome is success of weaning from extracorporeal membrane oxygenation, with the secondary outcomes of 1-month mortality (28 or 30 days), ECMO duration, hospital or intensive care unit (ICU) length of stay, and use of vasoactive drugs. RESULTS: 1772 patients altogether from 15 publications were incorporated in our meta-analysis. We used fixed and random-effect models to combine odds ratio (OR) and 95% confidence interval (CI) for dichotomous outcomes and standardized mean difference (SMD) for continuous outcomes. The weaning success rate in the levosimendan group was considerably higher in contrast to the comparison (OR = 2.78, 95% CI 1.80-4.30; P < 0.00001; I2 = 65%), and subgroup analysis showed that there was less heterogeneity in patients after cardiac surgery (OR = 2.06, 95% CI, 1.35-3.12; P = 0.0007; I2 = 17%). In addition, the effect of levosimendan on improving weaning success rate was statistically significant only at 0.2 mcg/kg/min (OR = 2.45, 95% CI, 1.11-5.40; P = 0.03; I2 = 38%). At the same time, the 28-day or 30-day proportion of deaths in the sample receiving levosimendan also decreased (OR = 0.47, 95% CI, 0.28-0.79; P = 0.004; I2 = 73%), and the difference was statistically significant. In terms of secondary outcomes, we found that individuals undergoing levosimendan treatment had a longer duration of VA-ECMO support. CONCLUSIONS: In patients receiving VA-ECMO, levosimendan treatment considerably raised the weaning success rate and helped lower mortality. Since most of the evidence comes from retrospective studies, more randomized multicenter trials are required to verify the conclusion.

The association between levosimendan and mortality in patients with sepsis or septic shock: a systematic review and meta-analysis.

BACKGROUND: Levosimendan is increasingly being used in patients with sepsis or septic shock because of its potential to improve organ function and reduce mortality. We aimed to determine if levosimendan can reduce mortality in patients with sepsis or septic shock via meta-analysis. EVIDENCE SOURCES AND STUDY SELECTION: We comprehensively searched the PubMed, Embase, Web of Science, and Cochrane Library databases from inception through 1 October 2022. Literature evaluating the efficacy of levosimendan in patients with sepsis or septic shock was included. DATA EXTRACTION AND OUTCOME MEASUREMENTS: Two reviewers extracted data and assessed study quality. A meta-analysis was performed to calculate an odds ratio (OR), 95% confidence intervals (CI), and P -values for 28-day mortality (primary outcome). Secondary outcomes included changes in indexes reflecting cardiac function before and after treatment, changes in serum lactate levels in the first 24 h of treatment, and the mean SOFA score during the study period. Safety outcomes included rates of tachyarrhythmias and total adverse reactions encountered with levosimendan. RESULTS: Eleven randomized controlled trials were identified, encompassing a total of 1044 patients. After using levosimendan, there was no statistical difference between groups for 28-day mortality (34.9% and 36.2%; OR: 0.93; 95% CI [0.72-1.2]; P  = 0.57; I 2  = 0%; trial sequential analysis-adjusted CI [0.6-1.42]) and sequential organ failure assessment (SOFA) score, and more adverse reactions seemed to occur in the levosimendan group, although the septic shock patient's heart function and serum lactate level improved. CONCLUSION: There was no association between the use of levosimendan and 28-day mortality and SOFA scores in patients with septic shock, though there was statistically significant improvement in cardiac function and serum lactate.

Repeated Levosimendan Infusions in the Management of Advanced Heart Failure: Review of the Evidence and Meta-analysis of the Effect on Mortality.

ABSTRACT: In the latest years, several studies described the impact of repetitive/intermittent i.v. levosimendan treatment in the management of advanced heart failure. For this updated review, we systematically searched the literature for clinical trials, registries , and real-world data and identified 31 studies that we commented in a narrative review: 3814 patients were described, of whom 1744 were treated repetitively with levosimendan. On the basis of the nature of the study protocols and of the end points, out of those studies, we further selected 9 that had characteristics, making them suitable for a meta-analysis on mortality. This short list describes data from 680 patients (of whom 399 received repeated doses of levosimendan) and 110 death events (of which 50 occurred in the levosimendan cohort). In the meta-analysis, repetitive/intermittent therapy with i.v. levosimendan was associated with a significant reduction in mortality at the longest time point available: 50 of 399 (12.5%) versus 60 of 281 (21.4%) in the control arms, with a risk ratio of 0.62 (95% confidence interval, 0.42-0.90; P < 0.01). In a sensitivity analysis, removing each trial and reanalyzing the remaining data set did not change the trend, magnitude, or significance of the results. A visual inspection of the funnel plot did not suggest publication bias. The results provide a very strong rationale for continuing to investigate the repetitive use of levosimendan in patients with advanced heart failure by properly powered regulatory clinical trials. Meanwhile, it seems that the use of repetitive/intermittent i.v. levosimendan infusions has become one of the few effective options for preserving the hemodynamic and symptomatic balance in such patients.

Safety of Levosimendan in Pediatric Patients: An Up-to-Date Systematic Review.

BACKGROUND: The potential risks associated with the use of levosimendan in the pediatric population has not been systematically evaluated. This study aimed to review the available evidence regarding the safety of this treatment. METHODS: Bio Med Central, PubMed, Embase, and the Cochrane Central Register of clinical trials were searched for studies describing levosimendan administration in the pediatric population in any setting. Relevant studies were independently screened, selected, and their data extracted by two investigators. The authors excluded: reviews, meta-analyses, as well as basic research and trials involving patients >18 years old. The primary outcome was the number and the type of adverse side effects reported during levosimendan administration. RESULTS: The updated systematic review included 48 studies, enrolling a total of 1,271 pediatric patients who received levosimendan as treatment (790 patients in the 11 studies that reported side effects). The primary adverse effects of levosimendan administration were hypotension and cardiac arrhythmias, particularly tachycardia. Hypotension occurred in approximately 28.9% of patients, while arrhythmia occurred in about 12.3% of patients. Meta analysis of RCTs revealed a rate of all-cause mortality of 2.0% (8 out of 385) in the levosimendan group compared to 3.9% (15 out of 378) in the control group (dobutamine, milrinone or placebo) (risk ratio [RR] = 0.55; 95% confidence interval [CI] = 0.25-1.21; P = 0.14; I2 = 0%) CONCLUSIONS: Hypotension and cardiac arrhythmia are the most reported side effects of levosimendan in pediatric patients. However, adverse events remain underreported, especially in randomized trials.

Meta-Analysis of the Efficacy of Levosimendan in the Treatment of Severe Sepsis Complicated with Septic Cardiomyopathy.

INTRODUCTION: Sepsis is a medical condition characterized by acute organ dysfunction and uncontrolled inflammation. Organ dysfunction in sepsis is the primary cause of mortality in patients with myocardial dysfunction. Levosimendan is a vasodilating and inotropic agent used in patients with acute heart failure and has resulted in decreased morbidity and mortality in these patients. Our main objective is to examine levosimendan's efficacy in treating severe sepsis complicated with septic cardiomyopathy. METHODS: We systematically searched five databases, PubMed, Web of Science, Embase, Cochrane Library and BioMed Central, for articles and publications from their inception to 2023. Our study adopted the PICOS approach in identifying suitable publications during the systematic search. Inclusion criteria included randomized, controlled trials utilizing levosimendan in adult patients diagnosed with septic shock or severe sepsis. We excluded non-English publications and non-randomized controlled trials. The Newcastle-Ottawa scale (NOS) scale was used to assess the methodological quality, while the risk of bias was assessed through the Cochrane Risk of bias tool. All statistical analyses were performed using RevMan version 5.4. RESULTS: Eight studies met the eligibility criteria and were included in the analysis. There was a statistically significant positive effect on cardiac input in patients treated with levosimendan compared to those treated with dobutamine (p < 0.001). Similarly, there were positive effects on left ventricular ejection fraction (LVEF) (p < 0.001) and left ventricular stroke work index (LVSWI) (p < 0.001). We observed a significant reduction in mortality (p < 0.01) and serum levels of lactic acid (p < 0.01). DISCUSSION: Levosimendan is a calcium sensitizer associated with an influx of calcium ions and activation of ATP-dependent potassium channels that increases myocardial contractility contractions, enhances vasodilation and improves oxygen supply to the cells and tissues. CONCLUSION: Levosimendan is highly efficacious and safe in the management of sepsis and sepsis-induced cardiomyopathy.

Heart failure risk scores in advanced heart failure patients: insights from the LEVO-D registry.

AIMS: The prevalence of advanced heart failure (HF) is increasing due to the growing number of patients with HF and their better treatment and survival. There is a scarcity of data on the accuracy of HF web-based risk scores in this selected population. This study aimed to assess mortality prediction performance of the Meta-Analysis Global Group in Chronic HF (MAGGIC-HF) risk score and the model of the Barcelona Bio-HF Risk Calculator (BCN-Bio-HF) containing N terminal pro brain natriuretic peptide in HF patients receiving intermittent inotropic support with levosimendan as destination therapy. METHODS AND RESULTS: Four hundred and three advanced HF patients from 23 tertiary hospitals in Spain receiving intermittent inotropic support with levosimendan as destination therapy were included. Discrimination for all-cause mortality was compared by area under the curve (AUC) and Harrell's C-statistic at 1 year. Calibration was assessed by calibration plots comparing observed versus expected events based on estimated risk by each calculator. The included patients were predominantly men, aged 71.5 [interquartile range 64-78] years, with reduced left ventricular ejection fraction (27.5 ± 9.4%); ischaemic heart disease was the most prevalent aetiology (52.5%). Death rate at 1 year was 26.8%, while the predicted 1-year mortality by BCN-Bio-HF and MAGGIC-HF was 17.0% and 22.1%, respectively. BCN-Bio-HF AUC was 0.66 (Harrell's C-statistic 0.64), and MAGGIC-HF AUC was 0.62 (Harrell's C-statistic 0.61). CONCLUSIONS: The two evaluated risk scores showed suboptimal discrimination and calibration with an underestimation of risk in advanced HF patients receiving levosimendan as destination therapy. There is a need for specific scores for advanced HF.

Use of levosimendan in hemodynamic management of heart failure in two neonates with intracranial arteriovenous shunts: a case series.

BACKGROUND: The hemodynamic status of newborns with intracranial arteriovenous shunts (AVSs) may be extremely complex. Mini-invasive hemodynamic monitoring through innovative techniques such as Near-Infrared Spectroscopy (NIRS) and Pressure Recording Analytical Method (PRAM) may help in understanding hemodynamics in newborns with AVSs. Levosimendan is a calcium sensitizer and inodilator, and it is known to improve ventricular function, but its use in newborns is limited. In our cases, we evaluated the effect of levosimendan on hemodynamics through NIRS and PRAM. CASE PRESENTATION: Herein, we report the cases of two neonates with intracranial arteriovenous shunts, in whom we used levosimendan to manage cardiac failure refractory to conventional treatment. Levosimendan was used at a dosage of 0.1 mcg/kg/min for 72 h. Combined use of NIRS and PRAM helped in real-time monitoring of hemodynamic effects; in particular, levosimendan determined significant improvement in myocardium contractility as well as a reduction of heart rate. CONCLUSION: In two neonatal cases of AVSs, levosimendan led to an overall hemodynamic stabilization, documented by the combination of NIRS and PRAM. Our results suggest introducing levosimendan as a second-line treatment in cases of severe cardiac dysfunction due to AVSs without improvement using standard treatment strategies. Future prospective and larger studies are highly warranted.

Proarrhythmic changes in human cardiomyocytes during hypothermia by milrinone and isoprenaline, but not levosimendan: an experimental in vitro study.

BACKGROUND: Accidental hypothermia, recognized by core temperature below 35 °C, is a lethal condition with a mortality rate up to 25%. Hypothermia-induced cardiac dysfunction causing increased total peripheral resistance and reduced cardiac output contributes to the high mortality rate in this patient group. Recent studies, in vivo and in vitro, have suggested levosimendan, milrinone and isoprenaline as inotropic treatment strategies in this patient group. However, these drugs may pose increased risk of ventricular arrhythmias during hypothermia. Our aim was therefore to describe the effects of levosimendan, milrinone and isoprenaline on the action potential in human cardiomyocytes during hypothermia. METHODS: Using an experimental in vitro-design, levosimendan, milrinone and isoprenaline were incubated with iCell2 hiPSC-derived cardiomyocytes and cellular action potential waveforms and contraction were recorded from monolayers of cultured cells. Experiments were conducted at temperatures from 37 °C down to 26 °C. One-way repeated measures ANOVA was performed to evaluate differences from baseline recordings and one-way ANOVA was performed to evaluate differences between drugs, untreated control and between drug concentrations at the specific temperatures. RESULTS: Milrinone and isoprenaline both significantly increases action potential triangulation during hypothermia, and thereby the risk of ventricular arrhythmias. Levosimendan, however, does not increase triangulation and the contractile properties also remain preserved during hypothermia down to 26 °C. CONCLUSIONS: Levosimendan remains a promising candidate drug for inotropic treatment of hypothermic patients as it possesses ability to treat hypothermia-induced cardiac dysfunction and no increased risk of ventricular arrhythmias is detected. Milrinone and isoprenaline, on the other hand, appears more dangerous in the hypothermic setting.