***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: INTRODUCTION AND OBJECTIVES The use of levosimendan to treat postoperative low cardiac output syndrome ( LCOS ) has been studied in only small patient series and in r and omized trials focusing on hemodynamic variables . The objective of the present study was to assess the effectiveness of levosimendan , compared with dobutamine , as a treatment for postoperative LCOS . METHODS Patients with LCOS were r and omly assigned to receive either levosimendan ( loading dose , 10 microg/kg , followed by 0.1 microg/kg per min for 24 h ) or dobutamine ( starting dose , 5 microg/kg per min ) . Hemodynamic and clinical parameters ( including postoperative mortality and major complications ) , the need for the coadministration of another drug ( such as an inotrope or a vasopressor ) or for balloon counterpulsation , and length of stay in intensive care were all monitored . RESULTS The study included 137 patients : 69 received levosimendan , while 68 were treated with dobutamine . Although both agents improved hemodynamic parameters , the effect of levosimendan was greater and occurred earlier than that of dobutamine . In addition , levosimendan use result ed in lower postoperative mortality ( 8.7 % vs. 25 % ; P < .05 ) , a lower incidence of major postoperative complications , and less need for an additional inotropic drug ( 8.7 % vs. 36.8 % ; P < .05 ) , a vasopressor ( 11.6 % vs. 30.9 % ; P < .05 ) , or balloon counterpulsation ( 2.9 % vs. 14.7 % ; P<0.05 ) . The length of stay in intensive care was also less ( 66 vs. 158 h ; P < .05 ) . CONCLUSIONS In this r and omized study , levosimendan proved more effective than dobutamine .  Postoperative morbidity and mortality were lower , fewer patients required either an additional inotropic drug , a vasopressor or intra-aortic balloon counterpulsation , and the length of stay in intensive care was shorter The calcium sensitizer levosimendan may counteract stunning after reperfusion of ischaemic myocardium , but no r and omized placebo‐controlled trials exist regarding its use in PCI‐treated ST‐segment elevation infa rct ion ( STEMI ) . We evaluated the efficacy and safety of levosimendan in patients with a primary PCI‐treated STEMI complicated by symptomatic heart failure ( HF ) Background Clinical evidence continues to exp and and is increasingly difficult to overview . We aim ed at conceptualizing a visual assessment tool , i.e. , a matrix for overviewing studies and their data in order to assess the clinical evidence at a glance . Methods A four-step matrix was constructed using the three dimensions of systematic error , r and om error , and design error . Matrix step I ranks the identified studies according to the dimensions of systematic errors and r and om errors . Matrix step II orders the studies according to the design errors . Matrix step III assesses the three dimensions of errors in studies . Matrix step IV assesses the size and direction of the intervention effect . Results The application of this four-step matrix is illustrated with two examples : peri-operative beta-blockade initialized in relation to surgery versus placebo for major non-cardiac surgery , and antiarrhythmics for maintaining sinus rhythm after cardioversion of atrial fibrillation .  When clinical evidence is deemed both internally and externally valid , the size of the intervention effect is to be assessed . Conclusion The error matrix provides an overview of the validity of the available evidence at a glance , and may assist in deciding which interventions to use in clinical practice INTRODUCTION Although beta-blockers are highly effective in the treatment of heart failure ( HF ) , many patients with HF receiving a beta-blocker continue to become decompensated and require hospitalization for worsening HF . Levosimendan and dobutamine are used to manage decompensated HF , but their comparative effects on left ventricular ( LV ) function in patients prescribed beta-blockers are unknown . AIMS The aim of this study was to compare the effects of dobutamine and levosimendan on LV systolic and diastolic functions in chronic HF patients treated chronically with carvedilol . Forty patients with chronic HF who had NYHA class III to IV symptoms , a LV ejection fraction ( LVEF ) < 40 % , and ongoing treatment with carvedilol  were enrolled in this r and omized ( 1:1 ) , dobutamine controlled , open-label study . Before and 24 h after treatment , LVEF , mitral inflow peak E and A wave velocity , E/A ratio , the deceleration time of the E wave ( DT ) , isovolumic relaxation time ( IVRT ) , peak systolic ( Sm ) and early diastolic ( Em ) mitral annular velocity , and systolic pulmonary artery pressure ( SPAP ) were measured by echocardiography . RESULTS Levosimendan produced a statistically significant increase in LVEF ( 28+/-5 % vs. 33+/-3 % ) , Sm ( 6.5+/-1.2 cm/s vs. 7.4+/-0.9 cm/s ) , DT ( 120+/-10 ms vs. 140+/-15 ms ) , and Em ( 7.5+/-0.4 cm/s vs. 8.1+/-0.5 cm/s ) and significant decrease in E/A ratio ( 2.1+/-0.3 vs. 1.7+/-0.4 ) and SPAP ( 55+/-5 mmHg vs. 40+/-7 mmHg ) . No significant change occurred in LV systolic and diastolic function parameters , or SPAP with dobutamine treatment . Levosimendan did not significantly alter the heart rate ( 72+/-4 bpm vs. 70+/-3 bpm ) , systolic ( 105+/-5 mmHg vs. 102+/-4 mmHg ) , or diastolic blood pressure ( 85+/-5 mmHg vs. 83+/-5 mmHg ) whereas with dobutamine treatment , all these parameters significantly increased . CONCLUSIONS Dobutamine and levosimendan have different effects on LV functions in patients treated chronically with carvedilol . These differences should be considered when selecting inotropic therapy for decompensated HF receiving long-term carvedilol Introduction The purpose of the present study was to investigate microcirculatory blood flow in patients with septic shock treated with levosimendan  as compared to an active comparator drug ( i.e. dobutamine ) . The primary end point was a difference of ≥ 20 % in the microvascular flow index of small vessels ( MFIs ) among groups . Methods The study was design ed as a prospect i ve , r and omized , double-blind clinical trial and performed in a multidisciplinary intensive care unit . After achieving normovolemia and a mean arterial pressure of at least 65 mmHg , 40 septic shock patients were r and omized to receive either levosimendan 0.2 μg·kg-1·min-1 ( n = 20 ) or an active comparator ( dobutamine 5 μg·kg-1·min-1 ; control ; n = 20 ) for 24 hours . Sublingual microcirculatory blood flow of small and medium vessels was assessed by sidestream dark-field imaging . Microcirculatory variables and data from right heart catheterization were obtained at baseline and 24 hours after r and omization . Baseline and demographic data were compared by means of Mann-Whitney rank sum test or chi-square test , as appropriate . Microvascular and hemodynamic variables were analyzed using the Mann-Whitney rank sum test . Results Microcirculatory flow indices of small and medium vessels increased over time and were significantly higher in the levosimendan group as compared to the control group ( 24 hrs : MFIm 3.0 ( 3.0 ; 3.0 ) vs. 2.9 ( 2.8 ; 3.0 ) ; P = .02 ; MFIs 2.9 ( 2.9 ; 3.0 ) vs. 2.7 ( 2.3 ; 2.8 ) ; P < .001 ) . The relative increase of perfused vessel density vs. baseline was significantly higher in the levosimendan group than in the control group ( dMFIm 10 ( 3 ; 23)% vs. 0 ( -1 ; 9)% ; P = .007 ; dMFIs 47 ( 26 ; 83)% vs. 10 ( -3 ; 27 ) ; P < .001 ) . In addition , the heterogeneity index decreased only in the levosimendan group ( dHI -93 ( -100 ; -84)% vs. 0 ( -78 ; 57)% ; P < .001 ) . There was no statistically significant correlation between systemic and microcirculatory flow variables within each group ( each P > .05 ) . Conclusions Compared to a st and ard dose of 5 μg·kg-1·min-1 of dobutamine , levosimendan at 0.2 μg·kg-1·min-1 improved sublingual microcirculatory blood flow in patients with septic shock , as reflected by changes in microcirculatory flow indices of small and medium vessels . Trial registration NCT00800306 BACKGROUND  Atrial fibrillation ( AF )  often occurs after coronary artery bypass grafting ( CABG ) and can result in increased morbidity and mortality due to complications . In the present study , our goal was to investigate whether the use of levosimendan can reduce the frequency of AF after coronary artery bypass grafting in patients with poor left ventricle function . MATERIAL AND METHODS To investigate the effectiveness of levosimendan in the prophylaxis of AF , we conducted a prospect i ve , r and omized , placebo-controlled clinical study on 200 consecutive patients in whom we performed elective CABG operations . Baseline characteristics were similar in both groups . A control group of 100 patients were treated with placebo ( 500 mL saline solution ) , whereas the levosimendan group ( n = 100 patients ) was treated with levosimendan .  High-sensitivity C-reactive protein , cardiac troponin , and creatine kinase – MB levels were measured before surgery and 5 days postoperatively . RESULTS AF occurred in 12 % of the levosimendan group and 36 % of the control group . The occurrence of AF was significantly lower in the levosimendan group ( P < 0.05 ) . The duration of AF in the levosimendan group was significantly shorter than that in the control group ( 4.83 ± 1.12 and 6.50 ± 1.55 hours , respectively ; P = 0.028 ) . Our research showed that C-reactive protein was higher postoperatively in the control group than in the levosimendan group ( P < 0.05 ) . CONCLUSIONS The incidence of postoperative AF in the levosimendan group was reduced significantly in patients with poor left ventricle function after CABG operations Background We determined the short-term hemodynamic and clinical effects of levosimendan , a novel calcium-sensitizing agent , in patients with decompensated heart failure . Methods and Results One hundred forty-six patients with New York Heart Association functional class III or IV heart failure ( mean left ventricular ejection fraction 21±1 % ) who had a pulmonary capillary wedge pressure ≥15 mm Hg and a cardiac index ≤2.5 L · min−1 · m−2 were enrolled in a multicenter , double-blind , placebo-controlled study and r and omized 2:1 to intravenous infusion of levosimendan or placebo . Drug infusions were uptitrated over 4 hours from an initial infusion rate of 0.1 & mgr;g · kg−1 · min−1 to a maximum rate of 0.4 & mgr;g · kg−1 · min−1 and maintained at the maximal tolerated infusion rate for an additional 2 hours . Levosimendan caused dose-dependent increases in stroke volume and cardiac index beginning with the lowest infusion rate and achieving maximal increases in stroke volume and cardiac index of 28 % and 39 % , respectively . Heart rate increased modestly ( 8 % ) at the maximal infusion rate and was not increased at the 2 lowest infusion rates . Levosimendan caused dose-dependent decreases in pulmonary capillary wedge , right atrial , pulmonary arterial , and mean arterial pressures  . Levosimendan appeared to improve dyspnea and fatigue , as assessed by the patient and physician , and was not associated with a significant increase in adverse events . Conclusions Levosimendan caused rapid dose-dependent improvement in hemodynamic function in patients with decompensated heart failure . These hemodynamic effects appeared to be accompanied by symptom improvement and were not associated with a significant increase in the number of adverse events . Levosimendan may be of value in the short-term management of patients with decompensated heart failure CONTEXT Because acute decompensated heart failure causes substantial morbidity and mortality , there is a need for agents that at least improve hemodynamics and relieve symptoms without adversely affecting survival . OBJECTIVE To assess the effect of a short-term intravenous infusion of levosimendan or dobutamine on long-term survival . DESIGN , SETTING , AND PATIENTS The Survival of Patients With Acute Heart Failure in Need of Intravenous Inotropic Support ( SURVIVE ) study was a r and omized , double-blind trial comparing the efficacy and safety of intravenous levosimendan or dobutamine in 1327 patients hospitalized with acute decompensated heart failure who 
    Output:
    
Conclusions The available evidence is inconclusive whether or not levosimendan may have a beneficial effect on mortality due to risks of systematic errors and r and om errors .