Levosimendan May Prevent Postoperative Atrial Fibrillation Through Anti-inflammatory and Antioxidant Modulation

Effect of intravenous levosimendan or milrinone on left atrial pressure in patients undergoing off-pump coronary artery bypass grafting-A prospective double-blind, randomized controlled trial

Background

Maintaining a low left atrial pressure (LAP) in off-pump coronary artery bypass grafting (OPCAB) is desirable. This study was done to compare the effects of intravenous levosimendan or milrinone on LAP at different stages of OPCAB.

Materials and Methods

After institutional ethics committee clearance, this two-arm double-blind randomized control trial was done in 44 adult patients with triple vessel coronary artery disease undergoing OPCAB at cardiac OT of IPGME&R, Kolkata. The patients were randomly allocated into two groups receiving intraoperative either levosimendan or milrinone. Pulmonary capillary wedge pressure (PCWP) was compared as the primary outcome parameter, whereas other echocardiographic and hemodynamic parameters were also assessed during six stages of OPCAB, that is, after sternotomy, proximal(s), left anterior descending artery (LAD), obtuse marginal (OM), posterior descending artery (PDA) grafting, and before sternal closure. Numerical parameters were compared using Student's unpaired two-tailed t-test.

Results

PCWP was found to be significantly lower (P < 0.05) in the levosimendan group during proximal (P = 0.047), LAD (P = 0.018), OM (P < 0.0001), PDA grafting (P = 0.028), and before sternal closure (P = 0.015). Other parameters indicate LAP, that is, from mitral early diastolic inflow velocity to mitral annular early diastolic velocity ratio (E/e'), which indicated significantly lower LAP in levosimendan group during LAD, OM, and PDA grafting and before sternal closure. Conclusion: Levosimendan may be used as a primary inotrope in terms of better reduction in left atrial pressure during different stages of OPCAB, translating to a decrease in left ventricular end-diastolic pressure, therefore maintaining optimum coronary perfusion pressure, which is the primary goal of the surgery.

Anti-inflammatory drugs in the prevention of post-operative atrial fibrillation: a literature review

Atrial fibrillation (AF) is a serious and common complication following heart surgery. Cardiac surgery triggers inflammation in the heart and makes it susceptible to the incidence of AF. Therefore, anti-inflammatory drugs may reduce the rate of AF incidence in the post-surgery conditions. Immunosuppressant agents, steroidal anti-inflammatory drugs (corticosteroids), non-aspirin non-steroid anti-inflammatory drugs (NSAIDs), colchicine and omega-3 unsaturated fatty acids (n-3 UFA) are drugs with well-known anti-inflammatory properties. The efficacy, safety and other aspects of using these drugs in the prevention of post-operative AF (POAF) have been reviewed here. Studies evaluating the efficacy of colchicine have shown that it could be effective in the prevention of POAF. However, there is a need for additional studies to find a colchicine regimen with optimal efficacy and higher tolerability. The use of corticosteroids may also be of value based on the most of meta-analyses. In the case of n-3 polyunsaturated fatty acids and NSAIDs, current data fail to support their efficacy in POAF prevention. Moreover, perioperative administration of NSAIDs may be associated with some severe safety considerations. Immunosuppressant agents have not been used for the prevention of POAF. Further studies are needed to find the most effective strategy for POAF prevention with the least safety considerations and the highest health benefits.

Prophylactic preoperative levosimendan for off-pump coronary artery bypass grafting in patients with left ventricular dysfunction: Single-centered randomized prospective study

Background:

Off-pump coronary artery bypass surgery (OPCAB) is often complicated by hemodynamic instability, especially in patients with prior left ventricular (LV) dysfunction and appropriate choice of inotrope plays a vital role in perioperative management of these patients.

Aim and Objective:

To study hemodynamic effects and immediate outcome of prophylactic infusion of levosimendan in patients with the LV dysfunction undergoing OPCAB surgery and whether this strategy helps in successful conduct of OPCAB surgery.

Materials and Methods:

After Institutional Ethics Committee approval, 60 patients posted for elective OPCAB surgery were randomly divided into two groups (n = 30 each). Patients with the LV ejection fraction <30% were included. Study group was started on injection levosimendan (@ 0.1 μg/kg/min) in the previous night before surgery and continued for 24 h including intraoperative period. Hemodynamic monitoring included heart rate, invasive blood pressure, cardiac index (CI), pulmonary capillary wedge pressure (PCWP), pulse oximetry, and arterial blood gases with serum lactates at as T0 (baseline), T1 (15 min after obtuse marginal and/or PDA anastomoses), T2 (at end of surgery), T3 (6 h after surgery in Intensive Care Unit [ICU]), T4 (12 h after surgery), and T5 (24 h after surgery in ICU). Vasopressor was added to maintain mean arterial pressure >60 mmHg. Chi-square/Fisher's exact/Mid P exact test and Student's t-tests were applied for categorical and continuous data.

Results:

CI was greater and PCWP reduced significantly in Group L during intraoperative and early postoperative period. Serum lactate concentration was lower in patients pretreated with levosimendan. Incidence of postoperative atrial fibrillation (POAF) (36.6 vs. 6.6%; P = 0.01), low cardiac output syndrome (LCOS) (30% vs. 6%; P = 0.02), and acute kidney injury (23.3% vs. 6.7%; P = 0.04) was less in Group L. Three patients (10%) in control group required conversion to cardiopulmonary bypass (CPB) as compared to none in the study group. There was no difference regarding ICU or hospital stay and mortality in both groups.

Conclusion:

Preoperative levosimendan helps in successful conduct of OPCAB and reduces the incidence of LCOS, POAF, conversion to CPB, and requirement of intra-aortic balloon pump.

Study of levosimendan during off-pump coronary artery bypass grafting in patients with LV dysfunction: a double-blind randomized study

Objectives:

Levosimendan is a calcium sensitizer drug which has been used in cardiac surgery for the prevention of postoperative low cardiac output syndrome (LCOS) and in difficult weaning from cardiopulmonary bypass (CPB). This study aims to evaluate perioperative hemodynamic effects of levosimendan pretreatment in patients for off-pump coronary artery bypass graft (OPCABG) surgery with low left ventricular ejection fractions (LVEF < 30%).

Materials and Methods:

Fifty patients undergoing OPCABG surgery with low LVEF (<30%) were enrolled in the study. Patients were randomly divided in two groups: Levosimendan pretreatment (Group L) and placebo pretreatment (Group C) of 25 each. Group L, patients received levosimendan infusion 200 μg/kg over 24 h and in Group C Patients received placebo. The clinical parameters measured before and after the drug administration up to 48 h were heart rate (HR; for the hour after drug infusion), cardiac index (CI), and pulmonary capillary wedge pressure (PCWP). The requirement of inotropes, intraaortic balloon pump (IABP), CPB, intensive care unit (ICU) stay, and hospital stay were also measured.

Results:

The patients in group L exhibited higher CI and PCWP during operative in early postoperative period as compared to control group C. Group L also had a less requirement for inotropes, CPB support and IABP with shorter ICU stay as well as hospital stay.

Conclusion:

Levosimendan pretreatment (24 h infusion) in patient for OPCABG with poor LVEF shows better outcomes and hemodynamics in terms of inotropes, CPB and IABP requirements. It also reduces ICU stay.

Levosimendan - a calcium sensitising agent with potential anti-arrhythmic properties

Levosimendan is a 'Ca(2+)sensitiser', which exerts its inotropic effect by increasing the affinity of troponin C for Ca(2+), directly stabilising the Ca(2+)-induced conformation of troponin C. It leads to a positive inotropic effect without impairing diastolic relaxation and causing cytosolic Ca(2+) ion overload, which might result in cardiac myocyte dysfunction, arrhythmias and cell death. Levosimendan may also have significant anti-inflammatory properties. Data from various studies suggest that levosimendan might have anti-arrhythmic effects, although the outcome of clinical trials on the effect of this agent in (for example) atrial fibrillation (AF) remains controversial. Currently, on the basis of available data, it is especially worth emphasising the potential role of this drug in the termination of AF after cardiac surgery, which significantly influences early- and long-term morbidity and mortality. This review considers the putative anti-arrhythmic properties of levosimendan and discusses the potential clinical application of such a drug.