Meta-analysis of Randomized Trials of Effect of Milrinone on Mortality in Cardiac Surgery: An Update

Survival of Left-to-Right Shunt Repair in Children with Pulmonary Arterial Hypertension at a Tertiary Hospital in a Low-to-Middle-Income Country

Background

In low-to-middle-income countries, repair of the left-to-right shunts congenital heart disease (CHD) are often done with existing pulmonary arterial hypertension (PAH). Long-term outcomes data of this condition in either low-to-middle or high-income countries are limited. We conducted a study to evaluate the outcomes of children with PAH related to left-to-right shunt CHD who underwent surgical or transcatheter repair.

Methods

All cases of PAH related to left-to-right shunt CHD repairs from 2015-2018 were retrospectively reviewed with additional new patients who underwent repair within our study period (2019-2020). Cases with complex congenital heart disease and incomplete hemodynamic echocardiography or catheterization measurements were excluded. Kaplan-Meier curves, log-rank test, Cox regression with Firth's correction and restricted mean survival time were used for survival analysis.

Results

Of the 118 patients, 103 patients were enrolled and 15 patients were excluded due to complex congenital heart disease and missing hemodynamic measurements prior to repair. Overall, median age at intervention was 44 months, mPAP mean was 43.17 ± 16.05 mmHg and Pulmonary Vascular Resistance index (PVRi) mean was 2.84 ± 2.09 (WU.m2). Nine patients died after repair. The survival rate for patients with PAH-CHD at 1 day, 30 days and 1400 days (4 years) was 96.1%, 92.1%, and 91.0% respectively. Patients with persisting PAH after correction had -476.1 days (95% confidence interval [CI]: -714.4, -237,8) shorter survival over 4 years of follow up compared to patients with reversed PAH. PVRi was found to be the influencing covariate of the difference of restricted mean survival time between these groups.

Conclusion

In low-to-middle income settings, with accurate PAH reversibility assessment prior to intervention, repair of left-to-right shunt CHD with existing PAH in children has a favourable outcome. Inferior survival is found in patients with persistence of PAH. PVRi at baseline predicts between-group survival difference.

Preoperative, Multidisciplinary Clinical Optimization of Patients with Severely Depressed Left Ventricular Ejection Fraction Who Are Undergoing Coronary Artery Bypass Grafting

Coronary artery bypass grafting (CABG) remains a routine operation despite major advancements in angioplastic procedures. Around 200,000 CABG procedures are performed annually in the U.S. Patients who are not candidates for angioplasty intervention often have advanced coronary disease and comorbidities that raise the risk of heart failure with decreased ejection fraction to around 25%. Over the years, significant developments in various preoperative interventions have occurred; in this paper, we suggest a multidisciplinary preoperative algorithm that can be included in a regularly scheduled multidisciplinary care plan.

The effect of milrinone on mortality in adult patients who underwent CABG surgery: a systematic review of randomized clinical trials with a meta-analysis and trial sequential analysis

Background

As an inodilator, milrinone is commonly used for patients who undergo coronary artery bypass graft (CABG) surgery because of its effectiveness in decreasing the cardiac index and mitral regurgitation. The aim of this study was to perform a systematic review and meta-analysis of existing studies from the past 20 years to evaluate the impact of milrinone on mortality in patients who undergo CABG surgery.

Methods

We performed a systematic literature search on the application of milrinone in patients who underwent CABG surgery in studies published between 1997 and 2017 in BioMed Central, PubMed, EMBASE, and the Cochrane Central Register. The included studies evaluated milrinone groups compared to groups receiving either placebo or standard treatment and further compared the systemic administration.

Results

The network meta-analysis included 723 patients from 16 randomized clinical trials. Overall, there was no significant difference in mortality between the milrinone group and the placebo/standard care group when patients underwent CABG surgery. In addition, 9 trials (with 440 randomized patients), 4 trials (with 212 randomized patients), and 10 trials (with 470 randomized patients) reported that the occurrence of myocardial infarction (MI), myocardial ischemia, and arrhythmia was lower in the milrinone group than in the placebo/standard care group. Between the milrinone treatment and placebo/standard care groups, the occurrence of myocardial infarction, myocardial ischemia, and arrhythmia was significantly different. However, the occurrence of stroke and renal failure, the duration of inotropic support (h), the need for an intra-aortic balloon pump (IABP), and mechanical ventilation (h) between these two groups showed no differences.

Conclusions

Based on the current results, compared with placebo, milrinone might be unable to decrease mortality in adult CABG surgical patients but can significantly ameliorate the occurrence of MI, myocardial ischemia, and arrhythmia. These results provide evidence for the further clinical application of milrinone and of therapeutic strategies for CABG surgery. However, along with milrinone application in clinical use, sufficient data from randomized clinical trials need to be collected, and the potential benefits and adverse effects should be analyzed and reevaluated.

Effects of milrinone on renal perfusion, filtration and oxygenation in patients with acute heart failure and low cardiac output early after cardiac surgery

PURPOSE

Early postoperative heart failure is common after cardiac surgery, and inotrope treatment may impact renal perfusion and oxygenation. We aimed to study the renal effects of the inodilator milrinone when used for the treatment of heart failure after weaning from cardiopulmonary bypass (CPB).

MATERIAL AND METHODS

In 26 patients undergoing cardiac surgery with CPB, we used renal vein catheterization to prospectively measure renal blood flow (RBF), glomerular filtration rate (GFR), and renal oxygenation. Patients who developed acute heart failure and low cardiac output (cardiac index <2.1 L/min/m²) at 30 min after weaning from CPB (n = 7) were given milrinone, and the remaining patients (n = 19) served as controls. Additional measurements were made at 60 min after CPB.

RESULTS

In patients with acute postoperative heart failure, before receiving milrinone, renal blood flow was lower (-33%, p < .05) while renal oxygen extraction was higher (41%, p < .05) compared to the control group. Milrinone increased cardiac index (21%, p < .001), RBF (36%, p < .01) and renal oxygen delivery (35%, p < .01), with no significant change in GFR and oxygen consumption compared to the control group.

CONCLUSIONS

In patients with acute heart failure after weaning from CPB, the milrinone-induced increase in cardiac output was accompanied by improved renal oxygenation.

TRIAL REGISTRATION

ClinicalTrials.gov; identifier NCT02405195, date of registration; March 27, 2015, and NCT02549066, date of registration; 9 September 2015.

Adrenergic Downregulation in Critical Care: Molecular Mechanisms and Therapeutic Evidence

Catecholamines remain the mainstay of therapy for acute cardiovascular dysfunction. However, adrenergic receptors quickly undergo desensitization and downregulation after prolonged stimulation. Moreover, prolonged exposure to high circulating catecholamines levels is associated with several adverse effects on different organ systems. Unfortunately, in critically ill patients, adrenergic downregulation translates into progressive reduction of cardiovascular response to exogenous catecholamine administration, leading to refractory shock. Accordingly, there has been a growing interest in recent years toward use of noncatecholaminergic inotropes and vasopressors. Several studies investigating a wide variety of catecholamine-sparing strategies (eg, levosimendan, vasopressin, β-blockers, steroids, and use of mechanical circulatory support) have been published recently. Use of these agents was associated with improvement in hemodynamics and decreased catecholamine use but without a clear beneficial effect on major clinical outcomes. Accordingly, additional research is needed to define the optimal management of catecholamine-resistant shock.

Calcium Administration During Weaning From Cardiopulmonary Bypass: A Narrative Literature Review

The search for safe and effective patient management strategies during weaning from cardiopulmonary bypass is ongoing; intravenous calcium is occasionally used as a first-line drug. The physiologic role of calcium suggests that it can support the function of the cardiovascular system during this critical period. Patients may be mildly hypocalcemic after cardiopulmonary bypass; however, this degree of hypocalcemia does not significantly impair the cardiovascular system. The transient beneficial effects of calcium administration (increase in arterial blood pressure, systemic vascular resistance, cardiac index, stroke volume, and coronary perfusion pressure) might be helpful in cases of moderate contractility reduction or vasoplegia. Nonetheless, effects on clinically relevant endpoints are unknown, and possible systemic side effects, such as transient reduction in internal mammary artery graft flow, attenuation of the effects of β-sympathomimetics, "stone heart" phenomenon, and pancreatic cellular injury, may limit the use of calcium salts. Further studies are needed to expand the understanding of the effects of calcium administration on patient outcomes.

Levosimendan in patients with low ejection fraction undergoing cardiac surgery

Introduction

Significant impairment of left ventricular function causes low cardiac output syndrome in the immediate postoperative period in 3-14% of patients undergoing surgery, increasing the mortality 15-fold.

Aim

To assess the use of levosimendan in patients undergoing cardiac surgery in 2016.

Material and methods

The analysis included 14 patients: 3 (21.4%) women and 11 (78.6%) men aged 65.4 ±11.8 years. The mean value of left ventricular ejection fraction amounted to 20 ±6.25%. In 11 patients, levosimendan infusion was started immediately after the induction of anesthesia. Three patients received the agent during the early postoperative period due to low cardiac output syndrome refractory to conventional therapy. The dosage was modified within the range of 0.05-0.2 μg/kg/min. On the day of the surgery, all patients received continuous infusion of adrenaline and levonor.

Results

The cardiac index amounted to 2.8 ±0.71 l/m² after several hours of infusion and 2.9 ±0.1 l/m² the next morning. The first examination showed that the mean systemic vascular resistance was 1010 dyn/s^-5 and the second: 940 ±100 dyn/s^-5; mixed venous blood saturation amounted to 66 ±7.5% and 65.5 ±8%, respectively. Respectively, the mean concentration of lactates was 2.0 ±0.96 mmol/l and 1.8 ±0.24 mmol/l. Mechanical lung ventilation lasting more than 48 hours was required in 50% of the patients. Two patients with chronic kidney disease required bedside renal replacement therapy before the procedure. Two (14.3%) patients died. Nine (64.3%) patients were discharged home, and three were transferred to cardiac wards.

Conclusions

Levosimendan therapy proved safe in the study group. The nature of the study and the small sample size preclude the formulation of detailed conclusions.

The Perspective of the Intensivist on Inotropes and Postoperative Care Following Pediatric Heart Surgery: An International Survey and Systematic Review of the Literature

Introduction:

Inotropes are frequently being used in children undergoing heart surgery to prevent or treat low cardiac output syndrome (LCOS). There is only limited evidence that inotropes actually positively influence postoperative outcome. Our aim was to describe the current international practice variation in the use of inotropes following congenital heart surgery.

Methods:

We developed an online survey regarding the postoperative use of inotropes. We sent an invitation to all 197 registered members of the Pediatric Cardiac Intensive Care Society (PCICS) to participate in the survey. We also performed a systematic review of the literature.

Results:

Ninety-eight people (50%) responded, representing 62 international centers. Milrinone is routinely used perioperatively by 90 respondents (97%). Adrenaline/epinephrine is routinely used by 43%, dopamine by 36%, dobutamine by 11%, and levosimendan by 6%. Steroids are used routinely by 54% before initiating cardiopulmonary bypass. Vasopressin is used by 44% of respondents. The development of LCOS is monitored with lactate in 99% of respondents, physical examination (98%), intermittent mixed venous saturation (76%), continuous mixed venous saturation (13%), echocardiography (53%), core–peripheral temperature gap (29%), near-infrared spectrometry (25%), and 4% use cardiac output monitors (PiCCO, USCOM). To improve cardiac output, 42% add/increase milrinone, 37% add adrenaline, and 15% add dopamine. Rescue therapy is titrated individually, based on the patients’ pathophysiology. A systematic review of the literature failed to show compelling evidence with regard to the benefit of inotropes.

Conclusions:

Despite the lack of sufficient evidence, milrinone is used by the vast majority of caregivers following congenital heart surgery.

Milrinone for cardiac dysfunction in critically ill adult patients: a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis

INTRODUCTION

Milrinone is an inotrope widely used for treatment of cardiac failure. Because previous meta-analyses had methodological flaws, we decided to conduct a systematic review of the effect of milrinone in critically ill adult patients with cardiac dysfunction.

METHODS

This systematic review was performed according to The Cochrane Handbook for Systematic Reviews of Interventions. Searches were conducted until November 2015. Patients with cardiac dysfunction were included. The primary outcome was serious adverse events (SAE) including mortality at maximum follow-up. The risk of bias was evaluated and trial sequential analyses were conducted. The quality of evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation criteria.

RESULTS

A total of 31 randomised clinical trials fulfilled the inclusion criteria, of which 16 provided data for our analyses. All trials were at high risk of bias, and none reported the primary composite outcome SAE. Fourteen trials with 1611 randomised patients reported mortality data at maximum follow-up (RR 0.96; 95% confidence interval 0.76-1.21). Milrinone did not significantly affect other patient-centred outcomes. All analyses displayed statistical and/or clinical heterogeneity of patients, interventions, comparators, outcomes, and/or settings and all featured missing data.

DISCUSSION

The current evidence on the use of milrinone in critically ill adult patients with cardiac dysfunction suffers from considerable risks of both bias and random error and demonstrates no benefits. The use of milrinone for the treatment of critically ill patients with cardiac dysfunction can be neither recommended nor refuted. Future randomised clinical trials need to be sufficiently large and designed to have low risk of bias.

Outcomes in Patients with Persistent Ventricular Dysfunction After Stage I Palliation for Hypoplastic Left Heart Syndrome

We sought to describe the clinical course for patients with hypoplastic left heart syndrome and persistent ventricular dysfunction and identify risk factors for death or transplantation before stage II palliation. 138 children undergoing stage I palliation from 2004 to 2011 were reviewed. Twenty-two (16 %) patients (seven Hybrid, 15 Norwood) with two consecutive echocardiograms reporting at least moderate dysfunction were included and compared to case-matched controls. Eleven of the 22 patients with dysfunction (50 %) underwent stage II, seven (32 %) were transplanted, and four (18 %) died prior to stage II. Of the patients who survived to hospital discharge (n = 17) following stage 1, 14 (82 %) required readmission for heart failure (HF) compared to only two (10 %) for controls (p < 0.001). Among patients with ventricular dysfunction, there was an increased use of ACE inhibitors or beta-blockers (82 vs. 25 %; p = 0.001), inotropes (71 vs. 15 %; p = 0.001), ventilation (58 vs. 10 %; p = 0.001), and ECMO (29 vs. 0 %; p = 0.014) for HF management post-discharge when compared to controls. There was a lower heart transplant-free survival at 7 months in patients with dysfunction compared to controls (50.6 vs. 90.9 %; p = 0.040). ECMO support (p = 0.001) and duration of inotropic support (p = 0.04) were significantly associated with death or transplantation before stage II palliation. Patients with ventricular dysfunction received more HF management and related admissions. Longer inotropic support should prompt discussion regarding alternative treatment strategies given its association with death or transplant.

Outcome of inotropic therapy: is less always more?

PURPOSE OF REVIEW

Positive inotropic agents are widely used in the management of the critical ill patient presenting with low cardiac output state. Different inotropic agents are available, and different effects on hemodynamic endpoints may be recognized, but data on relevant clinical endpoints are scarce. A growing body of literature suggests that overuse of inotropes may have detrimental effects on cardiomyocytes, resulting in an increased risk of morbidity and mortality. The present review will summarize recent literature, focusing on outcome studies among adult patients related to use of inotropes in different clinical settings.

RECENT FINDINGS

Use of inotropic therapy shows a manifold variation between hospitals and individual providers even after risk standardization. No recent studies have shown inotropic therapy to provide short-term and long-term improvement of morbidity and mortality in patients with advanced nonsurgical heart failure or septic shock or as part of goal-directed treatment in high-risk noncardiac surgery. Levosimendan may show beneficial effect on mortality in cardiac surgery.

CONCLUSION

A 'less is more' approach may show to be appropriate when relating to routine use of inotropes. Inotropic therapy should be restricted to patients with heart failure and clinical signs of end-organ hypoperfusion.

Does intravenous sildenafil clinically ameliorate pulmonary hypertension during perioperative management of congenital heart diseases in children? - a prospective randomized study

BACKGROUND

Pulmonary hypertension (PHT), if present, can be a significant cause of increased morbidity and mortality in children undergoing surgery for congenital heart diseases (CHD). Various techniques and drugs have been used perioperatively to alleviate the effects of PHT. Intravenous (IV) sildenafil is one of them and not many studies validate its clinical use.

AIMS AND OBJECTIVES

To compare perioperative PaO 2 - FiO 2 ratio peak filling rate (PFR), systolic pulmonary artery pressure (PAP) - systolic aortic pressure (AoP) ratio, extubation time, and Intensive Care Unit (ICU) stay between two groups of children when one of them is administered IV sildenafil perioperatively during surgery for CHDs.

MATERIALS AND METHODS

Patients with ventricular septal defects and proven PHT, <14 years of age, all American Society of Anesthesiologists physical status III, undergoing cardiac surgery, were enrolled into two groups - Group S (IV sildenafil) and Group C (control) - over a period of 14 months, starting from October 2013. Independent t-test and Mann-Whitney U-test were used to compare the various parameters between two groups.

RESULTS

PFR was higher throughout, perioperatively, in Group S. PAP/AoP was 0.3 and 0.4 in Group S and Group C, respectively. In Group S, mean group extubation time was 7 ± 7.34 h, whereas in Group C it was 22.1 ± 10.6. Postoperative ICU stay in Group S and Group C were 42.3 ± 8.8 h and 64.4 ± 15.9 h, respectively.

CONCLUSION

IV sildenafil, when used perioperatively, in children with CHD having PHT undergoing corrective surgery, improves not only PaO 2 - FiO 2 ratio and PAP - AoP ratio but also reduces extubation time and postoperative ICU stay.

Postoperative Critical Care of the Adult Cardiac Surgical Patient. Part I: Routine Postoperative Care

OBJECTIVES

Cardiac surgery, including coronary artery bypass, cardiac valve, and aortic procedures, is among the most common surgical procedures performed in the United States. Successful outcomes after cardiac surgery depend on optimum postoperative critical care. The cardiac intensivist must have a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. In this concise review, targeted at intensivists and surgeons, we discuss the routine management of the postoperative cardiac surgical patient.

DATA SOURCE AND SYNTHESIS

Narrative review of relevant English-language peer-reviewed medical literature.

CONCLUSIONS

Critical care of the cardiac surgical patient is a complex and dynamic endeavor. Adequate fluid resuscitation, appropriate inotropic support, attention to rewarming, and ventilator management are key components. Patient safety is enhanced by experienced personnel, a structured handover between the operating room and ICU teams, and appropriate transfusion strategies.

Perioperative pharmacological management of pulmonary hypertensive crisis during congenital heart surgery

Pulmonary hypertensive crisis is an important cause of morbidity and mortality in patients with pulmonary arterial hypertension secondary to congenital heart disease (PAH-CHD) who require cardiac surgery. At present, prevention and management of perioperative pulmonary hypertensive crisis is aimed at optimizing cardiopulmonary interactions by targeting prostacyclin, endothelin, and nitric oxide signaling pathways within the pulmonary circulation with various pharmacological agents. This review is aimed at familiarizing the practitioner with the current pharmacological treatment for dealing with perioperative pulmonary hypertensive crisis in PAH-CHD patients. Given the life-threatening complications associated with pulmonary hypertensive crisis, proper perioperative planning can help anticipate cardiopulmonary complications and optimize surgical outcomes in this patient population.

Intermittent levosimendan improves mid-term survival in chronic heart failure patients: meta-analysis of randomised trials

AIMS

Standard inotropic treatment is often necessary in end-stage heart failure but may be harmful. We performed a meta-analysis of randomized controlled trials to investigate the effect of repeated administration of levosimendan on survival in patients with chronic heart failure.

METHODS AND RESULTS

Four investigators independently searched in CENTRAL, Google Scholar MEDLINE/PubMed, Scopus and the Cochrane Central Register of clinical trials to identify any randomized study ever performed with intermittent levosimendan intravenous administration in adult patients with chronic heart failure with no restrictions on dose or time of administration. Data from a total of 326 patients from six randomized controlled studies using intermittent levosimendan in a cardiological setting were included in the analysis. Levosimendan was associated with a significant reduction in mortality at the longest follow-up available [32 of 168 (19 %) in the levosimendan group 46 of 133 (35 %) in the control arm, RR = 0.55 (95 % CI 0.37-0.84), p for effect = 0 0.005, p for heterogeneity = 0.3, I (2) = 23.4 %, NNT = 6 with 5 studies included]. Brain natriuretic peptide values, ejection fraction and number of patients with New York Heart Association ≥ III status were similar in survivors of both groups.

CONCLUSIONS

A large randomized trial is necessary to confirm the promising beneficial effects of intermittent levosimendan administration on the mid-term survival of patients with chronic heart failure.