Variation in use of peroperative inotropic support therapy in cardiac surgery: time for reflection?

Use of Vasoactive Medications after Cardiac Surgery in the United States

Rationale: Patients undergoing cardiac surgery often require vasopressor or inotropic ("vasoactive") medications, but patterns of postoperative use are not well described.Objectives: This study aimed to describe vasoactive medication administration throughout hospitalization for cardiac surgery, to identify patient- and hospital-level factors associated with postoperative use, and to quantify variation in treatment patterns among hospitals.Methods: Retrospective study using the Premier Healthcare Database. The cohort included adult patients who underwent coronary artery bypass grafting or open valve repair or replacement (or in combination) from January 1, 2016, to June 30, 2018. Primary outcome was receipt of vasoactive medication(s) on the first postoperative day (POD1). We identified patient- and hospital-level factors associated with receipt of vasoactive medications using multilevel mixed-effects logistic regression modeling. We calculated adjusted median odds ratios to determine the extent to which receipt of vasoactive medications on POD1 was determined by each hospital, then calculated quotients of Akaike Information Criteria to compare the relative contributions of patient and hospital characteristics and individual hospitals with observed variation.Results: Among 104,963 adults in 294 hospitals, 95,992 (92.2%) received vasoactive medication(s) during hospitalization; 30,851 (29.7%) received treatment on POD1, most commonly norepinephrine (n = 11,427, 37.0%). A median of 29.0% (range, 0.0-94.4%) of patients in each hospital received vasoactive drug(s) on POD1. After adjustment, hospital of admission was associated with twofold increased odds of receipt of any vasoactive medication on POD1 (adjusted median odds ratio, 2.07; 95% confidence interval, 1.93-2.21). Admitting hospital contributed more to observed variation in POD1 vasoactive medication use than patient or hospital characteristics (quotients of Akaike Information Criteria 0.58, 0.44, and <0.001, respectively).Conclusions: Nearly all cardiac surgical patients receive vasoactive medications during hospitalization; however, only one-third receive treatment on POD1, with significant variability by institution. Further research is needed to understand the causes of variability across hospitals and whether these differences are associated with outcomes.

A Descriptive Study of Perioperative Hemodynamics in Open Cardiac Surgery Patients

OBJECTIVES

The purpose of the present study was to describe how the perioperative hemodynamic profile before and after cardiopulmonary bypass during cardiac surgery is influenced by age and to describe the association between postoperative hemodynamics and one-year mortality.

DESIGN

A retrospective registry-based study.

SETTING

University Hospital of Aarhus, Denmark.

PARTICIPANTS

The study comprised 6,595 patients undergoing elective on-pump cardiac surgery from 2006 to 2016.

MEASUREMENTS AND MAIN RESULTS

Perioperative hemodynamic values were derived from computerized anesthesia and intensive care reports, including mean arterial pressure, cardiac index, and oxygenation saturation from mixed venous blood in the pulmonary artery, during the perioperative period. Perioperative hemodynamic values were stratified according to age. Logistic regression was applied to predict the crude probability of death within one year from surgery according to hemodynamic values at six hours after surgery, stratified by age and use of inotropic agents, respectively. Lower values for cardiac index and mixed venous blood in the pulmonary artery with increasing age, across all points in time in the perioperative course, were observed. Higher probability of death was associated with lower hemodynamic values in the postoperative phase, and the probability of death was modified by age and the need for inotropic agents.

DISCUSSION

This is a large registry based study describing the perioperative hemodynamic profile of patients undergoing cardiac surgery and the results enhance our understanding of age-differentiated values of CI and SvO2 in this specific population.

Intraoperative milrinone versus dobutamine in cardiac surgery patients: a retrospective cohort study on mortality

Background

Several choices of inotropic therapy are available and used in relation to cardiac surgery. Comparisons are necessary to select optimal therapy. In Denmark, dobutamine and milrinone are the two inotropic agents most commonly used to treat post-bypass low cardiac output syndrome. This study compares all-cause mortality with these drugs.

Methods

In a retrospective observational study we investigated 10,700 consecutive patients undergoing cardiac surgery from 1 April 2006 to 31 December 2013 at Aarhus and Aalborg University Hospitals in the Central and Northern Denmark Region. Prospectively entered data in the Western Danish Heart Registry on intraoperative use of inotropes were used to identify 952 patients treated with milrinone, 418 patients treated with dobutamine, and 82 patients receiving a combination of the two inotropes. All-cause mortality among patients receiving dobutamine was compared to all-cause mortality among milrinone receivers.

Multiple logistic regression analyses including preoperative and intraoperative variables along with g-formula analyses were used to model 30-day and 1-year mortality risks. Reported were standardized mortality risk differences between the treatment groups.

Results

Among patients receiving intraoperative dobutamine, 18 (4.3%) died within 30 days and 49 (11.7%) within 1 year. Corresponding 30-day and 1-year mortality for milrinone receivers were 81 (8.5%) and 170 (17.9%). Risk of death within 30 days and 1 year was increased for intraoperative milrinone compared to dobutamine with a standardized risk difference of 4.06% (confidence interval (CI) 1.23; 6.89, p = 0.005) and 4.77% (CI 0.39; 9.15, p = 0.033), respectively. Sensitivity analyses including adjustment for milrinone preference, hemodynamic instability prior to cardiopulmonary bypass, and separate analyses on hospital level all confirmed a sign toward increased mortality among milrinone receivers.

Conclusions

Intraoperative use of milrinone in cardiac surgery may be associated with an increase in all-cause mortality compared to use of dobutamine.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-1969-1) contains supplementary material, which is available to authorized users.

Pharmacologic agents for acute hemodynamic instability: recent advances in the management of perioperative shock- a systematic review

Despite the growing body of evidence evaluating the efficacy of vasoactive agents in the management of hemodynamic instability and circulatory shock, it appears no agent is superior. This is becoming increasingly accepted as current guidelines are moving away from detailed algorithms for the management of shock, and instead succinctly state that vasoactive agents should be individualized and guided by invasive hemodynamic monitoring. This extends to the perioperative period, where vasoactive agent selection and use may still be left to the discretion of the treating physician with a goal-directed approach, consisting of close hemodynamic monitoring and administration of the lowest effective dose to achieve the hemodynamic goals. Successful therapy depends on the ability to rapidly diagnose the etiology of circulatory shock and thoroughly understand its pathophysiology as well as the pharmacology of vasoactive agents. This review focuses on the physiology and resuscitation goals in perioperative shock, as well as the pharmacology and recent advances in vasoactive agent use in its management.

Early levosimendan administration is associated with decreased mortality after cardiac surgery

PURPOSE

The aim of this study was to assess the effects on postoperative outcome of levosimendan with respect to timing of its administration in cardiac surgery patients.

MATERIALS AND METHODS

Levosimendan administration was triggered by a severely reduced left ventricular systolic function (left ventricular ejection fraction, <35%) and/or signs of a low cardiac output syndrome. A total of 159 patients were retrospectively assigned depending on an early (perioperatively up to the first hour after intensive care unit [ICU] admission) vs late (later than the first hour after ICU admission) start of treatment.

RESULTS

Patients receiving levosimendan after the first hour of ICU admission (n = 89) had a significantly increased inhospital (P = .004) and 1-year (P = .027) mortality. Duration of mechanical ventilation (P = .002), incidence of renal dysfunction (P = .002), and need of renal replacement therapy (P = .032) were significantly increased in the late start group. A late start of levosimendan treatment was associated with an odds ratio of 2.258 (95% confidence interval, 1.139-4.550; P = .021) for inhospital mortality and an adjusted hazard ratio of 1.827 (95% confidence interval, 1.155-2.890; P = .010) for 1-year survival.

CONCLUSIONS

Findings of this retrospective analysis favor an "early," that is, intraoperatively up to the first hour after ICU admission, start of perioperative levosimendan treatment to maximize its ability to reduce mortality and morbidity.

Health Outcomes with and without Use of Inotropic Therapy in Cardiac Surgery

Background:

Inotropes used to obtain short-term hemodynamic benefits in cardiac surgery may carry a risk of increased myocardial ischemia and adverse outcomes. This study investigated the association between intra- and postoperative use of inotropes and mortality and postoperative complications.

Methods:

A historic cohort study using prospective data from the Western Denmark Heart Registry on 6,005 consecutive cardiac surgery cases from three university hospitals. Propensity matching on pre- and intraoperative variables was used to identify a subgroup of patients receiving inotropic therapy (n = 1,170) versus comparable nonreceivers (n = 1,170) for outcome analysis.

Results:

Two thousand ninety-seven patients (35%) received inotropic therapy; 3,908 (65%) did not receive any inotropic or vasopressor support perioperatively. Among propensity-matched cohort including 2,340 patients 30-day mortality was 3.2% and 1-yr mortality was 7.6%. In the matched cohort, patients exposed to inotropes had a higher 30-day mortality (adjusted hazards ratio, 3.7; 95% CI, 2.1 to 6.5) as well as a higher 1-yr mortality rate (adjusted hazards ratio, 2.5; 95% CI, 1.8 to 3.5) compared with nonreceivers. Among propensity-matched, the following absolute events rates were observed: myocardial infarction 2.4%, stroke 2.8%, arrhythmia 35%, and renal replacement therapy 23.9%. Inotropic therapy was independently associated with postoperative myocardial infarction (adjusted odds ratio, 2.1; 95% CI, 1.4 to 3.0), stroke (adjusted odds ratio, 2.4; 95% CI, 1.4 to 4.3), and renal replacement therapy (adjusted odds ratio, 7.9; 95% CI, 3.8 to 16.4).

Conclusion:

Use of intra- and postoperative inotropes was associated with increased mortality and major postoperative morbidity.

Influence of levosimendan on organ dysfunction in patients with severely reduced left ventricular function undergoing cardiac surgery

OBJECTIVES

Levosimendan is an inotropic drug with organ-protective properties due to its activation of mitochondrial K(ATP) channels. This prospective, randomized, double-blind, placebo-controlled study investigated whether administration of levosimendan prior to cardiopulmonary bypass could reduce organ dysfunction and influence subsequent secondary endpoints.

PATIENTS AND METHODS

Patients with left ventricular ejection fraction <30% scheduled for elective coronary artery bypass surgery (with or without valve surgery) received either levosimendan (12.5 mg, 0.1 µg kg(-1) per min; n = 17) or placebo (n = 16) central venous infusion, immediately after anaesthesia induction, as add-on medication to a goal-orientated treatment algorithm.

RESULTS

A total of 33 patients completed the study. There were no statistically significant differences in Sequential Organ Failure Assessment scores, survival, haemodynamic parameters, time to extubation, time in intensive care unit, need for haemodialysis or health-related quality-of-life at 6 months post operation. The levosimendan group compared with the placebo group had significantly lower use of epinephrine (35% versus 81%) and nitroglycerine (6% versus 44%) 24 h postoperation, and significantly less frequent serious adverse events (13% versus 47%).

CONCLUSIONS

These preliminary results show that timely perioperative levosimendan treatment is feasible, has a favourable safety profile safe and may help to prevent low cardiac output syndrome. However, organ function was not preserved. Further studies, using larger sample sizes, are required.