Dopamine in critically ill patients with cardiac dysfunction: A systematic review with meta-analysis and trial sequential analysis

Role of Dopamine in the Heart in Health and Disease

Dopamine has effects on the mammalian heart. These effects can include an increase in the force of contraction, and an elevation of the beating rate and the constriction of coronary arteries. Depending on the species studied, positive inotropic effects were strong, very modest, or absent, or even negative inotropic effects occurred. We can discern five dopamine receptors. In addition, the signal transduction by dopamine receptors and the regulation of the expression of cardiac dopamine receptors will be of interest to us, because this might be a tempting area of drug development. Dopamine acts in a species-dependent fashion on these cardiac dopamine receptors, but also on cardiac adrenergic receptors. We will discuss the utility of drugs that are currently available as tools to understand cardiac dopamine receptors. The molecule dopamine itself is present in the mammalian heart. Therefore, cardiac dopamine might act as an autocrine or paracrine compound in the mammalian heart. Dopamine itself might cause cardiac diseases. Moreover, the cardiac function of dopamine and the expression of dopamine receptors in the heart can be altered in diseases such as sepsis. Various drugs for cardiac and non-cardiac diseases are currently in the clinic that are, at least in part, agonists or antagonists at dopamine receptors. We define the research needs in order to understand dopamine receptors in the heart better. All in all, an update on the role of dopamine receptors in the human heart appears to be clinically relevant, and is thus presented here.

Dopamine receptor 3: A mystery at the heart of cardiac fibrosis

Dopamine receptors have been extensively studied in the mammalian brain and spinal cord, as dopamine is a vital determinant of bodily movement, cognition, and overall behavior. Thus, dopamine receptor antagonist antipsychotic drugs are commonly used to treat multiple psychiatric disorders. Although less discussed, these receptors are also expressed in other peripheral organ systems, such as the kidneys, eyes, gastrointestinal tract, and cardiac tissue. Consequently, therapies for certain psychiatric disorders which target dopamine receptors could have unidentified consequences on certain functions of these peripheral tissues. The existence of an intrinsic dopaminergic system in the human heart remains controversial and debated within the literature. Therefore, this review focuses on literature related to dopamine receptors within cardiac tissue, specifically dopamine receptor 3 (D3R), and summarizes the current state of knowledge while highlighting areas of research which may be lacking. Additionally, recent findings regarding crosstalk between D3R and dopamine receptor 1 (D1R) are examined. This review discusses the novel concept of understanding the role of the loss of function of D3R may play in collagen accumulation and cardiac fibrosis, eventually leading to heart failure.

Dopamine use and its consequences in the intensive care unit: a cohort study utilizing the Japanese Intensive care PAtient Database

Background

Dopamine is used to treat patients with shock in intensive care units (ICU) throughout the world, despite recent evidence against its use. The aim of this study was to identify the latest practice of dopamine use in Japan and also to explore the consequences of dopamine use in a large Asian population.

Methods

The Japanese Intensive Care PAtient Database (JIPAD), the largest intensive care database in Japan, was utilized. Inclusion criteria included: 1) age 18 years or older, 2) admitted to the ICU for reasons other than procedures, 3) ICU length of stay of 24 h or more, and 4) treatment with either dopamine or noradrenaline within 24 h of admission. The primary outcome was in-hospital mortality. Multivariable regression analysis was performed, followed by a propensity score-matched analysis.

Results

Of the 132,354 case records, 14,594 records from 56 facilities were included in this analysis. Dopamine was administered to 4,653 patients and noradrenaline to 11,844. There was no statistically significant difference in facility characteristics between frequent dopamine users (N = 28) and infrequent users (N = 28). Patients receiving dopamine had more cardiovascular diagnosis codes (70% vs. 42%; p < 0.01), more post-elective surgery status (60% vs. 31%), and lower APACHE III scores compared to patients given noradrenaline alone (70.7 vs. 83.0; p < 0.01). Multivariable analysis showed an odds ratio for in-hospital mortality of 0.86 [95% CI: 0.71–1.04] in the dopamine ≤ 5 μg/kg/min group, 1.46 [95% CI: 1.18–1.82] in the 5–15 μg/kg/min group, and 3.30 [95% CI: 1.19–9.19] in the > 15 μg/kg/min group. In a 1:1 propensity score matching for dopamine use as a vasopressor (570 pairs), both in-hospital mortality and ICU mortality were significantly higher in the dopamine group compared to no dopamine group (22.5% vs. 17.4%, p = 0.038; 13.3% vs. 8.8%, p = 0.018), as well as ICU length of stay (mean 9.3 days vs. 7.4 days, p = 0.004).

Conclusion

Dopamine is still widely used in Japan. The results of this study suggest detrimental effects of dopamine use specifically at a high dose.

Trial registration Retrospectively registered upon approval of the Institutional Review Board and the administration office of JIPAD.

Vasopressor and inotrope treatment for septic shock: An umbrella review of reviews

PURPOSE

To review the characteristics, findings and quality of systematic reviews (SRs) on the effect of any vasopressor/inotrope on outcomes in adult patients with sepsis compared with either no treatment, another vasopressor or inotrope or fluids.

MATERIALS AND METHODS

We systematically searched Cochrane Central Register of Controlled Trials, PubMed and Embase (January 1993-March 2021). Descriptive statistics were used.

RESULTS

Among the 28 SRs identified, mortality was the primary outcome in most (26/28) and mortality was usually (23/28) studied using randomised controlled trials (RCTs). Fifteen SRs focused exclusively on patients with sepsis or septic shock. Sepsis and septic shock were always grouped for the analysis. Publication bias was consistently low when studied. The most consistent findings were a survival advantage with norepinephrine versus dopamine, which disappeared in analyses restricted to 28-day mortality, and more arrhythmias with dopamine. However, these analyses were dominated by a single study. Only 2 SRs were judged to be of moderate-high quality. Lack of blinding and attrition bias may have affected the outcomes.

CONCLUSIONS

The quality of SRs on the effect of vasopressors/inotropes on the outcomes of adult patients with sepsis can be improved, but high-quality, multicenter, RCTs should be preferred to additional SRs on this topic.

Dopamine D1 receptor alleviates doxorubicin-induced cardiac injury by inhibiting NLRP3 inflammasome

Doxorubicin (DOX) is a broad-spectrum antineoplastic drug; however, its serious cardiotoxic side effects in inflammatory responses limit its use in clinical applications. Dopamine D1 receptor (DRD1), a G protein-coupled receptor, is crucial for the development and function of the nervous system; additionally, it also play a role in immune regulation. However, the specific role of DRD1 in DOX-induced cardiac inflammation has not yet been clarified. Here, we discovered that DRD1 expression was induced by DOX treatment in H9C2 cardiomyocytes. DRD1 activation by A-68930, a DRD1-specific agonist, decreased DOX-induced nucleotide-binding domain-like receptor protein 3 (NLRP3) expression, caspase-1 activation, and IL-1β maturation in H9C2 cells. Expression of the cytokines IL-1β and IL-18 in the supernatants was also inhibited by A-68930 treatment. DRD1 knockdown, using siRNA, abolished the effects of A-68930 on the DOX-induced NLRP3 inflammasome. Furthermore, we found that DRD1 signaling downregulated the NLRP3 inflammasome in H9C2 cells through cyclic adenosine monophosphate (cAMP). Moreover, application of A-68930 to activate DRD1 reduced cardiac injury and fibrosis in a DOX-treated mouse model by suppressing the NLRP3 inflammasome in the heart. These findings indicate that DRD1 signaling may protect against DOX-induced cardiac injury by inhibiting the NLRP3 inflammasome-mediated inflammation.

Sepsis With Preexisting Heart Failure: Management of Confounding Clinical Features

Preexisting heart failure (HF) in patients with sepsis is associated with worse clinical outcomes. Core sepsis management includes aggressive volume resuscitation followed by vasopressors (and potentially inotropes) if fluid is inadequate to restore perfusion; however, large fluid boluses and vasoactive agents are concerning amid the cardiac dysfunction of HF. This review summarizes evidence regarding the influence of HF on sepsis clinical outcomes, pathophysiologic concerns, resuscitation targets, hemodynamic interventions, and adjunct management (ie, antiarrhythmics, positive pressure ventilatory support, and renal replacement therapy) in patients with sepsis and preexisting HF. Patients with sepsis and preexisting HF receive less fluid during resuscitation; however, evidence suggests traditional fluid resuscitation targets do not increase the risk of adverse events in HF patients with sepsis and likely improve outcomes. Norepinephrine remains the most well-supported vasopressor for patients with sepsis with preexisting HF, while dopamine may induce more cardiac adverse events. Dobutamine should be used cautiously given its generally detrimental effects but may have an application when combined with norepinephrine in patients with low cardiac output. Management of chronic HF medications warrants careful consideration for continuation or discontinuation upon development of sepsis, and β-blockers may be appropriate to continue in the absence of acute hemodynamic decompensation. Optimal management of atrial fibrillation may include β-blockers after acute hemodynamic stabilization as they have also shown independent benefits in sepsis. Positive pressure ventilatory support and renal replacement must be carefully monitored for effects on cardiac function when HF is present.

Dopamine outside the brain: The eye, cardiovascular system and endocrine pancreas

Dopamine (DA) and DA receptors (DR) have been extensively studied in the central nervous system (CNS), but their role in the periphery is still poorly understood. Here we summarize data on DA and DRs in the eye, cardiovascular system and endocrine pancreas, three districts where DA and DA-related drugs have been studied and the expression of DR documented. In the eye, DA modulates ciliary blood flow and aqueous production, which impacts on intraocular pressure and glaucoma. In the cardiovascular system, DA increases blood pressure and heart activity, mostly through a stimulation of adrenoceptors, and induces vasodilatation in the renal circulation, possibly through D1R stimulation. In pancreatic islets, beta cells store DA and co-release it with insulin. D1R is mainly expressed in beta cells, where it stimulates insulin release, while D2R is expressed in both beta and delta cells (in the latter at higher level), where it inhibits, respectively, insulin and somatostatin release. The formation of D2R-somatostatin receptor 5 heteromers (documented in the CNS), might add complexity to the system. DA may exert both direct autocrine effects on beta cells, and indirect paracrine effects through delta cells and somatostatin. Bromocriptine, an FDA approved drug for diabetes, endowed with both D1R (antagonistic) and D2R (agonistic) actions, may exert complex effects, resulting from the integration of direct effects on beta cells and paracrine effects from delta cells. A full comprehension of peripheral DA signaling deserves further studies that may generate innovative therapeutic drugs to manage conditions such as glaucoma, cardiovascular diseases and diabetes.

Dopamine in critically ill patients with cardiac dysfunction: A systematic review with meta-analysis and trial sequential analysis

Background

Dopamine has been used in patients with cardiac dysfunction for more than five decades. Yet, no systematic review has assessed the effects of dopamine in critically ill patients with cardiac dysfunction.

Methods

This systematic review was conducted following The Cochrane Handbook for Systematic Reviews of Interventions. We searched for trials including patients with observed cardiac dysfunction published until 19 April 2018. Risk of bias was evaluated and Trial Sequential Analyses were conducted. The primary outcome was all‐cause mortality at longest follow‐up. Secondary outcomes were serious adverse events, myocardial infarction, arrhythmias, and renal replacement therapy. We used GRADE to assess the certainty of the evidence.

Results

We identified 17 trials randomising 1218 participants. All trials were at high risk of bias and only one trial used placebo. Dopamine compared with any control treatment was not significantly associated with relative risk of mortality (60/457 [13%] vs 90/581 [15%]; RR 0.91; 95% confidence interval 0.68‐1.21) or any other patient‐centred outcomes. Trial Sequential Analyses of all outcomes showed that there was insufficient information to confirm or reject our anticipated intervention effects. There were also no statistically significant associations for any of the outcomes in subgroup analyses by type of comparator (inactive compared to potentially active), dopamine dose (low compared to moderate dose), or setting (cardiac surgery compared to heart failure).

Conclusion

Evidence for dopamine in critically ill patients with cardiac dysfunction is sparse, of low quality, and inconclusive. The use of dopamine for cardiac dysfunction can neither be recommended nor refuted.

Current use of vasopressors in septic shock

Background

Vasopressors are commonly applied to restore and maintain blood pressure in patients with sepsis. We aimed to evaluate the current practice and therapeutic goals regarding vasopressor use in septic shock as a basis for future studies and to provide some recommendations on their use.

Methods

From November 2016 to April 2017, an anonymous web-based survey on the use of vasoactive drugs was accessible to members of the European Society of Intensive Care Medicine (ESICM). A total of 17 questions focused on the profile of respondents, triggering factors, first choice agent, dosing, timing, targets, additional treatments, and effects of vasopressors. We investigated whether the answers complied with current guidelines. In addition, a group of 34 international ESICM experts was asked to formulate recommendations for the use of vasopressors based on 6 questions with sub-questions (total 14).

Results

A total of 839 physicians from 82 countries (65% main specialty/activity intensive care) responded. The main trigger for vasopressor use was an insufficient mean arterial pressure (MAP) response to initial fluid resuscitation (83%). The first-line vasopressor was norepinephrine (97%), targeting predominantly a MAP > 60–65 mmHg (70%), with higher targets in patients with chronic arterial hypertension (79%). The experts agreed on 10 recommendations, 9 of which were based on unanimous or strong (≥ 80%) agreement. They recommended not to delay vasopressor treatment until fluid resuscitation is completed but rather to start with norepinephrine early to achieve a target MAP of ≥ 65 mmHg.

Conclusion

Reported vasopressor use in septic shock is compliant with contemporary guidelines. Future studies should focus on individualized treatment targets including earlier use of vasopressors.