Left ventricular function during sepsis

Association of sepsis-induced cardiomyopathy and mortality: a systematic review and meta-analysis

BACKGROUND

The implication of sepsis-induced cardiomyopathy (SIC) to prognosis is controversial, and its association with mortality at different stages remains unclear. We conducted a systematic review and meta-analysis to understand the association between SIC and mortality in septic patients.

METHODS

We searched and appraised observational studies regarding the mortality related to SIC among septic patients in PubMed and Embase from inception until 8 July 2021. Outcomes comprised in-hospital and 1-month mortality. We adopted the random-effects model to examine the mortality risk ratio in patients with and without SIC. Meta-regression, subgroup, and sensitivity analyses were applied to examine the outcome's heterogeneity.

RESULTS

Our results, including 20 studies and 4,410 septic patients, demonstrated that SIC was non-statistically associated with increased in-hospital mortality, compared to non-SIC (RR 1.28, [0.96-1.71]; p = 0.09), but the association was statistically significant in patients with the hospital stay lengths longer than 10 days (RR 1.40, [1.02-1.93]; p = 0.04). Besides, SIC was significantly associated with a higher risk of 1-month mortality (RR 1.47, [1.17-1.86]; p < 0.01). Among SIC patients, right ventricular dysfunction was significantly associated with increased 1-month mortality (RR 1.72, [1.27-2.34]; p < 0.01), while left ventricular dysfunction was not (RR 1.33, [0.87-2.02]; p = 0.18).

CONCLUSIONS

With higher in-hospital mortality in those hospitalized longer than 10 days and 1-month mortality, our findings imply that SIC might continue influencing the host's system even after recovery from cardiomyopathy. Besides, right ventricular dysfunction might play a crucial role in SIC-related mortality, and timely biventricular assessment is vital in managing septic patients.

Human immunodeficiency virus-associated heart failure in sub-Saharan Africa: evolution in the epidemiology, pathophysiology, and clinical manifestations in the antiretroviral era

The survival of patients with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) who have access to highly active antiretroviral therapy (ART) has dramatically increased in recent times. This review focuses on HIV‐associated heart failure in sub‐Saharan Africa (SSA). In HIV infected persons, heart failure may be related to pathology of the pericardium, the myocardium, the valves, the conduction system, or the coronary and pulmonary vasculature. HIV‐associated heart failure can be because of direct consequences of HIV infection, autoimmune reactions, pro‐inflammatory cytokines, opportunistic infections (OIs) or neoplasms, use of ART or therapy for OIs and presence of traditional cardiovascular risk factors. Myocardial involvement includes diastolic dysfunction, asymptomatic left ventricular dysfunction, cardiomyopathy, myocarditis, fibrosis, and steatosis. Pericardial diseases include pericarditis, pericardial effusions (rarely causing tamponade), pericardial constriction, and effusive‐constrictive syndromes. Coronary artery disease is commonly reported in industrial nations, although its prevalence is thought to be low in HIV‐infected persons from SSA.

Assessment of Myocardial Function in Children before and after Autologous Peripheral Blood Stem Cell Transplantation

BACKGROUND

Increased interest is focused on the long-term adverse effects of bone marrow transplantation. Subclinical cardiac involvement appears common in adults, but only a few reports have examined pediatric patients.

MATERIALS AND METHODS

A prospective case-control study of 19 children with normal cardiac function undergoing autologous hematopoietic stem cell transplantation (HSCT) was performed. Tissue Doppler imaging (TDI) and echocardiographic measurements were obtained according to the guidelines of the American Society of Echocardiography before and 3 months after HSCT.

RESULTS

Lateral mitral annulus before HSCT showed significant reduced mitral systolic annular velocity (P < 0.0001), early diastolic annular velocity (P < 0.0001), late diastolic annular velocity (P = 0.02) and prolonged isovolumetric relaxation time (IRT) (P < 0.0001) compared with control. Significant reduced mitral systolic annular velocity (P < 0.0001), early diastolic annular velocity (P = 0.0005) and Em/Am ratio (P = 0.004), with higher late diastolic annular velocity (P = 0.02) and prolonged isovolumetric contraction time (ICT) (P = 0.003) and IRT (P = 0.002) after HSCT, were observed. Investigation of lateral tricuspid annulus showed nearly similar results as the lateral mitral annulus. LV and RV Tei indices were higher before HSCT compared with control and remained high after HSCT.

CONCLUSION

TDI detected subtle abnormalities in systolic and diastolic functions before and after HSCT, which suggests that a conditioning regimen may affect cardiac function.

Prognostic value of echocardiographic and Doppler parameters in horses admitted for colic complicated by systemic inflammatory response syndrome

OBJECTIVE

To assess the prognostic value of echocardiographic parameters of left ventricular (LV) function in horses with systemic inflammatory response syndrome (SIRS).

DESIGN

Prospective observational study.

SETTING

Veterinary teaching hospital.

ANIMALS

Forty-one horses admitted for colic with clinical evidence of SIRS.

INTERVENTIONS

All horses underwent Doppler echocardiographic examination on admission. LV echocardiographic parameters, including pulsed-wave tissue Doppler imaging parameters, were compared between nonsurvivors (n = 29) and horses that survived to discharge (n = 12).

MEASUREMENTS AND MAIN RESULTS

With comparable heart rate and LV preload estimate, LV stroke volume index, the velocity time integral, deceleration time, ejection time of Doppler aortic flow, and peak early diastolic myocardial velocity were lower in the nonsurviving than in the surviving horses, while pre-ejection period to ejection time ratio (PEP/ET) of Doppler aortic flow and the peak early diastolic filling velocity to peak early diastolic myocardial velocity ratio (E/Em) were higher (P < 0.05). A cut-off value of 0.26 for PEP/ET predicted mortality with 100% sensitivity and 42% specificity (area under the receiver operating characteristic curve: 0.71), whereas a cut-off value of 2.67 for E/Em predicted mortality with 100% sensitivity and 83% specificity (area under the receiver operating characteristic curve: 0.89).

CONCLUSIONS

Echocardiography may provide prognostic information in colic horses with clinical evidence of SIRS. Especially, PEP/ET and E/Em could be useful markers of systolic and diastolic dysfunction, respectively, to detect horses with a high risk of death requiring more intensive cardiovascular monitoring as it has been reported in human patients with septic shock.

Cardiac assessment of patients for haematopoietic stem cell transplantation

The expanding role of haematopoietic stem-cell transplantation (HSCT) renders the previous policy of avoiding transplantation in high-risk cardiac patients obsolete. Patients with amyloid, autoimmune conditions, sickle-cell disease, or thalassaemia, and patients over the age of 60 years are increasingly being offered HSCT. It is evident that the policy of avoiding transplantation in patients with impaired systolic function fails to identify all high-risk patients in such groups, and will deprive some patients of the benefits of HSCT unnecessarily. The development of an appropriate algorithm for cardiac pre-assessment and peri-transplant management is hampered by an inadequate understanding of the predictive value of various tests of cardiovascular function, the rapid evolution of advanced management strategies for cardiac dysfunction, and the development of non-cardiotoxic conditioning regimens. To meet this need we propose that an algorithm based on evidence from other clinical situations - already been found to be successful in the management of HSCT in patients with systemic sclerosis - should be used uniformly, and registry studies should be undertaken to distinguish those aspects of the algorithm that positively help to expand the remit of HSCT from those that add little of value.

LEFT VENTRICULAR DIASTOLIC FILLING CHARACTERISTICS ARE NOT IMPAIRED BUT SYSTOLIC PERFORMANCE WAS AUGMENTED IN THE EARLY HOURS OF EXPERIMENTAL ENDOTOXEMIA IN HUMANS

This study was performed to determine whether endotoxemia causes diastolic cardiac dysfunction. Eleven healthy volunteers, 30 +/- 6 years of age, underwent comprehensive transthoracic echocardiographic assessment including two-dimensional, M-mode transmitral and tissue Doppler of systolic and diastolic function at baseline and at 3 and 5 h after intravenous administration of purified Escherichia coli endotoxin (4 ng/kg). Data were analyzed by analysis of variance; P values of less than 0.05 were considered significant. Endotoxin administration resulted in a hyperdynamic state characterized by decreased mean arterial pressure and significant increase in cardiac index. This was accompanied by increases in several load-dependent systolic performance indices (3 and 5 h). Robust increases in peak systolic blood pressure/end-systolic volume index, one of the relatively load-independent contractility parameter, were also observed at 3 h after endotoxin administration. Transmitral peak early velocity (E), which represents early filling, significantly increased at 3 h after infusion. Late diastolic velocity (A), which represents atrial contraction, significantly increased at 3 and 5 h after infusion. The E/A ratio indicative of delayed relaxation significantly decreased due to increases in A (transmitral) and A (tissue Doppler) at 3 and 5 h after infusion. As expected, endotoxin infusion resulted in a hyperdynamic state associated with increases in systolic function indices including endocardial systolic velocities. The observed decreases in E/A (transmitral) and E/A (tissue Doppler) ratio were primarily due to increases in A and A. Moreover, isovolumic relaxation time and time constant for left ventricular relaxation, a load-independent parameter for ventricular relaxation, remained unchanged at 3 and 5 h after endotoxin infusion. Therefore, our findings are more likely due to enhanced atrial contractility resulting from increased sympathetic activity in response to reduction in left ventricular afterload and not due to altered diastolic filling characteristics.

Impact of Human Immunodeficiency Virus Infection on Cardiovascular Disease in Africa

Background— Human immunodeficiency virus (HIV) infection is the single greatest health challenge facing Africa today. However, the impact of the HIV epidemic on the cardiovascular system in Africans has received scant attention in the world literature.

Methods and Results— We searched MEDLINE (January 1, 1980, to December 31, 2004) and reference lists of literature on HIV and the heart in Africa and contacted experts in the field. The search for this review yielded 22 articles involving HIV and the cardiovascular system from 8 countries in Africa.

Conclusions— The available information suggests that there are unique features in the etiology, presentation, and spectrum of HIV-associated cardiovascular disorders in people living in Africa. First, pericardial disease may be the initial manifestation of HIV infection in the early stages of the illness. Second, the etiology of cardiac disease tends to reflect the prevalent infectious diseases, such as tuberculosis. Third, unique cardiovascular disorders such as aneurysm of large vessels have been reported in association with HIV infection in several parts of Africa. Finally, the HIV/AIDS pandemic has put pressure on the meager healthcare resources and fragile infrastructure in many African countries, making the diagnosis and treatment of heart disease unrelated to HIV even more difficult.

CARDIAC TROPONIN I LEVELS ARE A RISK FACTOR FOR MORTALITY AND MULTIPLE ORGAN FAILURE IN NONCARDIAC CRITICALLY ILL PATIENTS AND HAVE AN ADDITIVE EFFECT TO THE APACHE II SCORE IN OUTCOME PREDICTION

Cardiac troponin I (cTnI) is a specific marker of myocardial damage used in the diagnosis of acute coronary syndrome (ACS). Recent studies have shown that cTnI levels can also be elevated in patients without ACS, such as in sepsis and trauma patients, and that this is associated with an adverse prognosis. We have evaluated the clinical implications and prognostic significance of serum cTnI levels in noncardiac critically ill patients in a prospective observational study in a general medical intensive care unit at a tertiary-level hospital. A total of 108 consecutive patients without ACS or other cardiac disease was enrolled. Serum cTnI levels were measured on admission using enzyme-linked immunoabsorbant assay kits. Clinical laboratory parameters and outcome were compared between patients with elevated and normal cTnI levels. The prognostic significance of cTnI levels and the Acute Physiology And Chronic Health Evaluation (APACHE) II score was also analyzed. Forty-nine patients (45%) had elevated cTnI levels and 59 (55%) had normal levels. Compared with patients with normal cTnI levels, patients with elevated levels had a higher incidence of new failure of two or more organs, had a lower left ventricular ejection fraction during admission, were more likely to be associated with bacteremia, and had a higher intensive care unit mortality; they also had a significantly shorter survival over a 180-day follow up, before and after stratification by the APACHE II score. Multiple organ failure was the leading cause of mortality in patients with elevated cTnI levels. By multivariate analysis, elevated cTnI levels, a high APACHE II score, and underlying cancer were the three most important independent predictors for a shorter survival. Combination analysis showed a shorter survival in patients with a high APACHE II score plus elevated cTnI levels than in patients with a high APACHE II score or elevated cTnI levels alone. In conclusion, elevated serum cTnI levels is a risk factor for multiple organ failure and mortality in noncardiac critically ill patients, and the cTnI levels and APACHE II score have an additive effect in outcome prediction.

Effects of intraaortic balloon augmentation in a porcine model of endotoxemic shock

OBJECTIVE

Patients with septic shock commonly have myocardial dysfunction associated with lactic acid production and troponin I release. The purpose of this study was to evaluate the effects on intraaortic balloon pump (IABP) support on myocardial dysfunction.

DESIGN

Prospective, randomized controlled study.

SETTING

Animal research laboratory.

METHODS

Ten pigs had arterial, pulmonary arterial, and coronary catheters inserted. After receiving endotoxin infusion over 30 min, half the animals received IABP support.

RESULTS

Coronary sinus lactic acid levels (P< 0.05 for both 90 min versus baseline and 60 min versus baseline) and arterial lactic acid levels (P < 0.05 for both 90 min versus baseline and 60 min versus baseline) increased with time but did not differ between IABP and sham groups. While overall there was no difference with time in myocardial lactic acid consumption or production (calculated as arterial lactic acid level minus coronary sinus lactic acid level), the IABP group showed net myocardial lactic acid consumption at 90 min, while the sham group showed myocardial lactic acid production. Three of five animals in each group showed troponin I release. The levels were similar and did not differ between groups.

CONCLUSION

IABP had no benefits in this porcine model of endotoxemic shock.

Association between hypophosphatemia and cardiac arrhythmias in the early stages of sepsis

BACKGROUND: The purpose of this study was to evaluate a possible association between serum phosphate levels and the incidence of cardiac arrhythmias in the early stages of sepsis. METHODS: We conducted a prospective, controlled study in the General Intensive Care Unit (GICU) of a university hospital. Sixteen patients with sepsis, but without any previous cardiac disease, were studied during their first 24 h in the GICU. Patients were connected to a continuous ECG recording device. Blood samples for serum phosphate level determinations were drawn during the first 6 h after admission to the unit. RESULTS: Ten of 16 patients had 21 episodes of atrial and ventricular arrhythmias. These patients had higher mean Apache II scores (20.2+/-6.2) than the six patients without arrhythmias (13.2+/-1.7; P<0.05) and significantly lower mean phosphate levels (0.73+/-0.16 vs. 1.02+/-0.32 mmol/l; P<0.03). No association was found between serum phosphate levels and mortality among patients with arrhythmias, or when all survivors (with and without arrhythmia) were compared to all non-survivors. CONCLUSIONS: The results indicate that patients with sepsis and low serum phosphate levels are at a greater risk of developing cardiac arrhythmias. We suggest that phosphate supplementation in the early stages of sepsis may prevent cardiac arrhythmias.

Myocardial dysfunction in septic shock

Over the last decade, it has become clear that myocardial depression, like vascular dysfunction, is typical of human septic shock. Human septic myocardial depression is characterized by reversible biventricular dilatation, decreased ejection fraction, and decreased response to fluid resuscitation and catecholamine stimulation (in the presence of overall hyperdynamic circulation). A circulating myocardial depressant substance, not myocardial hypoperfusion, is responsible for this phenomenon. This substance has been shown to represent low concentrations of TNF-alpha and IL-1 beta acting in synergy on the myocardium through mechanisms that include NO and cGMP generation. Despite major advances in our understanding of the hemodynamics and pathogenesis of cardiac dysfunction in sepsis, successful attempts to modulate these mechanisms to improve clinical outcomes in human trials have not been demonstrated to date. For the moment, the therapeutic approach to the patient with cardiac dysfunction in distributive or septic shock must be primarily aimed at reestablishing adequate organ perfusion and oxygen delivery by vigorous fluid resuscitation and vasopressor or inotropic support. In the long term, however, only continued research regarding the cellular mechanisms of organ dysfunction, including septic myocardial depression, will lead to successful therapeutic strategies. These strategies will likely involve direct manipulation of intracellular signaling processes that lead to organ dysfunction as manifested by septic myocardial dysfunction and septic shock.

Serum cardiac troponin T as a prognostic marker in early sepsis

STUDY OBJECTIVE

Sepsis is the leading cause of death in the noncardiologic ICU. Maldistributed nutritive blood flow and altered convective and diffusive oxygen transport during sepsis can lead to organ dysfunction and multiple organ failure. One of the causes of myocardial dysfunction is thought to be myocardial ischemia in sepsis; however, conventional biochemical parameters to detect myocardial ischemia lack sensitivity and specificity. Serum cardiac troponin T (S-TnT) was reported to have higher sensitivity and specificity in diagnosing minor myocardial injury. The aim of this study was to investigate if and how often S-TnT is pathologically elevated in patients with sepsis and to evaluate whether S-TnT might be a prognostic marker in early sepsis.

DESIGN

Prospective study.

SETTING

Surgical ICU.

PATIENTS

Twenty-six patients with sepsis were included in this study within 24 h of the onset of sepsis. The patients were allocated a priori to a high S-TnT group (S-TnT > or = 0.2 microg/L) and a low S-TnT group (S-TnT<0.2 microg/L).

MEASUREMENT

Blood samples for the determination of S-TnT and conventional myocardial ischemia markers as well as for adhesion molecules were drawn. Hemodynamic measurements were performed every 4 h during the first 24 h and then once per day over 7 days. S-TnT was determined by enzyme-linked immunosorbent sandwich assay.

RESULTS

Eighteen patients had pathologically high S-TnT values. High S-TnT values were associated with an increased mortality rate (15/18 in the high S-TnT group vs 3/8 in the low S-TnT group; p=0.02). Significant differences between the two groups were found in the norepinephrine dosages at maximum values of S-TnT. Soluble intercellular adhesion molecule-1 was significantly elevated in the high S-TnT group.

CONCLUSIONS

As high S-TnT values were associated with an increased mortality rate, it seems reasonable to further evaluate S-TnT as a prognostic marker of myocardial ischemia in patients with sepsis under different therapeutic regimens.

Cardiac dysfunction during septic shock

Cardiac dysfunction is common in sepsis and septic shock. An understanding of this pathophysiology is crucial in treatment of this disorder. This article reviews the numerous studies of septic shock in humans that focus on cardiovascular physiology, briefly addresses the possible etiology, and concludes with therapeutic implications.

Cardiovascular parameters and scoring systems in the evaluation of response to therapy in sepsis and septic shock

In 47 medical and postoperative ICU patients with 57 episodes of sepsis and septic shock, cardiovascular parameters including systemic vascular resistance (SVR), cardiac index (CI), stroke volume index (SVI), left ventricular stroke work index (LVSWI) as well as six scoring systems (APACHE II, Elebute, Goris, HIS, SAPS and SSS) were studied regarding their usefulness in the assessment of disease progression and evaluation of response to supplemental sepsis therapy (immunoglobulins, plasmapheresis). Among the hemodynamic parameters, only a prompt SVR improvement significantly discriminated between ultimate survivors and nonsurvivors. Thus, an increase in SVR (greater than 160 dyn*cm-5*sec, within days 0 to 4, persisting for greater than 24 hours) can serve as a prognostically validated "response" criterion (responders/non-responders: 26/31; mortality: 27% vs. 77%). Non-invasively, the APACHE II score was best suited (specificity: 88%, sensitivity: 67%) to classify hemodynamically defined responders to supplemental sepsis treatment (score-reduction greater than or equal to 4 on day 4 after onset of therapy).