Metabolic and nutritional support in acute cardiac failure

The prognostic value of modified NUTRIC score for patients in cardiothoracic surgery recovery unit: A retrospective cohort study

BACKGROUND

Malnutrition is highly prevalent in critically ill patients. The modified Nutrition Risk in the Critically ill (mNUTRIC) score has been introduced to evaluate the nutritional risk of patients in an intensive care unit (ICU). The mNUTRIC score is a predictive factor of mortality for patients in a medical or mixed ICU, whereas the relationship between mNUTRIC and prognosis of patients in a cardiothoracic surgery recovery unit (CSRU) is unclear and related researches are limited.

METHODS

We conducted this retrospective cohort study to explore the value of mNUTRIC score in CSRU patients. We identified totally 4059 patients from the Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC III) database.

RESULTS

The optimal cut-off value of mNUTRIC score was 4 and a total of 1498 (36.9%) patients were considered to be at high nutritional risk (mNUTRIC ≥ 4). A multivariate logistic regression model indicated that patients at high nutritional risk have higher hospital mortality compared to those at low nutritional risk (odds ratio = 2.49, 95% confidence interval (CI) = 1.32-4.70, p = 0.005]. Furthermore, a Cox regression model was established adjusted for age, white blood cell and body mass index. The Kaplan-Meier curve indicated that patients at high nutritional risk have poorer 365-days [hazard ratio (HR) = 1.76, 95% CI = 1.30-2.37, p < 0.001] and 1000-days (HR = 2.30, 95% CI = 1.87-2.83, p < 0.001) overall survival.

CONCLUSIONS

The mNUTRIC score could not only predict hospital mortality, but also be an independent prognostic factor for long-term survival in CSRU patients. More well-designed clinical trials are needed to verify and update our findings.

Prognostic Impact of the Geriatric Nutritional Risk Index on Long-Term Outcomes in Patients Who Underwent Percutaneous Coronary Intervention

Malnutrition has been identified as an important predictor of poor clinical outcomes in patients with heart failure. The aim of this study is to examine the prognostic impact of nutritional status in patients with coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI). The impact of nutrition, assessed using the geriatric nutritional risk index (GNRI) calculated by serum albumin and body mass index, was evaluated in 2,853 patients with CAD who underwent their first PCI between 2000 and 2011. Patients were assigned to tertiles based on their GNRI levels. The incidences of all-cause death and cardiac death were assessed. The median GNRI values were 101 (interquartile range 95 to 106). Lower GNRI levels were associated with older age and higher prevalence of acute coronary syndrome and chronic kidney disease. During the median follow-up period of 7.4 years, Kaplan-Meier curves showed ongoing divergence in rates of mortality among tertiles (GNRI <98: 35.1%; 98 to 104: 20.6%; ≥104: 12.1%; log-rank p <0.0001). Stratification analysis by age also showed that the lowest GNRI tertile was associated with mortality in both patients <65 years and those ≥65 years. After adjusting for established cardiovascular risk factors, lower GNRI was an independent predictor of all-cause death (hazard ratio 1.55 per 10 decrease, 95% confidence interval 1.30 to 1.84, p <0.0001) and cardiac death (hazard ratio 1.44, 95% confidence interval 1.08 to 1.90, p = 0.01). In conclusion, nutritional status was associated with long-term clinical outcomes in CAD patients after PCI. Evaluation of GNRI carries important prognostic information and may guide the therapeutic approach to such patients.

Risk stratification based on nutritional screening on admission: Three-year clinical outcomes in hospitalized patients with acute heart failure syndrome

BACKGROUND

Several blood tests are commonly used to assess nutritional status, including serum albumin levels (SAL) and lymphocyte counts (LC). The aim of this study is to investigate whether nutritional screening on admission can be used to determine risk levels for adverse clinical events in acute heart failure syndrome (AHFS) patients.

METHODS

In 432 consecutive AHFS patients, we measured SAL and LC and prospectively followed the patients for their combined clinical events (all-cause death and re-hospitalization for heart failure) for three years from admission. The classification and regression tree (CART) tool identified the cut-off criteria for SAL and LC to differentiate among patients with different risks of clinical events as 3.5g/dl and 963/mm³, respectively.

RESULTS

The CART tool classified 15.5% patients as high risk, 15.7% as intermediate risk, and 68.8% as low risk. The CART for nutritional status (CART-NS) values were strongly correlated with combined clinical events [hazard ratio of 2.13 (low vs high risk), 95% confidence interval of 1.42-3.16, p<0.001], even after adjusting for plasma brain natriuretic peptide levels. The CART-NS analysis improved the specificity (89.5%) of predictions of clinical outcomes with the comparable sensitivity (36.3%) compared with the use of a single criterion (SAL <3.5g/dl: 70.2, 42.4% or LC <963/mm³: 73.4, 41.7%, respectively).

CONCLUSION

A substantial proportion of AHFS patients are at risk of malnutrition, and this risk is associated with poor clinical outcomes. We demonstrate that this algorithm for nutritional screening, even in emergency clinical settings, can determine risk levels for further adverse events in AHFS patients.

Are brain and heart tissue prone to the development of thiamine deficiency?

Thiamine deficiency is a continuing problem leading to beriberi and Wernicke's encephalopathy. The symptoms of thiamine deficiency develop in the heart, brain and neuronal tissue. Yet, it is unclear how rapid thiamine deficiency develops and which organs are prone to development of thiamine deficiency. We investigated these issues in a thiamine deficient animal model. Twenty-four male Lewis rats were fed a thiamine deficient diet, which contained 0.04% of normal thiamine intake. Six control rats were fed 200 μg of thiamine per day. Every week a group of six rats on the thiamine-deficient diet was sacrificed and blood, urine and tissue were stored. Blood and tissue transketolase activity, thiamine and thiamine metabolites were measured and PCR of thiamine transporter-1 (ThTr-1) was performed. Transketolase activity was significantly reduced in red blood cells, liver, lung, kidney and spleen tissue after two weeks of thiamine deficient diet. In brain tissue, transketolase activity was not reduced after up to four weeks of thiamine deficient diet. The amount of thiamine pyrophosphate was also significantly conserved in brain and heart tissue (decrease of 31% and 28% respectively), compared to other tissues (decrease of ~70%) after four weeks of thiamine deficient diet. There was no difference between tissues in ThTr-1 expression after four weeks of thiamine deficient diet. Despite the fact that the heart and the brain are predilection sites for complications from thiamine deficiency, these tissues are protected against thiamine deficiency. Other organs could be suffering from thiamine deficiency without resulting in clinical signs of classic thiamine deficiency in beriberi and Wernicke's encephalopathy.

Nutrition intervention in the critically ill cardiothoracic patient

Despite acute myocardial infarction and cardiac surgery accounting for 2 of the most common reasons patients are admitted to the intensive care unit, little attention and investigation have been directed specifically for these patients. This patient population therefore deserves special attention as they are often malnourished but require emergent interventions, making nutrition intervention challenging. This article reviews current medical interventions implemented in critically ill cardiothoracic patients and discusses evidence-based nutrition therapy, including enteral and parenteral feeding, glycemic control, and antioxidant provision.

Nutrition and heart failure: impact of drug therapies and management strategies

Nutrition impairment commonly occurs in patients with heart failure and affects disease progression. Vitamin and mineral deficiencies are associated with early mortality, particularly in patients classified as cachectic. Guideline-based therapies approved for heart failure, such as loop diuretics, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, aldosterone antagonists, and beta-adrenergic blockers, can lead to electrolyte abnormalities and predispose to some vitamin and micronutrient deficits. Clinical trial evidence in support of supplementary vitamin and mineral therapies for heart failure patients is limited with the exception of documented calcium and possibly vitamin D, thiamine, and coenzyme Q10 deficiencies. This area is gaining significant attention, and research is ongoing. The clinician can help minimize morbidity from nutrition impairment through appropriate monitoring and correction of baseline and medication-induced electrolyte imbalances, in addition to vitamin and mineral supplementation when appropriate.

Enteral nutrition in the cardiothoracic intensive care unit: challenges and considerations

Cardiovascular disease is a common preexisting condition among hospitalized patients. Acute myocardial infarction and cardiac surgery account for 2 of the most common reasons patients are admitted to the intensive care unit. Determining how and when to feed these patients is a constant challenge presented to nutrition support practitioners. Enteral nutrition has emerged as the preferred route of feeding particularly in critical illness. By providing enteral nutrition instead of parenteral nutrition, the natural physiologic pathway is being followed and gut immunity preserved. However, obstacles such as upper gastrointestinal intolerance, hypoperfusion vasopressor support, and glycemic control make the task of initiating feeds a challenge. Once a patient has successfully tolerated feeds, the nutrition support clinician must still determine how much to feed and if specialty formulas such as those containing omega-3 fatty acids are beneficial for their patient. The purpose of this review is to present recent research on the feeding challenges in the critical care population with a focus on the cardiothoracic population and an emphasis on improving patient outcomes.

The patient with circulatory shock: to feed or not to feed?

Controversy continues to surround the appropriate form and timing of nutrition support for the patient with circulatory shock. Clinical studies have demonstrated improvements in outcome with the administration of enteral nutrition to critically ill patients; however, the provision of enteral nutrition to critically ill patients with ongoing shock remains controversial. This article reviews gut perfusion during normal states and during circulatory shock as well as alterations in perfusion when enteral feeding is provided. Pharmaconutrients studied during ischemia and reperfusion are discussed.

Nutrient intake and serum cytokine pattern in elderly people with heart failure

BACKGROUND

Heart failure (HF) is frequently complicated by malnutrition. We estimated nutrient intake in HF patients and evaluated the correlation between serum cytokines and dietary pattern.

METHODS

We studied 124 elderly (>or=60 years) patients with severe HF (N=62) or without HF (controls, N=62), matched for age and sex. Nutritional data were obtained from the European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire. We compared the intake of macro- and micronutrients in the two groups; in the HF group nutritional intake was correlated with serum cytokines.

RESULTS

HF patients had a lower energy intake (26.8 Kcal/Kg of ideal weight vs. 37.3 Kcal /Kg ideal weight in controls, P<0.001) due to a lower intake of all macronutrients. The energy intake was lower than the recommended (30 Kcal/Kg of ideal body weight) in 72% of HF and 34% of the controls. The intake of several minerals and vitamins was inferior to the recommended dietary allowance (RDA) in most participants. Those HF patients with a caloric intake below the median (22.6 Kcal/Kg ideal weight) did not differ substantially from those with higher caloric intake with regard to age, functional characteristics, and lean body mass as expressed by the mid-arm muscle circumference, however, they had a higher concentration of IL4 (61.5 pg/ml vs. 37.7 pg/ml, P=0.075) and of IL10 (6.32 pg/ml vs. 2.06 pg/ml, P=0.046).

CONCLUSIONS

Nutritional intake is frequently inadequate in patients with severe HF. Our results suggest that some interleukins might affect caloric intake in patients with HF.

The nutritional and metabolic support of heart failure in the intensive care unit

PURPOSE OF REVIEW

Heart failure and cardiovascular disease are common causes of morbidity and mortality, contributing to many ICU admissions. Nutritional deficiencies have been associated with the development and worsening of chronic heart failure. Nutritional and metabolic support may improve outcomes in critically ill patients with heart failure. This review analyzes the role of this support in the acute care setting of the ICU.

RECENT FINDINGS

Cardiac cachexia is a complex pathophysiologic process. It is characterized by inflammation and anabolic-catabolic imbalance. Nutritional supplements containing selenium, vitamins and antioxidants may provide needed support to the failing myocardium. Evidence shows that there is utility in intensive insulin therapy in the critically ill. Finally, there is an emerging metabolic role for HMG-CoA reductase inhibition, or statin therapy, in the treatment of heart failure.

SUMMARY

Shifting the metabolic milieu from catabolic to anabolic, reducing free radicals, and quieting inflammation in addition to caloric supplementation may be the key to nutritional support in the heart failure patient. Tight glycemic control with intensive insulin therapy plays an expanding role in the care of the critically ill. Glucose-insulin-potassium therapy probably does not improve the condition of the patient with heart failure or acute myocardial infarction.

Risks and benefits of nutritional support during critical illness

Critically ill patients who depend on intensive care for more than a few days reveal profound erosion of lean body mass, which is thought to contribute to high morbidity and mortality. Despite a shortfall of evidence that supplemental feeding actually alters clinical outcome of these life-threatening disease states, this observation evoked an almost universal, albeit often inappropriate, use of nutritional support (NS) in the critically ill, administered via the parenteral or the enteral route. Lack of knowledge and overenthusiasm subsequently resulted in complications associated with both parenteral nutrition (PN) and enteral nutrition (EN), which led to the standing controversy over which should be preferred. With time, however, it became clear that EN and PN are not mutually exclusive and that critically ill patients requiring NS should be fed according to the functional status of the gastrointestinal tract. In addition, tight blood glucose control with insulin is advised in fed critically ill patients because overall metabolic control appears to surpass any outcome benefit attributed to the route of feeding. Recently, various special nutritional formulas have been suggested to prevent or treat multiorgan failure in the critically ill, among other pathways via modulation of immune function. Although special nutritional formulas may be promising in a variety of clinical settings, based on currently available data, these cannot be recommended for routine use in critically ill patients.

Acute perioperative heart failure

PURPOSE OF REVIEW

Changes in epidemiology and advances in the treatment of coronary artery disease, hypertension and diabetes mellitus have increased the prevalence of heart failure in the general population, and also the number of patients with heart failure presenting for surgery. Particularly in the perioperative period, patients with chronic heart failure are faced with numerous triggers of acute decompensation that can partly be avoided or treated. Patients without preexisting myocardial contractile dysfunction may sustain severe perioperative complications, e.g. myocardial infarction, with subsequent acute heart failure as a consequence. Approaches for diagnosis and treatment in these situations may vary considerably.

RECENT FINDINGS

Patients with preexisting heart failure undergoing non-cardiac surgery suffer substantial morbidity and mortality despite advances in perioperative care. The importance of heart failure as an independent risk factor is underlined by the fact that patients with coronary artery disease but without heart failure have a similar 30-day mortality rate to the general population. B-type natriuretic peptide testing is an attractive and non-invasive tool in non-surgical patients for the diagnosis of heart failure, but its role in the perioperative period for the diagnosis of myocardial contractile dysfunction is less clear. For inotropic support, levosimendan, a myofilament calcium sensitizer, has become available in several European countries, and encouraging positive reports have recently been published in this area.

SUMMARY

The role of B-type natriuretic peptide testing in the perioperative period is confounded by several variables that limit its use in that setting. New developments in positive inotropic therapy are challenging older and potentially harmful treatment strategies.

Enteral nutrition in critically ill patients with severe hemodynamic failure after cardiopulmonary bypass

BACKGROUND & AIMS

The study was designed to investigate and quantify nutritional support, and particularly enteral nutrition (EN), in critically ill patients with severe hemodynamic failure.

METHODS

Prospective, descriptive study in a surgical intensive care unit (ICU) in a university teaching hospital: patients aged 67+/-13 yrs (mean+/-SD) admitted after cardiac surgery with extracorporeal circulation, staying 5 days in the ICU with acute cardiovascular failure. Severity of disease was assessed with SAPS II, and SOFA scores. Variables were energy delivery and balance, nutrition route, vasopressor doses, and infectious complications. Artificial feeding delivered according to ICU protocol. EN was considered from day 2-3. Energy target was set 25 kcal/kg/day to be reached stepwise over 5 days.

RESULTS

Seventy out of 1114 consecutive patients were studied, aged 67+/-17 years, and staying 10+/-7 days in the ICU. Median SAPS II was 43. Nine patients died (13%). All patients had circulatory failure: 18 patients required intra-aortic balloon-pump support (IABP). Norepinephrine was required in 58 patients (83%). Forty patients required artificial nutrition. Energy delivery was very variable. There was no abdominal complication related to EN. As a mean, 1360+/-620 kcal/kg/day could be delivered enterally during the first 2 weeks, corresponding to 70+/-35% of energy target. Enteral nutrient delivery was negatively influenced by increasing dopamine and norepinephrine doses, but not by the use of IABP.

CONCLUSION

EN is possible in the majority of patients with severe hemodynamic failure, but usually results in hypocaloric feeding. EN should be considered in patients with careful abdominal and energy monitoring.