Pathophysiology of Acute Decompensated Heart Failure

The Role of the Vasculature in Heart Failure

The contribution of the vasculature in the development and progression of heart failure (HF) syndromes is poorly understood and often neglected. Incorporating both arterial and venous systems, the vasculature plays a significant role in the regulation of blood flow throughout the body in meeting its metabolic requirements. A deterioration or imbalance between the cardiac and vascular interaction can precipitate acute decompensated HF in both preserved and reduced ejection fraction phenotypes. This is characterised by the increasingly recognised concept of ventricular-arterial coupling: a well-balanced relationship between ventricular and vascular stiffness, which has major implications in HF. Often, the cause of decompensation is unknown, with international guidelines mainly centred on arrhythmia, infection, acute coronary syndrome and its mechanical complications as common causes of decompensation; the vascular component is often underrecognised. A better understanding of the vascular contribution in cardiovascular failure can improve risk stratification, earlier diagnosis and facilitate earlier optimal treatment. This review focuses on the role of the vasculature by integrating the concepts of ventricular-arterial coupling, arterial stiffness and venous return in a failing heart.

Anesthetic Considerations in Pediatric Patients With Acute Decompensated Heart Failure

Acute decompensated heart failure (ADHF) in pediatrics is a significant cause for morbidity and mortality in children. Congenital heart disease and cardiomyopathy are the leading etiologies of ADHF. It is common for these children to undergo diagnostic, therapeutic, or surgical procedure under anesthesia, which may be associated with significant morbidity and mortality. The importance of preanesthetic multidisciplinary planning with all involved teams, including anesthesia, cardiology, intensive care, perfusion, and cardiac surgery, cannot be emphasized enough. In order to safely manage these patients, it is imperative for the anesthesiologist to understand the complex pathophysiological interactions between cardiopulmonary systems and anesthesia during these procedures. This review discusses the etiology, pathophysiology, clinical manifestations, and perioperative management of these patients.

Single baseline serum creatinine measurements predict mortality in critically ill patients hospitalized for acute heart failure

Background

Acute heart failure (AHF) is a leading cause of death in critically ill patients and is often accompanied by significant renal dysfunction. Few data exist on the predictive value of measures of renal dysfunction in large cohorts of patients hospitalized for AHF.

Methods

Six hundred and eighteen patients hospitalized for AHF (300 male, aged 73.3 ± 10.3 years, 73% New York Heart Association Class 4, mean hospital length of stay 12.9 ± 7.7 days, 97% non‐ischaemic AHF) were included in a retrospective single‐centre data analysis. Echocardiographic data, serum creatinine/urea levels, estimated glomerular filtration rate (eGFR), and clinical/laboratory markers were recorded. Mean follow‐up time was 2.9 ± 2.1 years. All‐cause mortality was recorded, and univariate/multivariate analyses were performed.

Results

Normal renal function defined as eGFR > 90 mL/min/1.73 m² was noted in only 3% of AHF patients at baseline. A significant correlation of left ventricular ejection fraction with serum creatinine levels and eGFR (all P < 0.002) was noted. All‐cause mortality rates were 12% (90 days) and 40% (at 2 years), respectively. In a multivariate model, increased age, higher New York Heart Association class at admission, higher total cholesterol levels, and lower eGFR independently predicted death. Patients with baseline eGFR < 30 mL/min/1.73 m² had an exceptionally high risk of death (odds ratio 2.80, 95% confidence interval 1.52–5.15, P = 0.001).

Conclusions

In a large cohort of patients with mostly non‐ischaemic AHF, enhanced serum creatinine levels and reduced eGFR independently predict death. It appears that patients with eGFR < 30 mL/min/1.73 m² have poorest survival rates. Our data add to mounting data indicating that impaired renal function is an important risk factor for non‐survival in patients hospitalized for AHF.

Extracorporeal ultrafiltration for heart failure: focus on organ cross talk and clinical trials

Despite major advances in pharmacological therapy and cardiac devices, heart failure patients continue to be frequently (re-)hospitalized with signs and symptoms of fluid overload. Diuretics improve the symptoms of fluid overload, but their effectiveness is reduced by a number of factors including excess salt intake, underlying chronic kidney disease, renal adaptation to their actions and neurohormonal activation. Ultrafiltration (UF) is a mechanical method of fluid removal with several potential advantages over diuretic-based conventional therapies: several recent studies have demonstrated favorable clinical response to UF therapy. Such studies have shown that removal of large amounts of isotonic fluid, in addition to relieving symptoms of congestion, can improve exercise capacity, reduce cardiac filling pressures, restore diuretic responsiveness, and portend a favorable effect on cardio-pulmonary, cardiorenal interactions, and neurohormonal hyperactivation. However, despite these proposed benefits, so far, no clinical study has yet been carried out to explore the impact of UF therapy on hard clinical endpoints such as long-term mortality. In this article, we review a number of mechanistic aspects of UF therapy, with particular emphasis on cardio-pulmonary and cardiorenal interactions, and revisit the results of more recent clinical trials in order to highlight the characteristics that can help identify patients who are more likely to benefit from this therapeutic modality.

Early emergency management of acute decompensated heart failure

PURPOSE OF REVIEW

Acute decompensated heart failure (ADHF) is characterized by a complex spectrum of pathophysiology that emerges as a common clinical disease state, which manifests as a failure of the circulation to provide for the needs of the body systems. Whereas ADHF is often characterized by the findings of pulmonary congestion and dyspnea, a variety of clinical presentations are possible, with each requiring differing management strategies. This review examines the approach of the four-quadrant clinical profile for differentiation of the ADHF patient during the emergent resuscitative phase of the decompensation.

RECENT FINDINGS

Clinical and diagnostic information can be used to determine the relative degree of pulmonary congestion and peripheral tissue perfusion in patients suspected of ADHF. This information can be used in a four-quadrant approach to differentiate patients into pathophysiologic categories. These profiles can then be translated into management strategies from a physiology based perspective in which the specific mechanisms of the failure are targeted.

SUMMARY

ADHF can present in a variety of clinical forms in the emergent setting. Categorization of the ADHF patient according to their individual hemodynamic profile can assist in management decisions during the emergent resuscitative phase of the decompensation based upon an approach that targets causative pathophysiologic mechanisms.

Body weight loss after myocardial infarction in rats as a marker of early heart failure development

BACKGROUND AND AIMS

We evaluated the use of body weight (BW) loss soon after acute myocardial infarction (MI) in rats as a marker of acute heart failure (HF).

METHODS

Female Wistar rats (200-240 g) were submitted either to sham operation or to coronary artery occlusion. In individual cages, daily BW and food and water intake were measured. Seven days later, cardiac function was evaluated by left ventricular catheterization. HF was defined by a left ventricular end-diastolic pressure greater than the upper limit of the 95% confidence interval. MI group was then divided into those that developed HF (n = 27; MI-HF) and those that did not (n = 47; MI).

RESULTS

The MI-HF group experienced increased BW loss (sham: 4.2 ± 0.6% MI: 0.4 ± 0.8%, MI-HF: -4.9 ± 1.2%; p <0.05) and reduced water and food intake compared with other groups. HF animals showed greater lung weight (sham: 1.460 ± 0.076 g, MI: 1.748 ± 0.086 g, MI-HF: 2.033 ± 0.13 g; p <0.05). Infarct area was significantly different between the groups (MI: 35.9 ± 0.9%, MI-HF: 39.7 ± 1.3%; p <0.05). ROC curve showed that BW loss over 7 days has 100% sensitivity and 72.3% specificity for identifying acute HF. Moreover, excluding the effect of infarct area on these results, a sample of animals with the same infarct area displayed similar morphometric and hemodynamic patterns as the entire sample. Multivariate linear regression analysis confirmed that BW loss is a HF marker independent of infarct area.

CONCLUSIONS

BW is an easy and reliable noninvasive method to detect HF early after MI in rats.

Effect of adding nitroglycerin to early diuretic therapy on the morbidity and mortality of patients with chronic kidney disease presenting with acute decompensated heart failure

BACKGROUND

Loop diuretics are considered first-line therapy for patients with acute decompensated heart failure (ADHF). Adding nitroglycerin (NTG) to diuretic therapy for alleviation of acute shortness of breath has been advocated in our institution. We evaluated the benefits of adding NTG to diuretics in the emergency department for patients with ADHF and chronic kidney disease (CKD).

METHODS

430 consecutive patients with ADHF who were admitted with a chief complaint of dyspnea were included in this retrospective study. Patients were divided into 3 groups. Group A patients were treated with neither diuretics nor NTG; Group B patients were treated with diuretics only; and Group C patients were treated with both diuretics and NTG. Estimated glomerular filtration rate (GFR) was calculated according to the Cockcroft-Gault formula. Follow-up was 36 ± 9 (mean ± standard deviation [SD]) months. Primary endpoints were readmission rate at 30 days and mortality at 24 months.

RESULTS

430 patients were included in this study (42% men; age, 69 ± 14 [mean ± SD] years); mean New York Heart Association class was 2.4 ± 0.7 (mean ± SD) and mean ejection fraction was 28% ± 17% (mean ± SD). Group A included 257 (59%) patients, Group B had 127 (29%) patients, and Group C had 46 (11%) patients. Group C patients were older (mean age, 72 ± 13 years) with lower body mass index (26 ± 7 kg/m2), lower estimated GFR (55.8 ± 38 mL/min per 1.73 m2), higher B-type natriuretic peptide levels (1112 ± 876 pg/mL; P = nonsignificant [NS]), and higher systolic and diastolic blood pressures on admission (P = 0.001). The primary endpoint was assessed as a composite of all-cause mortality and ADHF readmission seen in 143 (56%) Group A patients, 68 (53%) Group B patients, and 22 (48%) Group C patients (P = NS). At 30 days there were 53 (12%) readmissions--26 in Group A, 20 in Group B, and 7 in Group C (P = NS). However, survival at 24 months was higher in Group C (87%) compared with Groups A (79%) and B (82%) (P = 0.002). Using the Cox proportional-hazards regression module, early administration of NTG and Lasix (95% confidence interval [CI], 1.06-1.62; P = 0.01) followed by CKD stage (95% CI, 1.00-1.35; P = 0.04) were the only predictors for survival.

CONCLUSION

There is a role for early administration of NTG in addition to diuretic therapy in patients admitted to the emergency department with ADHF, with resultant decreased length of stay and a trend toward a decrease in the composite endpoint of all-cause mortality and ADHF readmission. The mortality benefit at 2 years reported in our study is thought-provoking and raises a premise to be proven in randomized clinical trials.