The cardiorenal syndrome in heart failure: cardiac? renal? syndrome?

Back to the basics: The need for an etiological classification of chronic heart failure

The left ventricular (LV) ejection fraction (LVEF), despite its severe limitations, has had an epicentral role in heart failure (HF) classification, management, and risk stratification for decades. The major argument favoring the LVEF based HF classification has been that it defines groups of patients in which treatment is effective. However, this reasoning has recently collapsed, since medical treatment with neurohormonal inhibitors, has proved beneficial in most HF patients regardless of the LVEF. In addition, there has been compelling evidence, that the LVEF provides poor guidance for device treatment of chronic HF (implantation of cardioverter defibrillator, cardiac resynchronization therapy) since sudden cardiac death may occur and cardiac dyssynchronization may be disastrous in all HF patients. The same holds true for LV assist device implantation, in which the LVEF has been used as a surrogate for LV size. In this review article we update the evidence questioning the use of LVEF-based HF classification and argue that guidance of chronic HF treatment should transition to more contemporary concepts. Specifically, we propose an etiologic chronic HF classification predominantly based on epidemiological data, which will be foundational for further higher resolution phenotyping in the emerging era of precision medicine.

Hypertensive Heart Failure

Despite overwhelming epidemiological evidence, the contribution of hypertension (HTN) to heart failure (HF) development has been undermined in current clinical practice. This is because approximately half of HF patients have been labeled as suffering from HF with preserved left ventricular (LV) ejection fraction (EF) (HFpEF), with HTN, obesity, and diabetes mellitus (DM) being considered virtually equally responsible for its development. However, this suggestion is obviously inaccurate, since HTN is by far the most frequent and devastating morbidity present in HFpEF. Further, HF development in obesity or DM is rare in the absence of HTN or coronary artery disease (CAD), whereas HTN often causes HF per se. Finally, unlike HTN, for most major comorbidities present in HFpEF, including anemia, chronic kidney disease, pulmonary disease, DM, atrial fibrillation, sleep apnea, and depression, it is unknown whether they precede HF or result from it. The purpose of this paper is to provide a contemporary overview on hypertensive HF, with a special emphasis on its inflammatory nature and association with autonomic nervous system (ANS) imbalance, since both are of pathophysiologic and therapeutic interest.

Coexisting Morbidity Burden in Hospitalized Elderly Patients with New-Onset Heart Failure vs Acutely Decompensated Chronic Heart Failure

Coexisting morbidities (CM) are common in patients with heart failure (HF). This study evaluated the CM burden and its clinical significance in elderly hospitalized patients with new-onset (De-novo) HF (n = 84) and acutely decompensated chronic HF (ADCHF) (n = 122). All had HF symptoms associated with: (a) LVEF <50%, or, (b) left ventricular ejection fraction (LVEF) ≥50% and NT-proBNP ≥300 pg/mL. The primary endpoint was the composite of all-cause death/HF rehospitalization at 6 months. Age was similar between patients with new-onset HF and ADCHF [82 (12.5) vs 80 (11) years, respectively; P = .549]. The CM burden was high in both groups. However, the number of CM [3 (2) vs 4 (1.75)] and the prevalence of multimorbidity [CM ≥2; 65 (77.4%) vs 108 (88.5%)] were lower in new-onset HF ( P = .016 and P = .035, respectively). The survival probability without the primary endpoint was higher in new-onset HF than in ADCHF ( P = .001) driven by less rehospitalizations ( P = .001). In the total study population significant primary endpoint predictors were red blood cell distribution width (RDW), urea, and coronary artery disease (CAD) prevalence (AUC of the model =.7685), whereas significant death predictors were RDW, urea, and the number of CM (AUC = .7859), all higher in ADCHF. Thus, the higher CM burden in ADCHF than in new-onset HF most likely contributed to the worse outcome.

Insights of Worsening Renal Function in Type 1 Cardiorenal Syndrome: From the Pathogenesis, Biomarkers to Treatment

Type-1 cardiorenal syndrome refers to acute kidney injury induced by acute worsening cardiac function. Worsening renal function is a strong and independent predictive factor for poor prognosis. Currently, several problems of the type-1 cardiorenal syndrome have not been fully elucidated. The pathogenesis mechanism of renal dysfunction is unclear. Besides, the diagnostic efficiency, sensitivity, and specificity of the existing biomarkers are doubtful. Furthermore, the renal safety of the therapeutic strategies for acute heart failure (AHF) is still ambiguous. Based on these issues, we systematically summarized and depicted the research actualities and predicaments of the pathogenesis, diagnostic markers, and therapeutic strategies of worsening renal function in type-1 cardiorenal syndrome.

The Pathogenesis of End-Stage Renal Disease from the Standpoint of the Theory of General Pathological Processes of Inflammation

Chronic kidney disease can progress to end-stage chronic renal disease (ESRD), which requires the use of replacement therapy (dialysis or kidney transplant) in life-threatening conditions. In ESRD, irreversible changes in the kidneys are associated with systemic changes of proinflammatory nature and dysfunctions of internal organs, skeletal muscles, and integumentary tissues. The common components of ESRD pathogenesis, regardless of the initial nosology, are (1) local (in the kidneys) and systemic chronic low-grade inflammation (ChLGI) as a risk factor for diabetic kidney disease and its progression to ESRD, (2) inflammation of the classical type characteristic of primary and secondary autoimmune glomerulonephritis and infectious recurrent pyelonephritis, as well as immune reactions in kidney allograft rejection, and (3) chronic systemic inflammation (ChSI), pathogenetically characterized by latent microcirculatory disorders and manifestations of paracoagulation. The development of ChSI is closely associated with programmed hemodialysis in ESRD, as well as with the systemic autoimmune process. Consideration of ESRD pathogenesis from the standpoint of the theory of general pathological processes opens up the scope not only for particular but also for universal approaches to conducting pathogenetic therapies and diagnosing and predicting systemic complications in severe nephropathies.

Red blood cell distribution width in elderly hospitalized patients with cardiovascular disease

BACKGROUND

Red blood cell distribution width (RDW) is elevated in patients with cardiovascular disease (CVD).

AIM

To determine RDW values and impact of CV and non-CV coexisting morbidities in elderly patients hospitalized with chronic CVD.

METHODS

This prospective study included 204 consecutive elderly patients (age 77.5 [7.41] years, female 94 [46%], left ventricular ejection fraction 53.00% [37.50, 55.00]) hospitalized with chronic CVD at the Cardiology Department of Larissa University General Hospital (Larissa, Greece) from January 2019 to April 2019. Elderly patients were selected due to the high prevalence of coexisting morbidities in this patient population. Hospitalized patients with acute CVD (acute coronary syndromes, new-onset heart failure [HF], and acute pericarditis/myocarditis), primary isolated valvular heart disease, sepsis, and those with a history of blood transfusions or cancer were excluded. The evaluation of the patients within 24 h from admission included clinical examination, laboratory blood tests, and echocardiography.

RESULTS

The most common cardiac morbidities were hypertension and coronary artery disease, with acutely decompensated chronic heart failure (ADCHF) and atrial fibrillation (AF) also frequently being present. The most common non-cardiac morbidities were anemia and chronic kidney disease followed by diabetes mellitus, chronic obstructive pulmonary disease, and sleep apnea. RDW was significantly elevated 15.48 (2.15); 121 (59.3%) of patients had RDW > 14.5% which represents the upper limit of normal in our institution. Factors associated with RDW in stepwise regression analysis were ADCHF (coefficient: 1.406; 95% confidence interval [CI]: 0.830-1.981; P < 0.001), AF (1.192; 0.673 to 1.711; P < 0.001), and anemia (0.806; 0.256 to 1.355; P = 0.004). ADCHF was the most significant factor associated with RDW. RDW was on average 1.41 higher for patients with than without ADCHF, 1.19 higher for patients with than without AF, and 0.81 higher for patients with than without anemia. When patients were grouped based on the presence or absence of anemia, ADCHF and AF, heart rate was not increased in those with anemia but was significantly increased in those with ADCHF or AF.

CONCLUSION

RDW was elevated in elderly hospitalized patients with chronic CVD. Factors associated with RDW were anemia and CV factors associated with elevated heart rate (ADCHF, AF), suggesting sympathetic overactivity.

Obesity, inflammation, and heart failure: links and misconceptions

Obesity has been linked with heart failure (HF) with preserved left ventricular (LV) ejection fraction (HFpEF). This link has been attributed to obesity-induced metabolic and inflammatory disturbances leading to HFpEF. However, HF is a syndrome in which disease evolvement is associated with a dynamic unraveling of functional and structural changes leading to unique disease trajectories, creating a spectrum of phenotypes with overlapping distinct characteristics extending beyond the LV ejection fraction (LVEF). In this regard, despite quantitative differences between the two extremes (HFpEF and HF with reduced LVEF, HFrEF), there is important overlap between the phenotypes along the entire spectrum. In this paper, we describe the systemic pro-inflammatory state that is present throughout the HF spectrum and emphasize that obesity intertwines with HF beyond the LVEF construct.

Relationship of High Circulating Cystatin C to Biochemical Markers of Bone Turnover and Bone Mineral Density in Elderly Males with a Chronic Heart Failure

Background

The aim of the study was to investigate the association of Cystatin C (CysC) to biochemical markers of bone turnover and bone mass, and to evaluate its prognostic significance in elderly males with chronic heart failure (CHF).

Methods

A prospective cohort study was executed on sixtyeight males (mean age 68±7 years) with mild to moderate CHF, together with 19 of corresponding age- and body mass index-matched healthy individuals who underwent cardio vascular, bone mineral density (BMD), and body com position assessment. Biochemical assessment of all subjects included NT-pro-BNP, parathyroid hormone (PTH), 25-hydroxy vitamin D (25(OH)D), CysC, and biochemical markers of bone turnover including osteocalcin (OC), alkaline phosphatase (ALP), β-CrossLaps (β-CTx), osteoprotegerin (OPG), and receptor activator of nuclear factor κB ligand (RANKL).

Results

Serum CysC was significantly increased in males with CHF in comparison to healthy control ones. A significant positive association was found between CysC levels and OC in males with CHF, while OC and β-CTx increased in increasing CysC tertiles. In multivariate regression analysis, OC and smoking were a significant determinant of CysC in males with CHF. Level of CysC was found to be positively associated with an increased fatal risk in males with CHF.

Conclusions

Serum osteocalcin is an independent predictor of CysC level in elderly males with CHF. Higher CysC level showed a negative relation to survival and bone loss in males with CHF. Further research is needed to confirm the potential role of CysC in the crosstalk between heart, kidney, bone, and energy metabolism in CHF.

Response and outcomes of cardiac resynchronization therapy in patients with renal dysfunction

PURPOSE

Renal dysfunction is often associated with chronic heart failure, leading to increased morbi-mortality. However, data regarding these patients after cardiac resynchronization therapy (CRT) is sparse. We sought to evaluate response and long-term mortality in patients with heart failure and renal dysfunction and assess renal improvement after CRT.

METHODS

We analyzed 178 consecutive patients who underwent successful CRT device implantation (age 64 ± 11 years; 69% male; 92% in New York Heart Association (NYHA) functional class ≥ III; 34% with ischemic cardiomyopathy). Echocardiographic response was defined as ≥ 15% reduction in left ventricular end-systolic diameter and clinical response as a sustained improvement of at least one NYHA functional class. Renal dysfunction was defined as an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m².

RESULTS

Renal dysfunction was present in 34.7%. Renal dysfunction was not an independent predictor of echocardiographic response (OR 1.109, 95% CI 0.713-1.725, p 0.646) nor clinical response (OR 1.003; 95% CI 0.997-1.010; p 0.324). During follow-up (mean 55.2 ± 32 months), patients with eGFR < 60mL/min/1.73 m² had higher overall mortality (HR 4.902, 95% CI 1.118-21.482, p 0.035). However, clinical response in patients with renal dysfunction was independently associated with better long-term survival (HR 0.236, 95% CI 0.073-0.767, p 0.016). Renal function was significantly improved in patients who respond to CRT (ΔeGFR + 5.5 mL/min/1.73 m² at baseline vs. follow-up, p 0.049), while this was not evident in nonresponders. Improvements in eGFR of at least 10 mL/min/1.73 m² were associated with improved survival in renal dysfunction patients (log-rank p 0.036).

CONCLUSION

Renal dysfunction was associated with higher long-term mortality in CRT patients, though, it did not influence echocardiographic nor functional response. Despite worse overall prognosis, renal dysfunction patients who are responders showed long-term survival benefit and improvement in renal function following CRT.

The potential of cystatin-C to evaluate the prognosis of acute heart failure: A comparative study

BACKGROUND

The prognosis of acute heart failure (HF) can be determined by cardio-renal function which is assessed by cystatin-C (Cys-C). We evaluated whether Cys-C could be a more useful prognostic indicator in acute HF, compared with uric acid (UA) and N-terminal pro-B-type natriuretic peptide (NT-proBNP).

METHODS

Two hundred thirty-two HF patients in the emergency room were studied using measurements of Cys-C, UA, and NT-proBNP. During the follow-up, cardiac events, defined as the composites of recurrent HF or cardiac death, were determined.

RESULTS

Seventy-seven cardiac events (28 cardiac deaths, 49 recurrent HFs) occurred over two years. The events group revealed higher levels of Cys-C, UA, and NT-proBNP. They showed increased blood urea nitrogen and creatinine, reduced septal tissue Doppler velocity (TVI-Sm), and low frequencies of beta-blockers (BB), diuretics and angiotensin-converting enzyme inhibitors/-receptor blockers. Cys-C (the best cutoff: 1.7 mg/l) had a steady, persistent hazard ratio (HR) over two years. On multivariate analysis, Cys-C, TVI-Sm, and BB were significant predictors for adverse events. Cys-C provided an incremental value for prognosis more than NT-proBNP and UA did over the follow-up period.

CONCLUSIONS

Compared with UA and NT-proBNP, Cys-C could be better prognostic biomarker for cardiac events two years after acute HF.

Approach to Hyponatremia in Congestive Heart Failure: A Survey of Canadian Specialist Physicians and Trainees

Background

Hyponatremia is a recognized complication of congestive heart failure (CHF) and is associated with reduced survival. Therefore, early identification and appropriate management of hyponatremia is important. The aim of this study was to determine the general approach amongst Canadian healthcare practitioners and trainees to the identification and management of hyponatremia complicating CHF.

Methods

Respondents completed 15 multiple-choice style questions in 3 case scenarios regarding the approach to management of hyponatremia complicating CHF using an online survey on UKidney.com between November 2012 and May 2013. Results were presented as a proportion of averaged correct/incorrect responses amongst Canadian nephrologists, cardiologists, internists and trainees in each of two domains; pathophysiology and management. Management was further subdivided into correct and incorrect use of diuretic therapy, hypertonic saline, oral urea tablets, vasopressin receptor antagonists (vaptans) and rate of sodium correction. Correct responses were determined by an expert panel of Canadian nephrologists and cardiologists based on review of evidence informed guidelines and current recommendations.

Results

There were 1757 responses to our online survey amongst 455 Canadian respondents, 1139 of which were from cardiologists, nephrologists, general internists, or trainees. Overall, the pathophysiology governing hyponatremia in CHF was correctly identified 68.7 % of the time (n = 380 responses, averaged over 4 questions). Hyponatremia was managed inappropriately 43.6 % of the time, with trainees scoring best overall with correct responses 60.3 % of the time (n = 759 responses, over 11 questions). Importantly, an incorrect rate for sodium correction was selected 61.1 % of the time overall, (n = 211 responses, averaged over 3 questions).

Conclusions

This study identified that there are differences in the understanding of pathophysiology and management strategies for hyponatremia in the context of CHF amongst Canadian specialist physicians and trainees. A more consistent approach to hyponatremia is required and might best be achieved through formal knowledge translation.

Electronic supplementary material

The online version of this article (doi:10.1186/s40697-016-0094-9) contains supplementary material, which is available to authorized users.

Water and sodium in heart failure: a spotlight on congestion

Despite all available therapies, the rates of hospitalization and death from heart failure (HF) remain unacceptably high. The most common reasons for hospital admission are symptoms related to congestion. During hospitalization, most patients respond well to standard therapy and are discharged with significantly improved symptoms. Post-discharge, many patients receive diligent and frequent follow-up. However, rehospitalization rates remain high. One potential explanation is a persistent failure by clinicians to adequately manage congestion in the outpatient setting. The failure to successfully manage these patients post-discharge may represent an unmet need to improve the way congestion is both recognized and treated. A primary aim of future HF management may be to improve clinical surveillance to prevent and manage chronic fluid overload while simultaneously maximizing the use of evidence-based therapies with proven long-term benefit. Improvement in cardiac function is the ultimate goal and maintenance of a "dry" clinical profile is important to prevent hospital admission and improve prognosis. This paper focuses on methods for monitoring congestion, and strategies for water and sodium management in the context of the complex interplay between the cardiac and renal systems. A rationale for improving recognition and treatment of congestion is also proposed.

Current strategies for preventing renal dysfunction in patients with heart failure: a heart failure stage approach

Renal dysfunction is common during episodes of acute decompensated heart failure, and historical data indicate that the mean creatinine level at admission has risen in recent decades. Different mechanisms underlying this change over time have been proposed, such as demographic changes, hemodynamic and neurohumoral derangements and medical interventions. In this setting, various strategies have been proposed for the prevention of renal dysfunction with heterogeneous results. In the present article, we review and discuss the main aspects of renal dysfunction prevention according to the different stages of heart failure.

Current status of mechanical circulatory support: a systematic review

Heart failure is a major public health problem and its management requires a significant amount of health care resources. Even with administration of the best available medical treatment, the mortality associated with the disease remains high. As therapeutical strategies for heart failure have been refined, the number of patients suffering from the disease has expanded dramatically. Although heart transplantation still represents the gold standard therapeutical approach, the implantation of mechanical circulatory support devices (MCSDs) evolved to a well-established management for this disease. The limited applicability of heart transplantation caused by a shortage of donor organs and the concurrent expand of the patient population with end-stage heart failure led to a considerable utilization of MCSDs. This paper outlines the current status of mechanical circulatory support.