Role of Diminished Renal Function in Cardiovascular Mortality

The Romanian Acute Heart Failure Syndromes (RO-AHFS) registry

AIMS

The objective of the RO-AHFS registry was to evaluate the epidemiology, clinical presentation, inpatient management, and hospital course in a population hospitalized for acute heart failure syndromes.

METHODS

During a 12-month period, 13 Romanian medical centers enrolled all consecutive patients hospitalized with a primary diagnosis of AHFS. Patients were classified into the following 5 clinical profiles at admission: acute decompensated heart failure, cardiogenic shock, pulmonary edema, right heart failure, and hypertensive heart failure. Statistical significance was assessed using Fisher exact test or the χ(2) test for categorical variables and a 1-way analysis of variance for continuous variables. Independent predictors of in-hospital all-cause mortality (ACM) were identified using a multivariate logistic regression model.

RESULTS

A total of 3,224 consecutive patients hospitalized with AHFS were enrolled. The cohort had a mean age of 69.2 ± 11.8 years and 56% were men. The mean left ventricular ejection fraction was 37.7% ± 12.5%. The percentage of patients treated with evidence-based heart failure therapies increased from admission to discharge, but even at discharge, only 56%, 66%, and 54% of patients were on a β-blocker, an angiotensin-converting enzyme inhibitors or an angiotensin receptor blocker, and a mineralocorticoid receptor antagonist, respectively. In-hospital ACM was 7.7% with substantial variation between sites (4.1%-11.0%). Increasing age, inotrope therapy, the presence of life-threatening ventricular arrhythmias, and elevated baseline blood urea nitrogen were all found to be independent risk factors for in-hospital ACM, whereas elevated systolic blood pressure and baseline treatment with a β-blocker had a protective effect.

CONCLUSIONS

The RO-AHFS study found substantial variation both among sites and between Romania and other European countries. National and regional registries have important clinical implications for patient care and the design and conduct of global clinical trials.

Relaxin induces rapid dilation of rodent small renal and human subcutaneous arteries via PI3 kinase and nitric oxide

The peptide hormone relaxin is a potent vasodilator with therapeutic potential in diseases complicated by vasoconstriction, including heart failure. However, the molecular mediators and magnitude of vasodilation may vary according to duration of exposure and artery type. The objective of these studies was to determine mechanisms of rapid (within minutes) relaxin-induced vasodilation and to examine whether relaxin dilates arteries from different animal species and vascular beds. Rat and mouse small renal, rat mesenteric, and human sc arteries were isolated, mounted in a pressure arteriograph, and treated with recombinant human relaxin (rhRLX; 1-100 ng/ml) after preconstriction with phenylephrine. Rat and mouse small renal as well as human sc arteries dilated in response to rhRLX, whereas rat mesenteric arteries did not. Endothelial removal or pretreatment with l-N(G)-monomethyl arginine (L-NMMA) abolished rapid relaxin-induced vasodilation; phosphatidylinositol-3-kinase (PI3K) inhibitors also prevented it. In cultured human endothelial cells, rhRLX stimulated nitric oxide (assessed using 4-amino-5-methylamino-2'7'-difluorofluorescein) as well as Akt and endothelial NO synthase (eNOS) phosphorylation by Western blotting but not increases in intracellular calcium (evaluated by fura-2). NO production was attenuated by inhibition of Gα(i/o) and Akt (using pertussis toxin and the allosteric inhibitor MK-2206, respectively), PI3K, and NOS. Finally, the dilatory effect of rhRLX in rat small renal arteries was unexpectedly potentiated, rather than inhibited, by pretreatment with the vascular endothelial growth factor receptor inhibitor SU5416. We conclude that relaxin rapidly dilates select arteries across a range of species. The mechanism appears to involve endothelial Gα(i/o) protein coupling to PI3K, Akt, and eNOS but not vascular endothelial growth factor receptor transactivation or increased calcium.

[Heart failure in haemodialysis patients: evaluation and treatment]

Cardiovascular diseases are the leading cause of death in patients on haemodialysis. Cardiovascular mortality rate in these patients is approximately 9% per year, with the highest prevalence of left ventricular hypertrophy, ischemic heart disease and congestive heart failure being the most frequent cardiovascular complications. Risk factors for cardiac failure include hypertension, disturbed lipid metabolism, oxidative stress, microinflammation, hypoalbuminemia, anaemia, hyperhomocysteinemia, and increased concentration of asymmetric dimethylarginine, increased shunt blood flow and secondary hyperparathyroidism. Diagnostic strategy for early detection of patients with increased risk for the development of asymptomatic disturbances of systolic and diastolic left ventricular function should include echocardiografic examination, tests for determining coronary vascular disease, as well as tests of myocardial function (BNP, Nt-proBNP). Early detection of patients with a high risk of congestive heart failure enables timely implementation of adequate therapeutic strategy to provide high survival rate of HD patients.

Relaxin: a new approach for the treatment of acute congestive heart failure

Relaxin, a naturally-occurring hormone in the insulin family, was discovered to have a physiologic role in pregnancy. Named initially for its relaxing effect on the pubic ligament, relaxin receptors have since been found to be widely distributed in many organs in both males and females. Acting through multiple pathways, including the stimulation of gelatinases leading to activation of endothelin type B receptors and subsequently nitric oxide, relaxin has been shown to cause vasodilation. In animal models and studies in humans, relaxin has been shown to increase cardiac output and renal perfusion. Due to these effects, relaxin has been examined as a treatment for acute heart failure. The results of phase I and II trials have shown favorable clinical trends without any major adverse events, suggesting that relaxin has the potential to be an effective medication for acute heart failure in conjunction with or in place of current treatments.

Relationship between renal function and heart failure in hypertensive patients

The HICAP (Hypertension and Heart Failure in Primary Care) study is a cross-sectional, multicentre, epidemiological study conduced in primary care centres in Spain. The results indicate that among hypertensive patients without heart failure (HF), diagnosed renal dysfunction is associated with the risk for developing HF and that the renal function evaluation using the Modification of Diet in Renal Disease Study Group formula could be useful to detect hypertensive patients at high risk of developing HF.

Cardiorenal syndrome in acute heart failure syndromes

Impaired cardiac function leads to activation of the neurohumoral axis, sodium and water retention, congestion and ultimately impaired kidney function. This sequence of events has been termed the Cardiorenal Syndrome. This is different from the increase in cardiovascular complications which occur with primary kidney disease, that is, the so-called Renocardiac Syndrome. The present review discusses the pathogenesis of the Cardiorenal Syndrome followed by the benefits and potential deleterious effects of pharmacological agents that have been used in this setting. The agents discussed are diuretics, aquaretics, natriuretic peptides, vasodilators, inotropes and adenosine α1 receptor antagonists. The potential role of ultrafiltration is also briefly discussed.

Cardiorenal syndrome and heart failure

PURPOSE OF REVIEW

Concomitant anemia, heart failure, and renal disease can be seen in a large proportion of patients with heart failure. The purpose of this review is to discuss the current definitions and mechanisms involved in this pathophysiological relationship, as well as the potential management and treatment options available for these patients.

RECENT FINDING

Dysfunctional heart can promote the dysfunction of the kidneys through a variety of pathophysiological mechanism, the reciprocal holds true as well. Heart failure has been considered as the most common type of cardiovascular complication seen in patients with renal failure. Central to this relationship lies anemia, which can be the result or the cause of either heart or kidney disease.

SUMMARY

Cardiorenal syndrome is a complex condition, which requires the collaboration and resources from cardiology, cardiac surgery, nephrology, and critical care. Of great importance is recognizing the presence of cardiorenal syndrome and appreciating the impact it can play on treatment options and survival.

Ultrafiltration in the management of acute decompensated heart failure

PURPOSE OF REVIEW

Admissions to hospital for acute decompensated heart failure continue to increase and represent a significant burden on both patients' and healthcare resources. The majority of these admissions are for the control of volume overload; however, standard treatment with intravenous diuretics is not always effective and can lead to increased renal morbidity. One alternative to standard therapy is mechanical fluid removal with ultrafiltration, this review will highlight the current evidence and efficacy regarding ultrafiltration use in acute heart failure.

RECENT FINDINGS

Multiple recent clinical trials have demonstrated the safety and feasibility of ultrafiltration in the management of acute heart failure. Ultrafiltration may be more effective at removing fluid than standard diuretic therapy and has been associated with beneficial long-term results. However, it remains to be determined whether ultrafiltration is truly nephroprotective and when and how this therapy is best utilized.

SUMMARY

Ultrafiltration is an attractive alternative to standard diuretic therapy in the management of volume overload from acute heart failure. Further research is needed to confirm the cost-effectiveness and to determine long-term impacts on morbidity and mortality.

Renal function is related to severity of coronary artery calcification in elderly persons: the Rotterdam study

Background

Coronary artery calcification (CAC) has been proposed to be the underlying mechanism of the increased risk of coronary heart disease with reductions in glomerular filtration rate (GFR). Since renal function diminishes with aging we examined the association between GFR and CAC in the Rotterdam Study, a population-based study of elderly individuals.

Methods

The study was performed in 1703 subjects without a history of coronary heart disease. GFR was estimated using the modification of diet in renal disease equation. We used analysis of covariance to test for mean differences in CAC between GFR tertiles.

Results

The mean CAC scores in the middle and lowest GFR tertile did not significantly differ from the mean CAC score in the highest GFR tertile (geometric mean CAC score 4.1 and 4.3 vs 4.2). In a multivariable model the mean CAC score did also not differ between the GFR tertiles. As the interaction term between age and GFR was significant (P = 0.037), we divided the population in two age categories based on median age of 70 years. Below 70 years, the mean CAC scores did not differ between the GFR tertiles. Above median age, mean CAC score in the lowest GFR tertile was significantly higher than the mean CAC score in the highest tertile in a multivariable model (CAC 4.9 vs 4.5, p = 0.010).

Conclusion

In this population-based study we observed that the association between CAC and GFR is modified by age. In participants at least 70 years of age, a decrease in GFR was associated with increased CAC.

Burden of sodium abnormalities in patients hospitalized for heart failure

Hyponatremia presumably is associated with adverse clinical outcomes in patients with congestive heart failure (CHF), but risk thresholds and economic burden are less studied. The authors analyzed 115,969 patients hospitalized for CHF and grouped them by serum sodium levels (severe hyponatremia, ≤130 mEq/L; hyponatremia, 131-135 mEq/L; normonatremia, 136-145 mEq/L; hypernatremia, >145 mEq/L). Univariable and multivariable analyses on the associated clinical and economic outcomes were performed. The most common abnormality was hyponatremia (15.9%), followed by severe hyponatremia (5.3%) and hypernatremia (3.2%). Hospital mortality was highest for severe hyponatremia (7.6%), followed by hypernatremia (6.7%) and hyponatremia (4.9%) (P<.0001). Compared with normonatremia, risk-adjusted mortality was highest for severe hyponatremia (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.59-1.99), followed by hypernatremia (OR, 1.55; 95% CI, 1.34-1.80) and hyponatremia (OR, 1.29; 95% CI, 1.19-1.40; all P<.0001). Risk-adjusted hospital prolongation was greater for each level of sodium abnormality than for normonatremia, ranging from 0.42 (CI, 0.26-0.60) days for hypernatremia to 1.28 (CI, 1.11-1.47) days for severe hyponatremia. Risk-adjusted attributable hospital cost increase was highest for severe hyponatremia ($1132; CI, $856-$1425; all (P<.0001). Sodium abnormalities were common in patients hospitalized for CHF. Adverse outcomes resulted not only from severe hyponatremia, but also from mild hyponatremia and hypernatremia.

Efficacy and Safety of Carvedilol in Treatment of Heart Failure with Chronic Kidney Disease

Background—

The safety and efficacy of different types of β-blocker therapy in patients with non–dialysis-dependent chronic kidney disease (CKD) and systolic heart failure (HF) are not well described. We assessed whether treatment of systolic HF with carvedilol is efficacious and safe in adults with CKD.

Methods and Results—

We performed a post hoc analysis of pooled individual patient data (n=4217) from 2 multinational, double-blinded, placebo-controlled, randomized trials, CAPRICORN (Carvedilol Postinfarct Survival Control in Left Ventricular Dysfunction Study) and COPERNICUS (Carvedilol Prospective Randomized, Cumulative Survival study). Primary outcome was all-cause mortality. Secondary outcomes included cardiovascular mortality, HF mortality, first HF hospitalization, the composite of cardiovascular mortality or first HF hospitalization, and sudden cardiac death. Non–dialysis-dependent CKD was defined by estimated glomerular filtration rate ≤60 mL/min/1.73 m 2 , using the abbreviated Modification of Diet in Renal Disease equation. CKD was present in 2566 of 4217 (60.8%) of the cohort, 50.4% of whom were randomly assigned to carvedilol therapy. Within the CKD group, treatment with carvedilol decreased the risks of all-cause mortality (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.63 to 0.93; P =0.007), cardiovascular mortality (HR, 0.76; 95% CI, 0.62 to 0.94; P =0.011), HF mortality (HR, 0.68; 95% CI, 0.52 to 0.88; P =0.003), first hospitalization for HF (HR, 0.74; 95% CI, 0.61 to 0.88; P =0.0009), and the composite of cardiovascular mortality or HF hospitalization (HR, 0.75; 95% CI, 0.65 to 0.87; P <0.001) but was without significant effect on sudden cardiac death (HR, 0.76; 95% CI, 0.56 to 1.05; P =0.098). There was no significant interaction between treatment arm and study type. Carvedilol was generally well tolerated by both groups of patients, with an increased relative incidence in transient increase in serum creatinine without need for dialysis and other electrolyte changes in the CKD patients. However, in a sensitivity analysis among HF subjects with estimated glomerular filtration rate <45 mL/min/1.73 m 2 (CKD stage 3b), the efficacy of carvedilol was not significantly different from placebo.

Conclusions—

This analysis suggests that the benefits of carvedilol therapy in patients with systolic left ventricular dysfunction with or without symptoms of HF are consistent even in the presence of mild to moderate CKD. Whether carvedilol therapy is similarly efficacious in HF patients with more advanced kidney disease requires further study.

Diuretic therapy in heart failure: current controversies and new approaches for fluid removal

Hospitalization for heart failure is a major health problem with high in-hospital and postdischarge mortality and morbidity. Non-potassium-sparing diuretics (NPSDs) still remain the cornerstone of therapy for fluid management in heart failure despite the lack of large randomized trials evaluating their safety and optimal dosing regimens in both the acute and chronic setting. Recent retrospective data suggest increased mortality and re-hospitalization rates in a wide spectrum of heart failure patients receiving NPSDs, particularly at high doses. Electrolyte abnormalities, hypotension, activation of neurohormones, and worsening renal function may all be responsible for the observed poor outcomes. Although NPSD will continue to be important agents to promptly resolve signs and symptoms of heart failure, alternative therapies such as vasopressine antagonists and adenosine blocking agents or techniques like veno-venous ultrafiltration have been developed in an effort to reduce NPSD exposure and minimize their side effects. Until other new agents become available, it is probably prudent to combine NPSD with aldosterone blocking agents that are known to improve outcomes.

Loop diuretics can cause clinical natriuretic failure: a prescription for volume expansion

Ultrafiltration enhances volume removal and weight reduction vs diuretics. However, their differential impact on total body sodium, potassium, and magnesium has not been described. Fifteen patients with congestion despite diuretic therapy had urine electrolytes measured after a diuretic dose. Ultrafiltration was initiated and ultrafiltrate electrolytes were measured. The urine sodium after diuretics (60+/-47 mmol/L) was less than in the ultrafiltrate (134+/-8.0 mmol/L) (P=.000025). The urine potassium level after diuretics (41+/-23 mmol/L) was greater than in the ultrafiltrate (3.7+/-0.6 mmol/L) (P=.000017). The urine magnesium level after diuretics (5.2+/-3.1 mg/dL) was greater than in the ultrafiltrate (2.9+/-0.7 mg/dL) (P=.017). In acute decompensated heart failure patients with congestion despite diuretic therapy, diuretics are poor natriuretics and cause significant potassium and magnesium loss. Ultrafiltration extracts more sodium while sparing potassium and magnesium. The sustained clinical benefits of ultrafiltration compared with diuretics may be partly related to their disparate effects on total body sodium, potassium, and magnesium, in addition to their differential efficacy of volume removal.

Inhibition of p38 mitogen-activated protein kinase reduces inflammation after coronary vascular injury in humans

OBJECTIVE

To evaluate whether a p38α/β mitogen-activated protein kinase inhibitor, SB-681323, would limit the elevation of an inflammatory marker, high-sensitivity C-reactive protein (hsCRP), after a percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Coronary artery stents provide benefit by maintaining lumen patency but may incur vascular trauma and inflammation, leading to myocardial damage. A key mediator for such stress signaling is p38 mitogen-activated protein kinase. Patients with angiographically documented coronary artery disease receiving stable statin therapy and about to undergo PCI were randomly selected to receive SB-681323, 7.5 mg (n=46), or placebo (n=46) daily for 28 days, starting 3 days before PCI. On day 3, before PCI, hsCRP was decreased in the SB-681323 group relative to the placebo group (29% lower; P=0.02). After PCI, there was a statistically significant attenuation in the increase in hsCRP in the SB-681323 group relative to the placebo group (37% lower on day 5 [P=0.04]; and 40% lower on day 28 [P=0.003]). There were no adverse safety signals after 28 days of treatment with SB-681323.

CONCLUSIONS

In the setting of statin therapy, SB-681323 significantly attenuated the post-PCI inflammatory response, as measured by hsCRP. This inflammatory dampening implicates p38 mitogen-activated protein kinase in the poststent response, potentially defining an avenue to limit poststent restenosis.

Is left ventricular hypertrophy a powerful predictor of progression to dialysis in chronic kidney disease?

BACKGROUND

The role of cardiovascular factors in predicting renal outcome has not been extensively elucidated. Herein, we report a prospective evaluation of the impact of left ventricular hypertrophy (LVH) on outcome in non-diabetic patients with chronic kidney disease (CKD).

METHODS

We studied 144 patients (99 men; age 62±14 years) with stage 3-4 CKD, with baseline assessment of left ventricular mass index (LVMi) by echocardiography, estimated glomerular filtration rate (eGFR) by MDRD equation, 24-h blood pressure profile and 24-h proteinuria. Combined end point was progression to ESRD requiring dialysis, or death within 5 years.

RESULTS

Forty-nine patients (34%) progressed to dialysis, 24 (17%) died, 57 (39%) were dialysis-free after 5 years and 14 were lost to follow-up. Multivariate Cox proportional hazards analysis showed that increased LVMi (HR 1.28, 95% CI 1.17-1.40 for each 10-g/m2 increase, P<0.0001) and reduced eGFR (5% risk increase for each 1-mL/min reduction, P=0.027) were the significant predictors of the combined end point in stage 3 CKD patients, whereas LVMi proved to be the only significant predictor of the combined end point in patients with stage 4 CKD (HR 1.19, 95% CI 1.09-1.31, P<0.0001). The same analysis showed that LVMi was the only significant predictor of progression to dialysis in stage 3 CKD patients (HR 1.42, 95% CI 1.23-1.64 for each 10-g/m2 increase, P<0.0001), while a 20% increase in the risk of progression to ESRD was observed for each 10-g/m2 increase in LVMi (P<0.0001), and a 10% increase for each 1-mL/min reduction in eGFR (P=0.046) in patients with stage 4 CKD. When evaluating the predictive role of LVMi on outcome using AUC-ROC curves, the overall performance of the model including LVMi (AUC 0.877, 95% CI 0.8-0.954) was superior to the model including eGFR (AUC 0.737, 95% CI 0.656-0.817) for the end point of progression to dialysis (P=0.026, Hanley test).

CONCLUSIONS

LVH proved to be the strongest predictor of the risk of progression to dialysis in non-diabetic CKD, especially among patients with less advanced renal dysfunction. Regardless of whether it is a simple marker or a pathogenetic factor, LVH encompasses all factors possibly affecting renal and general outcome in CKD patients.

Therapeutic strategies for heart failure in cardiorenal syndromes

Cardiorenal syndromes are disorders of the heart and kidneys whereby acute or long-term dysfunction in one organ may induce acute or long-term dysfunction of the other. The management of cardiovascular diseases and risk factors may influence, in a beneficial or harmful way, kidney function and progression of kidney injury. In this review, we assess therapeutic strategies and discuss treatment options for the management of patients with heart failure with decreased kidney function and highlight the need for future high-quality studies in patients with coexisting heart and kidney disease.

Renal function, cardiovascular disease risk factors' prevalence and 5-year disease incidence; the role of diet, exercise, lipids and inflammation markers: the ATTICA study

BACKGROUND

We aimed to evaluate the association between renal function and various cardiovascular disease (CVD) risk factors, as well as 5-year incidence of CVD, in a sample of CVD free adults.

METHODS

(i) Cross-sectional information from n = 1975. Greek men and women (>18 years) without CVD and hypertension at baseline examination and (ii) 5-year (2001-06) survival data from n = 2101 individuals without CVD at baseline, all participants in the ATTICA study, were analysed in this work. Kidney function was quantified by the baseline estimated creatinine clearance rate (C(cr)), using the Cockcroft-Gault formula and the National Kidney Foundation recommendations. Outcome of interest was the development of CVD that was defined according to WHO-ICD-10 criteria.

RESULTS

At baseline, the prevalence of moderate-to-severe renal dysfunction (i.e. C(cr) < 60) was 2.8% in males and 7.7% in females. Physical activity status, cigarette smoking, hypercholesterolemia and homocysteine levels and greater adherence to the Mediterranean diet were inversely associated with C(cr) rate (P < 0.05), while no association was found with history of diabetes. During the 5-year follow-up, people with moderate-to-severe renal dysfunction as compared with normal, had 3.21 times higher CVD risk [95% confidence interval (CI) 1.98-5.19], after adjusting for history of hypertension (hazard ratio = 2.15, 95% CI 1.48-3.11), hypercholesterolemia (1.37, 0.98-1.98), diabetes (3.28, 2.15-5.00), smoking habits (0.89, 0.60-1.32) and physical activity status (0.86, 0.56-1.21).

CONCLUSION

Renal function seems to be associated with the levels of lifestyle and bio-clinical CVD risk factors and contribute to the long-term incidence of cardiac events. Public health care practitioners should take into account renal function in better preventing the burden of CVD at individual, and population level, as well.

Epidemiology of cardiorenal syndrome

The interdependence of cardiac and renal dysfunction has emerged as a focus of intense interest in heart failure management due to the substantial associated morbidity and mortality. Captured in the clinical entity known as cardiorenal syndrome, recent definitions afford discussion of the acute and longitudinal evaluation and management of these patients. This article discusses potential pathophysiologic mechanisms of cardiorenal syndrome, epidemiology, inpatient and long-term care (including investigational therapies and mechanical fluid removal), and end-of-life and palliative care.

Combined cardiac CT and MRI for the comprehensive workup of hemodynamically relevant coronary stenoses

OBJECTIVE

The purpose of our study was to prospectively evaluate the accuracy of a comprehensive assessment of coronary artery disease (CAD) with prospectively ECG-gated coronary CT angiography (CTA) and perfusion-cardiac MRI for the detection of hemodynamically relevant coronary stenoses.

SUBJECTS AND METHODS

Forty-seven consecutive patients underwent k-space and time broad-use linear acquisition speed-up technique accelerated perfusion-cardiac MRI at 1.5 T and dual-source coronary CTA. Catheter coronary angiography (CA), coronary CTA, and perfusion-cardiac MRI were all performed within a median time interval of 7.5 days. Detection of hemodynamically relevant stenoses by the combination of coronary CTA plus perfusion-cardiac MRI was compared with the combination of CA plus perfusion-cardiac MRI, the latter serving as the standard of reference.

RESULTS

CA identified stenoses in 75 of 141 coronary arteries (53.2%) in 33 of 47 patients (70.2%). Cardiac MRI revealed perfusion defects in 30 of 47 patients (63.8%). Image quality of coronary CTA was diagnostic in 635 of 638 segments (99.5%). Coronary CTA revealed stenoses greater than 50% in 76 of 141 coronary arteries (53.9%) of 33 of 47 patients (70.2%). Sensitivity, specificity, negative and positive predictive value, and accuracy of coronary CTA and perfusion-cardiac MRI versus CA and perfusion-cardiac MRI for the detection of hemodynamically relevant stenoses were 96.7%, 100%, 94.4%, 100%, and 97.9%, respectively.

CONCLUSION

The combination of coronary CTA and perfusion-cardiac MRI shows diagnostic performance comparable to that of CA and perfusion-cardiac MRI. Preliminary data suggest that coronary CTA may replace CA in the diagnosis of hemodynamically relevant CAD.

The critical link of hypervolemia and hyponatremia in heart failure and the potential role of arginine vasopressin antagonists

BACKGROUND

Hypervolemia and hyponatremia resulting from activation of the neurohormonal system and impairment of renal function are prominent features of decompensated heart failure. Both conditions share many pathophysiologic and prognostic features and each has been associated with increased morbidity and mortality. When both conditions coexist, therapeutic options are limited.

METHODS AND RESULTS

This review presents a concise digest of the pathophysiology, clinical significance, and pharmacological therapy of hyponatremia complicating heart failure with a special emphasis on vasopressin antagonists and their aquaretic effects in the absence of neurohormonal activation along with their ability to correct hyponatremia.

CONCLUSIONS

Hypervolemia and hyponatremia share many pathophysiologic and prognostic features in heart failure. Vasopressin antagonists provide a viable option for their management and a potentially unique role when both conditions coexists.

Relationship between renal dysfunction and severity of coronary artery disease in Japanese patients

BACKGROUND

The relationship between renal dysfunction and the severity of coronary artery disease (CAD) was examined.

METHODS AND RESULTS

The severity of CAD in 572 patients was graded according to the number of stenotic coronary arteries, and the estimated glomerular filtration rate (eGFR) was monitored for 3 years. Patients were stratified into 3 eGFR groups: normal (>75 ml x min(-1) x 1.73 m(-2)), mild reduction (60-75) and chronic kidney disease (CKD: <60). There were 161 patients in the CKD group. The average number of stenotic coronary arteries was larger in the CKD group than in the other groups (normal vs mild reduction vs CKD =1.35+/-0.07 (SE) vs 1.22+/-0.08 vs 1.69+/-0.08 vessel disease (VD), P<0.001). During the 3-year follow-up, the renal function of 13.8% of the patients worsened. Those who showed more deterioration of eGFR had more severe CAD than those who did not (1.20+/-0.06 vs 1.61+/-0.06 VD, P<0.001). Multivariate analysis revealed that the severity of CAD was independently and significantly associated with the deterioration of eGFR.

CONCLUSIONS

Patients with CKD had more severe CAD, which may explain the high rate of cardiovascular events in these patients. Moreover, the prognosis of renal function was poor in patients with severe CAD, and CAD was found to be an independent risk factor for worsening of renal dysfunction.

Pulmonary vein isolation for the maintenance of sinus rhythm in patients with atrial fibrillation: a meta-analysis of randomized, controlled trials

BACKGROUND

Catheter ablation is an established yet evolving nonpharmacologic intervention for the maintenance of sinus rhythm in patients with atrial fibrillation (AF). The efficacy and safety of pulmonary vein isolation (PVI) compared with medical therapy remain in question.

METHODS AND RESULTS

We conducted a meta-analysis of all randomized, controlled trials comparing PVI and medical therapy for the maintenance of sinus rhythm. The primary end point in this analysis was freedom from recurrent AF at 12 months. The relative efficacy of PVI was estimated using random-effects modeling according to intention to treat. We identified 6 trials that randomized a total of 693 patients with AF to PVI or control. PVI was associated with markedly increased odds of freedom from AF at 12 months of follow-up (n=266/344 [77%] versus n=102/346 [29%]; odds ratio, 9.74; 95% CI, 3.98 to 23.87). When we excluded the trial that only enrolled patients with persistent AF (Q-statistic, 2.485; P=0.647 after exclusion), PVI was associated with even greater odds of AF-free survival (15.78; 95% CI, 10.07 to 24.73). PVI was associated with a decreased hospitalization for cardiovascular causes (14 versus 93 per 100 person-years; rate ratio, 0.15; 95% CI, 0.10 to 0.23). Among those randomly assigned to PVI, 17% required a repeat PVI ablation before 12 months. The rate of major complications was 2.6% (n=9/344) in the catheter ablation group.

CONCLUSIONS

Compared with a nonablation treatment strategy, PVI results in dramatically increased freedom from AF at 1 year. Although the procedure can be associated with major complications, the risk of these complications is comparable to other interventional procedures.

Chronic kidney disease as a predictor of coronary lesion morphology

Coronary artery disease (CAD) is the main cause of death in patients with chronic kidney disease (CKD). We investigated whether CKD stage affected coronary lesion morphology in patients with established CAD. Coronary angiograms of 264 patients were evaluated. Chronic kidney disease was staged using the estimated glomerular filtration rate (eGFR) from the serum creatinine prior to coronary angiography. Patients were divided into 3 groups: dialysis or severe decrease in GFR <30 mL/min per 1.73 m(2) (group 1; n = 60), patients with moderate kidney failure (group 2; n = 116), and patients with normal renal function or mild decrease in GFR (group 3; n = 88). The likelihood of CAD and lesion complexity increased with decreasing eGFR (P = .001). Patients with CKD also had more significant CAD. The risk of significant coronary obstruction and lesion complexity increased progressively with decreasing eGFR. The eGFR may predict lesion complexity among patients with CKD undergoing coronary angiography.

Cardiorenal syndrome in acute decompensated heart failure

Renal dysfunction is highly prevalent in patients with heart failure. Furthermore, worsening renal function in patients with acute decompensated heart failure (ADHF), the so-called cardiorenal syndrome, impacts short and long-term morbidity and mortality. In recent years, more evidence has surfaced from clinical trials and heart failure registries that a complex cross-talk between the kidney and heart in patients with ADHF exists. Meanwhile, management of patients presenting with ADHF and concomitant renal dysfunction continues to be challenging. Therefore, understanding the interaction of the heart and kidneys is pivotal in tailoring therapy of these patients. We have extensively reviewed the pathophysiology of ADHF, the role of neurohoromones as well as other biomarkers and predictors of mortality in these patients based on the current evidence. Moreover, we have discussed the current and future pharmacologic and non-pharmacologic therapies for treatment of this deadly disease. The strength of the evidence is limited, however, due to a paucity of randomized controlled trials in this patient population. What is evident from current national statistics; however, are the poor results in treating the congestion of ADHF. In this regard, the role of secondary hyperaldosteronism is discussed in the diuretic section as well as diuretic resistance in ADHF. In conclusion, since renal function is the single most important prognostic factor in the outcome of patients with ADHF, a better understanding of the pathophysiology of the cardiorenal syndrome is needed to target therapy and ultimately improve the mortality of patients with ADHF.

Increased mortality among survivors of myocardial infarction with kidney dysfunction: the contribution of gaps in the use of guideline-based therapies

Background

We assessed the degree to which differences in guideline-based medical therapy for acute myocardial infarction (AMI) contribute to the higher mortality associated with kidney disease.

Methods

In the PREMIER registry, we evaluated patients from 19 US centers surviving AMI. Cox regression evaluated the association between estimated glomerular filtration rate (GFR) and time to death over two years, adjusting for demographic and clinical variables. The contribution of variation in guideline-based medical therapy to differences in mortality was then assessed by evaluating the incremental change in the hazard ratios after further adjustment for therapy.

Results

Of 2426 patients, 26% had GFR ≥ 90, 44% had GFR = 60- < 90, 22% had GFR = 30- < 60, and 8% had GFR < 30 ml/min/1.73 m². Greater degrees of renal dysfunction were associated with greater 2-year mortality and lower rates of guideline-based therapy among eligible patients. For patients with severely decreased GFR, adjustment for differences in guideline-based therapy did not significantly attenuate the relationship with mortality (HR 3.82, 95% CI 2.39–6.11 partially adjusted; HR = 3.90, 95% CI 2.42–6.28 after adjustment for treatment differences).

Conclusion

Higher mortality associated with reduced GFR after AMI is not accounted for by differences in treatment factors, underscoring the need for novel therapies specifically targeting the pathophysiological abnormalities associated with kidney dysfunction to improve survival.

Sodium Retention in Heart Failure and Cirrhosis

Patients with cirrhosis and heart failure (HF) share the pathophysiology of decreased effective arterial blood volume because of splanchnic vasodilatation in cirrhosis and decreased cardiac output in HF, with resultant stimulation of the renin-angiotensin-aldosterone system. Hyperaldosteronism plays a major role in the pathogenesis of ascites and contributes to resistance to loop diuretics. Therefore, the use of high doses of aldosterone antagonist (spironolactone up to 400 mg/day) is the main therapy to produce a negative sodium balance in cirrhotic patients with ascites. Hyperaldosteronism also has increasingly been recognized as a risk factor for myocardial and vascular fibrosis. Therefore, low-dose aldosterone antagonists are being used in patients with HF for cardioprotective action. However, the doses (25 to 50 mg/day) at which they are being used in cardiac patients as reported in the Randomized Aldactone Evaluation Study are not natriuretic. It is likely, therefore, that the mortality benefit relates primarily from their effect on cardiac and vascular fibrosis. Resistance to commonly used loop diuretics is frequently present in patients with advanced HF. In patients with decompensated HF with volume overload who are loop diuretic resistant, ultrafiltration may be the only available option. This is, however, an invasive procedure. For these patients, natriuretic doses of aldosterone antagonists (spironolactone >50 mg/day) may be a potential option. The competitive natriuretic response of aldosterone antagonists is related to activity of the renin-angiotensin-aldosterone system: the higher the renin-angiotensin-aldosterone system activity, the higher the dose of aldosterone antagonist required to produce natriuresis. This article will discuss the potential use of natriuretic doses of aldosterone antagonists in patients with HF, including the potential side effect of hyperkalemia.

Ultrafiltration for congestive heart failure

Relief of congestive symptoms is a primary goal in treating heart failure. Ultrafiltration is a tool that can be used to safely remove sodium and water from whole blood at a controlled rate. Ultrafiltration decreases symptoms, relieves congestion, and improves hemodynamics, neurohormonal balance, and exercise capacity. This article describes the importance of congestion as a therapeutic target in heart failure and outlines the development of ultrafiltration as a treatment to address this important physiologic state.