The association among renal insufficiency, pharmacotherapy, and outcomes in 6,427 patients with heart failure and coronary artery disease

Chronic kidney disease and mortality risk: a systematic review

Current guidelines identify people with chronic kidney disease (CKD) as being at high risk for cardiovascular and all-cause mortality. Because as many as 19 million Americans may have CKD, a comprehensive summary of this risk would be potentially useful for planning public health policy. A systematic review of the association between non-dialysis-dependent CKD and the risk for all-cause and cardiovascular mortality was conducted. Patient- and study-related characteristics that influenced the magnitude of these associations also were investigated. MEDLINE and EMBASE databases were searched, and reference lists through December 2004 were consulted. Authors of 10 primary studies provided additional data. Cohort studies or cohort analyses of randomized, controlled trials that compared mortality between those with and without chronically reduced kidney function were included. Studies were excluded from review when participants were followed for < 1 yr or had ESRD. Two reviewers independently extracted data on study setting, quality, participant and renal function characteristics, and outcomes. Thirty-nine studies that followed a total of 1,371,990 participants were reviewed. The unadjusted relative risk for mortality in participants with reduced kidney function compared with those without ranged from 0.94 to 5.0 and was significantly more than 1.0 in 93% of cohorts. Among the 16 studies that provided suitable data, the absolute risk for death increased exponentially with decreasing renal function. Fourteen cohorts described the risk for mortality from reduced kidney function, after adjustment for other established risk factors. Although adjusted relative hazards were consistently lower than unadjusted relative risks (median reduction 17%), they remained significantly more than 1.0 in 71% of cohorts. This review supports current guidelines that identify individuals with CKD as being at high risk for cardiovascular mortality. Determining which interventions best offset this risk remains a health priority.

Use of beta-blockers and aspirin after myocardial infarction by patient renal function in the Department of Defense health care system

BACKGROUND

Whether the previously reported underutilization of standard-of-care medications in the management of patients with acute myocardial infarction (AMI) persists in more recent years or differs by ward of admission has not been reported.

METHODS

We performed a retrospective cross-sectional study of patients hospitalized with a discharge diagnosis of incident AMI to a Department of Defense hospital (Walter Reed Army Medical Center, Washington, DC) from 2001 through 2004. Use of beta-blockers and aspirin at the time of discharge after AMI was assessed according to Modification of Diet in Renal Disease (MDRD) estimated glomerular filtration rate (eGFR) in milliliters per minute per 1.73 m2, stratified by admission to the coronary care unit (CCU) versus other wards. Adjusted odds ratios for discharge beta-blocker and aspirin therapy were calculated by using logistic regression.

RESULTS

Among 431 patients, overall discharge use of beta-blockers was 86.8%, and aspirin, 86.8%, both significantly greater after CCU admission than admission to other wards (93%, aspirin use; 91.7%, beta-blocker use; P < 0.001 and P < 0.001). In logistic regression, CCU admission was the only independent factor associated with either beta-blocker or aspirin use; MDRD eGFR was not associated significantly with beta-blocker and aspirin use regardless of admission to the CCU or non-CCU.

CONCLUSION

Future studies of disparities in use of standard-of-care medications after AMI according to renal function should account for the primary site of admission, particularly CCU versus others. In addition, legitimate contraindications to the use of beta-blockers and aspirin may be subtle, including appropriate end-of-life decisions.

Renal impairment and outcomes in heart failure: systematic review and meta-analysis

OBJECTIVES

We estimated the prevalence of renal impairment in heart failure (HF) patients and the magnitude of associated mortality risk using a systematic review of published studies.

BACKGROUND

Renal impairment in HF patients is associated with excess mortality, although precise risk estimates are unclear.

METHODS

A systematic search of MEDLINE (through May 2005) identified 16 studies characterizing the association between renal impairment and mortality in 80,098 hospitalized and non-hospitalized HF patients. All-cause mortality risks associated with any renal impairment (creatinine >1.0 mg/dl, creatinine clearance [CrCl] or estimated glomerular filtration rate [eGFR] <90 ml/min, or cystatin-C >1.03 mg/dl) and moderate to severe impairment (creatinine > or =1.5, CrCl or eGFR <53, or cystatin-C > or =1.56) were estimated using fixed-effects meta-analysis.

RESULTS

A total of 63% of patients had any renal impairment, and 29% had moderate to severe impairment. After follow-up > or =1 year, 38% of patients with any renal impairment and 51% with moderate to severe impairment died versus 24% without impairment. Adjusted all-cause mortality was increased for patients with any impairment (hazard ratio [HR] = 1.56; 95% confidence interval [CI] 1.53 to 1.60, p < 0.001) and moderate to severe impairment (HR = 2.31; 95% CI 2.18 to 2.44, p < 0.001). Mortality worsened incrementally across the range of renal function, with 15% (95% CI 14% to 17%) increased risk for every 0.5 mg/dl increase in creatinine and 7% (95% CI 4% to 10%) increased risk for every 10 ml/min decrease in eGFR.

CONCLUSIONS

Renal impairment is common among HF patients and confers excess mortality. Renal function should be considered in risk stratification and evaluation of therapeutic strategies for HF patients.

Cardiac assessment for renal transplantation

Cardiac death is common in patients with end-stage renal failure. Screening for coronary artery disease prior to renal transplantation is advisable in high-risk patients. The optimal screening test has not been defined; however, myocardial perfusion studies are more sensitive than exercise electrocardiography and are less invasive than coronary angiography, which remains the gold standard. The management of coronary artery disease prior to transplantation is contentious. Revascularization of coronary artery stenoses is associated with high mortality and morbidity in the renal failure population, and there is little data to indicate that most patients with asymptomatic coronary lesions will benefit from prophylactic coronary intervention. In addition, beta-blockers and aspirin are under-utilized in the renal population. This paper reviews the literature and proposes algorithms for the cardiac assessment and management of patients prior to renal transplantation.

Chronic Kidney Disease as a Situation of High Added Risk in Hypertensive Patients

Recent guidelines for the management of hypertension have recognized the relevance of renal function on cardiovascular prognosis of hypertensive patients. In fact, growing evidences have confirmed that as soon as renal function exhibits minor derangements, cardiovascular risk starts a continuous rise until the development of end-stage renal disease. Both estimated glomerular filtration rate and urinary albumin excretion are associated with an increased incidence of cardiovascular events and death among hypertensive patients and in general population. Consequently, hypertensive patients presenting with chronic kidney disease are considered by guidelines as high-risk patients, and strict blood pressure control should be considered as a part of an integrative therapeutic approach, including correction of anemia, treatment of dyslipidemia, cessation of tobacco use, and antiplatelet therapy. This paper briefly reviews the most recent evidences about pharmacologic therapies in high-risk patients, focusing on benefits related to improvement of cardiovascular risk factors in hypertensive patients with chronic kidney disease.

Non-cardiac comorbidities in chronic heart failure

Non-cardiac comorbidity complicates heart failure care and is prevalent in one form or another for the majority of elderly patients with heart failure. This wide range of comorbidities, which includes respiratory comorbidities, renal dysfunction, anaemia, arthritis, cognitive dysfunction and depression, contributes to the progression of the disease and may alter the response to treatment. Polypharmacy is inevitable in these patients. Cardiologists and other physicians caring for patients with chronic heart failure (CHF) need to be vigilant to comorbid conditions that may complicate the care of these patients. Future trials should focus on optimal strategies for the comprehensive management of the elderly patients with CHF with multiple comorbidities rather than the isolated effects of single drugs in younger patients with few or no comorbidities.

Outcomes in patients with chronic kidney disease undergoing cardiac rehabilitation

BACKGROUND

Chronic kidney disease (CKD) is associated with an adverse prognosis in patients with coronary heart disease. Cardiac rehabilitation (CR) improves morbidity and mortality among patients with coronary heart disease, but its impact on patients with concomitant CKD has not been described.

METHODS

We compared baseline characteristics of patients with CKD (calculated glomerular filtration rate <60 mL/min per 1.73 m2) and without CKD who completed CR between 1996 and 2004 using t tests and chi2 tests. CR outcomes were evaluated by comparing the degree of change in clinical and behavioral variables within and between groups with paired and unpaired t testing, respectively, and by comparing the proportion of patients who achieved secondary prevention goals between groups using chi2 testing.

RESULTS

Among 376 patients, CKD was present in 115 (31%). Patients with CKD were older, had more cardiac risk factors and comorbidities, and had lower functional capacity and perceived health status than patients without CKD. Both groups achieved significant improvements in diet scores, body weight, lipid profiles, 6-minute walk distances, physical activity level, and perceived health status. The proportion of patients who achieved secondary prevention goals was also similar, but patients with CKD continued to have lower high-density lipoprotein cholesterol, lower physical component health status summary scores, and lower functional capacity than patients without CKD.

CONCLUSIONS

CKD is common among CR participants. Patients with CKD have a high cardiovascular risk factor and comorbidity burden. CR is as effective in improving coronary risk profiles among patients with CKD as it is among patients with normal renal function.

Effect of pravastatin in people with diabetes and chronic kidney disease

Although diabetes is a major cause of chronic kidney disease (CKD), limited data describe the cardiovascular benefit of hydroxymethyl glutaryl CoA reductase inhibitors (statins) in people with both of these conditions. This study sought to determine whether pravastatin reduced the incidence of first or recurrent cardiovascular events in people with non-dialysis-dependent CKD and concomitant diabetes, using data from three randomized trials of pravastatin 40 mg daily versus placebo. CKD was defined by estimated GFR <60 or 60 to 89.9 ml/min per 1.73 m2 with proteinuria. Of 19,737 patients, 4099 (20.8%) had CKD but not diabetes at baseline, 873 (4.4%) had diabetes but not CKD, and 571 (2.9%) had both conditions. The primary composite outcome was time to myocardial infarction, coronary death, or percutaneous/surgical coronary revascularization. Median follow-up was 64 mo. After adjustment for trial and random treatment assignment, the incidence of the primary outcome was lowest in individuals with neither CKD nor diabetes (15.2%), intermediate in individuals with only CKD (18.6%) or only diabetes (21.3%), and highest in individuals with both characteristics (27.0%). Pravastatin reduced the relative likelihood of the primary outcome to a similar extent in subgroups defined by the presence or absence of CKD and diabetes. For example, pravastatin was associated with a significant reduction in the relative risk of the primary outcome by 25% in patients with CKD and concomitant diabetes and by 24% in individuals with neither characteristic. However, the absolute reduction in the risk of the primary outcome as a result of pravastatin use was highest in patients with both CKD and diabetes (6.4%) and lowest in individuals with neither characteristic (3.5%). In conclusion, stage 2 or early stage 3 CKD and diabetes both are associated with higher cardiovascular risk, and pravastatin reduces cardiovascular event rates in people with neither, one, or both characteristics. Given the high absolute benefit of pravastatin in patient with diabetes and stage 2 or early stage 3 CKD, this population in particular should be targeted for widespread use of statins. Additional studies are needed to determine whether these benefits apply to patients with more severe CKD, and recruitment to such studies should be given high priority.

Improved clinical outcomes associated with metformin in patients with diabetes and heart failure

OBJECTIVE

Metformin is considered contraindicated in patients with heart failure because of concerns over lactic acidosis, despite increasing evidence of potential benefit. The aim of this study was to evaluate the association between metformin and clinical outcomes in patients with heart failure and type 2 diabetes.

RESEARCH DESIGN AND METHODS

Using the Saskatchewan Health databases, 12,272 new users of oral antidiabetic agents were identified between the years 1991 and 1996. Subjects with incident heart failure (n = 1,833) were identified through administrative records based on ICD-9 code 428 and grouped according to antidiabetic therapy: metformin monotherapy (n = 208), sulfonylurea monotherapy (n = 773), or combination therapy (n = 852). Multivariate Cox proportional hazards models were used to assess differences in all-cause mortality, all-cause hospitalization, and the combination (i.e., all-cause hospitalization or mortality).

RESULTS

Average age of subjects was 72 years, 57% were male, and average follow-up was 2.5 +/- 2.0 (SD) years. Compared with sulfonylurea therapy, fewer deaths occurred in subjects receiving metformin: 404 (52%) for sulfonylurea monotherapy versus 69 (33%) for metformin monotherapy (hazard ratio [HR] 0.70 [95% CI 0.54-0.91]) and 263 (31%) for combination therapy (0.61 [0.52-0.72]). A reduction in deaths or hospitalizations was also observed: 658 (85%) for sulfonylurea monotherapy versus 160 (77%) for metformin monotherapy (0.83 [0.70-0.99]) and 681 (80%) for combination therapy (0.86 [0.77-0.96]). There was no difference in time to first hospitalization between study groups.

CONCLUSIONS

Metformin, alone or in combination, in subjects with heart failure and type 2 diabetes was associated with lower morbidity and mortality compared with sulfonylurea monotherapy.

Cardio-renal insufficiency: the search for management strategies

PURPOSE OF REVIEW

This review focuses on the pathophysiology and treatment of an increasingly common entity, cardio-renal insufficiency. Cardio-renal insufficiency is more than a simultaneous cardiac and renal disease. Patients with this condition live within a fragile equilibrium challenged by the interaction of profibrogenic, atherosclerotic, neurohumoral, and other less known factors. Regarding therapy, the avoidance of oscillations between overfilled-decompensated and emptied-overtreated states becomes of critical importance. Particular focus should be paid to personalized treatment, adjusted according to heart and kidney reserve, the predictable complications of therapy, prevention of decompensations, simple measures-based follow-up and alternative procedures.

RECENT FINDINGS

Recent studies have established the important repercussions of unbalanced renal function on cardiovascular prognosis. In the heart failure setting, trials involving extensive cohorts of ageing or comorbidity-affected patients are presently under way. Special attention should be paid to recognize the presence of renal failure coexisting with heart failure, especially in patients with deceivingly near-normal plasma creatinine. Formulae to predict creatinine clearance are being increasingly incorporated into daily clinical practice. Disturbed renal function is an underappreciated prognostic factor in heart failure, and renal failure is frequently viewed as a relative contraindication to some proven efficacious therapies.

SUMMARY

Cardio-renal insufficiency is an emerging entity, with affected individuals surviving with extreme degrees of simultaneous heart failure and renal failure. Management of the condition is an intellectually demanding process. Crucial to this management is extensive medical expertise and an in-depth understanding of the particular renal, haemodynamic and internal milieu equilibrium of the patients.

Effect of pravastatin on rate of kidney function loss in people with or at risk for coronary disease

BACKGROUND

Limited data suggest that HMG-CoA reductase inhibitors (statins) reduce rates of kidney function loss. We performed this analysis to determine whether pravastatin reduced the rate of kidney function loss over approximately 5 years in people with or at high risk for coronary disease.

METHODS AND RESULTS

This was a post hoc subgroup analysis of data from 3 randomized double-blind controlled trials comparing pravastatin 40 mg/d and placebo in subjects with a previous acute coronary syndrome or who were at high cardiovascular risk. The primary outcome was the rate of change in estimated glomerular filtration rate (GFR; in mL/min per 1.73 m2/y). The Modified Diet and Renal Disease Study (MDRD) and Cockcroft-Gault equations were used to estimate GFR. We studied 18,569 participants, 3402 (18.3%) of whom had moderate chronic kidney disease as defined by an estimated GFR of 30 to 59.9 mL/min per 1.73 m2 body surface area. In subjects with moderate chronic kidney disease at baseline, pravastatin reduced the adjusted rate of kidney function loss by approximately 34%, although the absolute reduction in the rate of loss was small (0.22 mL/min per 1.73 m2/y by MDRD-GFR; 95% CI, 0.07 to 0.37). Pravastatin did not reduce the frequency of > or =25% decreases in kidney function in this group when MDRD-GFR was used to estimate GFR (relative risk [RR], 0.84; 95% CI, 0.66 to 1.06). When all 18,569 subjects were considered, pravastatin reduced the adjusted rate of kidney function loss by 8% (0.08 mL/min per 1.73 m2/y by MDRD-GFR; 95% CI, 0.01 to 0.15) and the risk of acute renal failure (RR, 0.60; 95% CI, 0.41 to 0.86) but did not significantly reduce the frequency of a > or =25% decline in kidney function by MDRD-GFR (RR, 0.94; 95% CI, 0.88 to 1.01).

CONCLUSIONS

Pravastatin modestly reduced the rate of kidney function loss in people with or at risk for cardiovascular disease. However, the primary indication for the use of statins in people with or at risk for coronary events remains the reduction in mortality that results from their use.

Evidence-based vs. ‘impressionist’ medicine: how best to implement guidelinesThe opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology

Implementing clinical practice guidelines improves outcomes. This has been shown by several large scale registries. However, in spite of this, guidelines are poorly implemented in clinical practice for a wide variety of reasons. We examine the reasons behind the low uptake of guidelines into routine medical practice. Many physicians are simply not aware that guidelines exist; or they do not believe in them; or they simply do not care to implement them. Economic and social factors may also influence uptake of guidelines. It is the role of professional societies to disseminate best scientific knowledge, and ensure optimum implementation of guidelines. This can be achieved through educational activities and CME credit. Close collaboration between the profession, health authorities, and maybe even the industry could improve uptake of clinical practice guidelines, and thereby improve patient outcome.