Pharmacologic therapy in patients with chronic heart failure and chronic kidney disease: a complex issue

Kidney Function, ACE-Inhibitor/Angiotensin Receptor Blocker Use, and Survival Following Hospitalization for Heart Failure: A Cohort Study

Background:

Angiotensin-converting enzyme inhibitors/angiotensin receptor blocker (ACE-I/ARB) improve outcomes in patients with heart failure and reduced left-ventricular (LV) systolic function. However, these medications can cause a rise in serum creatinine and their benefits in patients with HF accompanied by kidney disease are less certain.

Objective:

To characterize associations between estimated glomerular filtration rate (eGFR), patterns of ACE-Is and ARBs use, and 1-year survival following hospitalization for heart failure (HF).

Design:

We formed a retrospective cohort study of patients admitted with HF and followed HF medication prescriptions using the pharmaceutical information network, stratified by discharge eGFR.

Setting:

Cardiology services in 3 centers in Southern Alberta, Canada.

Patients:

The study cohort included patients admitted to hospital with a clinical diagnosis of HF.

Measurements:

eGFR was determined from inpatient laboratory data prior to discharge. Outpatient prescription data prior to and following the index hospitalization was obtained using the Pharmaceutical Information Network of Alberta and survival was determined from provincial vital statistics.

Methods:

Characteristics of the HF cohort were obtained from the Admissions Module of the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) database. Multivariable Cox proportional hazards models were used to evaluate the association between time-varying ACE-I/ARB use, and mortality, and to test whether eGFR modified this association.

Results:

Totally, 1404 patients were included. Within the first 3 months following discharge, ACE-I/ARBs were used in 71%, 67%, 62%, and 52% for those with eGFR > 90, 45-89, 30-44, and < 30 mL/min/1.73 m², respectively, with differences in use persisting after 1 year of follow-up. Patients with eGFR < 45 mL/min/1.73 m² had significantly lower rates of ACE-I/ARB use following hospitalization. In adjusted models, ACE-I/ARB use following discharge was associated with 25% lower risk of mortality (Hazard Ratio [HR]: 0.75, 95% confidence interval [CI]: 0.61-0.92; P < 0.01), without evidence that this association differed by eGFR (P = 0.75).

Limitations:

LV function measurements were not available for the cohort. Due to the observation design of the study, treatment-selection bias may be present.

Conclusion:

Patients with HF and reduced eGFR at time of hospital discharge were less likely to receive ACE-I/ARB despite these medications being associated with lower mortality independent of eGFR. These findings demonstrate the need for further research on strategies for safe use of ACE-I and ARB in patients with HF and kidney disease.

Calibrating the impact of dual RAAS blockade on the heart and the kidney - balancing risks and benefits

Overactivity of the renin-angiotensin-aldosterone system (RAAS) plays a key role in the pathophysiology of heart failure (HF) and chronic kidney disease (CKD). RAAS antagonists can significantly improve clinical outcomes, but monotherapy blocks but one step of the RAAS and can be bypassed through compensatory mechanisms. Providing more complete RAAS blockade by deploying drugs with complementary actions seemed logical - hence the practice of using dual (or triple) RAAS inhibitors. However, RAAS antagonists also exhibit dose-limiting side effects, including acute kidney injury, hyperkalaemia and hypotension, which blunt their overall effectiveness. Despite achieving better RAAS blockade, several trials failed to show clinical outcome improvements. Patients with concomitant CKD and HF (cardiorenal syndrome) are at the greatest risk of these adverse events and therefore the least able to benefit, yet they also have the worst prognosis. This paradox, where those most in need have fewest therapeutic options, poses three questions which are the focus of this review: whether (i) novel therapies that prevent adverse effects can restore therapeutic benefits to patients who would otherwise be RAAS-therapy intolerant, (ii) there are any validated alternatives to their use and (iii) newer approaches to the detection of fluid congestion are ready for implementation.

Heart failure in patients with chronic kidney disease: a systematic integrative review

Introduction. Heart failure (HF) is highly prevalent in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) and is strongly associated with mortality in these patients. However, the treatment of HF in this population is largely unclear. Study Design. We conducted a systematic integrative review of the literature to assess the current evidence of HF treatment in CKD patients, searching electronic databases in April 2014. Synthesis used narrative methods. Setting and Population. We focused on adults with a primary diagnosis of CKD and HF. Selection Criteria for Studies. We included studies of any design, quantitative or qualitative. Interventions. HF treatment was defined as any formal means taken to improve the symptoms of HF and/or the heart structure and function abnormalities. Outcomes. Measures of all kinds were considered of interest. Results. Of 1,439 results returned by database searches, 79 articles met inclusion criteria. A further 23 relevant articles were identified by hand searching. Conclusions. Control of fluid overload, the use of beta-blockers and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and optimization of dialysis appear to be the most important methods to treat HF in CKD and ESRD patients. Aldosterone antagonists and digitalis glycosides may additionally be considered; however, their use is associated with significant risks. The role of anemia correction, control of CKD-mineral and bone disorder, and cardiac resynchronization therapy are also discussed.