How is the Heart Best Protected in Chronic Dialysis Patients?

Continuous renal replacement therapy is associated with acute cardiac stunning in critically ill patients

INTRODUCTION

Intermittent renal replacement therapy induces cardiac stunning in chronic hemodialysis and acute kidney injury (AKI) patients. In chronic hemodialysis, recurrent stunning contributes to heart failure and cardiac death, with ultrafiltration and intradialytic hypotension being the principal determinants of this injury. Continuous renal replacement therapy (CRRT), with its lower ultrafiltration rates and improved hemodynamic profile, should protect against cardiac stunning in AKI. The objective of this study was to assess whether CRRT is associated with cardiac stunning in critically ill patients with AKI.

METHODS

We prospectively measured cardiac function using global and segmental longitudinal left ventricular strain using transthoracic echocardiography in 11 critically ill patients who were started on CRRT for AKI. We compared measurements at 4, 8, and 24 hours to baseline immediately prior to initiation of CRRT, with each patient serving as their own control. We also recorded blood pressure, heart rate, dose of vasoactive medications and intensive care unit mortality.

FINDINGS

Ten of 11 patients developed new regional cardiac stunning, with 8/11 within 4 hours of starting CRRT, despite stable hemodynamics. The number of affected left ventricular segments varied from 1 to 11 (out of 12). The stunning occurred both in patients with preserved and impaired baseline cardiac function, and 7/11 patients died in the intensive care unit.

DISCUSSION

Initiation of CRRT in critically ill patients with AKI is associated with cardiac stunning despite stable hemodynamics. This mechanism may explain lack of clinical benefit of CRRT over intermittent modalities and warrants further investigation to improve cardiovascular outcomes in critically ill patients with AKI.

More with Less: A Trial of Reduced-Intensity Treatment in Transplant-Ineligible Hemodialysis Patients

BACKGROUND

An increasing proportion of hemodialysis patients are ineligible for transplant. Often these patients are elderly, with multiple comorbidities and decreased functional status. Such patients may benefit from modified treatment goals to reduce symptom burden.

OBJECTIVE

To demonstrate the feasibility of a trial of reduced-intensity treatment in nontransplantable patients with end-stage renal disease (ESRD).

STUDY DESIGN

A 6-week study randomized patients to a reduced-intensity intervention versus usual care. Intervention subjects were treated with liberalized goals for serum phosphorus and parathyroid hormone (PTH) as well as predialysis blood pressure in comparison with usual care subjects. Outcomes included assessed feasibility of recruitment, randomization, and data collection.

SETTING AND POPULATION

Sixteen transplant-ineligible hemodialysis patients were recruited from two urban units.

MEASUREMENTS

Blood pressure was recorded weekly, while serum PTH and phosphorus were assessed every 10 days. A quality-of-life measure was administered before and after the trial.

RESULTS

Of 300 patients, 51 were eligible and 16 consented. All were randomized and completed the trial. Patients in the intervention group received significantly lower doses of phosphorus binders and vitamin D analogues, and were less likely to have their dry weight reduced. All patient surveys were completed.

CONCLUSIONS

High-risk hemodialysis patients may benefit from liberalized treatment guidelines but larger studies are necessary.