Congestive heart failure (CHF) and renal failure (RF) act synergistically to increase the levels of B-type natriuretic peptide (BNP) and its co-secreted biologically inactive N-terminal fragment (NT-proBNP). These two cardiac neurohormones are mainly secreted from the ventricles and, to a lesser extent, the atria. They have an established role as useful diagnostic tests for CHF in both the pediatric and adult population, including RF patients
RF and CHF represent two merging pathologies with a varying spectrum for speed of onset and severity. The intersection of cardiac and renal insufficiency is referred to as cardiorenal syndrome (Type 1 to 5)
, which is CHF as a result of RF or vice versa. Cardiac dysfunction in end-stage kidney disease (ESKD) patients, whether acute or chronic, is often due to disorders of perfusion (ischemic heart disease) or to disorders of structure and function. The disorders of structure and function and CHF are often collectively termed ‘uremic cardiomyopathy’ which is commonly associated with left ventricle (LV) hypertrophy secondary to volume overload and hypertension (HT). Cardiac disease accounts for >50% of deaths in patients with ESKD
The surgically-induced anephric (SIA) patients are a rarity. Despite this, health care providers such as general practitioners, emergency physicians, intensive care physicians and anesthetists will probably come across these anephric patients at some point in their working career. Little is known about the magnitude of natriuretic rise in response to developing CHF in this unique ‘anephric’ ESKD scenario.
We describe three consecutive SIA patients <60 years of age requiring high acute care in an Intensive Care Unit (ICU) or High Dependency Unit (HDU) at some point in their life between May 2004 and December 2009. The patients were all Caucasian adult women from a regional catchment population of 200,000 people in New South Wales, Australia. Using all information pertaining to their presentation obtained over varying periods of time (before and during their SIA states, and after having renal transplant in two of the three patients), including hospital records, results of diagnostic imaging and laboratory testing, we carefully studied each patient in both a prospective and retrospective manner specifically to determine the presence or absence of CHF.
The three subject patients were all on established hemodialysis (HD) thrice weekly (Monday-Wednesday-Friday schedule) for at least 30 days: the first session (Monday) was the dialysis session after a 72-hour inter-dialytic period whereas the second and third sessions were after a 48-hour period. All three patients were under the care of multidisciplinary teams; in particular under renal physicians to comprehensively manage their HD or post-renal transplant status.
The ‘zenith’ pre-dialysis, ‘nadir’ post-dialysis and ‘average’ inter-dialysis body fluid levels meant that their reflective blood samples were to be collected at (respectively) the start of a HD session, the end of a HD session and on a HD-free day. Whenever possible, hematological tests, biochemical tests, and specific hormone analysis for prolactin (ARCHITECT Prolactin assay; Abbott), BNP (ADVIA Centaur® BNP assay; Siemens Healthcare Diagnostics), and NT-proBNP (Elecsys® proBNP; Roche Diagnostics) were performed simultaneously on the same blood sample. Relevant data such as pre-dialysis ‘wet’ weight (kg) and post-dialysis ‘dry’ weight (kg) are used to estimate the net ultrafiltration volume removed as represented by a change in weight. Respectively, heart rate and respiratory rate are given in beats/minute and breaths/minute. Blood pressure (BP) in mmHg is recorded as systolic BP (SBP)/diastolic BP (DBP) with mean arterial pressure (MAP) computed from invasive arterial pressure waveform. Those same BP parameters were computed via the MAP = DBP +
(SBP – DBP) formula during electronic non-invasive BP measurements. ‘Severe HT’ is defined as SBP ≥180mmHg or DBP ≥120mmHg. ‘Resistant HT’ is defined as BP that remains above goal in spite of concurrent use of three anti-HT agents of different classes. The goal BP is less than 140/90mmHg in average risk HT patients.
Body mass index (BMI) is defined as (weight) ÷ (height)2 = kg/m2: normal (<25), overweight (25.0–29.9), and obese (≥30). Chronic kidney disease (CKD) is based on the abbreviated Modification of Diet in Renal Disease equation
 to yield an estimated glomerular filtration rate (eGFR). We utilize the 2002 Kidney Disease Outcomes Quality Initiative of the National Kidney Foundation classification of the stages of chronic RF or CKD with increasing severity as CKD Stage 1 to 5. CHF can be LV systolic heart failure, LV diastolic heart failure, or both. In this paper, the term CHF is taken to be synonymous with ‘LV systolic heart failure’ with severity objectively classified by LV ejection fraction (LVEF) into normal, >50%; moderate, 35%–50%; and severe, <35%. LVEF values were obtained from all available echocardiograms performed on the patients.