The Challenge of Sudden Death in Dialysis Patients

Abstract

A 60-yr-old patient with ESRD (82 kg/168 cm), hypertension for the previous 18 yr, and type 2 diabetes is found dead in bed by his wife at home on a Saturday morning. The patient's history is notable for having started dialysis 34 weeks previously. His last dialysis had been the previous day (on a Friday afternoon). Predialysis potassium had been 5.7 mmol/L, the dialysate K ϩ was 2.0 mmol/L, and Mg 2ϩ was 0.5 mmol/L. Autopsy was not performed.Before his morbid event, the patient had been doing well on dialysis. He had less than 6 episodes of hypotension (Ͻ100 mmHg) per month. His average predialytic weight gain was 4 kg, and, with fluctuations, his average predialysis BP was 155/65 mmHg. While continuing on gliquidone (an oral sulfonylurea hypoglycemic drug that does not accumulate in renal failure), he had no episodes of hypoglycemia, and his last glycosylated hemoglobin level was 7.2%. His medical history is of hypertension, type 2 diabetes, and left ventricular hypertrophy (LVH) with an ejection fraction of 55%. His electrocardiogram showed signs of LVH and flat T waves. He had no history of hypoglycemic episodes and no evidence of retinopathy. He reported no episodes of arrhythmia or precordial pain. A predialysis chest x-ray 2 wk before the terminal event had shown pulmonary congestion. His medications included 0.25 g/d calcitriol, calcium carbonate, 10 mg of folate, 80 mg of verapamil, and no ␤ blockers. In addition, he received varying doses of darbepoietin and iron gluconate as required. He did not receive a statin. Dr. Eberhard Ritz: This case, unfortunately, is the usual presentation of patients on dialysis who succumb to sudden death: There are few, if any, specific premonitory symptoms or signs, cardiac standstill is usually the presenting symptom, and autopsy is not performed, so more specific information on underlying cardiac pathology, if any, is not available. The lack of pathoanatomic confirmation of the underlying pathology or pathologies-as in this case-continues to remain a problem that in the future should come onto the radar screen of nephrologists.Nevertheless, this case presentation raises a number of unresolved issues and provides an occasion to discuss how the currently unsatisfactory results might be improved in the future. In this context, it is of interest to have a look at the recent 4D study.

Electrocardiography and Outcome in Patients with Diabetes Mellitus on Maintenance Hemodialysis

“…LVH diagnosed by ECG criteria was predictive of stroke and sudden death. This is in line with previous data in patients without kidney disease, reporting LVH to be among the risk factors for ischemic stroke and sudden death (17,18). With respect to total mortality and CVE, we found a significant association in the univariate, but not in the multivariate, analyses.…”

Disentangling the Ultrafiltration Rate–Mortality Association

“…By necessitating more rapid fluid removal in a compressed timeframe, shorter dialysis sessions expose patients to greater fluid shifts with attendant myocardial stunning and ischemia (15), intradialytic hypotension, hemodynamic destabilization (16), and resultant interruptions of end-organ perfusion. The cumulative consequences of these cardiac stresses have been linked to maladaptive changes in left ventricular geometry such as hypertrophy and fibrosis with derivative heart failure and conduction system abnormalities (15,(17)(18)(19)(20)(21)(22). Shorter dialysis sessions may also detrimentally affect survival through limiting removal of phosphorus, b2-microglobulin, and other middle molecules (23)(24)(25).…”

“…Chronic volume overload promotes maladaptive cardiac structural changes (e.g., left ventricular hypertrophy and fibrosis) through direct activation of the mammalian target of rapamycin pathway (26-28) and through upregulation of the sympathetic nervous system and renin-angiotensin-aldosterone pathways (29,30). This, in turn, distorts cardiac conduction pathway architecture and predisposes patients to arrhythmias and sudden cardiac death (18)(19)(20)(21)(22). Delineating the independent associations of IDWG and DSL with mortality has important therapeutic implications.…”

Low Plasma α-Tocopherol Concentrations and Adverse Clinical Outcomes in Diabetic Hemodialysis Patients

“…In this context, it has to be considered that the relative contribution of different causes of death to total mortality differs in advanced stages of CKD compared with the general population (8)(9)(10)(11). Although myocardial infarction represents the most frequent cause of death in the general population, sudden cardiac death (SCD) is the major occurring event in dialysis patients (2), which as a single cause, accounts for one quarter of all deaths (2,8).…”