Heart failure events in randomized controlled trials for adults receiving maintenance dialysis: a meta-epidemiologic study

BACKGROUND AND HYPOTHESIS: Heart failure is characterized as cardiac dysfunction resulting in elevated cardiac filling pressures with symptoms and signs of congestion. Distinguishing heart failure from other causes of similar presentations in patients with kidney failure is challenging but necessary, and is needed in randomized controlled trials (RCTs) to accurately estimate treatment effects. The objective of this study was to review heart failure events, their diagnostic criteria, and adjudication in RCTs of patients with kidney failure treated with dialysis. We hypothesized that heart failure events, diagnostic criteria, and adjudication were infrequently reported in RCTs in dialysis. METHODS: We conducted a meta-epidemiologic systematic review of RCTs from high-impact medical, nephrology, and cardiology journals from 2000 to 2020. RCTs were eligible if they enrolled adults receiving maintenance dialysis for kidney failure and evaluated any intervention. RESULTS: Of 561 RCTs in patients receiving dialysis, 36 (6.4%) reported heart failure events as primary (10, 27.8%) or secondary (31, 86.1%) outcomes. Ten of the 36 (27.8%) RCTs provided heart failure event diagnostic criteria and five of these (50%) adjudicated heart failure events. These 10 RCTs included event diagnostic criteria for heart failure or heart failure hospitalizations, and their criteria included dyspnoea (5/10), oedema (2/10), rales/crackles (4/10), chest X-ray pulmonary oedema or vascular redistribution (4/10), treatment in an acute setting (6/10), and ultrafiltration or dialysis (4/10). No study explicitly distinguished heart failure from volume overload secondary to non-adherence or underdialysis. CONCLUSION: Overall, we found that heart failure events are infrequently reported in RCTs in dialysis and are heterogeneously defined. Further research is required to develop standardized diagnostic criteria that are practical and meaningful to patients and clinicians.