Abstract
Cardiorenal syndrome impacts many heart failure (HF) patients, and the need for hemodialysis (HD) is associated with worsening HF and increased risk of death. The CardioMEMS system (Abbott Medical) was shown to have efficacy in the CHAMPION trial, but cardiorenal patients were excluded from enrollment. Our aim is to determine pulmonary artery (PA) pressure characteristics for HF outpatients receiving routine HD.
Eight HD-HF patients (54 ± 9 yrs, male =4, LVEF = 28 ± 8%) received the CardioMEMS system and were prospectively followed on an outpatient basis. PA pressures were transmitted twice on HD days (pre- and post- HD), and once on non-HD days. PA pressure was monitored weekly to observe long-term characteristics of parameter changes occurring at baseline and during meaningful clinical events (defined as emergent HD sessions or hospital encounter for volume overload). PA pressure was considered baseline if >21 days prior to clinical event or post-medication change. Paired t-test was used for comparisons; P-value <0.05 denoted statistical significance. The study was approved by the institutional IRB.
PA pressures were elevated at implant (mean PA diastolic pressure [PADP] = 29 ± 10 mmHg), remained consistently high even though patients were at "dry weight," and were highest on HD days prior to dialysis (Figure 1). There were significant differences in PA pressure in temporal relation to HD schedule (Figure 2A), with the exception of PADP when compared between non-HD vs post-HD values. 3 patients had a HF event (3 emergent HD, 1 hospitalization) and, compared to patients without HF events, PA pressures exhibited loss of cyclical pressure variation with progressive elevation prior to decompensation (Figure 2B).
HF outpatients with cardiorenal syndrome demonstrate elevated PA pressures at "dry weight." CardioMEMS reveals expected PA pressure changes in temporal association with HD-related fluid removal. Those experiencing HF decompensation do not demonstrate this pattern. Future studies are needed to determine if PA pressures can be used to determine HD-related fluid removal protocols to avoid HF decompensation in these patients.
