Short-term, intensive renal replacement therapy using hemodiafiltration after primary or urgent percutaneous coronary intervention (PCI) improves in-hospital and 1-year survival in acute coronary syndrome (ACS) patients with severe renal and cardiac dysfunction, according to an Italian pilot study published online October 24, 2014, ahead of print in Catheterization and Cardiovascular Interventions.

Giancarlo Marenzi, MD, of Centro Cardiologico Monzino (Milan, Italy), and colleagues enrolled 30 consecutive ACS patients (30% STEMI; 70% NSTEMI) who had a glomerular filtration rate (eGFR) ≤ 30 ml/min/1.73 m² and LVEF ≤ 40%. Patients were given 3 hours of prophylactic hemodiafiltration with isotonic, isovolemic replacement fluid within 1 hour after PCI from November 2009 to December 2011. Their results were compared with those of 30 retrospectively identified controls with similar baseline characteristics who were treated for ACS at a different hospital in Milan during the study period.

Patient age was 79 ± 8 years, and approximately half were male. LVEF was 31 ± 8% and eGFR 22 ± 6 ml/min/1.73 m², and diabetes was more prevalent in the hemodiafiltration group. Hemodiafiltration was performed successfully and without procedure-related complications in all patients who received it.

Short-, Long-term Mortality Reduced

Patients treated with hemodiafiltration experienced lower in-hospital mortality compared with controls. Though the difference did not reach significance, acute kidney injury (AKI) occurred less often in the hemodiafiltration group. Patients who received hemodiafiltration also had less severe AKI and reduced need for rescue renal replacement therapy (table 1).

Causes of in-hospital death were septic shock (n = 1) in the hemodiafiltration group and cardiogenic shock (n = 6) and refractory heart failure (n = 1) in the control group.

At hospital discharge, serum creatinine levels in surviving patients were 2.7 ± 1.0 mg dL^-1 for the hemodiafiltration group and 2.6 ± 0.8 mg dL^-1 for the control group (P = .67). No patient required dialysis at discharge.

By 1-year follow-up, there were 11 additional deaths, and 2 hemodiafiltration patients and 1 control had begun chronic hemodialysis. Overall, 1-year mortality remained lower in the hemodiafiltration group (10% vs 53%; P < .001), and Kaplan-Meier survival analysis confirmed greater freedom from death (P < .001).

Renal Protective Effect Apparent

The mechanism by which hemodiafiltration improves survival is not fully understood, the authors say, but they postulate that it may impact AKI “by preserving systemic and renal hemodynamic stability, blunting the negative effects of neurohumoral activation, and contributing to residual endogenous clearance of contrast media.”

Because of the relationship between AKI and mortality in high-risk patients, Dr. Marenzi and colleagues add, “prevention of AKI is expected to result in a more favorable outcome.”

The authors note that their results contrast those of other studies on renal replacement therapies in similar populations. They attribute the discrepancy to differences in “clinical context and… therapeutic target,” noting that the optimal conditions for elective angiography and urgent/emergency angiography are not necessarily the same; the latter requires “the support of renal function during hemodynamic instability.”

Furthermore, the amount of fluid exchanged per patient in the 3 hours of intense hemodiafiltration was equal to or greater than that used by other researchers, even where renal replacement therapy lasted up to 24 hours, they add.

Due to study limitations, the results can only be considered hypothesis generating, the authors advise. Specifically, they cite aspects such including the comparison of patients from 2 different hospitals, observational design, 85% use of radial access, imperfect patient matching, the ability of eGFR and LVEF measurements to “conceal different risk profiles,” and the arbitrary duration and amount of fluid replacement in the hemodiafiltration protocol.

Source:
Marenzi G, Mazzotta G, Londrino F, et al. Post-procedural hemodiafiltration in acute coronary syndrome patients with associated renal and cardiac dysfunction undergoing urgent and emergency coronary angiography. Catheter Cardiovasc Interv. 2014;Epub ahead of print.

Disclosure:

• Dr. Marenzi reports no relevant conflicts of interest.

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