Author + information
- Michele Esposito1,
- Ryan O'Kelly1,
- Nima Aghili1,
- Shiva Annamalai1,
- Anas Hamadeh1,
- Michael Kiernan1,
- Amanda Vest1,
- David DeNofrio1 and
- Navin Kapur1
Hemolysis is a complication of micro-axial impeller pumps (Impella). Markers of hemolysis among LVADs include lactate dehydrogenase (LDH) >2.5 times the upper limit of normal (ULN) and plasma-free hemoglobin (pf-Hb) >20mg/dL. We studied the predictive value of LDH or pf-Hb as hemolytic markers in patients with a left-sided Impella device for cardiogenic shock (CS).
We retrospectively studied 46 consecutive patients receiving an Impella at our institution between 2013-2015. LDH and pf-Hb values before and within 72 hours after device implant were available in 45 and 25 patients respectively. Area under receiver-operator characteristic curves (AUCs) for diagnosing hemolysis were calculated.
Mean age was 61±13 with an ejection fraction of 16±7%. Mean duration of support was 5.5±4.1 days. Pre-device LDH levels were >2.5x ULN in 56% (n=25) and pf-Hb levels were >20mg/dL in 36% (n=9) of patients. Based on these data, we were unable to use LDH or a pf-Hb>20 to identify hemolysis. We thus defined hemolysis as pf-Hb >40mg/dL within 72 hours post-implant and clinical evidence of device-related hemolysis. We identified that 19% (n=4) had hemolysis. Using receiver operating characteristic curve-derived cut-points, an increase in pf-Hb by>27mg/dL, not LDH, within 24 hours after implant (pf-Hb: C-statistic = 0.94, sensitivity: 75%, specificity: 94%, p<0.01) was highly predictive of hemolysis (Figure).
This is the first study to establish that a change in pf-Hb levels, not LDH levels, is a highly sensitive and specific marker of hemolysis for patients treated with an Impella device for cardiogenic shock.
CORONARY: Hemodynamic Support and Cardiogenic Shock