ORIGINAL ARTICLES  CARDIAC PAPERS 

The Journal of Cardiovascular Surgery 1999 October;40(5):637-44

Copyright © 2000 EDIZIONI MINERVA MEDICA

language: English

The significance of creatine kinase in cardiac patients with acute limb ischaemia

Brow T. D., Kakkar V. V., Das S. K.

From the Department of Surgery The Royal Brompton Hospital, London, UK

Objective. The val­ue of creatine ­kinase (CK) and aspar­tate trans­am­i­nase (AST) has not ­been pre­vi­ous­ly eval­u­at­ed fol­low­ing car­diac sur­gery in the diag­no­sis of ­acute ­limb ischae­mia. Our objec­tive was to ­assess the val­ue of CK and AST ­with ref­er­ence to the diag­no­sis of ­limb ischae­mia, ­effect on ­renal func­tion and prog­no­sis fol­low­ing car­diac sur­gery. Design: all ­patients enter­ing ICU had dai­ly CK and AST meas­ure­ments ­over a two -year peri­od. A ret­ro­spec­tive ­study of ­patients ­with CK val­ues >5,000 U/L was per­formed. Setting: adult inten­sive ­care ­unit of a sec­on­dary and ter­tiary refer­ral cen­tre for car­di­oth­o­rac­ic sur­gery ­with on ­site facil­ities for vas­cu­lar sug­ery. Patient: twenty-sev­en ­patients had CK val­ues great­er ­than 5,000 U/L. A fur­ther ran­dom sam­ple of 35 ­patients, ­with no ­limb ischae­mia ­were ­used to ­give ­medians for CK and AST fol­low­ing car­diac sur­gery. Interventions: twelve of twen­ty-sev­en (44%) ­patients ­were not­ed to ­have acute­ly ischaem­ic ­limbs; 6 of ­these (CK>16,000 U/L) under­went sur­gi­cal inter­ven­tion. Measures: serum lev­els of CK, Peak CK, AST, Peak AST and CK/AST ­ratios. Related to pro­ce­dure and out­come in ­terms of mor­tal­i­tay and mor­bid­ity includ­ing, ­acute ­limb ischae­mia ­defined on clin­i­cal ­grounds and ­renal fail­ure ­defined as crea­ti­nine >200 µ­moles/L.
Results. The ­median val­ues for CK and AST imme­di­ate­ly fol­low­ing uncom­pli­cat­ed car­diac sur­gery ­were 135 (IQR 36-383) and 43 (IQR 26-58) respec­tive­ly. Median CK for the ­patients (CK>5,000) with­out clin­i­cal ischae­mia was 7,440 U/L com­pared to the ­group ­with ischae­mia 17,472 U/L (p<0.05). Renal fail­ure devel­oped in 48% of all ­patients. Eight of the 9 ­patients ­with CK>15,000 devel­oped ­renal fail­ure com­pared to 5 of the 13 ­with CK 5,000-15,000 U/L (p<0.01). 30% of ­patients under­went hae­mof­il­tra­tion; of ­these, 87% ­died. For ­patients ­with ischae­mia ­peak CK and crea­ti­nine cor­re­lat­ed. (r=0.83, p<0.05) Day of peak CK and ­peak AST cor­re­lat­ed (r=0.92, p<0.01). Logged val­ues of CK ­with log val­ues of AST ­showed a high­ly sig­nif­i­cant rela­tion­ship (β=1.16, p<0.001). The over­all mor­tal­ity was 33%.
Conclusions. Patients who devel­op ­limb ischae­mia fol­low­ing car­diac sur­gery ­have a ­high mor­bid­ity and mor­tal­ity. A CK of 17,000 UIL (5667-46539) is indic­a­tive of seri­ous ­limb ischae­mia. Renal fail­ure is like­ly to devel­op in ­patients ­with CK>15,000 U/L. AST may ­become a use­ful addi­tion­al mark­er of ­limb ischae­mia.