Perioperative creatine phosphokinase (CPK) and troponin I trends after elective hip surgery.
BACKGROUND
Perioperative myocardial infarction (MI) is an important risk factor for cardiac morbidity and mortality after hip surgery. On the basis of the limitations of creatine kinase cardiac muscle isoenzyme (CK-MB) in the perioperative setting, and the high specificity of troponin I, we hypothesized that troponin I would be effective at detecting perioperative MI more frequently than CK-MB would be, after hip surgery.


METHODS
A prospective study of the serum levels of creatine phosphokinase (CPK), its isoenzyme CK-MB, and troponin I, in 90 patients with risk factors for coronary artery disease, undergoing hip surgery is reported. We measured these cardiac markers in the postoperative period for 5 days, after hemiarthroplasty, total hip arthroplasty, and hip intramedullary nailing.


RESULTS
We found increased levels of creatine phosphokinase and CK-MB, after all the types of operation, with maximum levels reached on the first postoperative day and the levels were more pronounced after total hip arthroplasty. False-elevated CK-MB index >6% without MI was evidenced in 43.3% of patients. Troponin I levels were elevated >3.1 ng/mL only in the patients who suffered MI postoperatively. All the patients who suffered MI had both CK-MB index and troponin I levels elevated. Also, we found high correlation between maximum CK-MB levels and size of implants, which means that reaming and its heating effect may be responsible for false-elevated CK-MB levels, except direct muscle damage caused by surgical incision.


CONCLUSIONS
CK-MB index and troponin I have the same sensitivity, but troponin I is more specific than CK-MB index in detecting MI after hip surgery.
Mouzopoulos
George
G
Orthopaedic Department of Evangelismos Hospital, Athens, Greece. gmouzop@yahoo.gr
Kouvaris
Christos
C
Antonopoulos
Dimitrios
D
Stamatakos
Mihalis
M
Tsembeli
Anastasia
A
Mouratis
George
G
Tzurbakis
Mathaios
M
Safioleas
Mihalis
M
D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods / Q000401:mortality; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood*; D017558:Elective Surgical Procedures; D005260:Female; D005500:Follow-Up Studies; D005594:Fracture Fixation, Intramedullary / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality; D019990:Perioperative Care; D011183:Postoperative Complications / Q000097:blood / Q000401:mortality; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D019210:Troponin I / Q000097:blood*
D015415:Biomarkers; D019210:Troponin I; D003402:Creatine Kinase