CRYOPROSTATECTOMY CONSISTENTLY ELEVATES SERUM CREATINE KINASE-MB ISOENZYME

Study Objective: To measure serum CK-MB, a market of myocardial infarc tion (MI), in in elderly men before and after cryoprostatectomy. Desig n: Serum CK-MB was measured on each patient before and after cryoprost atectomy. Each patient's preoperative result was used as control measu rement for comparison with measurements made after cryoprostatectomy. Setting: Inpatient operating room and postanesthetic recovery unit of university-affiliated general hospital. Patients: 38 male patients, me an (SEM) age 69.1 +/- 1.4 years, undergoing cryoprostatectomy. Interve ntions: All patients had a 12-lead ECG prior to surgery, in the recove ry room, and 24 hours after surgery. Serum CK-MB was measured prior to induction of anesthesia, on arrival in the recovery room, and at 8 an d 24 hours after surgery. Lactate dehydrogenase (LDH) and isoenzymes a lso were measured in 10 patients before and after cryoprostatectomy. M easurements and Main Results: All patients underwent uneventful cryopr ostatectomy. No patients had new ECG changes after surgery. All patien ts had normal serum CK and CK-MB concentrations before surgery. Serum CK and CK-MB were significantly elevated after cryoprostatectomy (p < 0.001). Enzyme values were greatest 8 hours after surgery: total CK me an 1453 +/- 145 U/L (range 199 to 3,356 U/L); CK-MB mean 52 +/- 3 ng/m l (range 12 to 114 ng/ml) or 5.0 +/- 0.5% of total CK (range 1.6% to 1 2.4%). All patients had significantly elevations of LDH after cryopros tatectomy but did not show an increase in the ratio of LDH(1) to LDH(2 ) isoenzymes. Finally, unlike patients with an acute MI, the activity of CK-MB isoenzyme when measured by gel electrophoresis was two to thr ee times greater (mean, 2.6 +/- 0.7) than the concentration measured w ith the monoclonal antibody assay in patients after cryoprostatectomy. Conclusion: Serum CK-MB is an unreliable test to diagnose a MI in pat ients who have undergone cryoprostatectomy.