Intracoronary Serum Smooth Muscle Myosin Heavy Chain Levels Following PTCA may Predict Restenosis

Abstract

Recently a novel biochemical method that uses an immunoassay to quantitate serum smooth muscle myosin heavy chain (SMMHC) levels was developed for diagnosis of aortic dissection.¹⁾ The purpose of this study was to determine whether SMMHC released from the coronary arterial wall can be used to predict restenosis after percutaneous transluminal coronary angioplasty (PTCA). Fifty-two consecutive patients undergoing successful PTCA for single vessel disease were examined (40 men, 12 women, 63±8 years). Intracoronary blood samples were obtained distal to the lesion, and from the femoral artery after PTCA. In 10 patients, blood samples were taken immediately after the final balloon inflation, and 10 and 20 minutes after PTCA. SMMHC levels were measured by ELISA using SMMHC-specific monoclonal antibodies. Follow-up coronary angiography was performed 3 months after PTCA. Intracoronary serum SMMHC levels were significantly higher than those obtained from the femoral artery (10.6±1.5 vs 2.1±0.1 ng/ ml, p≤0.001). Of 40 patients without apparent dissection, the 23 patients who did not develop restenosis in the follow-up study were found to have had higher levels of intracoronary SMMHC levels immediately after PTCA compared to the 17 patients with restenosis (15.2±2.9 vs 7.1±1.2 ng/ml, p≤0.05). We suggest that elevated intracoronary SMMHC levels after PTCA may reflect the extent of injury to the arterial wall. Intracoronary SMMHC may be a possible biochemical marker for the prediction of restenosis. (Jpn Heart J 2000; 41: 131-140)