Does coronary artery morphology predict favorable results of intracoronarythrombolysis in patients with unstable angina pectoris?

The efficacy of intracoronary thrombolysis (ICT) for unstable angina pector is (UAP) has been limited, despite the similar pathogenesis between UAP and acute myocardial infarction. To ascertain the subset of UAP suitable for I CT, the clinical responses to ICT were assessed in patients with UAP. Eight y-2 patients with medically refractory angina were divided into 2 groups ac cording to the coronary artery morphology of the culprit lesion before ICT: (1) lesions with acute cut off and/or filling defects (AC) and (2) lesions with a tapered shape (TA). The TIMI flow grade was determined from coronar y angiograms before and immediately after ICT. The diameter stenosis (%DS) and minimal lumen diameter (MLD) of the culprit lesion were determined usin g quantitative coronary angiographic analysis before and immediately after ICT. In addition, inhospital cardiac event rates including urgent/emergency coronary angioplasty or bypass surgery, nonfatal myocardial infarction or cardiac death were compared between the 2 groups. Multivariate logistic reg ression analysis was performed using 13 clinical factors contributing to su ccessful ICT. The results showed that all 3 coronary angiographic parameter s (TIMI flow, %DS, and MLD) significantly improved in the AC group (p < 0.0 1, p < 0.01 and p < 0.05, respectively), whereas none of these parameters i mproved in the TA group. The inhospital cardiac event rate after ICT was si gnificantly higher in the TA group (76%) than in the AC group (48%; p = 0.0 16). Odds ratio predicting successful ICT was 7.09 (p < 0.01) for the AC le sion, and 2.54 (p < 0.01) for new angina. In conclusion the AC lesions are more commonly associated with coronary thrombosis that responds to ICT than are the TA lesions. Thus, the coronary angiographic morphology may be an i mportant predictor for a successful ICT in patients with medically refracto ry UAP.