PROLIFERATIVE ACTIVITY IN CORONARY ATHERECTOMY TISSUE - CLINICAL, HISTOPATHOLOGIC, AND IMMUNOHISTOCHEMICAL CORRELATES

Study objective: Although cellular proliferation is considered one of the dominant processes leading to restenosis following coronary interv ention, controversy exists over the extent of cellular replication in atherosclerotic tissue. Accordingly, we sought to investigate the leve l and clinicopathologic correlates of proliferative activity in athero sclerotic tissue obtained via directional coronary atherectomy (DCA). Design: Prospective observational study. Setting: Tertiary care referr al hospital. Patients: Specimens retrieved via DCA from 37 lesions (pr imary, 26; restenosis, 11) were studied using single-label immunohisto chemical staining for the proliferating cell nuclear antigen and basic fibroblast growth factor (bFGF). Results: Restenosis tissue was signi ficantly more likely than primary tissue to contain areas of intimal h yperplasia (64 vs 23%; p<0.03). However, the frequency of positive sta ining for proliferating cell nuclear antigen (PCNA) was similar in pri mary and restenosis lesions (25 vs 30%; p=NS), and the mean percentage of positive cells per slide was similar in the two groups. Positive i mmunostaining for bFGF was present in 20 lesions (61%), and tended to be more frequently seen in restenotic lesions (80 vs 52%; p=0.25). How ever, there was no correlation or colocalization between immunostainin g for bFGF and proliferating cell nuclear antigen. We found no clinico pathologic correlations with respect to clinical outcome. Conclusion: Cellular replication, as measured by expression of the PCNA, occurs in a heterogeneous pattern in both primary and restenotic atheroscleroti c tissue obtained from patients undergoing coronary intervention.