901-120 Plaque Constituents in Patients with Stable and Unstable Angina: An Atherectomy Study

Abstract

Directional coronary atherectomy IDCAI is used both in patients with stable and unstable angina to relieve the coronary obstruction. Although the tissue retrieved during DCA has the disadvantage of being only a random portion of the atherosclerotic plaque, it offers a unique possibility to correlate the histological findings with the clinical picture. We studied 48 patients (pts) (mean age 57 ± 10 years), 34 with stable angina and 14 with unstable angina, who underwent DCA. Nine of the 34 pts with stable angina had thrombus in the DCA specimen (26%), and 8 of the 14 (57%) unstable pts (p NS). Cholesterol clefts and macrophages (CCM) were identified in 13/48 pts (27%), and were significantly associated with the presence of thrombus (p < 0.00006). A pattern of storiform smooth muscle cell proliferation in a connective stroma (rapid progression) was identified in 27 pts (56%), being more frequent in those patients with thrombus (12/17, 71%1, than in those without (15/31,48% p NS). A small subgroup of pts with stable angina who had episodes of pain at rest, all had the rapid progression pattern (11111, 100%). This pattern reflects healing of a previous plaque event, is identical to that observed post-angioplasty and can result in high degree stenosis The strong statistical association between the presence of thrombus and that of cholesterol and macrophages confirms – in live patients – previous autopsy data regarding the components of the plaque “at risk” for plaque disruption.