Recurrent unstable angina after directional coronary atherectomy is related to the extent of initial coronary plaque inflammation

OBJECTIVES This study was performed to evaluate the relationship between pl aque inflammation of the initial culprit lesion and the incidence of recurr ent angina for one year after directional coronary atherectomy (DCA). BACKGROUND A positive correlation between coronary plaque inflammation and angiographic restenosis has been reported. METHODS A total of 110 patients underwent DCA. Cryostat sections were immun ohistochemically stained with monoclonal antibodies CD68 (macrophages), CD- 3 (T lymphocytes) and alpha-actin (smooth muscle cells [SMCs]). The SMC and macrophage contents were planimetrically quantified as a percentage of the total tissue area. T lymphocytes were counted as the number of cells/mm(2) . The patients were followed for one year to document recurrent unstable an gina pectoris (UAP) or stable angina pectoris (SAP). RESULTS Recurrent UAP developed in 16 patients, whereas recurrent SAP devel oped in 17 patients. The percent macrophage areas were larger in patients w ith recurrent UAP (27 +/- 12%) than in patients with recurrent SAP (8 +/- 4 %; p = 0.0001) and those without recurrent angina (18 +/- 14%; p = 0.03). T he number of T lymphocytes was also greater in patients with recurrent UAP (25 +/- 14 cells/mm(2)) than in patients with recurrent SAP (14 +/- 8 cells /mm(2) p = 0.02) and those without recurrent angina (14 +/- 12 cells/mm(2); p = 0.002). Multiple stepwise logistic regression analysis identified macr ophage areas and T lymphocytes as independent predictors for recurrent UAP. CONCLUSIONS There is a positive association between the extent of initial c oronary plaque inflammation and the recurrence of unstable angina during lo ng-term follow-up after DCA. These results underline the role of ongoing sm oldering plaque inflammation in the recurrence of unstable angina after cor onary interventions. (J Am Cell Cardiol 2001;37:1271-6) (C) 2001 by the Ame rican College of Cardiology.