Abstract 5609: In-Stent Restenosis - Benign or Dangerous? Clinical Presentation of Coronary Restenosis in Sweden
Background Restenosis after percutaneous coronary intervention (PCI) was earlier thought to be a benign event clinically manifested as stable exertional angina. The aim of this prospective multicenter registry study was to investigate the incidence of acute coronary syndrome in patients with restenosis in Sweden.
Methods Using data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR), we analyzed all registered cases of PCI for restenosis (in-stent, after balloon angioplasty) from 1995 to 2005 in Sweden. Both multivessel and single vessel interventions were included. Restenosis presentations were classified as:
As routine angiographic screening was not performed, restenosis episodes were defined clinically based on symptoms.
Results We identified 6642 cases of restenosis in 2978 patients (4790 in men, 1852 in women). Restenosis presented in 39.7% of cases as stable angina, in 46.0% as unstable angina/non-STEMI, in 11.5% as STEMI and in 2.8% as other reasons. Cardiogenic shock was reported in 48 patients. Women had a higher incidence of unstable angina/non-STEMI compared with men (52.3% v. 43.6%) but a lower incidence of STEMI (9.6% v. 12.2%). The frequency of STEMI was lower with restenosis after balloon angioplasty v. in-stent restenosis (6.9% v. 13.8%), and after drug-eluting stents v. bare metal stents (7.9% v. 18.5%). Mortality rate was 1.7% at 30 days, 3.2% at 6 months and 4.6% at one year in patients with restenosis. These covariates were independent predictors of acute coronary syndrome: gender, age, vessel diameter, smoking, stent type, number of stents, treated vessel, previous stroke and previous infarction.
Conclusion The majority of patients with coronary restenosis present either with acute MI or unstable angina requiring hospitalization and new interventions. Women may have a higher risk of developing acute coronary syndrome due to restenosis. Prevention of restenosis may be an important target for improvement of “hard” clinical outcomes in patients undergoing coronary revascularization.