Restenosis history and symptoms

In-stent restenosis (ISR) can be clinically silent, but majority of them present with recurrent symptoms of angina. ISR is often thought to be a benign phenomenon since the process of neointimal formation and proliferation is of gradual onset and progressive in nature. However, there are several reports which have shown that ISR can present as an acute coronary syndrome. 26% to 53% and 3.5% to 20% of BMS ISR can present as unstable angina and myocardial infarction, respectively. Similarly, 16% to 66% and 1% to 20% of DES ISR can present as unstable angina and myocardial infarction, respectively. BMS ISR has been reported to occur usually after five and half months after stent implantation. The time frame for DES ISR presentation is not well-known with one study reporting a mean time duration of 12 months.