Before drug-eluting stents, patients with stable angina had a likelihood of returning within 3-6 months with recurrent symptoms due to in-stent restenosis.

“So before the era of what are now called drug eluding stents, This is back in the 1990s. If you did a stent on somebody, again, stable angina, you'd see that there was some likelihood that they'd come back within three to six months with recurrent symptoms. And you'd do a stress test. You'd see that there was looked like there was ischemia. You'd come back in, you angiogram, you'd look at the artery and there was narrowing again within the stent. And that was called instant restenosis.”