Unveiling a Hidden Threat: Wellens Syndrome as a Manifestation of Critical In-Stent Restenosis

Wellens syndrome is defined by characteristic T-wave changes seen on an electrocardiogram (ECG), indicating critical stenosis of the proximal or middle left anterior descending artery (LAD). Diagnosis is challenging, as patients often lack chest pain during ECG recording and have normal or mildly elevated troponin levels. Wellens syndrome classically arises de novo from a rupture of an atherosclerotic plaque, causing arterial obstruction. Although rare, some studies have reported Wellens syndrome secondary to in-stent restenosis (ISR). We present a case of Wellens syndrome caused by ISR of a previously implanted mid-LAD stent. The patient exhibited concerning ECG changes with new biphasic T-waves in leads V1 to V3, consistent with Wellens syndrome type A. Left heart catheterization revealed 80% ISR of his mid-LAD stent. We aim to highlight the critical importance of promptly recognizing the Wellens ECG pattern, not only in atherosclerotic disease but also in patients who have previously undergone stent placement.