Delayed spontaneous recanalization of a totally occluded right coronary artery following failed percutaneous coronary intervention with associated Type F dissection: case report and review

Non-invasive recanalization of first-generation sirolimus-eluting stent thrombosis due to stent fracture and coronary artery aneurysm after clopidogrel treatment 15 years after implantation

In 2020, a 48-year-old male patient was admitted to our hospital due to unstable angina. In 2005, three first-generation sirolimus-eluting stents (1st-SESs) had been deployed to his right coronary artery (RCA). Over the past 10 years or so, the patient has been treated with single antiplatelet therapy using aspirin. Coronary angiography (CAG) revealed severe stenosis in the left circumflex artery (LCx) and total occlusion at the proximal portion of the stented RCA. Furthermore, fluoroscopy showed multiple 1st-SES fractures. After ad hoc percutaneous coronary intervention of the LCx, dual antiplatelet therapy (DAPT) was resumed by adding the P2Y12 inhibitor clopidogrel to aspirin. Two months later, CAG revealed complete recanalization and multiple peri-stent coronary artery aneurysms (CAAs) in the RCA. Intravascular ultrasound revealed late-acquired stent malapposition (LSM) and formation of true aneurysms. Coronary angioscopy showed the uncovered struts of the 1st-SES and mural red thrombus. DAPT was continued thereafter, and 8 months later, follow-up CAG showed no significant RCA restenosis. To date, the patient remains free from cardiovascular events. This report documents a rare case of thrombotic occlusion of a 1st-SES with LSM, CAA, and stent fractures followed by non-invasive recanalization after clopidogrel treatment 15 years after 1st-SES implantation.

Learning objective

Stent thrombosis due to stent fracture and coronary aneurysm can occur even years after first-generation sirolimus-eluting stent (1st-SES) implantation. Risk assessment using coronary imaging should be made and long-term dual antiplatelet therapy (DAPT) should be recommended in patients with a high risk of stent thrombosis after 1st-SES implantation. In cases of stent thrombosis of the 1st-SES, resuming DAPT, including P2Y12 receptor inhibitors, may be a useful non-invasive treatment option.

Coronary dissection with ST elevation myocardial infarction responding to thrombolytic and conservative therapy alone

In this report, we describe a case of spontaneous coronary dissection involving left anterior descending artery presenting with acute anterior myocardial infarction successfully treated with thrombolytic and conservative therapy with a suggestion that spontaneous resolution of thrombus occurred before coronary intervention could be performed. As we did not have initial angiogram due to patient's refusal, this assumption is speculative. However, this case suggests that dissections may heal spontaneously and could be treated with conservative approach in selected cases based on best clinical judgment. It is important to realize that the clinical course of a major coronary artery dissection remains unpredictable. Therefore, cardiologists should always treat each case individually and consider coronary interventions if conservative treatment is not leading to resolution of ST elevation or in patients with hemodynamic compromise. This case is followed by discussion about conservative versus invasive management of spontaneous coronary dissections.