Is the pathology different between drug-eluting stent and bare stent related coronary aneurysms?

We read with great interest the case report by Furtado et al. [1]. We wanted to add a few things about the topic since the entity is rare and the responsible mechanism can be different from the bare metal stent-related coronary aneurysms. Percutaneous coronary intervention (PCI)-associated coronary stent infections have been reported in the literature, although this is a rare complication. Mostly, the presenting symptoms are fever and angina pectoris due to stent occlusion. The imaging modalities for diagnosis of coronary stent infection included transthoracic and transesophageal echocardiography, computed tomography, magnetic resonance imaging and coronary angiography with a finding of a coronary aneurysm. The exact incidence of coronary stent infection is unknown. However, the low number of published case reports suggests that coronary stent infections represent a rather uncommon complication of PCI. In line with this presumption is the low frequency of clinically significant bacteremia related to invasive non-surgical cardiological procedures found in various studies. The use of drug-eluting stents (DES) during coronary interventions has exploded in recent years because of their dramatic ability to inhibit neointimal proliferation [2]. However, DES may affect the normal healing process of the vessel wall after vascular injury, resulting in delayed endothelization [3]. The appearance of angiographic coronary aneurysms after coronary interventions is very rare [4]. The occurrence of angiographic coronary aneurysms after DES has generated great interest but, to date, this finding has only been marginally reported in large-scale clinical trials or described in anecdotal case reports. Currently, however, the clinical implications of coronary aneurysms remain uncertain. Some investigators have reported the exceedingly rare occurrence of mycotic aneurysms or coronary pseudoaneurysms after DES implantation [5]. It has been suggested that local DES infection may result from direct contamination of the device at the time of delivery or from subsequent bacteremia. DES might constitute a potentially predisposing factor by blunting the local inflammatory response of the vessel wall, favoring the maintenance or extension of the infection [5]. The immunosuppressive activity of DES could be implicated. In most cases Staphylococcus aureus infections have been shown [5]. These patients typically present with fever and systemic manifestations, including septicemia, and a clinical picture of fulminant infection with poor prognosis.