Background: Vascular response after intracoronary bare metal stent (BMS) implantation is biphasic, composed of early restenosis phase and chronic regression phase. The phase transition occurred at around 6 months after stenting. The biphasic vascular response after drug-eluting stent (DES) implantation has not yet been reported so far.

Aim: The aim of this study was to document if chronic neointimal regression occurs after implantation of Endeavor zotarolimus-eluting stent (E-ZES), the second-generation DES.

Methods: Enrolled were 12 E-ZES-implanted lesions without restenosis in 10 patients with coronary heart diseases. Coronary angioscopy was performed twice after stent implantation, at early phase (1–3 years) and chronic phase (3–6 years), to reveal neointimal coverage (NC) on stent struts. NC was semi-quantified from grade 0, no coverage; grade 1, thin coverage; grade 2, thick coverage; and grade 3, invisible stent struts fully embedded into thick neointima. Angioscopy also visualized presence of in-stent yellow plaques (YP) and mural thrombus (MT).

Results: Dominant NC grade at early phase was greater than that at chronic phase (2.91 ± 0.29 vs. 1.83 ± 0.83, P = 0.0008). YP was observed more frequently at early phase than at chronic phase (17% vs. 8%). MT was not detected at both phases.

Conclusions: Chronic neointimal regression occurred after E-ZES implantation although the vascular response to E-ZES progressed more slowly than BMS implantation.

Objective: Coronary stents generally consist of hoops and connectors. The number of connectors has been associated with longitudinal strength, flexibility, and deliverability of stents. However, a mid-term impact of number of connectors after stent implantation has been unclear. We sought to examine the effect of number of connectors on vessel healing and stent expansion using optical coherence tomography (OCT).

Materials and Methods: The study included 39 patients with 46 Promus PREMIER stents who underwent OCT examination at 8 months after stent deployment. Promus PREMIER stents have 4 or 5 connectors in a proximal few-millimeter segment of the stents and 2 connectors in the entire stents except the proximal few millimeters. We analyzed OCT cross-sectional images in the proximal 4- or 5-connector segments and adjacent 2-connector segments at 1-mm intervals. OCT parameters including stent apposition, neointimal coverage, the presence of peri-strut low-intensity area (PLIA), stent area, maximal and minimum stent diameters, and stent eccentricity index were compared between the 2 segments.

Results: The 4- or 5-connector segments had a significantly higher proportion of well-apposed struts without neointima (5.8% [interquartile range (IQR): 0–21.9%]) compared to the 2-connector segments (0% [IQR: 0–91.3%], p = 0.007). The proportion of struts with PLIA was higher in the 4- or 5-connector segments (7.1% [IQR: 0–32.0%]) than in the 2-connector segments (0% [IQR: 0–14.6%], p = 0.026). Stent area, maximal and minimum stent diameters, and stent eccentricity index were comparable between the 2 segments.

Conclusion: The number of connectors were associated with vessel healing processes including neointimal coverage and the presence of PLIA but did not restrict stent expansion.

COVID-19 has spread around the world rapidly. Outing restrictions are performed globally to prevent the further spread of infection. A healthy 49-year-old man was taken in the ambulance due to severe dyspnea. For the previous 10 days, he had been performing remote work at home mainly in a sitting position due to the outing restrictions for the prevention of COVID-19 spread. On admission, his blood pressure was low and could not be measured by automated sphygmomanometer, heart rate was 127 bpm, and oxygen saturation was 98% with oxygenation of 10L/min by a mask with a reservoir. Admission blood tests demonstrated markedly elevated D-dimer of 4.13μg/mL and NT-proBNP of 6973 pg/mL. Echocardiography demonstrated dilatation of the right ventricle and D-shaped deformity of the left ventricle without wall motion abnormality. We started continuous intravenous norepinephrine and dobutamine due to the pre-shock status, and chest computed tomography revealed pulmonary thromboembolism (PTE) from the bilateral main pulmonary arteries to the subsegmental arteries. We introduced extracorporeal membrane oxygenation and performed surgical embolectomy. After the surgery, his vital signs and circulation stabilized. Twenty days after the surgery, he was discharged from our hospital without any physical impediment. Since he had no apparent genetic factors for thrombotic disorder, long-term sitting at home during remote work could have contributed to the thrombus formation leading to PTE. Regardless of whether individuals are infected by COVID-19, we must be alert for thromboembolism in the context of outing restrictions during the pandemic.