Kounis syndrome caused by protamine shock after coronary intervention: A case report.

We report a case of Kounis syndrome that led to shock after protamine administration during percutaneous coronary intervention (PCI). A man in his 50s was admitted to the nearest hospital following the onset of acute myocardial infarction. Coronary angiography showed a single-vessel lesion in the left anterior descending artery (LAD). He was admitted for PCI. After heparin administration, the procedure was completed by implantation of a coronary stent with the usual procedure. For hemostasis, following protamine administration, the patient went into shock. Subsequently, electrocardiography showed bradycardia with ST-segment elevation at leads II, III, aVF, and V3-6. Cardiopulmonary resuscitation was started immediately. As pulseless electrical activity continued, extracorporeal membrane oxygenation (ECMO) was introduced. Coronary angiography demonstrated coronary spasm in the LAD. He was withdrawn from the ECMO on day 7. His intradermal tests were positive for protamine in the convalescent phase. The patient was diagnosed with protamine shock and type I Kounis syndrome. Protamine shock is not uncommon, but Kounis syndrome may be hidden in it. Thus, similar cases should not be treated as a simple protamine shock. .

Clinical and pathological characteristics of homogeneous and nonhomogeneous tissue of in-stent restenosis visualized by optical coherence tomography.

BACKGROUND: Although it is known that in-stent restenosis (ISR) patterns appear homogeneous or nonhomogeneous by optical coherence tomography (OCT), interpretations of the ISR inflammatory response, of the OCT image, and its pathological implications are unclear. The aim of this study was to use OCT to characterize ISR and its inflammatory index in patients after coronary stenting. METHODS: OCT was performed at follow-up in 100 angiographic ISR lesions. ISR lesions were divided into two groups: (a) homogeneous (n=48) and (b) nonhomogeneous (n=52) image groups. We assessed the ISR images produced by OCT for tissue heterogeneity and neo-intimal hyperplasia using the normalized standard deviation of OCT signal-intensity (OCT-NSD) observed in neo-intimal hyperplasia tissue. In some patients with a nonhomogeneous OCT image, we collected pathological tissue. RESULTS: The prevalence of drug-eluting stents was 48% in the nonhomogeneous group and 29% in the homogeneous group (P=0.05). The OCT-NSD value in the nonhomogeneous group (0.223±0.019) was significantly higher than that in the homogeneous group (0.203±0.025; P<0.0001). Pathological tissue showed fibrin thrombi with infiltrating macrophage in 12 cases of nonhomogeneous ISR. The area under the receiver operating characteristic curve for the prediction of a nonhomogeneous image was 0.73 for OCT-NSD (95% confidence interval: 0.62-0.83: P<0.0001). The odds ratio for the prediction of a nonhomogeneous image was 3.47 (95% confidence interval: 1.18-10.2: P=0.02) for smoking by logistic regression analysis. CONCLUSION: Nonhomogeneous ISR visualized by OCT showed a high OCT-NSD value, which was a useful predictor for nonhomogeneous images. Moreover, the nonhomogeneous ISR image visualized by OCT may show chronic inflammation and fibrin thrombi.

Spontaneous healing of saccular type aneurysm with ventricular septal lacerations after blunt chest trauma.

We present a case of spontaneous healing of saccular type aneurysm with ventricular septal lacerations after blunt chest trauma. A 50-year-old Japanese man was transferred to our hospital diagnosed with ventricular septal lacerations after blunt chest trauma. Electrocardiogram (ECG) at admission showed ST elevations in I, II, III, aVL, aVF, V2-through to V6 were observed. Laboratory data showed elevated creatine kinase. Echocardiogram revealed normal ventricular contraction and a saccular type ventricular septal laceration with an influx blood flow without septal shunt flow. After admission, serial echocardiogram and cardiac computed enhancement tomography showed disappearance of a saccular type ventricular septal laceration. Gadolinium-enhanced magnetic resonance imaging (MRI) was performed at day 30. MRI showed an enhanced scar of saccular type aneurysm with ventricular septal laceration; this image suggested some residual damage of ventricular septal laceration. At discharge, ECG was resolved with normal ST-T level and no Q wave, but persistent complete right bundle branch block and left axis deviation. After one year, repeat MRI showed a scar of saccular type aneurysm with ventricular septal laceration. .

Very late stent thrombosis after paclitaxel-eluting stent implantation with full neointimal tissue coverage visualized by optical coherence tomography.

We present findings of a very late stent thrombosis (VLST) involving paclitaxel-eluting stents (PESs) that were fully covered by thin neointima, visualized by optical coherence tomography (OCT) in a patient receiving dual antiplatelet therapy. A 69-year-old Japanese man had been treated with 2 overlapping PESs for chronic coronary artery disease in the proximal right coronary artery. A follow-up coronary computed tomography angiography showed no restenosis in the stent site, and the result of stress myocardial perfusion imaging showed no ischemic changes. Seventeen months after the percutaneous coronary intervention, he was transported to our clinic with a diagnosis of acute myocardial infarction. Emergency coronary angiography showed a total occlusion at the overlapping site of the 2 PESs. After thrombus aspiration therapy, the OCT image revealed a thin layer of neointimal tissue covering the stent struts with no stent malapposition or fracture. There was no plaque rupture site or intracoronary thrombus. Histopathologic study of an aspirated red thrombus revealed massive amounts of inflammatory infiltrates including eosinophils and neutrophils within the fibrin clot. These findings suggested the possibility that the patient's allergic and inflammatory reactions may have caused the onset of VLST. .

Effective delayed percutaneous coronary intervention for advanced atrial ventricular block in patients with recent myocardial infarction.

We present a case of effective late reperfusion for atrio-ventricular conduction recovery in a patient with recent myocardial infarction complicated by advanced atrio-ventricular block (AVB). A 50-year-old Japanese man was transferred to our hospital with a recent diagnosis of myocardial infarction 44 h after onset. We performed emergent coronary angiography on Day 5 because he developed bradycardia with two to one advanced AVB resistant to atropine without chest pain or ST-T changes. Coronary angiography showed the right coronary artery (RCA) with total proximal occlusion. Emergent percutaneous coronary intervention (PCI) was performed to the RCA. Just after PCI, the PR interval was shortened to 0.25 s. Moreover, the PR interval was shortened to 0.18 s at Day 16. This report shows the new finding that delayed PCI may be effective in patients with recent myocardial infarction complicated by new AVB outside of the usual therapeutic window of 12 h.

Morphological and quantitative analysis of vascular wall and neointimal hyperplasia after coronary stenting: comparison of bare-metal and sirolimus-eluting stents using optical coherence tomography.

BACKGROUND: It has been suggested that sirolimus-eluting stents (SES) provoke a more sustained inflammatory response (IR) in neointimal hyperplasia (NIH). The purpose of this study was to compare morphological vessel characteristics, including post-stent IR in NIH, between patients with SES and bare metal stents (BMS) using optical coherence tomography (OCT). METHODS AND RESULTS: Thirty-seven patients underwent OCT at their post-stent follow-up. OCT signal-intensity deviation (normalized standard-deviation; OCT-NSD) values in NIH were compared between the 2 groups. In addition, the serum concentration of high-sensitivity C-reactive protein (hs-CRP) was measured. Stent-malapposition rate (1.78% vs. 0.7%; P = 0.016), uncovered stent-strut rate (16% vs. 3.7%; P = 0.0002), peri-stent ulcer like appearance (PSUA; 50% vs. 0%; P = 0.006) were all significantly higher in the SES group than in the BMS group, respectively. The OCT-NSD value was also significantly higher in the SES group than in the BMS group (0.213 ± 0.005 vs. 0.198 ± 0.005; P < 0.001), as was the hs-CRP level (2.54 ± 1.89 vs. 0.64 ± 0.3 mg/L; P = 0.0006). In addition, a significant positive correlation was found between hs-CRP and OCT-NSD (r = 0.471; P = 0.0025). CONCLUSIONS: PSUA-morphology was specific in the SES group, and higher levels of OCT-NSD and hs-CRP after SES implantation suggest sustained IR in NIH compared with following BMS implantation. These different characteristics may be some of the background that promotes thrombus formation as a late-stage post-stent complication of SES.