Acute type B aortic dissection with multiple cholesterol embolism: an autopsy case report.

Background: Most cases of cholesterol embolism are known to be triggered by cardiac catheterization, cardiovascular surgery, anticoagulation, or fibrinolytic therapy; however, spontaneous cases after aortic dissection are rare. In this report, we describe a case of cholesterol embolism after type B aortic dissection, which rapidly developed into multiple organ failure and death. Case summary: A 65-year-old man with untreated hypertension was admitted to our hospital with sudden back pain and diagnosed with type B aortic dissection. The patient experienced a rapid progression of inflammation and developed respiratory and renal failure, despite computed tomography showing no obvious progression of dissection. We attributed them to a cytokine storm and acute respiratory distress syndrome, but steroid pulse therapy did not alleviate the symptoms. Finally, the patient died on Day 6 after admission, and an autopsy was performed, which revealed cholesterol crystal occlusions in the kidney, spleen, and the left lower leg. The lumen in the aorta is filled with atheroma and thrombus, and we suspect that aortic dissection triggered failure of the aortic plaques and released cholesterol crystals to distal arteries that led to cholesterol embolism. Discussion: We experienced a patient with a type B aortic dissection that led to cholesterol embolism and rapid progression of respiratory and renal failure, resulting in death. The aortic dissection combined with cholesterol embolism was considered to trigger the subsequent severe inflammation, leading to rapid respiratory and renal failure. Our case points to the possibility that cholesterol embolism can extensively escalate inflammation after aortic dissection.

Heterogeneous vascular response after implantation of bare nitinol self-expanding stents in the swine femoropopliteal artery.

BACKGROUND: Mechanism of femoropopliteal in-stent restenosis has been underappreciated. AIM: The aim of this animal study was to elucidate vascular response after femoropopliteal bare nitinol self-expanding stents (SESs) implantation. METHODS: Misago, Smart Flex, or Innova stent was randomly implanted in 36 swine femoropopliteal arteries. At week 4, quantitative vessel analysis (QVA) was performed on 36 legs, of which 18 underwent histological evaluation after angiography. The remaining 18 legs underwent QVA and histological evaluation at week 13. RESULTS: Fibrin deposition was excessive at week 4. Internal elastic lamina (IEL) progressively enlarged over time, and vessel injury developed from mild level at week 4 to moderate level at week 13. Vessel inflammatory reaction was mild to moderate at week 4, and was moderate to severe at week 13. Increased fibrin deposition was an early-acting, IEL enlargement and increased vessel inflammation were long-acting, and increased vessel injury and giant cells infiltration were late-acting contributors to neointimal hyperplasia (NIH). Stent type altered time-dependent process of vessel injury, vessel inflammation, eosinophils and giant cells infiltration. Misago had less fibrin deposition and vessel enlargement, and less progressive vessel injury, vessel inflammation, and eosinophils and giant cells infiltration. Net lumen as assessed by percent diameter stenosis or minimum lumen diameter was preserved with Misago, but was not preserved with the other stents. CONCLUSIONS: In the context of bare nitinol SES platform with less progressive mechanical stress and inflammatory reaction, the advantage of less NIH outweighed the disadvantage of less vessel enlargement, leading to net lumen preservation.

Effect of Hinge Motion on Stent Edge-Related Restenosis After Right Coronary Artery Treatment in the Current Drug-Eluting Stent Era.

BACKGROUND: Stent edge-related restenosis (SER) remains a potential limitation of drug-eluting stent (DES). Hinge motion at the stent edge could lead to mechanical stress and contribute to incidents of SER. We investigated the effect of hinge motion on SER after implantation of current-generation DES in the right coronary artery (RCA), where excessive vessel movement is commonly observed.Methods and Results:Of 647 consecutive lesions in the RCA treated with second-generation or later DESs, 426 with follow-up angiography were included in this study. Intravascular imaging analysis was performed for 584 stent edges and reference segments. Binary restenosis occurred in 42 lesions (9.9%), and 55% were SERs. The hinge angle was significantly larger in the SER group than in the other restenosis or the no-restenosis group (17.9° vs. 11.6° and 10.6°, respectively; P<0.001). Lesions with an excessive hinge angle (>11.5°) had an increased rate of target lesion revascularization (19.1% vs. 7.2%; P<0.001) during the median follow-up period of 1,578 days. In per-edge analysis, hinge angle and residual plaque burden were independent predictors of SER. The coexistence of excessive hinge motion and residual plaque burden had a synergistic effect on stenotic progression in quantitative angiographic analysis (Pinteraction<0.001) at follow-up angiography. CONCLUSIONS: Substantial stress determined by angulation at a stent edge and its interaction with residual plaque can be considered as one plausible mechanism for SER.

Intravascular ultrasound predictors of long-term outcomes following ABSORB bioresorbable scaffold implantation: A pooled analysis of the ABSORB III and ABSORB Japan trials.

BACKGROUND: The long-term prognostic impact of IVUS findings following Absorb BVS implantation remains uncertain. This study aimed to identify the IVUS predictors of long-term clinical outcomes following ABSORB bioresorbable vascular scaffold (BVS) implantation from the pooled IVUS substudy cohorts of the ABSORB III and Japan trials. METHODS: A total of 298 lesions in 286 patients were enrolled with 2:1 randomization to ABSORB BVS vs. cobalt-chromium everolimus-eluting stents. This sub-analysis included 168 lesions of 160 patients in the Absorb arm whose post-procedural quantitative IVUS were available. The primary endpoint of this analysis was device-oriented composite endpoint (DOCE) of target lesion failure, including cardiac death, target vessel-related myocardial infarction, or ischemia-driven target lesion revascularization. The median follow-up duration was 4.9 [3.1-5.0] years. RESULTS: During follow-up, DOCE occurred in 10.1% of lesions treated with Absorb BVS. Among several post-procedural IVUS indices associated with DOCE, non-uniform device expansion (defined as uniformity index = minimum / maximum device area) (hazard ratio 0.47 per 0.1 increase [95%CI 0.28 to 0.77]; p = 0.003) and residual reference plaque burden (hazard ratio 4.01 per 10% increase [95%CI 1.50 to 10.77]; p = 0.006) were identified as independent predictors of DOCE by Cox multivariable analysis. CONCLUSIONS: Nonuniform device expansion and substantial untreated residual plaque in reference segments were associated with long-term adverse events following BVS implantation. Baseline imaging to identify the appropriate device landing zone and procedural imaging to achieve uniform device expansion if possible (e.g. through post-dilatation) may improve clinical outcomes of BVS implantation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01751906 (ABSORB III); NCT01844284 (ABSORB Japan).

Scaffold underexpansion and late lumen loss after bioresorbable scaffold implantation: Insights from ABSORB JAPAN trial.

BACKGROUND: Device underexpansion is associated with late adverse outcomes after bioresorbable vascular scaffold (BVS) implantation. This study, representing official IVUS results of the ABSORB Japan trial, aimed to characterize IVUS findings, focusing specifically on acute device expansion, and to investigate its impact on late lumen loss (LLL) with Absorb-BVS compared with cobalt-chromium everolimus-eluting stents (CoCr-EES). METHODS: ABSORB Japan enrolled 148 patients (2:1 randomization) in the IVUS cohort. Serial IVUS was prescheduled at post-procedure and 3 years. Acute device expansion was evaluated with respect to the degree and uniformity of the implanted device. RESULTS: Overall, Absorb-BVS showed smaller and more nonuniform device expansion at post-procedure, compared with CoCr-EES, which was particularly prominent in small-vessel lesions. In serial analysis, Absorb-BVS showed unique associations of smaller device expansion (r = 0.40, p = 0.001) and more nonuniformity (r = 0.29, p = 0.007) at post-procedure with greater LLL at 3 years, primarily attributable to greater negative remodeling (r = 0.39, p = 0.006). In contrast, acute device expansion showed no relation with subsequent lumen change in CoCr-EES. In Absorb-BVS, ischemic-driven target lesion or vessel revascularization (ID-TLR or ID-TVR) at 3 years occurred more frequently in small- versus large-vessel lesions (12.5% vs. 0%, p = 0.04 for ID-TLR and 15.6% vs. 2.3%, p = 0.08 for ID-TVR). Conversely, Absorb BVS had no target lesion nor vessel failure, even in small-vessel lesions, when adequate device expansion was achieved at post-procedure. CONCLUSIONS: Unlike CoCr-EES, underexpansion was associated with greater negative remodeling and LLL in Absorb-BVS. This may in part account for the poorer outcomes of Absorb-BVS than CoCr-EES when under-expanded.

Empagliflozin attenuates neointimal hyperplasia after drug-eluting-stent implantation in patients with type 2 diabetes.

The effects of empagliflozin, a sodium-glucose co-transporter 2 inhibitor, on neointimal response after drug-eluting-stent (DES) implantation remains unknown. Insufficiently controlled diabetes patients with coronary artery disease planned for DES stenting were consecutively enrolled. The patients were assigned to receive empagliflozin in addition to standard therapy or intensive therapy using other glucose-lowering drugs (oGLD). The primary endpoint was thickness of neointimal hyperplasia (NIH) 12 months after stenting assessed by optical coherence tomography (OCT). A total of 28 patients were analyzed (n = 15 in the empagliflozin group, n = 13 in the oGLD group). The levels of glucose profile were not significantly different between both groups at follow-up [HbA1c; 7.2 ± 0.8 vs 7.3 ± 0.9%, p = 0.46]. In OCT analysis, neointima was significantly less in the empagliflozin group than the oGLD group [mean NIH thickness: 137 ± 32 vs 168 ± 39 µm, p = 0.02]. Changes of systolic and diastolic blood pressure (BP), changes of body mass index, and changes of hematocrit after additional treatment were significantly associated with NIH attenuation, whereas no correlation was observed in changes in blood glucose parameters. Multivariate logistic regression analysis revealed that changes in systolic BP was the strongest predictor for NIH attenuation, followed by changes in diastolic BP. In patients with type 2 diabetes, standard plus empagliflozin attenuated neointimal progression as compared with intensive standard therapy after DES implantation. Our data possibly support a beneficial effect of empagliflozin in type 2 diabetes required for coronary revascularization therapy.

Acute Myocardial Infarction Caused by Thrombotic Microangiopathy Complicated With Myelodysplastic Syndrome.

Thrombotic microangiopathy (TMA) is a rare but lethal multisystem disease characterized by peripheral thrombocytopenia, microangiopathic hemolytic anemia, fever, and various stages of renal and neurological dysfunctions.(1,2)) The causes of TMA are mainly thrombotic thrombocytopenic purpura (TTP) or hemolytic-uremic syndrome (HUS), and cases of TMA related to myelodysplastic syndrome (MDS) are quite rare. Herein, we report a case of acute myocardial infarction (AMI) caused by TMA which is strongly suspected to have a relationship to MDS, and discuss the treatment of our patient who needed antiplatelet or anticoagulant therapy after AMI, while on the other hand, had pancytopenia and a bleeding event due to MDS.

Noncompaction of the Ventricular Myocardium and Polycystic Kidney Disease: A Case Report.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary disorders, characterized by the formation of multiple cysts in the kidneys and other organs, as well as noncystic manifestations such as cerebral aneurysm. The most common cardiovascular disorders associated with ADPKD include valvular abnormalities and aortic aneurysm. An association between ADPKD and impaired left ventricular function has occasionally been reported. We describe a 74-year-old woman with ADPKD and exertional dyspnea. Impaired left ventricular function resulting from noncompaction of the ventricular myocardium (NVM) and secondary left ventricular aneurysm were diagnosed. Cardiac sarcoidosis and ischemic heart disease were ruled out. Myocardial ischemia resulting from NVM was the presumptive cause of the ventricular aneurysm. To our knowledge, this is the first report of concurrent isolated NVM and left ventricular aneurysm in a patient with ADPKD. ADPKD and various cardiomyopathies, including NVM, are all reported to involve mutations of sarcomere genes, suggesting a possible link between the conditions.

Usefulness of contrast computed tomography to detect left ventricular apical thrombus associated with takotsubo cardiomyopathy.

Left ventricular (LV) apical thrombus can rarely occur during the early phase of takotsubo cardiomyopathy. We report such a case that was depicted clearly in contrast computed tomography (CT) but not in initial echocardiography. Because LV thrombus may lead to thromboembolic events, we should evaluate all patients with takotsubo cardiomyopathy for the presence of a LV thrombus. LV thrombus is generally recognized with echocardiography in the course of follow-up, but limited depiction of the LV apex with echocardiography can make evaluation of LV thrombus difficult. Contrast CT is useful to detect LV apical thrombus associated with takotsubo cardiomyopathy.

Diverse contribution of bone marrow-derived late-outgrowth endothelial progenitor cells to vascular repair under pulmonary arterial hypertension and arterial neointimal formation.

AIMS: It is still controversial whether bone marrow (BM)-derived endothelial progenitor cells (EPCs) can contribute to vascular repair and prevent the progression of vascular diseases. We aimed to characterize BM-derived EPC subpopulations and to evaluate their therapeutic efficacies to repair injured vascular endothelium of systemic and pulmonary arteries. METHODS AND RESULTS: BM mononuclear cells of Fisher-344 rats were cultured under endothelial cell-conditions. Early EPCs appeared on days 3-6. Late-outgrowth and very late-outgrowth EPCs (LOCs and VLOCs) were defined as cells forming cobblestone colonies on days 9-14 and 17-21, respectively. Among EPC subpopulations, LOCs showed the highest angiogenic capability with enhanced proliferation potential and secretion of proangiogenic proteins. To investigate the therapeutic effects of these EPCs, Fisher-344 rats underwent wire-mediated endovascular injury in femoral artery (FA) and were concurrently injected intraperitoneally with 60mg/kg monocrotaline (MCT). Injured rats were then treated with six injections of one of three EPCs (1×10(6) per time). After 4weeks, transplanted LOCs, but not early EPCs or VLOCs, significantly attenuated neointimal lesion formation in injured FAs. Some of CD31(+) LOCs directly replaced the injured FA endothelium (replacement ratio: 11.7±7.0%). In contrast, any EPC treatment could neither replace MCT-injured endothelium of pulmonary arterioles nor prevent the progression of pulmonary arterial hypertension (PAH). LOCs modified protectively the expression profile of angiogenic and inflammatory genes in injured FAs, but not in MCT-injured lungs. CONCLUSION: BM-derived LOCs can contribute to vascular repair of injured systemic artery; however, even they cannot rescue injured pulmonary vasculature under MCT-induced PAH.

Angiogenic potential of early and late outgrowth endothelial progenitor cells is dependent on the time of emergence.

BACKGROUND: Recent studies have suggested that late-outgrowth endothelial progenitor cells (EPCs) derived from human peripheral blood mononuclear cells (hPBMNCs) might have higher angiogenic potential than classically-defined early-outgrowth EPCs (EOCs). However, it still remains unclear which of "so-called" EPC subpopulations defined in a variety of ways has the highest angiogenic potential. METHODS AND RESULTS: We classified hPBMNC-derived EPC subpopulations by the time of their emergence in culture. EOCs were defined as attached cells on culture days 3-7. Late-outgrowth EPCs, defined as the cell forming colonies with cobblestone appearance since day 10, were further classified as follows: "moderate"-outgrowth EPCs (MOCs) emerging on days 10-16, "late"-outgrowth EPCs (LOCs) on days 17-23, and "very late"-outgrowth EPCs (VOCs) on days 24-30. Flow cytometry analyses showed the clear differences of hematopoietic/endothelial markers between EOC (CD31(+)VE-cadherin(-)CD34(-)CD14(+)CD45(+)) and LOC (CD31(+)VE-cadherin(+)CD34(+)CD14(-)CD45(-)). We found that LOCs had the highest proliferation and tube formation capabilities in vitro along with the highest expression of angiogenic genes including KDR and eNOS. To investigate the in vivo therapeutic efficacies, each EPC subpopulation was intravenously transplanted into immunocompromised mice (total 4 × 10(5) cells) after unilateral hindlimb ischemia surgery. The LOC-treated mice exhibited significantly-enhanced blood flow recovery (flow ratios of ischemic/non-ischemic leg: 0.99±0.02 [LOC group] versus 0.67 ± 0.07 to 0.78 ± 0.09 [other groups]; P < 0.05) and augmented capillary collateral formation in ischemic leg, which were attributable to their direct engraftment into host angiogenic vessels (approximately 10%) and paracrine effects. CONCLUSION: hPBMNC-derived late-outgrowth EPCs emerging on culture days 17-23 are superior to other EPC subpopulations with regard to therapeutic angiogenic potential.

Takotsubo cardiomyopathy in siblings.

We report the case of apical ballooning syndrome (ABS) in a female sibling. A 64-year-old woman was admitted to our hospital with sudden-onset chest pain. Cardiac enzymes were mildly elevated and an electrocardiogram showed broad ST-T changes. Emergency coronary angiography revealed no culprit lesion and left ventriculography demonstrated focal akinesis of the apical wall, which was consistent with ABS. Myocardial functional sympathetic innervations assessed using [(123)I]metaiodobenzylguanidine was severely impaired in the apical region. Her clinical symptoms and cardiac dysfunction recovered spontaneously. Just 1 year prior to our patient's cardiac event, her elder sister had the same symptoms and was also diagnosed with ABS. Both sisters were postmenopausal. The familial case of ABS is exceedingly rare, but these cases suggest a possible genetic etiology.

Deletion of angiotensin-converting enzyme 2 promotes the development of atherosclerosis and arterial neointima formation.

AIMS: Angiotensin-converting enzyme 2 (ACE2) is known as a negative regulator of the renin-angiotensin system. We aimed to determine the roles of ACE2 on the development of vascular diseases. METHODS AND RESULTS: Using two diversely different models of vascular diseases, hyperlipidaemia-induced atherosclerosis in apolipoprotein E knockout (KO) mice and mechanical injury-induced arterial neointimal hyperplasia in C57Bl6 mice, we examined whether ACE2 deficiency could affect formation of the vascular lesions. ACE2 deficiency resulted in significantly larger vascular lesions in both aortic atherosclerotic plaques and arterial neointima formation, compared with ACE2(+) control. These ACE2-deficient vascular lesions exhibited enhanced accumulation of macrophages into the lesions and proliferation of vascular smooth muscle cells (VSMCs), accompanied with increased angiotensin-II (Ang-II) levels and enhanced expression of vascular inflammation-related genes, including vascular cell adhesion molecule (VCAM)-1, monocyte chemoattractant protein (MCP)-1, and matrix metalloproteinase (MMP)9 in aorta/artery tissues. Primary bone marrow macrophages and aortic VSMCs isolated from ACE2 KO mice also displayed enhanced pro-inflammatory responsiveness such as up-regulated gene/protein expression of VCAM-1, MCP-1, and MMP9 to stimulation with tumour necrosis factor-α and Ang-II. The similar phenotype was shown in human macrophages and aortic VSMCs that were transfected with ACE2-specific siRNA. In ACE2-deficient VSMCs, inhibition of c-Jun N-terminal kinase (JNK) by pharmacological blockade with SP600125 or genetic knockdown with JNK-specific siRNA significantly attenuated their pro-inflammatory phenotype. CONCLUSION: ACE2 deficiency promotes the development of vascular diseases associated with Ang-II-mediated vascular inflammation and activation of the JNK signalling, leading to the notion that ACE2 potentially confers protection against vascular diseases.

Endothelial dysfunction following drug-eluting stent implantation: a systematic review of the literature.

BACKGROUND: While several studies have reported endothelial dysfunction after drug-eluting stent (DES) implantation, their study methods differed and the results were varied. METHODS AND RESULTS: A literature search was performed using PubMed where 14 clinical studies (537 patients) including two randomized trials were identified. All studies assessed endothelial dysfunction 3-14 months after stent implantation. In the acetylcholine (ACh) loading studies, significant vasoconstrictions were observed in proximal and distal segments after implantation of sirolimus-eluting (SES) and paclitaxel-eluting stents (PES) and a milder diameter change was observed after zotarolimus-eluting stent (ZES) implantation. Coronary diameter changes were greater in distal segments. Significant diameter change was not detected after bare metal stent (BMS) implantation. In the exercise examinations, vasoconstriction was observed in distal and proximal segments following SES and PES implantation, whereas vasodilation was observed in BMS. In the pacing examinations, vasoconstriction was observed in both SES and PES implantations in distal and proximal segments, whereas vasodilation was observed in not only BMS but ZES and biolimus-eluting stents (BES) as well. CONCLUSION: In the chronic phase following stent implantation, marked abnormal vasoconstriction distally in the stent was observed in SES and PES implantation but not in ZES or BES, compared with BMS. To clarify the clinical implications and possible mechanisms of these findings, longer-term evaluation with larger patients is needed.