Pulmonary Tumor Thrombotic Microangiopathy with Administration of Pulmonary Vasodilator Resulting in Clinical Improvement Prior to Final Diagnosis.

BACKGROUND The pathophysiology of pulmonary tumor thrombotic microangiopathy (PTTM) was recently revealed by autopsy. Considered rare, we suggest that this fatal disease is not rare, but has not been diagnosed pre-mortem. Some patients with pulmonary thromboembolism with unknown thrombus source or with sudden death have been treated for malignant carcinoma. We report a patient with PTTM who was successfully rescued acutely by treatment with soluble guanylate cyclase (sGC), resulting in appropriate palliative care. CASE REPORT An 80-year-old Japanese woman was transferred to our emergency room for severe dyspnea owing to type I respiratory failure. Her clinical findings indicated pulmonary thromboembolism, but we found no thrombus in either the pulmonary artery or inferior vena cava. However, we incidentally found gallbladder cancer with peritoneal metastases. These findings raised the suspicion of PTTM. We began concurrent sGC and direct oral anticoagulant (DOAC) on the assumption that PTTM had occurred, while performing peripheral pulmonary artery sampling for cytology, and pulmonary perfusion scintigraphy. Cytology revealed several aplastic cells; consequently, we finally diagnosed PTTM. Because she did not wish to undergo examination and active treatment for carcinoma, we initiated palliative care while continuing sGC. She was able to spend time with her family for more than 100 days, without dyspnea. CONCLUSIONS We must recognize PTTM, which is a lesser-known disease, and introduce diagnostic therapy with a pulmonary vasodilator, such as sGC, immediately, when we suspect PTTM, leading to appropriate clinical care.

Low-intensity pulsed ultrasound ameliorates cardiac diastolic dysfunction in mice: a possible novel therapy for heart failure with preserved left ventricular ejection fraction.

AIMS: Heart failure with preserved left ventricular ejection fraction (HFpEF) is a serious health problem worldwide, as no effective therapy is yet available. We have previously demonstrated that our low-intensity pulsed ultrasound (LIPUS) therapy is effective and safe for angina and dementia. In this study, we aimed to examine whether the LIPUS therapy also ameliorates cardiac diastolic dysfunction in mice. METHODS AND RESULTS: Twelve-week-old obese diabetic mice (db/db) and their control littermates (db/+) were treated with either the LIPUS therapy [1.875 MHz, 32 cycles, Ispta (spatial peak temporal average intensity) 117-162 mW/cm2, 0.25 W/cm2] or placebo procedure two times a week for 4 weeks. At 20-week-old, transthoracic echocardiography and invasive haemodynamic analysis showed that cardiac diastolic function parameters, such as e', E/e', end-diastolic pressure-volume relationship, Tau, and dP/dt min, were all deteriorated in placebo-treated db/db mice compared with db/+ mice, while systolic function was preserved. Importantly, these cardiac diastolic function parameters were significantly ameliorated in the LIPUS-treated db/db mice. We also measured the force (F) and intracellular Ca2+ ([Ca2+]i) in trabeculae dissected from ventricles. We found that relaxation time and [Ca2+]i decay (Tau) were prolonged during electrically stimulated twitch contractions in db/db mice, both of which were significantly ameliorated in the LIPUS-treated db/db mice, indicating that the LIPUS therapy also improves relaxation properties at tissue level. Functionally, exercise capacity was also improved in the LIPUS-treated db/db mice. Histologically, db/db mice displayed progressed cardiomyocyte hypertrophy and myocardial interstitial fibrosis, while those changes were significantly suppressed in the LIPUS-treated db/db mice. Mechanistically, western blot showed that the endothelial nitric oxide synthase (eNOS)-nitric oxide (NO)-cGMP-protein kinase G (PKG) pathway and Ca2+-handling molecules were up-regulated in the LIPUS-treated heart. CONCLUSIONS: These results indicate that the LIPUS therapy ameliorates cardiac diastolic dysfunction in db/db mice through improvement of eNOS-NO-cGMP-PKG pathway and cardiomyocyte Ca2+-handling system, suggesting its potential usefulness for the treatment of HFpEF patients.

Marked Impairment of Endothelium-Dependent Digital Vasodilatations in Patients With Microvascular Angina: Evidence for Systemic Small Artery Disease.

OBJECTIVE: It remains to be elucidated whether and how endothelial functions are impaired in peripheral circulation of patients with coronary functional disorders, such as vasospastic angina (VSA) and microvascular angina (MVA). We simultaneously examined endothelial functions of peripheral conduit and resistance arteries in patients with coronary functional disorders, with a special reference to NO and endothelium-dependent hyperpolarization factors. Approach and Results: Based on the results of invasive coronary acetylcholine testing and coronary physiological measurements, we divided 43 patients into 3 groups; VSA, MVA, and VSA+MVA. Endothelium-dependent vasodilatations of the brachial artery and fingertip arterioles to intra-arterial infusion of bradykinin were simultaneously evaluated by ultrasonography and peripheral arterial tonometry, respectively. To assess NO and endothelium-dependent hyperpolarization factors, measurements were repeated after oral aspirin and intra-arterial infusion of NG-monomethyl-L-arginine. Additionally, endothelium-independent vasodilatations to sublingual nitroglycerin and plasma levels of biomarkers for endothelial functions were measured. Surprisingly, digital vasodilatations to bradykinin were almost absent in patients with MVA alone and those with VSA+MVA compared with those with VSA alone. Mechanistically, both NO- and endothelium-dependent hyperpolarization-mediated digital vasodilatations were markedly impaired in patients with MVA alone. In contrast, endothelium-independent vasodilatations to nitroglycerin were comparable among the 3 groups. Plasma levels of soluble VCAM (vascular cell adhesion molecule)-1 were significantly higher in patients with MVA alone compared with those with VSA alone. CONCLUSIONS: These results provide the first evidence that both NO- and endothelium-dependent hyperpolarization-mediated digital vasodilatations are markedly impaired in MVA patients, suggesting that MVA is a cardiac manifestation of the systemic small artery disease.

Important Roles of Endothelium-Dependent Hyperpolarization in Coronary Microcirculation and Cardiac Diastolic Function in Mice.

Endothelium-dependent hyperpolarization (EDH) factor is one of endothelium-derived relaxing factors and plays important roles especially in microvessels. We have previously demonstrated that endothelium-derived hydrogen peroxide (H2O2) is an EDH factor produced by all types of nitric oxide synthases (NOSs), including endothelial NOS (eNOS), neuronal NOS (nNOS), and inducible NOS. Recent studies have suggested the association between coronary microvascular dysfunction and cardiac diastolic dysfunction. However, the role of EDH in this issue remains to be fully elucidated. We thus examined whether EDH plays an important role in coronary microcirculation and if so, whether endothelial dysfunction, especially impaired EDH, is involved in the pathogenesis of cardiac diastolic dysfunction in mice. Using a Langendorff-perfused heart experiment, we examined the increase in coronary flow in response to bradykinin in the presence of indomethacin and N-nitro-L-arginine (EDH condition) in wild-type, eNOS-knockout (KO), and nNOS/eNOS-double-KO mice. Compared with wild-type mice, EDH-mediated relaxations were increased in eNOS-KO mice but were significantly reduced in n/eNOS-KO mice. Catalase, a specific H2O2 scavenger, markedly inhibited EDH-mediated relaxations in all 3 genotypes, indicating compensatory roles of nNOS-derived H2O2 as an EDH factor in coronary microcirculation. Although both eNOS-KO and n/eNOS-KO mice exhibited similar extents of cardiac morphological changes, only n/eNOS-KO mice exhibited cardiac diastolic dysfunction. The expression of oxidized protein kinase G I-α (PKGIα) in the heart was significantly increased in eNOS-KO mice compared with n/eNOS-KO mice. These results indicate that EDH/H2O2 plays important roles in maintaining coronary microcirculation and cardiac diastolic function through oxidative PKGIα activation.

Influence of cognitive impairment on cardiac mortality after percutaneous coronary intervention in very elderly patients: a retrospective observational study.

BACKGROUND: Cognitive impairment (CI) increases cardiac mortality among very elderly patients. Percutaneous coronary intervention (PCI) for ischemic heart disease (IHD) patients is considered a favorable strategy for decreasing cardiac mortality. Here, we investigated the influence of CI on cardiac mortality after PCI in very elderly patients. METHODS: We performed a retrospective observational analysis of patients who received PCI between 2012 and 2014 at the South Miyagi Medical Center, Japan. IHD patients over 80 years old who underwent the Mini-Mental State Examination for CI screening during hospitalization and/or who had been diagnosed with CI were included. Participants were divided into CI and non-CI groups, and cardiac mortality and incidence of adverse cardiac events in a 3-year follow-up period were compared between groups. Statistical analyses were performed using the t-test, χ2 test, and multivariable Cox regression analysis, with major comorbid illness and conventional cardiac risk factors as confounders. RESULTS: Of 565 patients, 95 were included (41 CI, 54 non-CI). Cardiac mortality during the follow-up period was significantly higher in the CI group (36%) compared with the non-CI group (13%) (OR = 4.3, 95% CI: 1.56-11.82, P < 0.05). CI was an independent cardiac prognostic factor after PCI and, for CI patients, living only with a CI partner was an independent predictor of cardiac death within three years. CONCLUSIONS: CI significantly affected cardiac prognosis after PCI in very elderly patients, particularly those living with a CI partner. To improve patients' prognoses, social background should be considered alongside conventional medical measures.

Important roles of endothelial caveolin-1 in endothelium-dependent hyperpolarization and ischemic angiogenesis in mice.

Although increased levels of reactive oxygen species (ROS) are involved in the pathogenesis of cardiovascular diseases, the importance of physiological ROS has also been emerging. We have previously demonstrated that endothelium-derived H2O2 is an endothelium-dependent hyperpolarization (EDH) factor and that loss of endothelial caveolin-1 reduces EDH/H2O2 in the microcirculation. Caveolin-1 (Cav-1) is a scaffolding/regulatory protein that interacts with diverse signaling pathways, including angiogenesis. However, it remains unclear whether endothelial Cav-1 plays a role in ischemic angiogenesis by modulating EDH/H2O2. In the present study, we thus addressed this issue in a mouse model of hindlimb ischemia using male endothelium-specific Cav-1 (eCav-1) knockout (KO) mice. In isometric tension experiments with femoral arteries from eCav-1-KO mice, reduced EDH-mediated relaxations to acetylcholine and desensitization of sodium nitroprusside-mediated endothelium-independent relaxations were noted ( n = 4~6). An ex vivo aortic ring assay also showed that the extent of microvessel sprouting was significantly reduced in eCav-1-KO mice compared with wild-type (WT) littermates ( n = 12 each). Blood flow recovery at 4 wk assessed with a laser speckle flowmeter after femoral artery ligation was significantly impaired in eCav-1-KO mice compared with WT littermates ( n = 10 each) and was associated with reduced capillary density and muscle fibrosis in the legs ( n = 6 each). Importantly, posttranslational protein modifications by reactive nitrogen species and ROS, as evaluated by thiol glutathione adducts and nitrotyrosine, respectively, were both increased in eCav-1-KO mice ( n = 6~7 each). These results indicate that endothelial Cav-1 plays an important role in EDH-mediated vasodilatation and ischemic angiogenesis through posttranslational protein modifications by nitrooxidative stress in mice in vivo. NEW & NOTEWORTHY Although increased levels of reactive oxygen species (ROS) are involved in the pathogenesis of cardiovascular diseases, the importance of physiological ROS has also been emerging. The present study provides a line of novel evidence that endothelial caveolin-1 plays important roles in endothelium-dependent hyperpolarization and ischemic angiogenesis in hindlimb ischemia in mice through posttranslational protein modifications by reactive nitrogen species and ROS in mice in vivo.

Important Role of Endothelial Caveolin-1 in the Protective Role of Endothelium-dependent Hyperpolarization Against Nitric Oxide-Mediated Nitrative Stress in Microcirculation in Mice.

AIMS: Nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) play important roles in maintaining cardiovascular homeostasis. We have previously demonstrated that endothelial NO synthase (eNOS) plays diverse roles depending on vessel size, as a NO generating system in conduit arteries and an EDH-mediated system in resistance arteries, for which caveolin-1 (Cav-1) is involved. However, the physiological role of endothelial Cav-1 in microvessels remains to be elucidated. METHODS AND RESULTS: We newly generated endothelium-specific Cav-1-knockout (eCav-1-KO) mice. eCav-1-KO mice showed loss of endothelial Cav-1/eNOS complex and had cardiac hypertrophy despite normal blood pressure. In eCav-1-KO mice, as compared to wild-type controls, the extent of eNOS phosphorylation at inhibitory Thr495 was significantly reduced in mesenteric arteries and the heart. Isometric tension and Langendorff-perfused heart experiments showed that NO-mediated responses were enhanced, whereas EDH-mediated responses were reduced in coronary microcirculation in eCav-1-KO mice. Immunohistochemistry showed increased level of 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), a marker of nitrative stress, in the heart from eCav-1-KO mice. S-guanylation of cardiac H-Ras in eCav-1-KO mice was also significantly increased compared with wild-type controls. CONCLUSIONS: These results suggest that eCav-1 is involved in the protective role of EDH against nitrative stress caused by excessive NO to maintain cardiac microvascular homeostasis.

Important role of endothelium-dependent hyperpolarization in the pulmonary microcirculation in male mice: implications for hypoxia-induced pulmonary hypertension.

Endothelium-dependent hyperpolarization (EDH) plays important roles in the systemic circulation, whereas its role in the pulmonary circulation remains largely unknown. Furthermore, the underlying mechanisms of pulmonary hypertension (PH) also remain to be elucidated. We thus aimed to elucidate the role of EDH in pulmonary circulation in general and in PH in particular. In isolated perfused lung and using male wild-type mice, endothelium-dependent relaxation to bradykinin (BK) was significantly reduced in the presence of Nω-nitro-l-arginine by ~50% compared with those in the presence of indomethacin, and the combination of apamin plus charybdotoxin abolished the residual relaxation, showing the comparable contributions of nitric oxide (NO) and EDH in the pulmonary microcirculation under physiological conditions. Catalase markedly inhibited EDH-mediated relaxation, indicating the predominant contribution of endothelium-derived H2O2. BK-mediated relaxation was significantly reduced at day 1 of hypoxia, whereas it thereafter remained unchanged until day 28. EDH-mediated relaxation was diminished at day 2 of hypoxia, indicating a transition from EDH to NO in BK-mediated relaxation before the development of hypoxia-induced PH. Mechanistically, chronic hypoxia enhanced endothelial NO synthase expression and activity associated with downregulation of caveolin-1. Nitrotyrosine levels were significantly higher in vascular smooth muscle of pulmonary microvessels under chronic hypoxia than under normoxia. A similar transition of the mediators in BK-mediated relaxation was also noted in the Sugen hypoxia mouse model. These results indicate that EDH plays important roles in the pulmonary microcirculation in addition to NO under normoxic conditions and that impaired EDH-mediated relaxation and subsequent nitrosative stress may be potential triggers of the onset of PH. NEW & NOTEWORTHY This study provides novel evidence that both endothelium-dependent hyperpolarization and nitric oxide play important roles in endothelium-dependent relaxation in the pulmonary microcirculation under physiological conditions in mice and that hypoxia first impairs endothelium-dependent hyperpolarization-mediated relaxation, with compensatory upregulation of nitric oxide, before the development of hypoxia-induced pulmonary hypertension.

Crucial roles of nitric oxide synthases in ß-adrenoceptor-mediated bladder relaxation in mice.

The specific roles of nitric oxide (NO) synthases (NOSs) in bladder smooth muscle remain to be elucidated. We examined the roles of NOSs in ß-adrenoceptor (AR)-mediated bladder relaxation. Male mice (C57BL6) deficient of neuronal NOS [nNOS-knockout (KO)], endothelial NOS (eNOS-KO), neuronal/endothelial NOS (n/eNOS-KO), neuronal/endothelial/inducible NOS (n/e/iNOS-KO), and their controls [wild-type (WT)] were used. Immunohistochemical analysis was performed in the bladder. Then the responses to relaxing agents and the effects of several inhibitors on the relaxing responses were examined in bladder strips precontracted with carbachol. Immunofluorescence staining showed expressions of nNOS and eNOS in the urothelium and smooth muscle of the bladder. Isoproterenol-induced relaxations were significantly reduced in nNOS-KO mice and were further reduced in n/eNOS-KO and n/e/iNOS-KO mice compared with WT mice. The relaxation in n/e/iNOS-KO mice was almost the same as in n/eNOS-KO mice. Inhibition of Ca2+-activated K+ (KCa) channel with charybdotoxin and apamin abolished isoproterenol-induced bladder relaxation in WT mice. Moreover, direct activation of KCa channel with NS1619 caused comparable extent of relaxations among WT, nNOS-KO, and n/eNOS-KO mice. In contrast, NONOate (a NO donor) or hydrogen peroxide (H2O2) (another possible relaxing factor from eNOS) caused minimal relaxations, and catalase (H2O2 scavenger) had no inhibitory effects on isoproterenol-induced relaxations. These results indicate that both nNOS and eNOS are substantially involved in ß-AR-mediated bladder relaxations in a NO- or H2O2-independent manner through activation of KCa channels.