Acute Myocardial Infarction in a Young Man with Hyperhomocysteinemia and Pulmonary Tuberculosis

Acute coronary syndrome with large thrombus successfully managed with no-stenting revascularization based on intravascular imaging in a patient with hyperhomocysteinemia: a case report

Background

Hyperhomocysteinemia is caused by genetic and environmental factors, which can result in systemic arteriosclerosis and arteriovenous thrombosis including acute coronary syndrome. Thrombus burden in patients with acute coronary syndrome and hyperhomocysteinemia might involve the culprit lesion as compared with those without any coagulopathy. The primary percutaneous coronary intervention with stent implantation had been established as the treatment strategy for patients with acute coronary syndrome. However, in patients with acute coronary syndrome with high thrombus burden or uncontrolled coagulopathy, stent implantation might lead to slow-flow phenomenon or stent thrombosis. Therefore, the treatment strategy in these patients was not established.

Case presentation

A 49-year-old Japanese man with history of splenic infarction of unknown cause had continued anticoagulant therapy since its diagnosis, but stopped taking the medication several months ago. He presented with sudden-onset chest dorsalgia. Contrast computed tomography showed a small pulmonary embolism and his troponin I level was elevated on initial laboratory test. Coronary angiography revealed a contrast defect caused by a large thrombus from the proximal to mid portion of the left anterior descending artery. Near-infrared spectroscopy–intravascular ultrasonography showed a large amount of thrombus without lipid plaque. Therefore, revascularization was performed using a thrombus-aspiration catheter and intracoronary thrombolysis. In addition, , hyperhomocysteinemia and a deep vein thrombosis occurred. He was diagnosed with acute coronary syndrome complicated with pulmonary embolism and deep vein thrombosis simultaneously induced by hyperhomocysteinemia. After 1 week of antithrombotic therapy, near-infrared spectroscopy–intravascular ultrasonography and optical coherence tomography revealed a decreased thrombus and no significant residual organic stenosis in the left anterior descending artery. He continued conservative therapy with antithrombotic medications including aspirin and warfarin and had no cardiovascular events after discharge. Follow-up coronary angiography and optical coherence tomography at 9 months revealed complete disappearance of the thrombus and no severe stenosis.

Conclusions

Hyperhomocysteinemia should be considered as a cause of arterial vein thrombosis of unknown cause. The antithrombotic therapy and percutaneous revascularization without stenting based on intravascular imaging might be a safe and effective treatment option in patients with acute coronary syndrome complicated with hyperhomocysteinemia.

Toxicoproteomic Profiling of hPXR Transgenic Mice Treated with Rifampicin and Isoniazid

Tuberculosis is a global health threat that affects millions of people every year, and treatment-limiting toxicity remains a considerable source of treatment failure. Recent reports have characterized the nature of hPXR-mediated hepatotoxicity and the systemic toxicity of antitubercular drugs. The antitubercular drug isoniazid plays a role in such pathologic states as acute intermittent porphyria, anemia, hepatotoxicity, hypercoagulable states (deep vein thrombosis, pulmonary embolism, or ischemic stroke), pellagra (vitamin B₃ deficiency), peripheral neuropathy, and vitamin B₆ deficiency. However, the mechanisms by which isoniazid administration leads to these states are unclear. To elucidate the mechanism of rifampicin- and isoniazid-induced liver and systemic injury, we performed tandem mass tag mass spectrometry-based proteomic screening of mPxr^-/- and hPXR mice treated with combinations of rifampicin and isoniazid. Proteomic profiling analysis suggested that the hPXR liver proteome is affected by antitubercular therapy to disrupt [Fe-S] cluster assembly machinery, [2Fe-2S] cluster-containing proteins, cytochrome P450 enzymes, heme biosynthesis, homocysteine catabolism, oxidative stress responses, vitamin B₃ metabolism, and vitamin B₆ metabolism. These novel findings provide insight into the etiology of some of these processes and potential targets for subsequent investigations. Data are available via ProteomeXchange with identifier PXD019505.

Inducible nitric oxide synthase: Good or bad?

Nitric oxide synthases (NOS) are a family of isoforms responsible for the synthesis of the potent dilator nitric oxide (NO). Expression of inducible NOS (iNOS) occurs in conditions of inflammation, and produces large amounts of NO. In pathological conditions iNOS is regarded as a harmful enzyme and is proposed to be a major contributor to diseases of the cardiovascular system such as atherosclerosis. In this review, we address the notion that iNOS is a detrimental enzyme in disease and discuss its potentially beneficial roles. Additionally, we describe other molecules associated with iNOS in diseases such as atherosclerosis, and current research on therapeutic inhibitors tested to reduced pathology associated with cardiovascular diseases (CVD).

Clinical evaluation of myocardial involvement in acute myopericarditis in young adults

BACKGROUND

Myocardial involvement in young adults has various causes. Acute myopericarditis is one of the myocardial involvements in young adults. It is easy to confuse with acute ST-elevation myocardial infarction because of the electrocardiographic features. This study aims to investigate a number of imaging techniques and clinical features for acute myopericarditis in young adults (<30 years of age).

METHODS

This retrospective study included 147 patients selected from the 2147 patients at the age of <30 with acute chest pain admitted into emergency service between 2010 and 2016. Of 147 patients, 77 patients were diagnosed with acute myopericarditis (group I) (between 18 and 30 aged) and 70 patients had ST-elevation myocardial infarction (group II). The echocardiographic pictures and information of the patients in both groups were rechecked in terms of impaired segmental wall-motion abnormalities, pericardial effusion, and additional features.

RESULTS

The patients in group I had focal echobright, which was defined as myocardial brightness in the left ventricle regions, especially in posterior and lateral wall. Focal echobright was observed in the 75 of 77 cases of acute myopericarditis in transthoracic echocardiogram. This sign was confirmed by cardiac magnetic resonance imaging. Focal echobright sensitivity was 95%; its specificity was 93%; its predictive was 95.2%. Pericardial effusion (83%) was observed in group I behind posterior wall. Its specificity was 81%; its sensitivity was 65%; predictivity was 73%.

CONCLUSIONS

Pericardial effusion and myocardial focal echobright in echocardiography can be quite sensitive indicators for acute myopericarditis in young adults.