A Case of Stress-Induced Cardiomyopathy After Ketamine Infusion.

We report the case of a 64-year-old female with a history of hypothyroidism and isolated parotid sarcoidosis who presented with acute-onset chest pain and dyspnea. Echocardiogram demonstrated transiently reduced ejection fraction with apical hypokinesis, without evidence of obstructive coronary lesions on angiography, compatible with stress-induced cardiomyopathy. She received a ketamine infusion as a mental health treatment shortly before the development of symptoms, suggesting that this medication may have precipitated her cardiomyopathy. In recent years, ketamine has become a popular option for treating mental health disorders, including major depressive disorder and substance use disorders. It should be used with caution in patients with known cardiovascular disease, and its cardiac effects warrant further study.

Refractory right ventricular myocarditis induced by immune checkpoint inhibitor despite therapy cessation and immune suppression.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are currently widely used for treatment of various types of cancers. ICI-induced myocarditis, though uncommon, accounts for high risk of major adverse cardiac events and mortality, which makes appropriate diagnosis important. We here present a unique, challenging case of ICI-induced, refractory and isolated right ventricular (RV) myocarditis. CASE PRESENTATION: A 32-year-old female with breast cancer presented with newly onset chest pain and dyspnea shortly after initiation of Pembrolizumab. Coronary angiography showed normal coronary arteries and a cardiac magnetic resonance (CMR) revealed myocarditis involving the right ventricle with chamber dilation and severe dysfunction. ICI therapy was stopped, and high dose steroid therapy was initiated and symptoms resolved. However, three months after initial presentation, the patient was hospitalized for DKA and decompensated right heart failure, and a repeat cardiac MRI at that time showed recurrent, isolated right ventricular myocardial inflammation/edema without LV involvement. High dose steroid therapy was started again and at 6-month follow up, surveillance CMR continued to show persistent right-sided myocarditis, patient was eventually treated with Abatacept with resolution of HF symptoms, RV dysfunction and biomarkers at 10-month follow up. CONCLUSIONS: We describe a unique case of isolated ICI-induced right ventricular myocarditis leading to right ventricular failure, that was refractory despite ICI therapy cessation and immune suppression by repeated high dose steroids. Co-stimulatory pathway modulation with Abatacept eventually lead to the normalization of RV function and dilation ten months after initial myocarditis onset.

Catastrophic Merkel Cell Carcinoma in a Liver Transplant Recipient.

Merkel cell carcinoma (MCC) is a rare skin cancer, is difficult to diagnose, and carries a high mortality rate. Solid organ transplant recipients (SOTR) are at a disproportionately increased risk of MCC and other malignancies due to chronic immunosuppression. We discuss the case of a 47-year-old woman with a remote history of liver transplant on chronic immunosuppression with tacrolimus for over a decade who presented for a third recurrence of MCC on her left forearm. This case report underscores the importance of a risk-stratified approach to regular dermatologic care and skin cancer screening in this vulnerable population.

A machine learning model in predicting hemodynamically significant coronary artery disease: A prospective cohort study.

Background: Coronary artery disease (CAD) costs healthcare billions of dollars annually and is the leading cause of death despite available noninvasive diagnostic tools. Objective: This study aims to examine the usefulness of machine learning in predicting hemodynamically significant CAD using routine demographics, clinical factors, and laboratory data. Methods: Consecutive patients undergoing cardiac catheterization between March 17, 2015, and July 15, 2016, at UNC Chapel Hill were screened for comorbidities and CAD risk factors. In this pilot, single-center, prospective cohort study, patients were screened and selected for moderate CAD risk (n = 185). Invasive coronary angiography and CAD prediction with machine learning were independently performed. Results were blinded from operators and patients. Outcomes were followed up for up to 90 days for major adverse cardiovascular and renal events (MACREs). Greater than 70% stenosis or a fractional flow reserve less than or equal to 0.8 represented hemodynamically significant coronary disease. A random forest model using demographic, comorbidities, risk factors, and lab data was trained to predict CAD severity. The Random Forest Model predictive accuracy was assessed by area under the receiver operating characteristic curve with comparison to the final diagnoses made from coronary angiography. Results: Hemodynamically significant CAD was predicted by 18-point clinical data input with a sensitivity of 81% ± 7.8%, and specificity of 61% ± 14.4% by the established model. The best machine learning model predicted a 90-day MACRE with specificity of 44.61% ± 14.39%, and sensitivity of 57.13% ± 18.70%. Conclusion: Machine learning models based on routine demographics, clinical factors, and lab data can be used to predict hemodynamically significant CAD with accuracy that approximates current noninvasive functional modalities.

Use of 68Ga DOTATATE, a new molecular imaging agent, for neuroendocrine tumors.

Neuroendocrine tumors (NET), such as insulinomas and carcinoid tumors, can be challenging to diagnose since patients often present with vague symptoms. Adding to the challenge, these tumors are often occult on typical cross-sectional imaging modalities. Because of these challenges, there has been an increase in the utilization of radiopharmaceuticals that take advantage of specific receptors expressed by NET. Among the multiple radiopharmaceuticals that can be used, 68Ga DOTATATE is emerging as the most sensitive and specific imaging agent. We present a case where 68Ga DOTATATE was used to diagnose a well-differentiated neuroendocrine tumor.

Electrochemical properties and C-H bond oxidation activity of [Ru(tpy)(pyalk)Cl]+ and [Ru(tpy)(pyalk)(OH)].

[Ru(tpy)(pyalk)Cl]Cl (pyalk = 2-(2'-pyridyl)-2-propanol) was synthesized and characterized crystallographically and electrochemically. Upon dissolution in water and acetonitrile, [Ru(tpy)(pyalk)Cl]Cl was found to form [Ru(tpy)(pyalk)Cl]+ and [Ru(tpy)(pyalk)(OH)]+, respectively. The Ru(ii/iii) couple of [Ru(tpy)(pyalk)Cl]+ was found to be relatively low compared to that of other Ru complexes in acetonitrile, but the Ru(iii/iv) couple was not significantly different than other Ru complexes bearing anionic ligands. Pourbaix diagrams were generated for [Ru(tpy)(phpy)(OH2)]+ (phpy = 2-phenylpyridine) and [Ru(tpy)(pyalk)(OH)]+ in water, and it was found that [Ru(tpy)(pyalk)(OH)]+ has a lower Ru(ii/iii) potential than [Ru(tpy)(phpy)(OH2)]+ under neutral to alkaline pH. [Ru(tpy)(pyalk)(OH)]+ was found to catalyze C-H bond hydroxylation of secondary alkanes and epoxidation of alkenes using cerium(iv) ammonium nitrate as the primary oxidant.