Non-bacterial thrombotic endocarditis in the context of pulmonary adenocarcinoma: a case report

Incidentally Discovered Endocarditis Leading to the Diagnosis of an Epidermal Growth Factor Receptor Mutant Metastatic Pulmonary Malignancy of Occult Primary Tumor

Introduction

Non-bacterial thrombotic endocarditis is well documented in the literature to occur in patients with known malignancies. It is, however, much less common for patients to be diagnosed with marantic endocarditis as the presenting sign of an unknown primary malignancy.

Case Presentation

We discuss a case in which a patient was undergoing routine surveillance for his known heart failure with a transthoracic echocardiogram when an aortic valve vegetation was discovered. After further investigation, he was found to have metastatic adenocarcinoma of the lung. Next-generation sequencing was utilized to identify an EGFR mutation, which led to the patient being treated with osimertinib.

Conclusion

Adequate treatment of his primary malignancy, along with anticoagulation, led to overall clinical improvement of the patient.

Postmortem Evaluation of Cardiac Valvular Disease in Bald Eagles (Haliaeetus leucocephalus) and a Golden Eagle (Aquila chrysaetos)

Limited data are available regarding cardiac diseases in birds of prey despite their prevalence in these avian species. Literature regarding valvular lesions in birds of prey is scarce and includes single reports of left atrioventricular valvular endocarditis in an adult, free-ranging, male bald eagle (Haliaeetus leucocephalus) and aortic valvular endocarditis in an adult, free-ranging, female red-tailed hawk (Buteo jamaicensis). The purpose of this study was to evaluate the prevalence, signalment, gross necropsy findings, and histologic lesions of valvular lesions in eagles. In this retrospective study, necropsy reports for 24 free-ranging and captive eagles were evaluated over a 15-year period (July 3, 2006-February 28, 2021). Six (25%; 95% confidence interval: 8.9-58.9) birds, 5 bald eagles and 1 golden eagle (Aquila chrysaetos), met the inclusion criteria. Five (83.3%) of the 6 birds had valvular degeneration, 2 (33.3%) had endocarditis, and Staphylococcus aureus was cultured from 1 (16.7%) of the endocarditis cases. The 6 eagles with valvular lesions were all captive adults. Four of the birds were female (66.7%), and the aortic and left atrioventricular valves were equally affected. Acute or chronic cerebral infarcts were present in all 6 birds. Valvular cardiac disease should be considered as a differential diagnosis in eagles exhibiting respiratory distress, neurologic signs, syncope, or in cases of sudden death.

Lung Cancer as a Leading Cause among Paraneoplastic Non-Bacterial Thrombotic Endocarditis: A Meta-Analysis of Individual Patients' Data

Hypercoagulability is strongly associated with cancer and may result in non-bacterial thrombotic endocarditis (NBTE). The aim of our meta-analysis was to explore the demographics and characteristics of this condition in cancer. Databases were systematically searched. The outcomes were to identify the annual trend in premortem diagnosis among the entire cohort and different subgroups and to identify differences in characteristics and survival in the considered population. A total of 121 studies with 144 patients were included. The proportion of marantic endocarditis associated with lung cancer was 0.29 (95% CI, 0.21-0.37; p < 0.001), that associated with pancreatic cancer was 0.19 (95% CI, 0.13-0.27; p < 0.001), that associated with advanced cancer stage (metastasis) was 0.69 (95% CI, 0.61-0.76; p < 0.001), and that associated with adenocarcinoma was 0.65 (95% CI, 0.56-0.72; p < 0.001). Median and 6-month overall survival (OS) were 1.3 months and 32.3%, respectively, with 6-month OS of 20.8% vs. 37.0% in lung vs. other cancers, respectively (p = 0.06) and 42.9% vs. 31.1% among those who underwent intervention vs. those who did not (p = 0.07). Cases discovered in recent years had better survival (HR = 0.98 (95% CI, 0.96-0.99; p = 0.003). While cancer-associated NBTE is a rare entity, lung cancers were the most common tumor site and are frequently associated with more advanced and metastatic cancer stages. The prognosis is dismal, especially among lung cancers.

A Patient’s Six-Month Journey From Low Sodium to Blue Toes to Stroke: Non-infective Thrombotic Endocarditis Due to Non-small Cell Lung Cancer

We report a patient's journey with a four-year history of hypertension (HTN) and hyperlipidemia (HLD), stable on beta-blocker and statin, monitored every six months by alternating visits between her cardiologist and primary care physician (PCP) in North Carolina (NC). Six months before relocating to New York (NY) she had been informed about incidental severe hyponatremia during her last outpatient visit, the need for repletion with sodium chloride tablets, and the critical importance of prompt follow-up to rule out malignancy by starting with a chest X-ray. She opted not to follow instructions, continued cigarettes, and decided to spend the summer season with her son in NY. Six months after being told of her low sodium, she presented to our NY hospital with an acute, painful right foot blue toe syndrome. During the ischemic right foot evaluation, she was discovered to have adenocarcinoma of the right lung (stage 4) and a normal transthoracic echocardiogram (TTE). Heparin was initiated and thromboembolectomy with an endovascular bovine patch to revascularize the foot was successful, and post-procedure apixaban was started.

Hyponatremia was attributed to the syndrome of inappropriate antidiuretic hormone release (SIADH) secondary to non-small cell lung cancer (NSCLC). The serum sodium was stabilized, and the patient was discharged with a plan for outpatient follow-up with the cardiologist and oncologist within two weeks for hypertension, hyperlipidemia, hyponatremia, and management of stage 4 NSCLC. During her cardiology follow-up, 10 days after discharge, complaints of mild dyspnea on exertion (DOE) prompted an ECG (electrocardiogram) that revealed new T wave inversions in leads V3-6, and the patient was readmitted for non-ST elevation myocardial infarction (NSTEMI) evaluation. On day one of the readmission troponins were negative with normal ejection fraction (EF) on TTE and an acute 2 g/dl hemoglobin (Hb) drop with melena. This led to discontinuation of anticoagulation, initiation of intravenous (IV) pantoprazole, and endoscopy (EGD) which revealed gastritis. On the third day, she developed sudden expressive aphasia. Computed tomography (CT) of the head did not show any bleed but same-day magnetic resonance imaging (MRI) demonstrated multiple evolving acute infarcts. Transesophageal echocardiogram (TEE) demonstrated two large, mobile masses on the mitral valve consistent with vegetative endocarditis. Cultures for bacteria, fungi, and evaluation for organisms associated with culture-negative acute bacterial endocarditis/subacute bacterial endocarditis were unrevealing, thus confirming malignancy-associated non-infectious thrombotic endocarditis or non-bacterial thrombotic endocarditis (NBTE).

Gastrointestinal (GI) bleeding ceased, and the patient initially started on a heparin drip and transitioned to enoxaparin as lifelong anticoagulation for malignancy-associated NBTE. She recovered neurologically and was given pembrolizumab. At her recent 15-month visit she continued to have no residual neurological impairments, however, new positron emission tomography (PET) detected metastasis to the liver, lung, and adrenals which prompted evaluation for hospice care. We, therefore, emphasize the need for timely diagnosis of NBTE and prompt initiation of anticoagulation in suitable patients to prevent complications such as in our patient. Additionally, hyponatremia secondary to SIADH in NSCLC is a poor prognostic indicator of overall survival.