Clinical Characteristics of Cohort of 113 Patients with Cancer-Associated Non Bacterial Thrombotic Endocarditis

Background: Clinical presentation of cancer-associated non-bacterial thrombotic endocarditis (Ca-NBTE) patients including type of malignancy, cardiac valves involved, type of thrombotic complications and hematological indices is limited to cases reports and one small clinical series.

Patients and Methods: An electronic search of Mayo Clinic clinical and laboratory records (03/31/2002-06/30/2022) with subsequent manual review was performed to identify adult patients with echocardiographically detected NBTE, diagnosis of active cancer, no infectious endocarditis or lupus anticoagulant/antiphospholipid antibodies.

Results: Ca-NBTE was diagnosed in 113 patients (mean age 63.3±9.7 years, 67.0% female). Majority of our patients had advanced cancer with 94 out of 107 (87.8%) with either stage IV (n=80) or stage III (n=14). Only 3 patients had stage I cancer. The most common origin of malignancy was lung cancer representing 42 cases (37.2%) and pancreatic cancer (n=19, 16.8%) followed by 15 cases (14.1%) of gynecological malignancies (including 9 ovarian, 4 endometrial, and 2 cervical cancers). Eight Ca-NBTE patients (7.1%) had gastrointestinal cancer equally distributed into upper and lower tract. Hematologic malignancy was diagnosed in 7 patients (6.2%) with 3 patients having myeloid malignancy and 4 lymphoid. Five patients in our cohort had two active cancers at the time of Ca-NBTE diagnosis. The predominant histological type of cancer was adenocarcinoma (n=80, 70.8 %). All pancreatic, over 90% of lung, near 90% of gastrointestinal, and almost half of genitourinary cancers were adenocarcinomas.

Vast majority of patients had thrombotic complications at the time of diagnosis with 92 (81.4%) patients with embolic complications to the brain, 10 (8.9%) to the spleen, 9 (8.0%) kidney, 6 (5.3) coronary and 3 (2.7%) to the extremities.

The platelet count ranged from 10 to 459 x 109/L with almost 50% of patients having thrombocytopenia (<150,000) at the time of Ca-NBTE diagnosis. There were no patients with creatinine clearance less than 30. Prior history of venous thromboembolism was noted in 61 (54.0%) patients of our cohort. Most often affected valve was mitral (n=68) followed by aortic (n=61). Only one heart valve was affected by Ca-NBTE in 93 patients (48 mitral, 42 aortic, and 3 tricuspid). Eighteen patients had Ca-NBTE affecting 2 valves (16 mitral and aortic, 1 mitral and tricuspid) with one patient having all 4 valves involved.

Of 104 anticoagulated patients, 76 received low molecular weight heparin, 16 apixaban, 22 unfractionated heparin, 16 warfarin, and 6 rivaroxaban.

Conclusion: Ca-NBTE is more common in female patients with underlying pulmonary and pancreatic cancers and will usually present with acute stroke. Mitral valve is the most common involved, but nearly 20% of patients had multiple valves involved. In our cohort most patients were treated with low molecular weight heparin.

No relevant conflicts of interest to declare.