Clinical Characteristics of Heart Failure from Case Reports Presented at the Regional Meeting of the Japanese Society of Internal Medicine

Objective To examine case reports presented at the Regional Meeting of the Japanese Society of Internal Medicine in order to clarify the underlying disease and prognosis of heart failure, which is often caused by non-cardiovascular diseases. Methods We examined 49,693 case reports from the Japanese Society of Internal Medicine database. A total of 2,893 reports were included after excluding 46,022 reports that did not include the term “heart failure” and 778 reports with no indications of symptoms of heart failure. We assessed each patient's basal disease, and according to the abstracts, we reported their prognosis as dead or alive. Results Of the 2,893 reports included, 1,952 (67.5%) and 941 (32.5%) had cardiovascular and non-cardiovascular diseases as the causes, respectively; these cases were attributed to 725 different diseases, 196 (27.0%) and 529 (73.0%) of which were cardiovascular and non-cardiovascular diseases, respectively. In addition, 91 different side effects were identified. The percentage of cases of heart failure-related mortality was significantly higher among the patients with non-cardiovascular diseases than in those with cardiovascular diseases (17.8% vs. 10.8%; p <0.001). Of the diseases reported as causes of heart failure in more than 10 reports, pulmonary tumor thrombotic microangiopathy (87%), multiple myeloma (50%), and amyloidosis (47%) accounted for the highest percentages of heart failure-related mortality. Conclusion Because heart failure is often caused by non-cardiovascular diseases, a broad study of case reports on internal medicine is important for cardiologists.