2018 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Analysis of in-hospital deaths in patients with critical limb ischemia necessitating invasive treatments: based on a Japanese nationwide database

Critical limb ischemia (CLI) is associated with systemic cardiovascular and non-cardiovascular diseases. Treatments primarily targeting limb-related outcomes may not improve overall life prognosis. We aimed to describe in-hospital mortality and the underlying etiologies in Japanese patients with CLI. We analyzed the Diagnosis Procedure Combination (DPC) database from approximately 1200 Japanese acute-care hospitals between April 2018 and March 2020. The definition of patients with CLI was based on the diagnostic codes listed as the most resource-intensive diagnosis and information regarding invasive procedures (endovascular treatment, bypass, or amputation). The DPC database provides information on whether in-hospital death was caused by the most resource-intensive diagnosis. Among 15,228 distinct patients with CLI, we identified 18,970 records, including 5,378 amputations. In-hospital death occurred in 1238 (6.5%) patients. Among them, 811 (65.5%) were due to causes unrelated to CLI. In patients who underwent amputation (n = 5378), causes unrelated to CLI accounted for 70.0% of in-hospital deaths, whereas among patients who did not undergo amputation (n = 13,592), this proportion was 60.1%. When compared to patients who died due to causes related to CLI, the prevalence of male patients was higher (62.6% vs 52.7%, p = 0.001), and amputation was more frequently performed (58.0% vs 47.1%, p < 0.001) in those who died due to causes unrelated to CLI. The majority of in-hospital deaths among patients with CLI necessitating endovascular treatment, bypass, or amputation were attributable to factors unrelated to the primary condition of CLI. Managing systemic cardiovascular and non-cardiovascular diseases beyond the affected limb is crucial to improve the prognosis of these patients.

2020 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The purpose of this project is to clarify the current status of the medical practice for the patients with CLI to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), is created on the National Clinical Database and collects data of patients' background, therapeutic measures, early results, and long-term prognosis as long as 5 years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated by surgery and/or endovascular treatment. In 2020, 1299 CLI limbs (male 890 limbs: 69%) were registered by 85 facilities. Arteriosclerosis obliterans has accounted for 99% of the pathogenesis of these limbs. In this manuscript, the background data and the early prognosis of the registered limbs are reported. (This is a translation of Jpn J Vasc Surg 2023; 32: 363-391.).

A Nomogram for Predicting the Risk of Critical Limb Ischemia in Adults with Hypertension: A Retrospective Study

Purpose

Peripheral arterial disease (PAD) presenting with underlying hypertension (HTN) poses a higher risk of bilateral lower limb amputation than PAD patients without HTN. While the role of HTN management of PAD patients has received limited attention. We analyzed the clinical characteristics of PAD in adults with HTN and explored risk factors for PAD to construct a nomogram for evaluating critical limb ischemia (CLI) and lesion severity.

Methods Patients and Methods

Between January 2014 and December 2019, we retrospectively evaluated 1886 patients with peripheral artery disease with coexisting HTN. Patients were randomly divided into training (n = 1320, 70%) and validation cohorts (n = 566, 30%), and according to the subjective experience of PAD [Fontaine classification (I–II vs III–IV)], patients were further classified into intermittent claudication (IC) and CLI groups. LASSO regression and multivariate Cox proportional hazard analyses were used to construct a nomogram using variables defined in the training cohort, which was validated in the validation cohort. The evaluation of the predictive discriminative, accuracy and clinical application are further analyzed.

Results

In the training cohort, optimal independent factors included age, male sex, body mass index, diabetes mellitus, heart rate, triglyceride, and uric acid (AM-BDHTU), which were included in the nomogram predicting the CLI risk (all P < 0.05). The C-index values for CLI risk in PAD with HTN patients were 0.729 (95% CI: 0.704–0.807) and 0.728 (95% CI: 0.652–0.744) in the training and validation sets, respectively. Calibration curves indicated good consistency between predicted and actual outcomes. DCA confirmed the clinical utility of the diagnostic model.

Conclusion

The AM-BDHTU nomogram, constructed and validated using simple to obtain clinical variables, when combined with the Fontaine classification, effectively predicts the risk of CLI among PAD patients with HTN.

2019 JAPAN Critical Limb Ischemia Database (JCLIMB) Annual Report

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The objective of this project is to elucidate the current status of the medical practice for CLI patients to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), is created on the National Clinical Database (NCD) and collects data of patients’ background, therapeutic measures, early results, and long-term prognosis as long as 5 years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated with surgery and/or endovascular treatment (EVT). In 2019, 1070 CLI limbs (male: 725 limbs, 68%) were registered by 83 facilities. Arteriosclerosis obliterans (ASO) accounted for 98% of the pathogenesis of these limbs. In this manuscript, the background data and the early prognosis of the registered limbs are reported. Although the registration format for the simultaneous surgery of bilateral limbs in NCD was changed to one patient and two limbs, JCLIMB still counted two patients and two limbs to eliminate discrepancy with the past annual reports. (This is a translation of Jpn J Vasc Surg 2022; 31: 157–185.)