Aim

This study investigated regional disparities in the incidence, management, and in-hospital outcomes of critical limb ischemia (CLI) in Japan to inform standardized care practices.

Methods

We conducted a retrospective cohort study using the nationwide Diagnosis Procedure Combination database, including patients ≥ 18 years old who were discharged from acute-care hospitals between April 2018 and March 2020. Patients with CLI were identified using ICD-10 codes and restricted to those undergoing invasive treatments including endovascular therapy (EVT), bypass surgery, or amputation. Regional differences in patient demographics, in-hospital management, and outcomes were analyzed across seven regions in Japan.

Results

In total, 19,699 records were identified. CLI admissions per million population were highest in the Kyushu region (112.1) and lowest in the Kanto region (59.9). The proportion of patients with a body mass index (BMI) ＜18.5 kg/m2 ranged from 17.8% (Kanto) to 23.9% (Kansai), while the proportion with a BMI ≥ 30.0 kg/m2 ranged from 3.3% (Kyushu) to 8.2% (Okinawa). The proportion of patients requiring dialysis ranged from 33.8% in the Chugoku-Shikoku region to 38.2% in the Okinawa region (P = 0.005). Anti-platelet agents were prescribed to 82.1% of patients with CLI, whereas statins were prescribed to 36.1% of patients. The EVT rates varied from 67.6% (Hokkaido-Tohoku) to 84.8% (Kansai) (P＜0.001), while the amputation rates varied from 22.2% (Kansai) to 33.4% (Chugoku-Shikoku) (P＜0.001). The in-hospital mortality rates varied from 5.7% (Chugoku-Shikoku) to 10.9% (Okinawa) (P = 0.001).

Conclusions

This study revealed significant regional disparities in CLI incidence, management, and outcomes across Japan. These findings highlight the need for standardized, evidence-based care strategies that address regional disparities to improve outcomes for patients with CLI.