Aims
To describe the practice patterns of evidence-based medical therapy (EBM) and overall mortality in high-risk patients with critical limb-threatening ischaemia (CLTI), compared with patients with myocardial infarction (MI).

Methods and results
Using Danish registries, we identified patients 40–100 years of age with a first-time hospitalization for CLTI or MI from 2008–2018 and grouped them into CLTI, MI, and CLTI and history of MI (CLTI + MI). We examined the likelihood of filling prescriptions with EBM [i.e. antiplatelets (Aps), lipid-lowering agents (LLAs), angiotensin-converting enzyme inhibitor (ACEi), or angiotensin II-receptor blockers (ARBs)] within 3 months after discharge among survivors. Further, we assessed the adjusted 3-year mortality rates. We included 92 845 patients: 14 941 with CLTI (54.7% male), 74 830 with MI (64.6% male) and 3,074 with CLTI + MI (65.2% male). Patients with CLTI and CLTI + MI were older and had more comorbidities than patients with MI. Compared with patients with MI, the unadjusted odds ratios of filling prescriptions were 0.15 [confidence interval (CI): 0.14–0.15] for AP, 0.26 (CI: 0.25–0.27) for LLA, and 0.71 (CI: 0.69–0.74) for ARB/ACEi in patients with CLTI, and 0.22 (CI: 0.20–0.24) for AP, 0.38 (CI: 0.35–0.42) for LLA, and 1.17 (CI: 1.08–1.27) for ARB/ACEi in patients with CLTI + MI. Adjusted analyses showed similar results. Compared with patients with MI, adjusted 3-year hazard ratios for mortality were 1.69 (CI: 1.64–1.74) in patients with CLTI and 1.60 (CI: 1.51–1.69) in patients with CLTI + MI.

Conclusion
Patients with CLTI were undertreated with EBM and carried a more adverse prognosis, as compared with patients with MI, despite similar guidelines.