Acute upon chronic limb ischemia

Lars Norgren | Apr 2020 | Diabetes / Hjärtkärlsjukdomar | Primärvård |

Lars Norgren
professor emeritus i kirurgi,
Örebro universitet

Acute limb ischemia (ALI) is caused by embolism, thrombosis or trauma and is defined as any sudden decrease in limb perfusion, inducing a potential threat to limb viability.1To be defined as acute, the condition should have appeared no more than 2 weeks earlier. In the 1990th the incidence of all ALI was found to be around 13 / 100,000.2Based on the rate of hospitalizations, Medicare figures pointed at a higher, but decreasing incidence from 45.7 / 100,000 in 1998 to 26.0 / 100,000 in 2009.3 Acute upon chronic ischemia4is usually caused by thrombosis, although embolic disease may coincide with chronic ischemia. Altogether, thrombosis constitutes about 70% of all ALI. The incidence and outcome of ALI in lower limb chronic peripheral arterial disease (PAD) is less well investigated. Some studies have included a PAD cohort when investigating the effect of antiplatelet treatment on MACE (major adverse cardiovascular events), but not included details on limb outcome, MALE (major adverse limb events). A study on the preventive effect of aspirin in asymptomatic persons with low ankle-brachial index (ABI) only noted the risk for limb revascularization or onset of intermittent claudication besides cardiovascular events.5In that respect, the risk was similar for treated and control subjects. The Japanese SEASON study on risk factors for MALE in patients with PAD and ABI <0.90 concluded an increased risk for ALI, but also for amputation and onset of critical limb ischemia.6The TRA2oP-TIMI 50 study included among patients with stable atherosclerotic disease 3,787 subjects with PAD who were randomized to either vorapaxar or placebo. The rate of ALI was 1.3% per year, and vorapaxar reduced a first ALI by 41%.7 Larger studies including exclusively a PAD population have not been implemented until the EUCLID trial.8 The EUCLID trial EUCLID, (Examining Use of Ticagrelor in Peripheral Artery Disease), designed to...