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The natural history of untreated severe or critical limb ischemia
Abd Moain Abu Dabrh1, Mark W Steffen2, Chaitanya Undavalli3
1Division of Preventive, Occupational, and Aerospace Medicine, Mayo Clinic, Rochester, Minn; The Knowledge Synthesis Unit, The Center for Healthcare Delivery, Mayo Clinic, Rochester, Minn.
Insights
Untreated critical limb ischemia (CLI) carries significant risks, with high rates of mortality and major amputation within one year. Recent studies suggest a potential improvement in these outcomes over time.
Area of Science:
- Vascular Surgery
- Clinical Outcomes Research
- Epidemiology of Peripheral Arterial Disease
Background:
- Critical limb ischemia (CLI) is a severe manifestation of peripheral arterial disease, characterized by high rates of morbidity and mortality.
- The natural history of CLI, particularly in patients not undergoing revascularization, is not well-defined, hindering optimal treatment decisions.
- Understanding the prognosis of untreated CLI is crucial for patients considering interventions.
Purpose of the Study:
- To systematically review and meta-analyze the natural history of critical limb ischemia in patients who did not receive revascularization.
- To quantify the incidence of mortality, major amputation, and wound healing in untreated CLI patients with a minimum follow-up of one year.
Main Methods:
- A systematic literature search was conducted across multiple databases for studies on CLI patients without revascularization.
- Included studies had a minimum follow-up of one year.
- Random-effects meta-analysis was employed to pool cumulative incidence data for mortality, major amputation, and wound healing.
Main Results:
- Thirteen studies comprising 1527 patients were analyzed.
- Over a median follow-up of 12 months, the all-cause mortality rate was 22% (95% CI: 12%-33%) and the major amputation rate was 22% (95% CI: 2%-42%).
- Worsening of wounds or ulcers occurred in 35% (95% CI: 10%-62%) of patients. A trend towards improved outcomes was observed in studies published after 1997, though evidence quality was low.
Conclusions:
- Untreated critical limb ischemia is associated with substantial rates of mortality and major amputation within one year.
- While outcomes remain serious, there is evidence suggesting recent improvements in mortality and amputation rates.
- Further high-quality research is needed to confirm these trends and inform clinical practice.
Objective:
Critical limb ischemia (CLI) is associated with high morbidity and mortality. Because most patients with CLI will eventually undergo some type of revascularization, the natural history of CLI is not well defined, although it is important to know when patients decide to pursue treatment.
Methods:
We systematically searched multiple databases for controlled and uncontrolled studies of patients with CLI who did not receive revascularization with a minimum follow-up of ≥1 year. Predefined outcomes of interest were mortality, major amputation, and wound healing. Random-effects meta-analysis was used to pool cumulative incidence across studies.
Results:
We identified 13 studies enrolling 1527 patients. During a median follow-up of 12 months, all-cause mortality rate was 22% (confidence interval [CI], 12%-33%) and major amputation rate was 22% (CI, 2%-42%). Worsened wound or ulcer was found at 35% (CI, 10%-62%). There was a trend toward improvement in mortality and amputation rate in studies done after 1997. The quality of evidence was low because of increased risk of bias and inconsistency.
Conclusions:
Mortality and major amputations are common in patients who have untreated CLI during a median follow-up of 1 year, although these outcomes have improved in recent times.
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