Risk Models and Scores in Patients with Peripheral Artery Disease and Chronic Limb-threatening Ischemia: A Comprehensive Review

Peripheral artery disease (PAD) affects more than 200 million patients worldwide and chronic limb-threatening ischemia (CLTI) is the most advanced stage of PAD with very high morbidity and mortality rates. Cardiovascular medicine is trending towards a more personalized approach where each individual patient will be managed according to specific risk factors, disease characteristics, expectations related to their disease and individualized assessment of potential outcomes. For this reason, a number of risk models and scores have been developed during the last few years. Our aim in this comprehensive review article is to provide an overview of selected risk models and scores for patients with PAD and CLTI. Given that some of the published scores were of low quality (minimal discriminatory ability), we included scores that were already externally validated or scores that had promising initial findings. Available scoring systems were grouped in the five following categories according to their utility: i) scores that can detect asymptomatic patients who should be screened for PAD, ii) scores for assessment of functional status and quality of life in patients with PAD, iii) scores assessing risk for amputation and other major adverse limb events among patients with CLTI, iv) scores for the optimal revascularization strategy in each patient and scores predicting successful procedural outcomes; v) scores predicting short or long-term cardiovascular and limb related outcomes after either revascularization or at least angiographic assessment. Limitations of available scoring systems include development and validation in specific populations, lack of external validation (for some of them) and also lack of synchrony with current era endovascular technology. However, with further optimization of current scores and the development of new scores, the field of PAD and CLI can be transitioned to a personalized medicine approach.