The Use of Pressure Indices, Such as Fractional Flow Reserve, in Peripheral Arterial Disease-A Review of Current Literature and Potential Prospects

PurposeTo assess the evidence in the current literature, identify the knowledge gaps and propose future standards for the use of pressure indices in peripheral arterial disease (PAD).MethodsA search of all medical databases was performed to identify studies performed between 01/01/2000 and 31/12/2024, looking at the use of FFR or IFR in the management of PAD. The Newcastle-Ottawa scale was used to assess the quality of the papers. A comparison of the studies was performed using various parameters including; study design, cohort demographics, aim, lesions treated, hyperaemic agent used/pressure indices utilised, FFR endpoint and clinical outcomes.Results136 studies were found in initial search. Only studies investigating FFR were identified, none looked at IFR. Following the application of the exclusion criteria, 8 relevant studies with a total of 247 patients were included in the final analyses. No randomised controlled or prospective trials were found. Significant heterogeneity was observed in the methodology and data collection among the included papers. Despite this, the analysis demonstrated initial evidence showing the potential of pressure measurements to revolutionise diagnostic, intra-procedural and prognostic decisions in PAD, akin to the data that already exists in coronary artery disease.ConclusionsFurther standardised research of FFR is needed in peripheral vascular disease to improve objective understanding of physiological parameters pre and post-treatment. To this end, a standardisation tool has been proposed to homogenise and aid future research in drawing more robust conclusions for the use of pressure indices in PAD.