Intimal and medial arterial calcification in peripheral arterial disease a systematic review and meta-analysis of imaging and histological evidence.

INTRODUCTION

Vascular calcification (VC) comprises intimal arterial calcification (IAC) and medial arterial calcification (MAC). To date, limited data exist on the prevalence of these calcification types in infrainguinal peripheral arterial disease (PAD).

EVIDENCE ACQUISITION: We conducted a systematic review according to PRISMA 2020 guidelines for studies investigating the prevalence of IAC and MAC in PAD.

EVIDENCE SYNTHESIS: Three CT-based and six histological studies, encompassing 545 patients and 1161 arteries, were included. The pooled prevalence of VC was 96.99% (95% CI: 84.21-99.49) for CT, and 85.75% (95% CI: 74.65-92.48) for histological studies. CT-based assessment displayed IAC predominance over MAC in the femoropopliteal region, OR 6.63 (95% CI: 4.02-10.94), an outcome replicated by histological studies upon sensitivity analysis, OR 4.86 (95% CI: 1.49-15.91). Conversely, pooling of histological studies identified MAC dominance over IAC in the infra-popliteal arteries, OR 0.10 (95% CI: 0.03-0.30). Meta-regression displayed positive associations between male sex and infra-popliteal IAC, type II diabetes mellitus and femoropopliteal IAC, and chronic limb threatening ischemia (CLTI) and infra-popliteal MAC. The pooled prevalence of bone was 14.62% (95% CI: 8.25-24.58), significantly associated with CLTI, chronic kidney disease, and female sex.

CONCLUSIONS

PAD is characterized by a high prevalence of VC, predominantly IAC in the femoropopliteal arteries and MAC within the infra-popliteal region. The association of IAC, MAC and bone formation with distinct patient characteristics further underscores the clinical relevance and biological complexity of VC. Interpretation of these results should, however, be tempered by the absence of segment-matched CT-histology validation.