Different Lower Extremity Arterial Calcification Patterns in Patients with Chronic Limb-Threatening Ischemia Compared with Asymptomatic Controls

Vascular calcification: High incidence sites, distribution, and detection

Vascular calcification is an important pathological change in a variety of disease states such as atherosclerosis (AS), diabetes, chronic kidney disease (CKD), hypertension, and is a strong predictor of cardiovascular events. The distribution and location of calcification in different vessels may have different clinical effects and prognosis. Therefore, the study of high-risk sites of vascular calcification will help us to better understand the prevention, diagnosis, and treatment of related diseases, as well as to evaluate the efficacy and prognosis. So far, although there are some studies on the sites with high incidence of vascular calcification, there is a lack of systematic sorting out the distribution and location of vascular calcification in humans. Based on this, relevant databases were searched, literatures were retrieved, analyzed, and summarized, and the locations of high incidence of vascular calcification and their distribution characteristics, the relationship between high incidence of vascular calcification and hemodynamics, and the common detection methods of high incidence of vascular calcification were systematically described, hoping to provide help for clinical and research.

Circumferential degree of tibial artery calcification is associated with infrapopliteal endovascular revascularization outcomes in patients with chronic limb-threatening ischemia

BACKGROUND

Tibial artery calcification (TAC) is correlated with an increased risk of amputation and mortality in patients with chronic limb-threatening ischemia (CLTI). The association between calcification characteristics and adverse limb events of CLTI. However, it has not been assessed. This study aims to assess the relationship between the characteristics of TAC based on computed tomography angiography (CTA) scans and postoperative outcomes in patients with CLTI undergoing infrapopliteal endovascular therapy.

METHODS

This was a retrospective study of patients who underwent infrapopliteal endovascular revascularization for CLTI and had a preoperative CTA scan. Based on CTA, TAC was divided into the following categories: annularity, thickness, continuity and severity. Cox regression models using generalized estimating equations were performed to assess the relationship between calcification characteristics and postoperative outcomes. The outcomes evaluated were the occurrence of all cause mortality (ACM) and unplanned amputation.

RESULTS

Among the 148 patients undergoing endovascular, there were 50 (33.8%) patients died and 26 (17.6%) patients underwent unplanned amputation. Annular calcification was more common in the ACM group than in the non-ACM group. No significant differences were found between the two groups with regard to the probability of calcification in the thickness and the continuity (P>0.05). Patients in the unplanned amputation group had significantly annular, thin and continuity calcifications (P<0.05) than those in the non-unplanned amputation group. The presence of annular calcification was an independent predictor of ACM (hazard ratio (HR), 3.186; 95% confidence interval (CI), 1.781-5.702; P<0.001) and unplanned amputation (HR, 3.739; 95% CI, 1.707-8.191; P<0.05).

CONCLUSIONS

Among patients with CLTI, the occurrence of annular calcification in the tibial artery are related to a greater chance of ACM and unplanned amputation in the postoperative period. The circumferential degree of TAC of the operated limb can be considered as a marker of clinical prognosis in this group of patients.

Treatment of arterial calcification in patients with chronic limb threatening ischemia with etidronate: protocol of an investigator-initiated multicenter, double blind, placebo-controlled, randomized clinical trial

Background

Pathologic studies have shown that in patients with critical limb threatening ischaemia (CLTI) medial arterial calcifications are frequently found and may be responsible for aggravating the disease. These extensive calcifitcations are found not only in arteries of the leg but also in the coronary arteries and the aorta. The progression of these calcifications is fast and they stiffen the vessel wall and may thus increase the cardiovascular risk.

Reduction of progression of calcification may not only reduce the burden of CLTI but may also reduce the high residual cardiovascular risk. Medial calcifications have been halted by etidronate in other trials. Its potential to reduce the burden from peripheral vascular disease in CLTI and residual cardiovascular risk remains to be established.

Methods

This is an investigator-initiated multicenter, double blind, placebo-controlled, randomized trial comparing the effects of etidronate versus placebo in patients with CLTI.

Subjects will be randomized to either treatment with etidronate for 12 months (cyclical 20 mg/kg for 2 weeks on and 10 weeks off) orally or placebo for 12 months (in a similar routine).

The primary endpoint is the change in arterial calcification as quantified by CT-scan.

Secondary endpoints are the number of amputations above and below the ankle, mortality, number of vascular interventions and quality of life.

Discussion

Up to now, the inert end stage of vascular disease in patients with CLTI, has been considered calcification of vessel walls. We believe there is reason to reverse causation and hypothesize that calcification causes vascular disease. This reversal can be proven in a clinical trial if halting the calcification process improves the outcome of the patient. Therefore we use etidronate, a bisphosphate that has proven to stop the calcification in several rare monogenetic calcifying diseases. We aim to perform this mechanistic proof-of-concept study hopefully leading to a clinical outcome study later on.

Automatic measurement of vascular calcifications in patients with aorto-iliac occlusive disease to predict the risk of re-intervention after endovascular repair

OBJECTIVE

There is currently a lack of consensus and tools to easily measure vascular calcification using computed tomography angiography (CTA). The aim of this study was to develop a fully automatic software to measure calcifications and to evaluate the interest as predictive factor in patients with aorto-iliac occlusive disease.

METHODS

This study retrospectively included 171 patients who had endovascular repair of an aorto-iliac occlusive lesion at the University Hospital of Nice between January 2011 and December 2019. Calcifications volumes were measured from CT-angiography (CTA) using an automatic method consisting in 3 sequential steps: image pre-processing, lumen segmentation using expert system and deep learning algorithms and segmentation of calcifications. Calcification volumes were measured in the infrarenal abdominal aorta and the iliac arterial segments, corresponding to the common and the external iliac arteries.

RESULTS

Among 171 patients included with a mean age of 65 years, the revascularization was performed on the native external and internal iliac arteries in respectively: 83 patients (48.5%); 107 (62.3%) and 7 (4.1%). The mean volumes of calcifications were 2759 mm³ in the infrarenal abdominal aorta, 1821 mm³ and 1795 mm³ in the right and left iliac arteries. For a mean follow up of 39 months, TLR was performed in 55 patients (32.2%). These patients had higher volume of calcifications in the right and left iliac arteries, compared with patients who did not have a re-intervention (2274 mm³ vs 1606 mm³, p=0.0319 and 2278 vs 1567 mm³, p=0.0213).

CONCLUSION

The development of a fully automatic software would be useful to facilitate the measurement of vascular calcifications and possibly better inform the prognosis of patients.