Systemic arterial calcium burden in patients with chronic limb-threatening ischemia

Thirty-day outcomes from the Disrupt PAD BTK II study of the Shockwave Intravascular Lithotripsy System for treatment of calcified below-the-knee peripheral arterial disease

BACKGROUND

Below-the-knee (BTK) lesions may be particularly challenging to treat owing to length, diffuse disease, and extent of calcification. Landmark interventional clinical studies have not reached consensus on the optimal standard of care for BTK lesions, and many published trials excluded patients with moderate or severe lesion calcification. Calcium modification with intravascular lithotripsy (IVL) was shown to be superior to percutaneous transluminal angioplasty in the femoropopliteal artery and successful in treating BTK lesions in pilot studies. The Disrupt BTK II study is a core laboratory-adjudicated, prospective, multicenter, single-arm study of patients with moderate to severely calcified BTK lesions treated with the Shockwave Medical Peripheral IVL System.

METHODS

Disrupt BTK II enrolled 250 subjects with calcified infrapopliteal lesions and Rutherford category 3-5 presentation from 38 sites in the United States and Europe. The primary safety endpoint was major adverse limb events or postoperative death at 30 days, a composite of all-cause death, above-ankle amputation of the index limb, and/or major reintervention of the index limb involving an infrapopliteal artery. The primary effectiveness endpoint was procedural success, defined as ≤50% residual stenosis for all treated target lesions without serious core laboratory-adjudicated serious angiographic complications. The study used independent angiographic and duplex ultrasound core laboratories, and follow-up is planned through 2 years.

RESULTS

A total of 305 lesions in 250 patients were treated with a procedural success of 97.9%. The mean target lesion length was 76 ± 65 mm, diameter stenosis was 78% ± 18%, and 84.8% had moderate or severe calcification as assessed by an independent angiographic core laboratory. After IVL, residual stenosis was reduced to 29%, and after optional postdilatation and/or stent implantation, to 26%. At 30 days, there were no deaths, major adverse limb event rate was 0.8%, and mean improvement in Vascular Quality of Life scores was 4.0 ± 5.0 (P < .0001). Of the patients with baseline wounds, 15.8% healed and 53.4% were improved at 30 days.

CONCLUSIONS

The Disrupt PAD BTK II study demonstrated that treatment with the Shockwave Medical Peripheral IVL System in patients with moderate-severe calcified lesions resulted in high procedural success, significant reduction in residual stenosis, improvements in patient quality of life, and wound healing, with minimal adverse events at 30-day follow-up.

"All in one" lipid-polymer nanodelivery system for gene therapy of ischemic diseases

Gene therapy offers a promising avenue for treating ischemic diseases, yet its clinical efficacy is hindered by the limitations of single gene therapy and the high oxidative stress microenvironment characteristic of such conditions. Lipid-polymer hybrid vectors represent a novel approach to enhance the effectiveness of gene therapy by harnessing the combined advantages of lipids and polymers. In this study, we engineered lipid-polymer hybrid nanocarriers with tailored structural modifications to create a versatile membrane fusion lipid-nuclear targeted polymer nanodelivery system (FLNPs) optimized for gene delivery. Our results demonstrate that FLNPs facilitate efficient cellular uptake and gene transfection via membrane fusion, lysosome avoidance, and nuclear targeting mechanisms. Upon encapsulating Hepatocyte Growth Factor plasmid (pHGF) and Catalase plasmid (pCAT), HGF/CAT-FLNPs were prepared, which significantly enhanced the resistance of C2C12 cells to H2O2-induced injury in vitro. In vivo studies further revealed that HGF/CAT-FLNPs effectively alleviated hindlimb ischemia-induced gangrene, restored motor function, and promoted blood perfusion recovery in mice. Metabolomics analysis indicated that FLNPs didn't induce metabolic disturbances during gene transfection. In conclusion, FLNPs represent a versatile platform for multi-dimensional assisted gene delivery, significantly improving the efficiency of gene delivery and holding promise for effective synergistic treatment of lower limb ischemia using pHGF and pCAT.

Reversion of the Inflammatory Markers in Patients With Chronic Limb-Threatening Ischemia

BACKGROUND

Peripheral artery disease is characterized by an intense inflammatory process that can be associated with a higher mortality rate, particularly in chronic limb-threatening ischemia (CLTI). This study aims to compare the evolution of inflammatory markers between patients with claudication with those with CLTI at 3, 6, and 12 months.

METHODS AND RESULTS

An observational, single-center, and prospective study was conducted. A total of 119 patients with peripheral artery disease (65 with claudication and 54 with CLTI) were observed and inflammatory markers collected at admission and 3, 6, and 12 months. At admission, patients with CLTI, when compared with patients with claudication, had significantly higher serum levels of C-reactive protein and fibrinogen (positive acute-phase proteins) and lower serum level of albumin, total cholesterol, and high-density lipoprotein (negative acute-phase proteins): C-reactive protein (g/dL), 2.90 (25th-75th percentile, 2.90-4.90) versus 6.80 (25th-75th percentile, 2.90-53.26) (P=0.000); fibrinogen (mg/dL), 293.00 (25th-75th percentile, 269.25-349.00) versus 415.50 (25th-75th percentile, 312.00-615.75) (P=0.000); total cholesterol (mg/dL), 161.79±95% [152.74-170.85] versus 146.42%±95% [135.30-157.53] (P=0.034); high-density lipoprotein (mg/dL), 50.00 (25th-75th percentile, 41.00-60.00) versus 37.00 (25th-75th percentile, 30.00-45.50) (P=0.000); albumin (g/dL): 4.00 (25th-75th percentile, 3.70-4.20) versus 3.60 (25th-75th percentile, 3.10-4.00) (P=0.003). The association between CLTI and total cholesterol was lost after adjusting for confounders. Three months after the resolution of the CLTI, there was an increase in the levels of negative acute-phase proteins and a decrease in positive acute-phase proteins. These inflammatory proteins did not register an evolution in patients with claudication. The differences in the inflammatory proteins between groups disappeared at 6 months.

CONCLUSIONS

CLTI has an inflammatory environment that can be partially reverted after resolution of the ischemic process, emphasizing the importance of timely intervention.

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.

Dynamic Perfusion Computed Tomography for the Assessment of Concomitant Coronary Artery Disease in Patients with a History of Percutaneous Transluminal Angioplasty for Chronic Limb-Threatening Ischemia-A Pilot Study

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is associated with high rates of long-term cardiovascular mortality. Exercise stress testing to detect obstructive coronary artery disease (CAD) can be difficult in this subset of patients due to inability to undergo exercise testing, presence of balanced ischemia and severe coronary artery calcification (CAC).

AIM

To test the feasibility of regadenoson stress dynamic perfusion computed tomography (DPCT) in CLTI patients.

METHODS

Between 2018 and 2023, coronary computed tomography angiography (CTA) and, in the case of a calcium score higher than 400, DPCT, were performed in 25 CLTI patients with a history of endovascular revascularization.

RESULTS

Of the 25 patients, 19 had a calcium score higher than 400, requiring DPCT image acquisition. Obstructive CAD could be ruled out in 10 of the 25 patients. Of the 15 CTA/DPCT+ patients, 13 proceeded to coronary angiography (CAG). Revascularization was necessary in all 13 patients. In these 13 patients, vessel-based sensitivity and specificity of coronary CTA/DPCT as compared to invasive evaluation was 75%, respectively. At follow-up (27 ± 21 months) there was no statistically significant difference in all-cause mortality between CTA/DPCT- positive and -negative patients (p = 0.065).

CONCLUSIONS

Despite a high prevalence of severe CAC, coronary CTA complemented by DPCT may be a feasible method to detect obstructive and functionally significant CAD in CLTI patients.