Paclitaxel Drug-Coated Balloon Angioplasty Suppresses Progression and Inflammation of Experimental Atherosclerosis in Rabbits

Abstract

Paclitaxel drug-coated balloons (DCBs) reduce restenosis, but their overall safety has recently raised concerns. This study hypothesized that DCBs could lessen inflammation and reduce plaque progression. Using 25 rabbits with cholesterol feeding- and balloon injury-induced lesions, DCB-percutaneous transluminal angioplasty (PTA), plain PTA, or sham-PTA (balloon insertion without inflation) was investigated using serial intravascular near-infrared fluorescence-optical coherence tomography and serial intravascular ultrasound. In these experiments, DCB-PTA reduced inflammation and plaque burden in nonobstructive lesions compared with PTA or sham-PTA. These findings indicated the potential for DCBs to serve safely as regional anti-atherosclerosis therapy.

Keywords: 2D, 2-dimensional; CSA, cross-sectional area; DCB, drug-coated balloon; EEM, external elastic membrane; IVUS, intravascular ultrasound; NIRF, near-infrared fluorescence; OCT, optical coherence tomography; PAD, peripheral arterial disease; PAV, percent atheroma volume; PB, plaque burden; PTA, percutaneous transluminal angioplasty; PTX, paclitaxel; TAV, total atheroma volume; atherosclerosis; drug-coated balloon; imaging; inflammation; peripheral arterial disease.

Graphical abstract

Figure 1

Experimental Study Design All 25 rabbits received 1.0% high-cholesterol diet (HCD) 2 weeks before aorta balloon injury, and for 4 weeks thereafter, followed by normal chow for the final 4 weeks. At 4 weeks after balloon injury, rabbits were intravenously injected with ProSense VM110 (400 nmol/kg). Rabbits underwent in vivo multimodal survival near-infrared fluorescence−optical coherence tomography (NIRF-OCT), intravascular ultrasound (IVUS), and x-ray angiography 24 h later. Then animals randomly underwent drug-coated balloon percutaneous transluminal angioplasty (DCB-PTA) (n = 10), PTA (n = 10), or sham-PTA (n = 5) therapy. Four weeks later at week 10, multimodal imaging NIRF-OCT and IVUS imaging were repeated, followed by sacrificed and ex vivo fluorescence imaging, as well as RNA and histopathological analysis. FRI = fluorescence reflectance imaging; IHC = immunohistochemistry; qPCR= quantitative polymerase chain reaction.

Figure 2

Representative NIRF Inflammation and IVUS Plaque Burden Imaging of DCB-PTA, PTA, and Sham-PTA Groups Depiction of 2D NIRF maps at 6-week and 10-week timepoints after injection (24 h prior) with ProSense VM110, comparing (A) DCB-PTA, (B) PTA, and (C) Sham-PTA representative subjects. The area subject to angioplasty is illustrated by the red dotted box (2D NIRF map). The accompanying 1D plots show the NIRF concentration and plaque burden by IVUS at both timepoints. Inset graphs demonstrate 6-week (blue) and 10-week (red) keys. IVUS white scale bar, 1 mm. Complete intravascular imaging data is presented in Supplemental Figures S1 to S3. 2D = 2-dimensional; 1D = 1-dimensional; other Abbreviations as in Figure 1.

Figure 3

Comparison of Atheroma Macrophage and Smooth Muscle Cell Presence, and Plaque Cathepsin RNA Expression in DCB-PTA, PTA, and Sham-PTA Subjects, as Well as in Vitro Assessment of the Effects of Paclitaxel on Cathepsin Expression in Human Aortic Smooth Muscle Cells Lesion sections from representative DCB-PTA, PTA, and sham-PTA animals underwent (A and B) RAM-11 macrophage (n = 143 sections) and (C and D) alpha-actin smooth muscle cell (n = 79 sections) immunohistochemical detection. The percent positively stained area in lesions was assessed; balloon dots are actual values per section; bars demonstrate median (25th and 75th percentiles). (E) Gene expression normalized to the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) (housekeeping gene), displayed using comparative Ct method (2^-ΔΔCt). mRNA expression of cathepsin genes measured by quantitative polymerase chain reaction. Verification of expression demonstrated by immunoblotting of cathepsin B, after protein extraction. Statistical comparisons made using Kruskal-Wallis H test, with a post hoc analysis using Dunn’s test of multiple comparisons. (F) In vitro human aortic smooth muscle cells were incubated with graded concentrations of paclitaxel, and then underwent RNA extraction to assess cathepsin transcripts. n = 4, bars demonstrate median (25th and 75th percentiles). ∗∗∗p < 0.001. Abbreviations as in Figure 1.