Three to four years outcomes of the absorb bioresorbable vascular scaffold versus second-generation drug-eluting stent: A meta-analysis.

OBJECTIVE: This meta-analysis sought to evaluate the outcomes of absorb bioresorbable vascular scaffolds (BVS) compared with second-generation drug-eluting stents (DES) after 3 years, the approximate time of complete polymer bioresorption. BACKGROUND: BVS were found to be inferior to second-generation DES in early and mid-term outcomes with a higher rate of target vessel myocardial infarction (TV-MI) and device thrombosis (DT). Improper implantation techniques and incomplete bioresorption of the poly-l-lactide (PLLA) polymer were sighted as possible reasons. METHODS: We conducted an electronic database search for all randomized control trials that compared absorb BVS to second-generation DES and reported outcomes of interest after 3 years of absorb BVS implantation. Assuming interstudy heterogeneity, a random-effects analysis was conducted with odds ratio as the effect size of choice to compare the event rates between the two groups. RESULTS: A total of four studies (n = 3,245, BVS = 2075, DES = 1,170) were included in the final analysis. Pooled analysis revealed that there was no difference between absorb BVS and second-generation DES with respect to target lesion failure (TLF) (OR = 1.23, 95% CI = 0.73-2.07, p = 0.44), TV-MI (OR = 1.03, 95% CI = 0.42-2.53, p = 0.95), target lesion revascularization (TLR) (OR = 1.61, 95% CI = 0.77-3.33, p = 0.20) and definite/probable DT (OR = 0.71, 95% CI = 0.10-5.07, p = 0.74). Also, there was no difference in cardiac mortality (OR = 0.66, 95% CI = 0.22-1.94, p = 0.45). CONCLUSIONS: Between 3 and 4 years of follow-up, patients receiving absorb BVS did not have significantly different outcomes, in terms of TLF, TV-MI, TLR, DT, and cardiac mortality, compared to DES.

Coronary Artery PET/MR Imaging: Feasibility, Limitations, and Solutions.

OBJECTIVES: The aims of this study were to describe the authors' initial experience with combined coronary artery positron emission tomographic (PET) and magnetic resonance (MR) imaging using 18F-fluorodeoxyglucose (18F-FDG) and 18F-sodium fluoride (18F-NaF) radiotracers, describe common problems and their solutions, and demonstrate the feasibility of coronary PET/MR imaging in appropriate patients. BACKGROUND: Recently, PET imaging has been applied to the aortic valve and regions of atherosclerosis. 18F-FDG PET imaging has become established for imaging inflammation in atherosclerosis in the aorta and carotid arteries. Moreover, 18F-NaF has emerged as a novel tracer of active microcalcification in the aortic valve and coronary arteries. Coronary PET imaging remains challenging because of the small caliber of the vessels and their complex motion. Currently, most coronary imaging uses combined PET and computed tomographic imaging, but there is increasing enthusiasm for PET/MR imaging because of its reduced radiation, potential to correct for motion, and the complementary information available from cardiac MR in a single scan. METHODS: Twenty-three patients with diagnosed or documented risk factors for coronary artery disease underwent either 18F-FDG or 18F-NaF PET/MR imaging. Standard breath-held MR-based attenuation correction was compared with a novel free-breathing approach. The impact on PET image artifacts and the interpretation of vascular uptake were evaluated semiquantitatively by expert readers. Moreover, PET reconstructions with more algorithm iterations were compared visually and by target-to-background ratio. RESULTS: Image quality was significantly improved by novel free-breathing attenuation correction. Moreover, conspicuity of coronary uptake was improved by increasing the number of algorithm iterations from 3 to 6. Elevated radiotracer uptake could be localized to individual coronary lesions using both 18F-FDG (n = 1, maximal target-to-background ratio = 1.61) and 18F-NaF (n = 7, maximal target-to-background ratio = 1.55 ± 0.37), including in 1 culprit plaque post-myocardial infarction confirmed by myocardial late gadolinium enhancement. CONCLUSIONS: The authors provide the first demonstration of successful, low-radiation (7.2 mSv) PET/MR imaging of inflammation and microcalcification activity in the coronary arteries. However, this requires specialized approaches tailored to coronary imaging for both attenuation correction and PET reconstruction.