Drug-Eluting Resorbable Scaffold versus Angioplasty for Infrapopliteal Artery Disease.

BACKGROUND: Among patients with chronic limb-threatening ischemia (CLTI) and infrapopliteal artery disease, angioplasty has been associated with frequent reintervention and adverse limb outcomes from restenosis. The effect of the use of drug-eluting resorbable scaffolds on these outcomes remains unknown. METHODS: In this multicenter, randomized, controlled trial, 261 patients with CLTI and infrapopliteal artery disease were randomly assigned in a 2:1 ratio to receive treatment with an everolimus-eluting resorbable scaffold or angioplasty. The primary efficacy end point was freedom from the following events at 1 year: amputation above the ankle of the target limb, occlusion of the target vessel, clinically driven revascularization of the target lesion, and binary restenosis of the target lesion. The primary safety end point was freedom from major adverse limb events at 6 months and from perioperative death. RESULTS: The primary efficacy end point was observed (i.e., no events occurred) in 135 of 173 patients in the scaffold group and 48 of 88 patients in the angioplasty group (Kaplan-Meier estimate, 74% vs. 44%; absolute difference, 30 percentage points; 95% confidence interval [CI], 15 to 46; one-sided P<0.001 for superiority). The primary safety end point was observed in 165 of 170 patients in the scaffold group and 90 of 90 patients in the angioplasty group (absolute difference, -3 percentage points; 95% CI, -6 to 0; one-sided P<0.001 for noninferiority). Serious adverse events related to the index procedure occurred in 2% of the patients in the scaffold group and 3% of those in the angioplasty group. CONCLUSIONS: Among patients with CLTI due to infrapopliteal artery disease, the use of an everolimus-eluting resorbable scaffold was superior to angioplasty with respect to the primary efficacy end point. (Funded by Abbott; LIFE-BTK ClinicalTrials.gov number, NCT04227899.).

Duration of Dual Antiplatelet Therapy for Patients at High Bleeding Risk Undergoing PCI.

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) among patients at high bleeding risk (HBR) is unknown. OBJECTIVES: The purpose of this analysis was to compare 1 vs 3 months of DAPT in HBR patients undergoing drug-eluting stent implantation. METHODS: The XIENCE Short DAPT program comprised 3 prospective, multicenter, single-arm studies of HBR patients treated with a short DAPT course followed by aspirin monotherapy after PCI with a cobalt-chromium everolimus-eluting stent. In this exploratory analysis, patients who received 1-month DAPT (XIENCE 28 USA and 28 Global) were compared with those on 3-month DAPT (XIENCE 90) using propensity score stratification. Ischemic and bleeding outcomes were assessed between 1 and 12 months after index PCI. RESULTS: A total of 3,652 patients were enrolled and 1,392 patients after 1-month DAPT and 1,972 patients after 3-month DAPT were eligible for the analyses. The primary endpoint of all-cause mortality or myocardial infarction was similar between the 2 groups (7.3% vs 7.5%; difference -0.2%; 95% CI: -2.2% to 1.7%; P = 0.41). The key secondary endpoint of BARC (Bleeding Academic Research Consortium) type 2-5 bleeding was lower with 1-month DAPT compared with 3-month DAPT (7.6% vs 10.0%; difference -2.5%; 95% CI: -4.6% to -0.3%; P = 0.012). Major BARC type 3-5 bleeding did not differ at 12 months (3.6% vs 4.7%; difference -1.1%; 95% CI: -2.6% to 0.4%; P = 0.082), but was lower with 1-month DAPT at 90 days (1.0% vs 2.1%; P = 0.015). CONCLUSIONS: Among HBR patients undergoing PCI, 1 month of DAPT, compared with 3 months of DAPT, was associated with similar ischemic outcomes and lower bleeding risk. (XIENCE 90 Study; NCT03218787; XIENCE 28 USA Study; NCT03815175; XIENCE 28 Global Study; NCT03355742).

3- or 1-Month DAPT in Patients at High Bleeding Risk Undergoing Everolimus-Eluting Stent Implantation.

OBJECTIVES: The aim of this study was to evaluate 2 abbreviated dual-antiplatelet therapy (DAPT) regimens in patients at high bleeding risk (HBR) undergoing percutaneous coronary intervention (PCI). BACKGROUND: Current-generation drug-eluting stents are preferred over bare-metal stents for HBR patients, but their optimal DAPT management remains unknown. METHODS: The XIENCE Short DAPT program included 3 prospective, multicenter, single-arm studies enrolling HBR patients who underwent successful PCI with a cobalt-chromium everolimus-eluting stent. After 1 month (XIENCE 28 USA and XIENCE 28 Global) or 3 months (XIENCE 90) of DAPT, event-free patients discontinued the P2Y12 inhibitor. The postmarketing approval XIENCE V USA study was used as historical control in a propensity score-stratified analysis. RESULTS: A total of 3,652 patients were enrolled. The propensity-adjusted rate of the primary endpoint of all-cause mortality or myocardial infarction was 5.4% among 1,693 patients on 3-month DAPT versus 5.4% in the 12-month DAPT historical control (Pnoninferiority = 0.0063) and 3.5% among 1,392 patients on 1-month DAPT versus 4.3% in the 6-month DAPT historical control (Pnoninferiority = 0.0005). Bleeding Academic Research Consortium (BARC) types 2 to 5 bleeding was not significantly lower with 3- or 1-month DAPT, while BARC types 3 to 5 bleeding was reduced in both experimental groups. The rate of definite or probable stent thrombosis was 0.2% in XIENCE 90 (P < 0.0001 for the performance goal of 1.2%) and 0.3% in XIENCE 28. CONCLUSIONS: Among HBR patients undergoing PCI with cobalt-chromium everolimus-eluting stents, DAPT for 1 or 3 months was noninferior to 6 or 12 months of DAPT for ischemic outcomes and may be associated with less major bleeding and a low incidence of stent thrombosis.

Impact of renal function in high bleeding risk patients undergoing percutaneous coronary intervention: a patient-level stratified analysis from four post-approval studies.

Data on ischemic and bleeding outcomes after percutaneous coronary intervention (PCI) in high bleeding risk (HBR) patients with chronic kidney disease (CKD) are scarce. We aimed to evaluate the association between CKD and ischemic and bleeding outcomes in HBR patients who underwent PCI. Among 10,502 patients in the four post-approval registries evaluating patients undergoing PCI, 2,300 patients presented with at least one major or two minor ARC-HBR criteria. CKD was defined as eGFR < 60 mL/min/1.73 m2. These HBR patients were divided into 3 groups: eGFR < 30 mL/min/1.73 m2 defined as severe CKD (N = 221), eGFR 30- < 60 mL/min/1.73 m2 defined as moderate CKD (N = 970), eGFR ≥ 60 mL/min/1.73 m2 defined as no CKD (N = 1,109). The primary endpoint was the composite of cardiac death, myocardial infarction, or stent thrombosis, and the safety endpoint was major bleeding up to 4-year follow-up. HBR patients with CKD were more often female and had higher rates of comorbidities compared to those without CKD. Reduced renal function was associated with higher rates of the primary endpoint (severe CKD vs. moderate CKD vs. no CKD: 30.2% vs. 12.5% vs. 9.1%, P < 0.01) as well as major bleeding (10.3% vs. 8.9% vs. 6.4%, P = 0.03). After adjustment, severe CKD and moderate CKD in HBR patients remained independent predictors for the primary endpoint (HR [95%CI] 2.84 [1.94-4.16], P < 0.01, 1.48 [1.10-2.00], P < 0.01) compared to those with no CKD. However, decreased renal function was no longer significantly associated with major bleeding after adjustment. In conclusions, in HBR patients undergoing PCI, CKD has an important impact on major ischemic events after PCI.

Sex-Related Differences in Patients at High Bleeding Risk Undergoing Percutaneous Coronary Intervention: A Patient-Level Pooled Analysis From 4 Postapproval Studies.

Background Women have been associated with higher rates of recurrent events after percutaneous coronary intervention than men, possibly attributable to advanced age at presentation and greater comorbidities. These factors also put women at higher risk of bleeding, which may influence therapeutic strategies and clinical outcomes. Methods and Results We performed a patient-level pooled analysis of 4 postapproval registries to evaluate sex-related differences in patients at high bleeding risk (HBR) undergoing percutaneous coronary intervention. HBR required fulfillment of at least 1 major or 2 minor criteria of the Academic Research Consortium definition. Outcomes of interest were major bleeding and major adverse cardiac events (composite of cardiac death, myocardial infarction, or definite/probable stent thrombosis). Of the total 10 502 patients, 2832 (27.0%) were women. The prevalence of HBR was higher in women compared with men (29.0% versus 20.5%, P<0.0001). Women at HBR were older and had more comorbidities, while men at HBR were more often smokers, with prior myocardial infarction and more complex coronary lesions. At 4 years, women at HBR had significantly higher major bleeding compared with men at HBR (10.8% versus 6.2%, P<0.0001); however, this difference was attenuated after multivariable adjustment (hazard ratio, 0.92; 95% CI, 0.41-2.08). Major adverse cardiac event rates between groups were similar (12.2% versus 12.6%, P=0.82) and remained consistent after adjustment (hazard ratio, 0.64; 95% CI, 0.32-1.28). Conclusions The prevalence of HBR was higher in women compared with men, with considerable differences in the distribution of criteria. Women at HBR experienced higher rates of major bleeding but similar major adverse cardiac event rates compared with men at HBR at 4 years.

Efficacy and Safety of the Absorb Bioresorbable Vascular Scaffold in Females and Males: Results of an Individual Patient-Level Pooled Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: Because females are under-represented in coronary trials, this study sought to assess the relative safety and efficacy of Absorb bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) and the Xience everolimus-eluting stent in females compared with males. BACKGROUND: The Absorb everolimus-eluting BVS provides drug delivery and mechanical support similar to a metallic drug-eluting stent, followed by resorption and restoration of more normal vascular structure with the potential to improve late clinical outcomes. METHODS: The ABSORB II, ABSORB III, ABSORB Japan, and ABSORB China trials were pooled. Baseline clinical, angiography, procedural variables, and 2-year outcomes were analyzed by sex and device. RESULTS: Among 3,384 randomized patients, 932 (27.5%) were female. Females were older, more often had diabetes and hypertension, but had less everolimus-eluting stent, 3-vessel disease, and smoking compared with males (all p≤0.001). The 2-year rates of target lesion failure with BVS versus everolimus-eluting stent in females were 8.9% versus 6.2% (study-level adjusted hazard ratio: 1.47; 95% confidence interval [CI]: 0.88 to 2.46) and 8.9% versus 6.4% in males (HR: 1.40; 95% CI: 1.02 to 1.92; pinteraction = 0.85). There were no significant interactions between sex and device type for any of the components of target lesion failure. CONCLUSIONS: The relative treatment effects of BVS and everolimus-eluting stent for the 2-year rates of target lesion failure and other cardiovascular outcomes were consistent in females and males.

Changes in natural killer cell subsets in pediatric liver transplant recipients.

NK cells are important in the immune response against tumors and virally infected cells. A balance between inhibitory and activating receptors controls the effector functions of NK cells. We examined the fate of circulating NK cells and the expression of the NK cell-activating receptors in pediatric liver transplant recipients. Blood specimens were collected from 38 pediatric liver transplant recipients before transplant, and at one wk, one, three, six, and nine months, and one yr post-transplant. PBMCs were isolated and analyzed for the levels of NK cell activation receptors NKp30, NKp46, and NKG2D in the CD56(dim) CD16(+) and CD56(bright) CD16(+/-) subsets of NK cells. We demonstrated that there is a significant decrease in the percentage of circulating NK cells post-transplant (pretransplant 7.69 ± 1.54 vs. one wk post-transplant 1.73 ± 0.44) in pediatric liver transplant recipients. Interestingly, NKp30 expression is significantly increased, while NKp46 and NKG2D levels remain stable on the NK cells that persist at one wk post-transplant. These data indicate that the numbers and subsets of circulating NK cells are altered in children after liver transplantation.

Identification of the rat NKG2D ligands, RAE1L and RRLT, and their role in allograft rejection.

NKG2D is a receptor expressed by NK cells and subsets of T lymphocytes. On NK cells, NKG2D functions as a stimulatory receptor that induces effector functions. We cloned and expressed two rat NKG2D ligands, both members of the RAE1 family, RAE1L and RRLT, and demonstrate that these ligands can induce IFN-gamma secretion and cytotoxicity by rat NK cells. To examine changes in expression of NKG2D and the NKG2D ligands RAE1L and RRLT after transplantation, we used a Dark Agouti (DA)-->Lewis rat model of liver transplantation. NKG2D expression was significantly increased in allogeneic liver grafts by day 7 post-transplant. Ligands of NKG2D, absent in normal liver, were readily detected in both syngeneic and allogeneic liver grafts by day 1 post-transplant. By day 7 post-transplant, hepatocyte RAE1L and RRLT expression was significantly and specifically increased in liver allografts. In contrast to acute rejection that develops in the DA-->Lewis model, transplantation of Lewis livers into DA recipients (Lewis-->DA) results in spontaneous tolerance. Interestingly, expression of RAE1L and RRLT is low in Lewis-->DA liver allografts, but significantly increased in DA-->Lewis liver allografts undergoing rejection. In conclusion, our results suggest that expression of NKG2D ligands may be important in allograft rejection.