Long-term outcomes after fractional flow reserve-guided percutaneous coronary intervention in patients with severe coronary stenosis

Objective To explore the safety and efficacy of FFR-guided percutaneous coronary intervention (PCI) in vessels with severe diameter stenosis. Methods & Results Of 1090 patients undergoing fractional flow reserve (FFR) assessment from 2002 to 2009,we identified 167 patients in whom FFR was measured in at least one 70%–89% stenotic lesion. These patients were subdivided into an FFR-defer group (n = 49) if PCI was deferred (FFR > 0.80),and an FFR-perform group (n = 118) if PCI was performed (FFR ≤ 0.80). Comparatively,an additional 1176 patients undergoing PCI in at least one lesion with 70%–89% stenosis but without measurement of FFR served as a control (angiography- guided) group. Clinical outcomes were compared during a median follow-up of 49.0 months. The 5-year Kaplan-Meier estimated revascularization rates were 16% in the FFR-defer group and 33% in the FFR-perform group (P = 0.046). The incidence of major adverse cardiac events were comparable in these two groups (HR = 0.82,95% CI: 0.37–1.82,P = 0.63). The number of stents placed was significantly lower in the FFR-guided group (0.9 ± 0.8 vs. 1.4 ± 0.8,P < 0.001). Conclusions Functional revascularization for lesions with visually severe stenosis is clinically safe and associated with fewer stents use. This study suggests that extending the use of FFR to more severe coronary lesions may be reasonable.

Carotid artery endarterectomy in patients with symptomatic non-stenotic carotid artery disease

Object We sought to determine the safety and efficacy in secondary stroke prevention of carotid endarterectomy(CEA)in patients with symptomatic non-stenotic carotid artery disease(SyNC).Methods This was a single-centre retrospective case series.All patients who underwent CEA for unilateral anterior circulation cerebrovascular events with ipsilateral<50%carotid stenosis from 2002 to 2020 were included.Imaging hallmarks including the degree of luminal stenosis and the presence of various vulnerable plaque characteristics(eg,intraplaque haemorrhage(IPH)on MR angiography,ulceration or low-density plaque on CT angiography)were assessed.The presence of vulnerable plaque characteristics was compared between arteries ipsilateral to the ischaemic event and contralateral arteries.The prevalence of perioperative/intraoperative complications,as well as recurrent ischaemic events at follow-up was determined.Results Thirty-two patients were included in the analysis,of which 25.0%were female.Carotid arteries ipsilateral to an ischaemic event had a significantly higher prevalence of IPH when compared with contralateral arteries(80.0%vs 0.0%;p<0.001).There were no intraoperative complications.One patient(3.1%)developed symptoms of transient ipsilateral ischaemia 1 day following CEA which resolved without treatment.In a median follow-up of 18.0 months(IQR 5.0-36.0),only one patient(3.1%)experienced a transient neurologic deficit with complete resolution(annualised rate of recurrent stroke after CEA of 1.5%for a total follow-up of 788 patient-months following CEA).All other patients(31/32,96.9%)were free of recurrent ischaemic events.Conclusion CEA appears to be safe and well-tolerated in patients with SyNC.Additional studies with larger cohorts and longer follow-up intervals are needed in order to determine the role of CEA in this patient population.

Augmented efficacy of exogenous extracellular vesicles targeted to injured kidneys

Dear Editor,Extracellular vesicles(EVs)derived from mesenchymal stem/stromal cells(MSCs)contain genetic and protein material that stimulate tissue repair and ameliorate injury in recipient cells.Advantages of particulate MSC-EVs over MSCs in treating kidney disease include better penetration of injured glomerular filtration barrier to access podocytes or tubular cells.However,systemic EV delivery yields low kidney retention efficiency,limiting their regenerative benefits.1 Previously,we coated adipose tissue-derived(AD)-MSC with antibodies against kidney injury molecule(KIM)‐1(ab-KIM1),a protein upregulated in damaged kidneys.2 Conjugating ab-KIM1 did not impair MSC function but increased their retention and reparative potency in murine renal artery stenosis(RAS).2 We hypothesized that ab-KIM1 conjugation would similarly enhance retention of exogenously delivered EVs in ischemic kidneys and confer superior therapeutic benefits.

Ex vivo evaluation of IVUS-VH imaging and the role of plaque structure on peripheral artery disease

Peripheral artery disease(PAD)results from the buildup of atherosclerotic plaque in the arterial wall,can progress to severe ischemia and lead to tissue necrosis and limb amputation.We evaluated a means of assessing PAD mechanics ex vivo using ten human peripheral arteries with PAD.Pressure-inflation testing was performed at six physiological pressure intervals ranging from 10 to 200 mmHg.These vessels were imaged with IVUS-VH to determine plaque composition and change in vessel structure with pressure.Statistical analysis was performed to determine which plaque structures and distributions of these structures had the greatest influence on wall deformation.We found that fibrous plaque,necrotic core,and calcification had a statistically significant effect on all variables(p<0.05).The presence of large concentrations of fibrous plaque was linked to reduced vessel compliance and ellipticity,which could lead to stent fractures and restenosis.For the plaque distribution we found that clustered necrotic core increased overall compliance while clustered calcification decreased overall compliance.The effect of plaque distribution on vessel wall deformation must be considered equally important to plaque concentration.