Optical frequency domain imaging (OFDI) represents a novel technique for the diagnosis of giant cell arteritis.

BACKGROUND/OBJECTIVES: Giant cell arteritis (GCA) is an inflammatory vascular disease in which prompt and accurate diagnosis is critical. The efficacy of temporal artery biopsy (TAB) is limited by 'skip' lesions and a delay in histological analysis. This first-in-man ex-vivo study aims to assess the accuracy of optical frequency domain imaging (OFDI) in diagnosing GCA. SUBJECTS/METHODS: 29 TAB samples of patients with suspected GCA were submerged in 0.9% sodium chloride and an OFDI catheter was passed through the lumen to create cross-sectional images prior to histological analysis. The specimens were then preserved in formalin for histological examination. Mean intimal thickness (MIT) on OFDI was measured, and the presence of both multinucleate giant cells (MNGCs) and fragmentation of the internal elastic lamina (FIEL) was assessed and compared with histology, used as the diagnostic gold standard. RESULTS: MIT in patients with/without histological evidence of GCA was 0.425 mm (±0.43) and 0.13 mm (±0.06) respectively compared with 0.215 mm (±0.09) and 0.135 mm (±0.07) on OFDI. MIT measured by OFDI was significantly higher in patients with histologically diagnosed arteritis compared to those without (p = 0.0195). For detecting FIEL and MNGCs, OFDI had a sensitivity of 75% and 28.6% and a specificity of 100% and 77.3% respectively. Applying diagnostic criteria of MIT > 0.20 mm, or the presence of MNGCs or FIEL, the sensitivity of detecting histological arteritis using OFDI was 91.4% and the specificity 94.1%. CONCLUSIONS: OFDI provided rapid imaging of TAB specimens achieving a diagnostic accuracy comparable to histological examination. In-vivo imaging may allow imaging of a longer arterial section.

Changes in coronary collateral function after successful chronic total occlusion percutaneous coronary intervention.

BACKGROUND: Contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) incorporates wire escalation and dissection/re-entry recanalisation strategies. AIMS: The purpose of the study was to investigate changes in collateral function after CTO PCI and to identify whether the mode of successful recanalisation influences collateral function regression. METHODS: Patients scheduled for elective CTO PCI with evidence of viability in the CTO territory by noninvasive imaging were included in this study. After successful CTO PCI, the aortic pressure (Pa) and distal coronary artery wedge pressure (Pw) during balloon occlusion were measured, both in a resting state and during infusion of intravenous adenosine, allowing the calculation of the pressure-derived collateral pressure index at rest and hyperaemia (CPIrest and the collateral fractional flow reserve [FFRcoll], respectively). Measurements were repeated 3 months later during angiographic follow-up. RESULTS: Eighty-one patients had physiological measurements at baseline and follow-up. In the final cohort the mean age was 64 years and 82% were male. The mean maximal stent diameter and total stent length were 3.2±0.5 mm and 68±31 mm, respectively. Successful strategies were antegrade wiring (64.2%), antegrade dissection re-entry (8.6%), and retrograde dissection re-entry (27.1%). Between the index procedure and follow-up, wedge pressure decreased from 34±11 mmHg to 21±8.5 mmHg (p<0.01), respectively. FFRcoll changed from 0.34±0.11 to 0.19±0.09 (p<0.01) at follow-up and CPIrest from 0.40±0.14 to 0.17±0.09 (p<0.01). Absolute maximum collateral flow decreased from 55±32 ml/min directly after PCI to 38±24 ml/min (p<0.01). There was no relation between the recanalisation technique and changes in FFRcoll. CONCLUSIONS: There was a significant reduction in collateral flow over time, independent of the recanalisation technique.

Impact of Intravascular Ultrasound on Chronic Total Occlusion Percutaneous Revascularization.

AIM: We sought to investigate the impact of IVUS use on chronic total occlusion (CTO) PCI using data from a contemporary registry of consecutive patients and applying a propensity score matching analysis. METHODS AND RESULTS: We evaluated 514 successful CTO-PCIs, median age: 67 years (IQR: 58-73), 83.5% males. IVUS-guided PCI was performed in 184 (35.8%) of cases. After using 1:1 propensity matching score analysis, two groups of 182 patients each (IVUS-guided vs. angiography-guided CTO-PCI group) were produced to form the study population. In the IVUS-guided group the median maximum stent diameter was larger and the median total stented segment was longer compared to the angiography-guided group [(3.5 mm, IQR: 3.0-4.0 vs. 3.2 mm, IQR: 3.0-3.5, p < 0.001) and (60.0 mm, IQR: 38.0-91.3 vs. 38.0 mm, IQR: 32.0-70.5, p < 0.001), respectively]. In the IVUS-guided group, retrograde recanalization was more frequently encountered compared to the angiography-guided PCI group (30.2% vs. 20.9%, p = 0.04). Procedural time was significantly longer in the IVUS-guided group, without any difference in fluoroscopy time, radiation dose and contrast volume. Multivariate linear regression analysis showed that IVUS use was the strongest independent factor associated with larger maximum diameter stents (p < 0.001) and a strong independent predictor for total stented segment length during CTO-PCI (p < 0.001). Up to 8 years follow-up, there was no difference in the incidence of the composite endpoint of all-cause death, cardiac death, myocardial infarction and target vessel revascularization between the IVUS-guided PCI and the angiography-guided PCI groups (hazard ratio: 13.7% vs. 15.9%, respectively, log-rank: p = 0.67, median follow-up time: 49.0 months, IQR: 33.0-67.0). CONCLUSIONS: Use of IVUS in CTO-PCI was associated with larger stent diameter and longer stented segments. Despite more frequent use of IVUS in retrograde CTO-PCI, there was no difference in long-term adverse events between IVUS and angiography CTO-PCI groups; nevertheless, the study was not powered to assess clinical outcomes.

In-hospital stroke after transcatheter aortic valve implantation: A UK observational cohort analysis.

OBJECTIVES: We sought to identify baseline demographics and procedural factors that might independently predict in-hospital stroke following transcatheter aortic valve implantation (TAVI). BACKGROUND: Stroke is a recognized, albeit infrequent, complication of TAVI. Established predictors of procedure-related in-hospital stroke; however, remain poorly defined. METHODS: We conducted an observational cohort analysis of the multicenter UK TAVI registry. The primary outcome measure was the incidence of in-hospital stroke. RESULTS: A total of 8,652 TAVI procedures were performed from 2007 to 2015. There were 205 in-hospital strokes reported by participating centers equivalent to an overall stroke incidence of 2.4%. Univariate analysis showed that the implantation of balloon-expandable valves caused significantly fewer strokes (balloon-expandable 96/4,613 [2.08%] vs. self-expandable 95/3,272 [2.90%]; p = .020). After multivariable analysis, prior cerebrovascular disease (CVD) (odds ratio [OR] 1.51, 95% confidence interval [CI 1.05-2.17]; p = .03), advanced age at time of operation (OR 1.02 [0.10-1.04]; p = .05), bailout coronary stenting (OR 5.94 [2.03-17.39]; p = .008), and earlier year of procedure (OR 0.93 [0.87-1.00]; p = .04) were associated with an increased in-hospital stroke risk. There was a reduced stroke risk in those who had prior cardiac surgery (OR 0.62 [0.41-0.93]; p = .01) and a first-generation balloon-expandable valve implanted (OR 0.72 [0.53-0.97]; p = .03). In-hospital stroke significantly increased 30-day (OR 5.22 [3.49-7.81]; p < .001) and 1-year mortality (OR 3.21 [2.15-4.78]; p < .001). CONCLUSIONS: In-hospital stroke after TAVI is associated with substantially increased early and late mortality. Factors independently associated with in-hospital stroke were previous CVD, advanced age, no prior cardiac surgery, and deployment of a predominantly first-generation self-expandable transcatheter heart valve.

Recovery of Absolute Coronary Blood Flow and Microvascular Resistance After Chronic Total Occlusion Percutaneous Coronary Intervention: An Exploratory Study.

Background This study aimed to investigate longitudinal physiological changes in the recanalized coronary chronic total occlusion (CTO) vessel and its dependent myocardium after successful percutaneous coronary intervention (PCI). Methods and Results In this pilot study, 25 patients scheduled for elective CTO PCI with viable myocardium and angiographically visible collaterals were included. Absolute coronary blood flow and absolute microvascular resistance were measured invasively using continuous thermodilution. Measurements were performed immediately after successful CTO PCI and at short-term follow-up. In a subgroup of patients, physiological measurements were performed at the predominant donor vessel before CTO PCI, immediately afterwards, and at follow-up. Absolute coronary blood flow in the recanalized CTO artery increased from 148±53 mL/min immediately after PCI to 221±77 mL/min at follow-up (P<0.001). In agreement, absolute resistance in the myocardial territory perfused by the CTO artery, decreased from 545±255 Wood units immediately after the procedure to 387±128 Wood units at follow-up (P=0.014). There were no significant changes in the absolute coronary blood flow and resistance in the predominant donor between baseline and follow-up. Positive remodeling of the distal CTO vessel with an increase in lumen diameter was observed. Conclusions After successful CTO PCI, blood flow in the recanalized artery and microvascular function of the dependent myocardium are not immediately normal but recover over time.

Transcatheter aortic valve implantation via the superficial femoral artery: An underused access route?

Common femoral arterial (CFA) access is the most commonly used access route for transcatheter aortic valve implantation (TAVI). In majority of cases, it is easily accessible percutaneously without requiring surgical cut down. However, in patients with high body mass index (BMI) or central obesity, it can be more than 8-10 cm below the skin making the procedure more technically demanding and satisfactory hemostasis more difficult to achieve. The superficial femoral artery (SFA) lies only a few centimeters distal to the CFA with little compromise on vessel caliber, yet can allow more suitable access in certain patients with a high BMI. We describe three cases in which SFA access was successfully used as the primary delivery route for TAVI.