Characterization of quantitative flow ratio and fractional flow reserve discordance using doppler flow and clinical follow-up.

The physiological mechanisms of quantitative flow ratio and fractional flow reserve disagreement are not fully understood. We aimed to characterize the coronary flow and resistance profile of intermediate stenosed epicardial coronary arteries with concordant and discordant FFR and QFR. Post-hoc analysis of the DEFINE-FLOW study. Anatomical and Doppler-derived physiological parameters were compared for lesions with FFR+QFR- (n = 18) vs. FFR+QFR+ (n = 43) and for FFR-QFR+ (n = 34) vs. FFR-QFR- (n = 139). The association of QFR results with the two-year rate of target vessel failure was assessed in the proportion of vessels (n = 195) that did not undergo revascularization. Coronary flow reserve was higher [2.3 (IQR: 2.1-2.7) vs. 1.9 (IQR: 1.5-2.4)], hyperemic microvascular resistance lower [1.72 (IQR: 1.48-2.31) vs. 2.26 (IQR: 1.79-2.87)] and anatomical lesion severity less severe [% diameter stenosis 45.5 (IQR: 41.5-52.5) vs. 58.5 (IQR: 53.1-64.0)] for FFR+QFR- lesions compared with FFR+QFR+ lesions. In comparison of FFR-QFR+ vs. FFR-QFR- lesions, lesion severity was more severe [% diameter stenosis 55.2 (IQR: 51.7-61.3) vs. 43.4 (IQR: 35.0-50.6)] while coronary flow reserve [2.2 (IQR: 1.9-2.9) vs. 2.2 (IQR: 1.9-2.6)] and hyperemic microvascular resistance [2.34 (IQR: 1.85-2.81) vs. 2.57 (IQR: 2.01-3.22)] did not differ. The agreement and diagnostic performance of FFR using hyperemic stenosis resistance (> 0.80) as reference standard was higher compared with QFR and coronary flow reserve. Disagreement between FFR and QFR is partly explained by physiological and anatomical factors. Clinical Trials Registration https://www.clinicaltrials.gov ; Unique identifier: NCT01813435. Changes in central physiological and anatomical parameters according to FFR and QFR match/mismatch quadrants.

P2Y12 blocker monotherapy after percutaneous coronary intervention.

For secondary prevention of coronary artery disease (CAD) antiplatelet therapy is essential. For patients undergoing a percutaneous coronary intervention (PCI) temporary dual antiplatelet platelet therapy (DAPT: aspirin combined with a P2Y12 blocker) is mandatory, but leads to more bleeding than single antiplatelet therapy with aspirin. Therefore, to reduce bleeding after a PCI the duration of DAPT is usually kept as short as clinically acceptable; thereafter aspirin monotherapy is administered. Another option to reduce bleeding is to discontinue aspirin at the time of DAPT cessation and thereafter to administer P2Y12 blocker monotherapy. To date, five randomised trials have been published comparing DAPT with P2Y12 blocker monotherapy in 32,181 stented patients. Also two meta-analyses addressing this novel therapy have been presented. P2Y12 blocker monotherapy showed a 50-60% reduction in major bleeding when compared to DAPT without a significant increase in ischaemic outcomes, including stent thrombosis. This survey reviews the findings in the current literature concerning P2Y12 blocker monotherapy after PCI.

The 2010s in clinical drug-eluting stent and bioresorbable scaffold research: a Dutch perspective.

Dutch researchers were among the first to perform clinical studies in bare metal coronary stents, the use of which was initially limited by a high incidence of in-stent restenosis. This problem was greatly solved by the introduction of drug-eluting stents (DES). Nevertheless, enthusiasm about first-generation DES was subdued by discussions about a higher risk of very-late stent thrombosis and mortality, which stimulated the development, refinement, and rapid adoption of new DES with more biocompatible durable polymer coatings, biodegradable polymer coatings, or no coating at all. In terms of clinical DES research, the 2010s were characterised by numerous large-scale randomised trials in all-comers and patients with minimal exclusion criteria. Bioresorbable scaffolds (BRS) were developed and investigated. The Igaki-Tamai scaffold without drug elution was clinically tested in the Netherlands in 1999, followed by an everolimus-eluting BRS (Absorb) which showed favourable imaging and clinical results. Afterwards, multiple clinical trials comparing Absorb and its metallic counterpart were performed, revealing an increased rate of scaffold thrombosis during follow-up. Based on these studies, the commercialisation of the device was subsequently halted. Novel technologies are being developed to overcome shortcomings of first-generation BRS. In this narrative review, we look back on numerous devices and on the DES and BRS trials reported by Dutch researchers.

Early mobilisation after transfemoral transcatheter aortic valve implantation: results of the MobiTAVI trial.

BACKGROUND: Immobilisation of patients after transfemoral transcatheter aortic valve implantation (TF-TAVI) is the standard of care, mostly to prevent vascular complications. However, immobilisation may increase post-operative complications such as delirium and infections. In this trial, we determine whether it is feasible and safe to implement early ambulation after TF-TAVI. METHODS: We prospectively included TF-TAVI patients from 2016 to 2018. Patients were assessed for eligibility using our strict safety protocol and were allocated (based on the time at which the procedure ended) to the EARLY or REGULAR group. RESULTS: A total of 150 patients (49%) were deemed eligible for early mobilisation, of which 73 were allocated to the EARLY group and 77 to the REGULAR group. The overall population had a mean age of 80 years, 48% were male with a Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score of 3.8 ± 1.8. Time to mobilisation was 4 h 49 min ± 31 min in the EARLY group versus 20 h 7 min ± 3 h 6 min in the REGULAR group (p < 0.0001). There were no differences regarding the primary endpoint. No major vascular complications occurred and a similar incidence of minor vascular complications was seen in both groups (4/73 [5.5%] vs 6/77 [7.8%], p = 0.570). The incidence of the combined secondary endpoint was lower in the EARLY group (p = 0.034), with a numerically lower incidence for all individual outcomes (delirium, infections, pain and unplanned urinary catheter use). CONCLUSION: Early mobilisation (ambulation 4-6 h post-procedure) of TF-TAVI patients is feasible and safe. Early ambulation decreases the combined incidence of delirium, infections, pain and unplanned urinary catheter use, and its adoption into contemporary TAVI practice may therefore be beneficial.

The Absorb bioresorbable vascular scaffold in real-world practice: long-term follow-up of the AMC Single Centre Real World PCI Registry.

BACKGROUND: Bioresorbable scaffolds have been introduced to overcome the shortcomings of drug-eluting stents. Higher rates of device thrombosis, however, have been reported up to 3 years after implantation of the Absorb bioresorbable vascular scaffold (BVS). In the current article, we therefore report long-term clinical outcomes of the AMC Absorb Registry. METHODS AND RESULTS: In the AMC Absorb Registry, all patients who underwent a percutaneous coronary intervention with Absorb BVS implantation between 30 August 2012 and 5 August 2013 at the Amsterdam University Medical Centre-Academic Medical Centre were included. The composite endpoint of this analysis was target-vessel failure (TVF). The median follow-up of the study cohort of the AMC Absorb Registry was 1534 days. At the time of the cross-sectional data sweep the clinical status at 4 years was known in 124 of 135 patients (91.9%). At long-term follow-up, the composite endpoint of TVF had occurred in 27 patients. The 4­year Kaplan-Meier estimate of TVF was 19.8%. At 4 years cardiac death had occurred in 4 patients (3.2%) and target-vessel myocardial infarction in 9 (6.9%) patients. Definite scaffold thrombosis occurred in 5 (3.8%) patients. We found 1 case of very late scaffold thrombosis that occurred at 911 days after device implantation in a patient who was not on dual anti-platelet therapy. CONCLUSION: In a patient population reflecting routine clinical practice, we found that cases of TVF continued to accrue beyond 2 years after Absorb BVS implantation.

Cardiology fellows-in-training are exposed to relatively high levels of radiation in the cath lab compared with staff interventional cardiologists-insights from the RECAP trial.

BACKGROUND: Interventional cardiologists are inevitably exposed to low-dose radiation, and consequently are at risk for radiation induced diseases like cataract and left-sided brain tumours. Operator behaviour may possibly be the largest influencer on radiation exposure. We hypothesised that awareness regarding radiation exposure grows as skill and the general experience in the catheterization laboratory increase. OBJECTIVES: In this study we determined the difference in the relative radiation exposure of staff interventional cardiologists compared with cardiology fellows-in-training. METHODS: During this prospective trial the operator's radiation exposure (E in µSv) was measured at chest height during 766 diagnostic catheterisations and percutaneous coronary interventions. Also, the patient exposure (DAP in mGy·cm2), representing the amount of radiation administered by the operator per procedure, was collected. The primary outcome of this study was the difference in relative exposure between staff interventional cardiologists versus cardiology fellows-in-training (E/DAP). RESULTS: From January to May 2017, staff interventional cardiologists performed 637 procedures and cardiology fellows-in-training 129 procedures. The performance of relatively complex procedures by staff interventional cardiologists resulted in a 74% higher use of radiation compared with fellows-in-training. Consequently, staff interventional cardiologists were exposed to 50% higher levels of actual radiation exposure. However, when correcting for the complexity of the procedure, by comparing the relative operator exposure (E/DAP), fellows-in-training were exposed to a 34% higher relative exposure compared with staff interventional cardiologists (p = 0.025). CONCLUSIONS: In the current study, when corrected for complexity, cardiology fellows-in-training were exposed to significantly higher radiation levels than staff interventional cardiologists during catheterisation procedures.

Appropriate use criteria for optical coherence tomography guidance in percutaneous coronary interventions : Recommendations of the working group of interventional cardiology of the Netherlands Society of Cardiology.

INTRODUCTION: Optical coherence tomography (OCT) enables detailed imaging of the coronary wall, lumen and intracoronary implanted devices. Responding to the lack of specific appropriate use criteria (AUC) for this technique, we conducted a literature review and a procedure for appropriate use criteria. METHODS: Twenty-one of all 184 members of the Dutch Working Group on Interventional Cardiology agreed to evaluate 49 pre-specified cases. During a meeting, factual indications were established whereupon members individually rated indications on a 9-point scale, with the opportunity to substantiate their scoring. RESULTS: Twenty-six indications were rated 'Appropriate', eighteen indications 'May be appropriate', and five 'Rarely appropriate'. Use of OCT was unanimously considered 'Appropriate' in stent thrombosis, and 'Appropriate' for guidance in PCI, especially in distal left main coronary artery and proximal left anterior descending coronary artery, unexplained angiographic abnormalities, and use of bioresorbable vascular scaffold (BVS). OCT was considered 'Rarely Appropriate' on top of fractional flow reserve (FFR) for treatment indication, assessment of strut coverage, bypass anastomoses or assessment of proximal left main coronary artery. CONCLUSIONS: The use of OCT in stent thrombosis is unanimously considered 'Appropriate' by these experts. Varying degrees of consensus exists on the appropriate use of OCT in other settings.

Trends in patient characteristics and clinical outcome over 8 years of transcatheter aortic valve implantation.

AIM: In the evolving field of transcatheter aortic valve implantations (TAVI) we aimed to gain insight into trends in patient and procedural characteristics as well as clinical outcome over an 8­year period in a real-world TAVI population. METHODS: We performed a single-centre retrospective analysis of 1,011 consecutive patients in a prospectively acquired database. We divided the cohort into tertiles of 337 patients; first interval: January 2009-March 2013, second interval: March 2013-March 2015, third interval: March 2015-October 2016. RESULTS: Over time, a clear shift in patient selection was noticeable towards lower surgical risks including Society of Thoracic Surgeons predicted risk of mortality score and comorbidity. The frequency of transfemoral TAVI increased (from 66.5 to 77.4%, p = 0.0015). Device success improved (from 62.0 to 91.5%, p < 0.0001) as did the frequency of symptomatic relief (≥1 New York Heart Association class difference) (from 73.8 to 87.1%, p = 0.00025). Complication rates decreased, including in-hospital stroke (from 5.0 to 2.1%, p = 0.033) and pacemaker implantations (from 10.1 to 5.9%, p = 0.033). Thirty-day mortality decreased (from 11.0 to 2.4%, p < 0.0001); after adjustment for patient characteristics, a mortality-risk reduction of 72% was observed (adjusted hazard ratio [HR]: 0.28, 95% confidence interval [CI]: 0.13-0.62). One-year mortality rates decreased (from 23.4 to 11.4%), but this was no longer significant after a landmark point was set at 30 days (mortality from 31 days until 1 year) (adjusted HR: 0.69, 95% CI: 0.41-1.16, p = 0.16). CONCLUSION: A clear shift towards a lower-risk TAVI population and improved clinical outcome was observed over an 8­year period. Survival after TAVI improved impressively, mainly as a consequence of decreased 30-day mortality.

Five-year clinical follow-up of the STENTYS self-apposing stent in complex coronary anatomy: a single-centre experience with report of specific angiographic indications.

OBJECTIVES: We sought to investigate angiographic indications for the use of the STENTYS technique and evaluated the long-term safety and clinical efficacy of the stent. BACKGROUND: Coronary lesions involving complex anatomy, including aneurysmatic, ectatic, or tapered vessel segments often carry a substantial risk of stent malapposition. The self-apposing stent technique may reduce the risk of stent malapposition and therefore improve clinical outcomes. METHODS: A total of 120 consecutive patients treated with the STENTYS stent were included (drug-eluting stent (DES) n = 101, bare-metal stent (BMS) n = 19). All lesions were scored for angiographic indications for the STENTYS stent, including aneurysms, ectasias, tapering, absolute diameters, bifurcation lesions, and saphenous vein grafts. Off-line quantitative coronary angiography analyses were performed pre-procedure and post-procedure. Five years follow-up was obtained including cardiac death, target vessel myocardial infarction (TV-MI), target vessel revascularisation, stent thrombosis, and the composite endpoint target vessel failure (cardiac death, TV-MI and target vessel revascularisation). RESULTS: Angiographic indications for STENTYS use were aneurysm (30%), ectasia (19%), tapering (27%), bifurcation lesions (8%), and saphenous vein graft lesions (16%) and absolute diameters (22%). Mean maximal diameter was 4.51 ± 0.99 mm. At 5­year follow-up target vessel failure rates were 24.1% in the total cohort (DES 22.8% vs. BMS 33%, p = 0.26). Definite stent thrombosis rate was 3.8% at 5­year follow-up in this cohort with complex and high-risk lesions (DES 4.5% vs. BMS 0%, p = 0.39). CONCLUSIONS: Angiographic indications for the use of the self-apposing stent were complex lesions with atypical coronary anatomy. Our data showed reasonable stent thrombosis rates at 5­year follow-up, considering the high-risk lesion characteristics.

Mid-term and long-term safety and efficacy of bioresorbable vascular scaffolds versus metallic everolimus-eluting stents in coronary artery disease: A weighted meta-analysis of seven randomised controlled trials including 5577 patients.

AIMS: Mid- and long-term safety and efficacy of the Absorb bioresorbable vascular scaffold (BVS) have been studied in randomised trials; however, most were not individually powered for clinical endpoints. We performed a weighted meta-analysis comparing mid- and long-term outcomes in patients treated with the BVS compared with the Xience metallic stent. METHODS AND RESULTS: Randomised trials comparing the BVS and Xience were identified by searching MEDLINE, EMBASE and conference abstracts. Seven trials were included (BVS n = 3258, Xience n = 2319) with follow-up between 1-3 years. The primary outcome of target lesion failure occurred more frequently in BVS compared with Xience [OR 1.34; 95% CI 1.11-1.62, p = 0.003]. Overall definite or probable device thrombosis occurred more frequently with the BVS [OR 2.86; 95% CI 1.88-4.36, p < 0.001] and this extended beyond 1 year of follow-up [OR 4.13; 95% CI 1.99-8.57, p < 0.001]. Clinically indicated or ischaemia driven target lesion revascularisation [OR 1.43; 95% CI 1.11-1.83, p = 0.005] and myocardial infarction (all MI) [OR 1.64; 95% CI 1.20-2.23, p = 0.002] were more frequently seen in the BVS compared with Xience. Rates of target vessel failure [OR 1.15; 95% CI 0.91-1.46, p = 0.25] and cardiac death [OR 0.91; 95% CI 0.57-1.46, p = 0.71] were not significantly different between BVS and Xience. CONCLUSION: This meta-analysis shows a higher rate of target lesion failure and an almost threefold higher rate of device thrombosis in BVS compared with Xience, which extends beyond the first year. Device thrombosis did not lead to an overall increased (cardiac) mortality.

Recommendations for the use of bioresorbable vascular scaffolds in percutaneous coronary interventions : 2017 revision.

BACKGROUND: To eliminate some of the potential late limitations of permanent metallic stents, the bioresorbable coronary stents or 'bioresorbable vascular scaffolds' (BVS) have been developed. METHODS: We reviewed all currently available clinical data on BVS implantation. RESULTS: Since the 2015 position statement on the appropriateness of BVS in percutaneous coronary interventions, several large randomised trials have been presented. These have demonstrated that achieving adequate 1 and 2 year outcomes with these first-generation BVS is not straightforward. These first adequately powered studies in non-complex lesions showed worse results if standard implantation techniques were used for these relatively thick scaffolds. Post-hoc analyses hypothesise that outcomes similar to current drug-eluting stents are still possible if aggressive lesion preparation, adequate sizing and high-pressure postdilatation are implemented rigorously. As long as this has not been confirmed in prospective studies the usage should be restricted to experienced centres with continuous outcome monitoring. For more complex lesions, results are even more disappointing and usage should be discouraged. When developed, newer generation scaffolds with thinner struts or faster resorption rates are expected to improve outcomes. In the meantime prolonged dual antiplatelet therapy (DAPT, beyond one year) is recommended in an individualised approach for patients treated with current generation BVS. CONCLUSION: The new 2017 recommendations downgrade and limit the use of the current BVS to experienced centres within dedicated registries using the updated implantation protocol and advise the prolonged usage of DAPT. In line with these recommendations the manufacturer does not supply devices to the hospitals without such registries in place.

How to define bifurcation lesion complexity and how to successfully perform percutaneous treatment.

Historically, percutaneous coronary interventions (PCI) of bifurcation lesions have been associated with a lower procedural success rate, a higher complication rate, and less favorable clinical outcomes, compared to PCI of non-bifurcation lesions. However, percutaneous treatment of coronary bifurcation lesions have been improved over the past decade due to improvements in stent design and the introduction of specific bifurcation stent techniques. Some even argue that PCI of bifurcation lesions should no longer be considered as being complex. However, recent studies have shown that there are still certain bifurcation lesion subtypes which are at higher risk for adverse cardiac events after PCI. Future efforts, including the development of a dedicated bifurcation device, should be focused on this specific high-risk subgroup, including distal left main bifurcations.

Self-expanding intracoronary stents in the treatment of coronary artery disease: new developments and future directions.

The first stent implanted in the human coronary circulation was a self-expandable (SE) stent and was introduced almost simultaneously with the first balloon-expandable (BE) stents in the late 1980s. Nowadays, the majority of the available stents are delivered by balloon expansion. While BE stents reach their final size at the time of implantation, the SE stent continues to enlarge days to weeks after implantation. Potential advantages of the self-expandable and self-apposing properties of nitinol stents, a super-elastic metallic alloy of nickel and titanium, could be reduction of acute and late acquired stent malapposition with a subsequently decreased risk of target vessel restenosis. Several nitinol stents have been developed and clinically evaluated and are now in use in daily clinical practice. However, it is important to further improve and optimize the SE stent design and apply newer strategies to the development of next generation SE stents. The present review will provide an overview of the development of these devices and the currently available clinical evidence of the contemporary SE stents.

Chest pain in sickle cell disease.

The differential diagnosis of chest pain in a patient with sickle cell disease is difficult and may encompass several serious conditions, including chest syndrome, pulmonary embolism and infectious complications. In this manuscript we provide an overview on the various underlying diseases that may cause chest pain in patients with sickle cell disease and provide clues for a proper diagnostic workup.

Bioresorbable scaffolds: talking about a new interventional revolution [corrected].

After the introduction of coronary balloon angioplasty, bare-metal, and drug-eluting stents, fully bioresorbable scaffolds (BRS) could be the fourth revolution in interventional cardiology. The BRS technology shares the advantages of metallic stents regarding acute gain and prevention of acute vessel occlusion by providing transient scaffolding, while potentially overcoming many of the safety concerns of drug-eluting stents. Furthermore, without a permanent metallic cage, the vessel could remodel favourably and atherosclerotic plaques could regress in the long-term. This attracted increased interest and several BRS have been developed. In this review we will describe all BRS which are thus far clinically evaluated and provide an overview of ongoing clinical studies. Although the technology seems to be very promising, more studies including patients with more complex lesions are needed to evaluate whether the BRS can be used in daily clinical practice and if it is indeed becoming a new interventional revolution.

Six-month clinical outcomes of the Tryton Side Branch Stent for the treatment of bifurcation lesions.

AIMS: Percutaneous coronary intervention (PCI) of a bifurcation lesion (BL) is still associated with poorer clinical outcomes when compared with PCI of a non-BL. Therefore, several dedicated coronary bifurcation stents, such as the Tryton Side Branch Stent™ (Tryton Medical, Durham, NC, USA), were developed to improve clinical outcomes. We investigated 6-month clinical outcomes after placement of a Tryton stent in 91 patients treated for 93 BLs in our centre. METHODS AND RESULTS: All consecutive patients who have undergone PCI of a BL treated with the Tryton stent in our centre were included. Outcomes were defined as any death, cardiac death, myocardial infarction (MI), any revascularisation, ischaemia-driven target vessel revascularisation (TVR), ischaemia-driven target lesion revascularisation (TLR), stent thrombosis, and target vessel failure (TVF; composite of cardiac death, MI, and ischaemia-driven TVR). Event rates were estimated using the Kaplan-Meier method. Thirty-eight (42 %) patients with acute coronary syndrome (ACS) were included (16 % ST-segment elevation MI (STEMI)). The 6-month event rates were 5.4 % (death), 4.3 % (cardiac death), 2.2 % (MI), 4.5 % (any revascularisation), 4.5 % (TVR), 4.5 % (TLR) and 9.7 % (TVF). CONCLUSION: In a real-world all-comers single-centre registry, the use of the Tryton Side Branch Stent was associated with acceptable procedural and promising clinical outcomes at 6 months, including ACS and STEMI patients.

Early regeneration of thymic progenitors in rhesus macaques infected with simian immunodeficiency virus.

The thymus plays a critical role in the maturation and production of T lymphocytes and is a target of infection by human immunodeficiency virus (HIV) and the related simian immunodeficiency virus (SIV). Using the SIV/macaque model of AIDS, we examined the early effects of SIV on the thymus. We found that thymic infection by SIV resulted in increased apoptosis 7-14 d after infection, followed by depletion of thymocyte progenitors by day 21. A marked rebound in thymocyte progenitors occurred by day 50 and was accompanied by increased levels of cell proliferation in the thymus. Our results demonstrate a marked increase in thymic progenitor activity very early in the course of SIV infection, long before marked declines in peripheral CD4(+) T cell counts.

Evaluation of anti-human antibodies for immunohistochemistry on archival nonhuman primate tissues.

A panel of commercially available antibodies which recognize specific antigens on human tissues was developed for use in immunohistochemistry on tissues from eight species of nonhuman primates. Antibodies were selected for potential usefulness in diagnostic pathology, and for effectiveness in formalin-fixed, paraffin-embedded tissues. Tissues from four species of macaques and four New World monkeys were evaluated. Using these antibodies we were able to identify 17/21 antigens examined in all eight species, and 21/21 antigens in the four species of macaques. Detailed immunohistochemistry protocols are presented, along with a systematic approach to developing a protocol for a new antibody.