Rapid and Precise Computation of Fractional Flow Reserve from Routine Two-Dimensional Coronary Angiograms Based on Fluid Mechanics: The Pilot FFR2D Study.

Objective: To present a novel pipeline for rapid and precise computation of fractional flow reserve from an analysis of routine two-dimensional coronary angiograms based on fluid mechanics equations (FFR2D). Material and methods: This was a pilot analytical study that was designed to assess the diagnostic performance of FFR2D versus the gold standard of FFR (threshold ≤ 0.80) measured with a pressure wire for the physiological assessment of intermediate coronary artery stenoses. In a single academic center, consecutive patients referred for diagnostic coronary angiography and potential revascularization between 1 September 2020 and 1 September 2022 were screened for eligibility. Routine two-dimensional angiograms at optimal viewing angles with minimal overlap and/or foreshortening were segmented semi-automatically to derive the vascular geometry of intermediate coronary lesions, and nonlinear pressure-flow mathematical relationships were applied to compute FFR2D. Results: Some 88 consecutive patients with a single intermediate coronary artery lesion were analyzed (LAD n = 74, RCA n = 9 and LCX n = 5; percent diameter stenosis of 45.7 ± 11.0%). The computed FFR2D was on average 0.821 ± 0.048 and correlated well with invasive FFR (r = 0.68, p < 0.001). There was very good agreement between FFR2D and invasive-wire FFR with minimal measurement bias (mean difference: 0.000 ± 0.048). The overall accuracy of FFR2D for diagnosing a critical epicardial artery stenosis was 90.9% (80 cases classified correctly out of 88 in total). FFR2D identified 24 true positives, 56 true negatives, 4 false positives, and 4 false negatives and predicted FFR ≤ 0.80 with a sensitivity of 85.7%, specificity of 93.3%, positive likelihood ratio of 13.0, and negative likelihood ratio of 0.15. FFR2D had a significantly better discriminatory capacity (area under the ROC curve: 0.95 [95% CI: 0.91-0.99]) compared to 50%DS on 2D-QCA (area under the ROC curve: 0.70 [95% CI: 0.59-0.82]; p = 0.0001) in predicting wire FFR ≤ 0.80. The median time of image analysis was 2 min and the median time of computation of the FFR2D results was 0.1 s. Conclusion: FFR2D may rapidly derive a precise image-based metric of fractional flow reserve with high diagnostic accuracy based on a single two-dimensional coronary angiogram.

Randomized comparison of Glidesheath Slender with conventional 5Fr arterial sheaths for coronary angiography through the distal radial artery.

BACKGROUND: The potential benefits of the thin-walled 5F Glidesheath Slender sheath in the distal transradial access (dTRA) have not been investigated. This study aimed to compare the Glidesheath Slender versus conventional 5Fr arterial sheaths in patients undergoing diagnostic coronary angiography (CAG) through the dTRA. METHODS: A total of 352 consecutive patients with an indication for CAG were randomized (1:1) to Glidesheath Slender 5Fr versus a conventional 5Fr arterial sheath for dTRA. The primary endpoint was the rate of successful hemostasis at 30 minutes after sheath removal. Follow-up ultrasound of the right radial and distal radial artery was performed 7-10 days after the procedure. RESULTS: After exclusion of patients where a 6Fr sheath or crossover of access site was required, 108 patients in the Glidesheath Slender and 105 patients in the conventional 5Fr arterial sheath group were included in the analysis. The crossover rate to conventional radial access and the rate of successful hemostasis at 30 minutes after sheath removal were similar between the two groups (18.9% in the Glidesheath slender vs. 22% in the control group; P=0.460, and 62% vs. 51.4%; P=0.118, respectively). The level of pain associated with the procedure was significantly lower in the Glidesheath Slender group (2.69 vs. 3.29 in the control group; P=0.02). No significant difference was recorded between the two groups in the rate of access-related complications. CONCLUSIONS: Use of Glidesheath Slender for dTRA did not increase the rate of early hemostasis compared with conventional arterial sheath.

Eosinophilic responses to stent implantation and the risk of Kounis hypersensitivity associated coronary syndrome.

The use of drug eluting stents constitutes a major breakthrough in current interventional cardiology because it is more than halves the need of repeat interventions. It is incontrovertible that coronary stents, in general, have been beneficial for the vast majority of patients. A small increase in thrombosis, following DES implantation, is offset by a diminished risk of complications associated with repeat vascularization. However, late and, especially, very late stent thrombosis is a much feared complication because it is associated with myocardial infarction with increased mortality. Despite that stent thrombosis is thought to be multifactorial, so far clinical reports and reported pathology findings in patients died from coronary stent thrombosis as well as animal studies and experiments, point toward a hypersensitivity inflammation. The stented and thrombotic areas are infiltrated by interacting, via bidirectional stimuli inflammatory cells including eosinophils, macrophages, T-cells and mast cells. Stented regions constitute an ideal surrounding for endothelial damage and dysfunction, together with hemorheologic changes and turbulence as well as platelet dysfunction, coagulation and fibrinolytic disturbances. Drug eluting stent components include the metal strut which contains nickel, chromium, manganese, titanium, molybdenum, the polymer coating and the impregnated drugs which for the first generation stents are: the antimicrotubule antineoplastic agent paclitaxel and the anti-inflammatory, immunosuppressive and antiproliferative agent sirolimus. The newer stents which are called cobalt-chromiun stents and elute the sirolimus analogs everolimus and zotarolimus both contain nickel and other metals. All these components constitute an antigenic complex inside the coronary arteries which apply chronic, continuous, repetitive and persistent inflammatory action capable to induced Kounis syndrome and stent thrombosis. Allergic inflammation goes through three phases, the early phase, the late phase and the chronic phase and these three phases correspond temporally with early (acute and sub acute), late and very late stent thrombosis. Bioabsorbable allergy free poly lactic acid self expanding stents, nickel free stainless steel materials, stent coverage with nitric oxide donors and antibodies with endothelial progenitor cell capturing abilities as well as stents eluting anti-inflammatory and anti-allergic agents might be the solution of this so feared and devastating stent complication.

Kounis syndrome is likely culprit of coronary vasospasm induced by capecitabine.

Capecitabine administration has been associated with various allergic reactions including acneiform skin rash, linchenoid photosensitive eruption, exudative non healing scalp, skin reactions, pyogenic granuloma, subacute cutaneous systemic lupus erythematosus, exudative hyponychia dermatitis, and hand-foot syndrome. A patient who developed ventricular fibrillation following capecitabine-induced coronary vasospasm and necessitating cardioverter-defibrillator implantation was published recently in.

Anomalous origin of the left main coronary artery from the main pulmonary artery in an elderly patient.

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) syndrome is an extremely rare diagnosis in elderly patients. We describe a 73-year-old female with ALCAPA who underwent successful repair of this coronary anomaly.

Nickel allergy, Kounis syndrome and intracardiac metal devices.

Metal-induced allergic reactions are not rare in every day practice but nickel, cobalt and chromium are the most common offenders. Other metal anions and metal alloys represent also emerging causes for hypersensitivity reaction in humans. The metal struts of endovascular and intracardiac devices are usually alloys containing nickel and constitute causes for allergic reactions with possible intracardiac and intracoronary mast cell activation resulting in the Kounis hypersensitivity coronary syndrome. Newer intracoronary stents avoid nickel thus making them less allergenic. It is advisable that, before any device implantation, careful history of any metal allergy should be taken and efforts should be made for the development of new devices with better biocompatibility.