Prosthesis Geometrical Predictors of Leaflet Thrombosis Following Transcatheter Aortic Valve Replacement With Intra-Annular Prostheses.

OBJECTIVE: To determine the association between prosthesis geometry with leaflet thrombosis (LT). BACKGROUND: Leaflet thrombosis following transcatheter aortic valve replacement (TAVR) is a recognised entity. The association between prosthesis geometry with LT is unclear but maybe a potential modifiable factor in its prevention. METHODS: Patients who received an intra-annular TAVR prosthesis and were prospectively planned to undergo post-procedural computed tomography (CT) imaging were included. Leaflet thrombosis was defined as at least 50% restricted leaflet motion on CT. Prosthesis expansion and eccentricity was measured at prosthesis inflow, annulus and outflow levels. Prosthesis misalignment was defined as the average angle deviation between native and prosthesis leaflet commissure, greater than 30°. RESULTS: Prevalence of LT was 13.7% in 117 patients. None of the patients with LT were on anticoagulation therapy. Patients with LT had reduced prosthesis annular expansion (89.4±5.2% vs 97.0±4.4%, p<0.01), greater prosthesis misalignment (81.3% vs 48.5%, p=0.02) and deeper implants (6.3±1.7 mm vs 4.3±1.5 mm, p<0.01). Threshold for the presence of LT on ROC analysis was an implant depth of 5.7 mm (AUC [area under curve]=0.81). Independent predictors of LT were annular under-expansion (Odds ratio [OR] 1.4, 95% confidence interval [CI] 1.2-1.7, p=0.03) prosthesis misalignment (OR 6.8, 95%CI 1.1-45.5, p=0.04) and implant depth (OR 1.9, 95%CI 1.1-3.2, p=0.03). Anticoagulation therapy was a protective factor (OR 0.2; 95%CI 0.1-0.4, p<0.01). CONCLUSION: Geometrical predictors of LT post intra-annular TAVR were reduced prosthesis expansion at the annular level, lower implant depth and greater prosthesis misalignment. These factors may be important considerations during procedural planning for TAVR.

Clinical predictors and sequelae of computed tomography defined leaflet thrombosis following transcatheter aortic valve replacement at medium-term follow-up.

BACKGROUND: The clinical predictors and sequelae of leaflet thrombosis (LT) following transcatheter aortic valve replacement (TAVR) is still unclear. Therefore, our aim was to determine the clinical predictors and sequelae at mid-term follow-up of computed tomography (CT)-defined LT following TAVR. METHODS AND RESULTS: We performed a prospective evaluation with a 320-multislice CT following TAVR for the presence of LT, defined as hypo-attenuated leaflet thickening (HALT). Four-dimensional CT image-rendering was performed to determine the presence of reduced leaflet motion (RELM). 172 patients [89 (51.7%) male, mean age 82.8 ± 5.7 years] treated with commercially available TAVR device (Lotus 54%, CoreValve 32% and Sapien 3 14%) were included, with median CT-scan at 6.0 weeks post-TAVR. Prevalence of HALT was 14.0% (24 cases) and RELM was 9.8% (17 cases). On multivariate analysis, patients with HALT were less prescribed oral anticoagulation (OAC) (OR 9.9), received larger TAVR prostheses (OR 5.7) and higher rates of moderate-severe para-valvular regurgitation (PVR) (OR 16.3). There was no difference in clinical outcomes at a median follow-up of 2.3 years. Patients with RELM had significantly higher transvalvular gradients after discharge when compared to those without RELM. CONCLUSIONS: Absence of OAC, large TAVR prostheses and moderate-severe PVR were predictors for LT. Transvalvular gradients were higher in patients that developed RELM but not HALT. Further studies are warranted to determine the long-term impact of LT on TAVR durability. Prevalence of different sub-types of CT-defined LT (HALT and RELM) and the clinical predictors of developing LT following TAVR. CT computed tomography, HALT hypo-attenuated leaflet thickening, LT leaflet thrombosis, RELM reduced leaflet motion, TAVR transcatheter aortic valve replacement.

Coronary artery ectasia presenting with ST-elevation myocardial infarction in a young indigenous man: a case report.

BACKGROUND: Coronary artery ectasia (CAE) is often an incidental finding on angiography, however, patients can present with acute coronary syndrome due to a large thrombus burden requiring treatment with percutaneous coronary intervention or with emergency surgery. CASE SUMMARY: A 26-year-old Indigenous Australian male was admitted with anterior ST-elevation myocardial infarction associated with an out of hospital ventricular fibrillation arrest. Coronary angiography demonstrated thrombotic occlusion of the proximal left anterior descending (LAD) artery with heavy thrombus burden and prominent vascular ectasia of all three coronary arteries. He was managed with surgical thrombectomy and coronary artery bypass graft of his LAD. DISCUSSION: This is the first case of triple CAE in an Indigenous Australian. The case highlights the lack of consensus approach in the management of CAE due to paucity of prospective studies.

CT-Derived Fractional Flow Reserve (CT-FFR) in the Evaluation of Coronary Artery Disease.

Fractional flow reserve derived from coronary computed tomography enables anatomical and haemodynamic assessment of coronary artery disease in a single non-invasive test. Its diagnostic performance has been established against invasive fractional flow reserve in multi-centre trials, and a growing body of evidence has demonstrated its utility in predicting clinical outcomes. The purpose of this article is to describe the physiological principles, review its diagnostic performance, and describe the role of this technology in a real world clinical application.

Fractional Flow Reserve following Percutaneous Coronary Intervention.

Fractional flow reserve (FFR) is routinely used to determine lesion severity prior to percutaneous coronary intervention (PCI). However, there is an increasing recognition that FFR may also be useful following PCI to identify mechanisms leading to restenosis and the need for repeat revascularization. Post-PCI FFR is associated with the presence and severity of stent under-expansion and may help identify peri-stent-related complications. FFR pullback may also unmask other functionally significant lesions within the target vessel that were not appreciable on angiography. Recent studies have confirmed the prognostic utility of performing routine post-PCI FFR and suggest possible interventional targets that would improve stent durability. In this review, we detail the theoretical basis underlying post-PCI FFR, provide practical tips to facilitate measurement, and discuss the growing evidence supporting its use.

The role of four-dimensional computed tomography in transcatheter aortic valve replacement prosthesis endocarditis with concurrent leaflet thrombosis: a case report.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is becoming increasingly utilized for the treatment of severe aortic valvular heart disease. Infective endocarditis of TAVR is rare but associated with higher mortality and morbidity. The potential for leaflet thrombosis following TAVR is also becoming increasingly recognized. Diagnosis of these conditions on echocardiography can be challenging due to prosthesis artefact. CASE SUMMARY: An 84-year-old man with a previous transcatheter aortic valve replacement presented with a febrile illness and bacteraemia. Transthoracic and transoesophageal echocardiography demonstrated high transvalvular gradients with features of prosthesis endocarditis, though leaflet morphology could not be fully assessed due to prosthesis artefact. Four-dimensional computed tomography revealed hypo-attenuated leaflet thickening with reduced leaflet motion, consistent with prosthesis leaflet thrombosis. The patient was successfully treated with antibiotics and anticoagulation, with resolution of the infection and normalization of the transvalvular gradient after 6 weeks. DISCUSSION: Echocardiography should be the first-line investigation for assessing leaflet morphology in suspected prosthetic valve endocarditis or leaflet thrombosis but its accuracy may be limited by artefact. Our case highlights that four-dimensional computed tomography provides further evaluation of prosthesis leaflet morphology/motion, providing valuable diagnostic information.

Systemic Mastocytosis, Kounis Syndrome and Coronary Intervention: Case Report and Systematic Review.

A 72-year-old male reported a long-standing history of unexplained syncope. Stress echocardiography demonstrated inducible anterior hypokinesis, and he proceeded to percutaneous coronary intervention for an 80% stenosis of the left anterior descending artery. Thirty minutes post-procedure, he experienced a pulseless electrical activity (PEA) cardiac arrest. Urgent repeat angiography demonstrated profound coronary artery spasm consistent with Kounis syndrome. Three days later, a second PEA arrest occurred. Systemic mastocytosis was ultimately diagnosed as the cause of his recurrent syncopal episodes and cardiac arrests. Our patient was discharged 56days after his cardiac arrest on appropriate immunotherapy, and has made an excellent event-free recovery. Systemic mastocytosis is the pathological accumulation of mast cells in organs, and it may cause life-threatening syncope and cardiac arrests. It is estimated to affect up to 1 in 10,000 people, however is often underdiagnosed. No previous reviews have examined cardiac manifestations of systemic mastocytosis. We undertook a structured systematic review of cardiac presentations of systemic mastocytosis in adults, screening 619 publications. Twenty-three cases met inclusion criteria; our review suggests that short-term mortality is high (22%), and patients with cardiac presentations are predominantly male (83%). Unexplained cardiac arrest (26%) may be the first presentation of this haematological disorder. From our review of the literature, we have also derived suggested management approaches for cardiologists encountering or suspecting systemic mastocytosis in a variety of clinical scenarios.