Publications
87 results found
Rosa A, Pye VE, Graham C, et al., 2021, SARS-CoV-2 can recruit a heme metabolite to evade antibody immunity, Science Advances, Vol: 7, Pages: 1-14, ISSN: 2375-2548
The coronaviral spike is the dominant viral antigen and the target of neutralizing antibodies. We show that SARS-CoV-2 spike binds biliverdin and bilirubin, the tetrapyrrole products of heme metabolism, with nanomolar affinity. Using cryo–electron microscopy and x-ray crystallography, we mapped the tetrapyrrole interaction pocket to a deep cleft on the spike N-terminal domain (NTD). At physiological concentrations, biliverdin significantly dampened the reactivity of SARS-CoV-2 spike with immune sera and inhibited a subset of neutralizing antibodies. Access to the tetrapyrrole-sensitive epitope is gated by a flexible loop on the distal face of the NTD. Accompanied by profound conformational changes in the NTD, antibody binding requires relocation of the gating loop, which folds into the cleft vacated by the metabolite. Our results indicate that SARS-CoV-2 spike NTD harbors a dominant epitope, access to which can be controlled by an allosteric mechanism that is regulated through recruitment of a metabolite.
Pereira C, Harris B, Di Giovannantonio M, et al., 2021, Antibody response to SARS-CoV-2 infection is not associated with Post-COVID-19 Syndrome in healthcare workers, Journal of Infectious Diseases, Vol: 223, Pages: 1671-1676, ISSN: 0022-1899
It is currently unknown how Post-COVID-19 Syndrome (PCS) may affect those infected with SARS-CoV-2. This longitudinal study reports on healthcare staff who tested positive for SARS-CoV-2 between March-April 2020 and follows their antibody titres and symptomatology. Over half (n=21/38) had PCS at 7-8 months. There was no statistically significant difference between initial RT-PCR viral titres or serial antibody levels between those who did and did not develop PCS. This study highlights the relative commonality of PCS in healthcare workers and this should be considered in vaccination scheduling and workforce planning to allow adequate frontline staffing numbers.
Koizia L, Dani M, Brown H, et al., 2021, Does the weather contribute to admissions of neck of femur fractures?, Geriatric Orthopaedic Surgery and Rehabilitation, Vol: 12, Pages: 1-6, ISSN: 2151-4585
Background: The effects of weather on overall mortality are well documented. Anecdotally, icy conditions are perceived to result in more falls and admissions for neck of femur (NOF) fractures. The aim of this pilot study was to determine whether relationships could be extracted or at least not ruled out by analysing a small dataset, and so give impetus to a larger project. Methods: Seven trauma units across North West London were identified and NOF fracture data extracted for five years. Visual inspection of the time series, consideration of the weather on specific days and correlation analysis were used to assess associations between fracture numbers and a variety of weather parameters (temperature, rainfall, wind and ice risk). Results: Overall, 10929 individuals with hip fractures were admitted over the five-year period. The highest number of admissions in a day was 14. No clear association was found between a weather parameter and daily admissions. However, when accumulated to a weekly timescale, a negative relationship with maximum temperature was found. No seasonal cycle was detected.Conclusion: The lack of a daily relationship and presence of a weekly relationship points to a possible delayed response to weather or insufficient daily data to extract a signal. The inconclusive results also indicate a larger data sample is required in future studies. In addition, even in cold weather an urban environment may not create icy conditions, being ameliorated by the heat island effect and gritting.
Koizia LJ, Dani M, Brown H, et al., 2021, DOES THE WEATHER CONTRIBUTE TO ADMISSIONS OF NECK OF FEMUR FRACTURES?, AGE AND AGEING, Vol: 50, ISSN: 0002-0729
Chauhan A, Morgan C, Fertleman M, et al., 2021, Face coverings Mask Effective Communication, Open Access Journal of Gerontology & Geriatric Medicine, Vol: 6, Pages: 144-144, ISSN: 2575-8543
Rosa A, Pye VE, Graham C, et al., 2021, SARS-CoV-2 recruits a haem metabolite to evade antibody immunity., medRxiv
The coronaviral spike is the dominant viral antigen and the target of neutralizing antibodies. We show that SARS-CoV-2 spike binds biliverdin and bilirubin, the tetrapyrrole products of haem metabolism, with nanomolar affinity. Using cryo-electron microscopy and X-ray crystallography we mapped the tetrapyrrole interaction pocket to a deep cleft on the spike N-terminal domain (NTD). At physiological concentrations, biliverdin significantly dampened the reactivity of SARS-CoV-2 spike with immune sera and inhibited a subset of neutralizing antibodies. Access to the tetrapyrrole-sensitive epitope is gated by a flexible loop on the distal face of the NTD. Accompanied by profound conformational changes in the NTD, antibody binding requires relocation of the gating loop, which folds into the cleft vacated by the metabolite. Our results indicate that the virus co-opts the haem metabolite for the evasion of humoral immunity via allosteric shielding of a sensitive epitope and demonstrate the remarkable structural plasticity of the NTD.
Chauhan D, Varma S, Dani M, et al., 2021, Nasogastric tube feeding in older patients: a review of current practice and challenges faced, Current Gerontology and Geriatrics Research, Vol: 2021, ISSN: 1687-7063
Nasogastric tube feeding is an essential way of delivering enteral nutrition when the oral route is insufficient or unsafe. Malnutrition is recognised as a reversible factor for sarcopenia and frailty. It is therefore crucial that malnutrition is treated in olderinpatients who have dysphagia and require enteral nutrition. Despite five National Patient Safety Alerts since 2005, “Never Events”related to nasogastric feeding persist. In addition to placement errors, current practice often leads to delays in feeding, whichsubsequently result in worse patient outcomes. It is crucial that tube placement is confirmed accurately and in a timely way.Medical advancements in this area have been slow to find a solution which meets this need. In this paper, we provide an updatedreview on the current use of feeding nasogastric tubes in the older population, the issues associated with confirming correctplacement, and innovative solutions for improving safety and outcomes in older patients.v
Radia U, Malietzis G, Dani M, et al., 2021, The difficulty of managing recurrent sigmoid volvulus in a frailpatient, Journal of Surgery, Vol: 6, Pages: 1-4, ISSN: 2575-9760
Abdominal pain is a common cause for presentation of the older patient to healthcare services. Sigmoid volvulus is one of the leading causes of acute large bowel obstruction in adults. It affects older, comorbid, frailer and institutionalized patients.In this report, we highlight some of the clinical and ethical dilemmas clinicians face when caring for patients with recurrent sigmoid volvulus. We endorse early involvement of geriatricians and palliative care services in these individuals to ensure maximum patient comfort, quality of life and dignity.
Harris BHL, Zuhair M, Di Giovannantonio M, et al., 2021, Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in a rehabilitation facility: evolution of the presence of nasopharyngeal SARS-CoV-2 and serological antibody responses., Journal of Infectious Diseases, Vol: 223, Pages: 192-196, ISSN: 0022-1899
At the start of the UK coronavirus disease 2019 epidemic, this rare point prevalence study revealed that one-third of patients (15 of 45) in a London inpatient rehabilitation unit were found to be infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) but asymptomatic. We report on 8 patients in detail, including their clinical stability, the evolution of their nasopharyngeal viral reverse-transcription polymerase chain reaction (RT-PCR) burden, and their antibody levels over time, revealing the infection dynamics by RT-PCR and serology during the acute phase. Notably, a novel serological test for antibodies against the receptor binding domain of SARS-CoV-2 showed that 100% of our asymptomatic cohort remained seropositive 3-6 weeks after diagnosis.
Harris BHL, Zuhair M, di Giovannantonio M, et al., 2021, Asymptomatic COVID-19 in a rehabilitation facility: evolution of the presence of nasopharyngeal SARS-CoV-2 and serological antibody responses, The Journal of Infectious Diseases, Vol: 223, Pages: 192-196, ISSN: 0022-1899
At the start of the UK COVID-19 epidemic, this rare point prevalence study reveals ⅓ of patients in a London inpatient rehabilitation unit were found to be infected with SARS-CoV 2, but asymptomatic (n=15/45). We report on eight patients in detail, including their clinical stability, the evolution of their nasopharyngeal viral RT-PCR burden and their antibody levels over time revealing the infection dynamics by RT-PCR and serology during the acute phase. Notably, a novel serological test for antibodies against the receptor binding domain of SARS40 CoV-2 (anti-RBD) showed 100% of our asymptomatic cohort remained seropositive between 3 to 6 weeks post-diagnosis.
Tedder RS, Parker E, Sureda-Vives M, et al., 2021, Detection and quantification of antibody to SARS-CoV-2 receptor binding domain provides enhanced sensitivity, specificity and utility, Publisher: Elsevier BV
Background: Accurate and sensitive detection of antibody to SARS-CoV-2 remains an essential component of the pandemic response. Measuring antibody that predicts neutralising activity and the vaccine response is an absolute requirement for laboratory-based confirmatory and reference activity.Methods: The viral receptor binding domain (RBD) constitutes the prime target antigen for neutralising antibody. A double antigen binding assay (DABA) provides the most sensitive format. It has been exploited in a novel hybrid manner employing an S1 solid-phase preferentially presenting RBD once solid-phase bound, coupled with a labelled RBD conjugate, used in a two-step sequential assay.Findings: This assay showed a specificity of 100% on 825 pre COVID-19 samples and a potential sensitivity of 99.6% on 276 recovery samples, predicting quantitatively the presence of neutralising antibody determined by pseudo-type neutralisation and by plaque reduction. Anti-RBD is also measurable in ferrets immunised with ChadOx1 nCoV-19 vaccine. The early response at presentation with illness, elevated responsiveness with disease severity, detection of asymptomatic seroconversion and persistence after the loss of antibody to the nucleoprotein (anti-NP) are all documented.Trial Registration: The ISARIC WHO CCP-UK study was registered at https://www.isrctn.com/ISRCTN66726260 and designated an Urgent Public Health Research Study by NIHR.Interpretation: The hybrid DABA displays the attributes necessary for an antibody test to be used in both clinical and reference serology. It allows the neutralising antibody response to be inferred early in infection and potentially in vaccine recipients. It is also of sufficient sensitivity to be used to provide serological confirmation of prior infection and provides a more secure measure for seroprevalence studies in the population generally than does anti-NP based on the Architect platform.Funding: This work is variously supported by grants from: the National I
Moledina S, Maini A, Gargan A, et al., 2020, Clinical characteristics and predictors of mortality in patients with COVID-19 infection outside intensive care, International Journal of General Medicine, Vol: 2020, Pages: 1157-1165, ISSN: 1178-7074
Background/introductionThe Coronavirus Disease 2019 (COVID-19) pandemic has affected all aspects of inpatient hospital medicine with patients admitted from Level 1 (general medical wards) through to Level 3 (intensive care). Often, there are subtle physiological differences in these cohorts of patients. In particular, in intensive care, patients tend to be younger and have increased disease severity. Data, to date, has combined outcomes from medical and intensive care cohorts, or looked exclusively at intensive care. We looked solely at the level 1 (medical) cohort to identify their clinical characteristics and predictors of outcome. MethodsThis was a retrospective study of adult patients admitted to a central London teaching hospital with a diagnosis of COVID-19 from 23rd March – 7th April 2020 identified from the hospital electronic database. Any patients who required level 2 or 3 care were excluded. Results229 patients were included for analysis. Increased age and frailty scores were associated with increased 30-day mortality. Reduced renal function and elevated troponin blood levels are also associated with poor outcome. Baseline observations showed increased oxygen requirement was predictive for mortality. A trend of increased mortality with lower diastolic blood pressure was noted. Lymphopenia was not shown to be related to mortality. ConclusionUrea and creatinine are the best predictors of mortality in the level 1 cohort. Unlike previous intensive care data, lymphopenia is not predictive of mortality. We suggest that these factors be considered when prognosticating and for resource allocation for the treatment and escalation of care for patients with COVID-19 infection.
Oleribe O, Ezechi O, Osita-Oliberi P, et al., 2020, Public perception of COVID-19 management and response in Nigeria: a cross-sectional survey, BMJ Open, Vol: 10, Pages: 1-7, ISSN: 2044-6055
Objectives: A study designed to assess the public perception of the response of government and its institutions to the COVID-19 pandemic in Nigeria. Setting: Self-selecting participants throughout Nigeria completed a self-administered questionnaire through an online cross-sectional survey. Participants: 495 Results: The majority of respondents were married (76.6%), were males (61.8%), had tertiary level education (91.0%), were public servants (36.8%), Christians (82.6%), and resident either in the Federal Capital Territory (Abuja) (49.1%) or in the South-East Region of Nigeria (36.6%). Over 95% of the respondents had heard of COVID-19 (98.8%) and knew it is a viral disease (95.4%). The government and its institutions response to the pandemic were rated as poor, with the largest rating as poor for Federal President’s Office (57.5%). Communication (50.0%) and prevention messages (43.7%) received the highest perception good rating. Female respondents and those less than 40 years generally rated the governmental responses as poor. Conclusions/Recommendations: It is recommended that as a public-private partnership approached was efficiently used to more effectively disseminate public health communication and prevention messages, the Nigerian Government should expand this collaboration to improve the quality of services provided in other areas of COVID-19 outbreak management.
Koizia LJ, Dani M, Sritharan G, et al., 2020, Collaborative working on a 7-day rota reduces length of stay., Future Healthc J, Vol: 7, ISSN: 2514-6645
A 7-day consultant-geriatrician-led service across five surgical wards, with integrated working among surgeons and physicians, was implemented in response to the COVID-19 pandemic. Our model has shown to increase discharge rates and improve MDT wellbeing. Embedded physician working with surgeons could be key in the recovery to COVID-19.
Fertleman M, Glickstein B, Philip H, 2020, Medical law and ethics, Medicine for MRCP, Editors: Besant, Birns, Charlotte, Oxford, Publisher: Oxford Specialty Training: Revision Texts, ISBN: 9780198779506
Medicine for MRCP provides a comprehensive review of the material that you need to pass the MRCP Parts 1 and 2 written papers. The twenty-seven chapters mapped out to the RCP syllabus, cover all areas from molecular medicine and genetics, through to medical law and ethics. Written by specialist contributors and educational experts, the content is carefully crafted to build your understanding for both papers. Each chapter begins with the basic science required for Part 1, before covering clinical medicine for Part 1, Part 2 and the PACES examinations.To ensure effective revision, material is presented in short sections with bullet lists, tables, and boxes. Over 150 drawings and photos illustrate key principles and clinical topics making them easier to retain. References to evidence-based protocols and directions to further reading allow for deeper understanding. Candidates can review their progress via the 180 end-of chapter self-assessment questions.Drawing on the authors' expertise, Medicine for MRCP is the ideal companion for the MRCP as well as a useful reference guide for practicing medical doctors.
Oleribe O, Osita-Oleribe P, Salako B, et al., 2020, COVID-19 Experience: Taking the right steps at the right time to prevent avoidable morbidity and mortality in Nigeria and other nations of the world, International Journal of General Medicine, Vol: 2020, Pages: 491-195, ISSN: 1178-7074
The 2020 Coronavirus pandemic has caused countless governmental and societal challenges around the world. Nigeria, Africa’s most populous nation, has been exposed in recent years to a series of epidemics including Ebola and Lassa Fever. In this paper we document our perception of the national response to COVID-19 in Nigeria. The response to the pandemic is with a healthcare system that has changed as a result of previous infectious disease outbreaks but in the context of scarce resources typical of many low-middle income countries. We make recommendations regarding what measures should be in place for future epidemics.
Varma S, Wilson MSJ, Naik M, et al., 2020, Sarcopenia in elderly major trauma; A single centre retrospective analysis of psoas and masseter muscle groups, Preprints
Lee A, Koizia L, Dani M, et al., 2020, 'Nipples to knees' in the 'Me Too' era (vol 20, pg 235, 2020), CLINICAL MEDICINE, Vol: 20, Pages: 379-379, ISSN: 1470-2118
Koizia L, Naik M, Peck G, et al., 2020, The utility of psoas muscle assessment in predicting frailty in patients undergoing transcatheter aortic valve replacement, Current Gerontology and Geriatrics Research, Vol: 2020, Pages: 1-7, ISSN: 1687-7063
Background. The rise in an ageing population has resulted in an increase in the prevalence of aortic stenosis. With the advent and rapid expansion in the use of transcatheter aortic valve replacements (TAVRs), patients with severe aortic stenosis, traditionally thought too high risk for surgical intervention, are now being treated with generally favourable results. Frailty is an important factor in determining outcome after a TAVR, and an assessment of frailty is fundamental in the identification of appropriate patients to treat. Objective. The objective of the study was to identify if the psoas muscle area is associated with frailty in TAVR patients and outcome after intervention. Method. In this prospective study, we measured outcomes of 62 patients who underwent TAVR procedures against the psoas muscle area and the Reported Edmonton Frail Scale (REFS). Our aim was to assess if psoas muscle assessment can be used as a simple method to predict frailty in our population group. Results. A total of 60 patients met the study criteria. Mean psoas-lumbar vertebral index was 0.61, with a lower value in the frail group. There was not a statistically significant correlation between the psoas measures, REFS score (indicative of frailty), and mortality. However, there was a statistically significant relationship between the psoas size and REFS score (). Conclusion. Psoas assessment can be useful in providing additional information when planning for patients to undergo a TAVR and can be used as a screening tool to help identify frail patients within this high-risk group.
Davies A, Heaton T, Sabharwal S, et al., 2020, Consent for surgery during the COVID-19 pandemic, Transient Journal of Trauma, Orthopaedics and the Coronavirus
Bassendine M, Taylor-Robinson S, Fertleman M, et al., 2020, Is Alzheimer's Disease a liver disease of the brain?, Journal of Alzheimer's Disease, Vol: 75, Pages: 1-14, ISSN: 1387-2877
Clinical specialization is not only a force for progress, but it has also led to the fragmentation of medical knowledge. The focus of research in the field of Alzheimer’s disease (AD) is neurobiology, while hepatologists focus on liver diseases and lipid specialists on atherosclerosis. This article on AD focuses on the role of the liver and lipid homeostasis in the development of AD. Amyloid-β (Aβ) deposits accumulate as plaques in the brain of an AD patient long before cognitive decline is evident. Aβ generation is a normal physiological process; the steady-state level of Aβ in the brain is determined by balance between Aβ production and its clearance. We present evidence suggesting that the liver is the origin of brain Aβ deposits and that it is involved in peripheral clearance of circulating Aβ in the blood. Hence the liver could be targeted to decrease Aβ production or increase peripheral clearance.
Lee A, Koizia L, Dani M, et al., 2020, 'Nipples to knees' in the 'Me Too' era, CLINICAL MEDICINE, Vol: 20, Pages: 235-236, ISSN: 1470-2118
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van der Kruk E, Silverman A, Koizia L, et al., 2020, CaReMoOC: Capacity, Reserve, Movement Objectives, and Compensation. A New Framework to Describe Mechanisms of Movement Limitations, Demonstrated for Ageing, Preprints
Pereira C, Fertleman M, 2019, Elder abuse: a common problem, commonly missed in trauma and orthopaedics, EUROPEAN GERIATRIC MEDICINE, Vol: 10, Pages: 839-841, ISSN: 1878-7649
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Ahmad Y, Vendrik J, Eftekhari A, et al., 2019, Determining the Predominant Lesion in Patients With Severe Aortic Stenosis and Coronary Stenoses: A Multicenter Study Using Intracoronary Pressure and Flow, Circulation: Cardiovascular Interventions, Vol: 12, ISSN: 1941-7640
Background:Patients with severe aortic stenosis (AS) often have coronary artery disease. Both the aortic valve and the coronary disease influence the blood flow to the myocardium and its ability to respond to stress; leading to exertional symptoms. In this study, we aim to quantify the effect of severe AS on the coronary microcirculation and determine if this is influenced by any concomitant coronary disease. We then compare this to the effect of coronary stenoses on the coronary microcirculation.Methods:Group 1: 55 patients with severe AS and intermediate coronary stenoses treated with transcatheter aortic valve implantation (TAVI) were included. Group 2: 85 patients with intermediate coronary stenoses and no AS treated with percutaneous coronary intervention were included. Coronary pressure and flow were measured at rest and during hyperemia in both groups, before and after TAVI (group 1) and before and after percutaneous coronary intervention (group 2).Results:Microvascular resistance over the wave-free period of diastole increased significantly post-TAVI (pre-TAVI, 2.71±1.4 mm Hg·cm·s−1 versus post-TAVI 3.04±1.6 mm Hg·cm·s−1 [P=0.03]). Microvascular reserve over the wave-free period of diastole significantly improved post-TAVI (pre-TAVI 1.88±1.0 versus post-TAVI 2.09±0.8 [P=0.003]); this was independent of the severity of the underlying coronary stenosis. The change in microvascular resistance post-TAVI was equivalent to that produced by stenting a coronary lesion with an instantaneous wave-free ratio of ≤0.74.Conclusions:TAVI improves microcirculatory function regardless of the severity of underlying coronary disease. TAVI for severe AS produces a coronary hemodynamic improvement equivalent to the hemodynamic benefit of stenting coronary stenoses with instantaneous wave-free ratio values <0.74. Future trials of physiology-guided revascularization in severe AS may consider us
Koizia LJ, Wilson F, Reilly P, et al., 2019, Delirium after emergency hip surgery – common and serious, but rarely consented for, World Journal of Orthopedics, Vol: 10, Pages: 228-234, ISSN: 2218-5836
A quarter of patients admitted with a proximal femoral fracture suffer from an acute episode of delirium during their hospital stay. Yet it is often unrecognised, poorly managed, and rarely discussed by doctors. Delirium is important not only to the affected individuals and their families, but also socioeconomically to the broader community. Delirium increases mortality and morbidity, leads to lasting cognitive and functional decline, and increases both length of stay and dependence on discharge. Delirium should be routinely and openly discussed by all members of the clinical team, including surgeons when gaining consent. Failing to do so may expose surgeons to claims of negligence. Here we present a concise review of the literature and discuss the epidemiology, causative factors, potential consequences and preventative strategies in the perioperative period.
Beedham W, Peck G, Richardson SE, et al., 2019, Head injury in the elderly - an overview for the physician, Clinical Medicine, Vol: 19, Pages: 177-184, ISSN: 1470-2118
Head injury is a common cause for hospital admission and additionally 250,000 UK inpatients fall during hospital admissions annually. Head injury most commonly occurs as a result of falls from standing height in older adults. Older adults are frequently frail and multi-morbid; many have indications for anticoagulation and antiplatelet agents. The haemorrhagic complications of head injury occur in up to 16% of anticoagulated patients sustaining a head injury. These patients suffer adverse outcomes from surgery as a result of medical complications. Although geriatric trauma models are evolving to meet the demand of an ageing trauma population, medical support to trauma services is commonly delivered by general physicians, many of whom lack experience and training in this field. Determining the role of surgery and interrupted anticoagulation requires careful personalised risk assessment. Appreciation of the opposing risks can be challenging; it requires an understanding of the evidence base in both surgery and medicine to rationalise decision making and inform communication. This article aims to provide an overview for the physician with clinical responsibility for patients who have sustained head injury.
Lee A, Ehsanullah J, Chawla S, et al., 2019, Improving Perioperative Care In Patients Over 60 Years With A Fractured Neck Of Femur A Lee, J Ehsanullah, S Chawla, D Shenoy, M Fertleman, British Geriatrics Society Spring Meeting
Ahmad Y, Gotberg M, Cook C, et al., 2018, Coronary haemodynamics in patients with severe aortic stenosis and coronary artery disease undergoing Transcatheter Aortic Valve Replacement: implications for clinical indices of coronary stenosis severity, JACC: Cardiovascular Interventions, Vol: 11, Pages: 2019-2031, ISSN: 1936-8798
Objectives In this study, a systematic analysis was conducted of phasic intracoronary pressure and flow velocity in patients with severe aortic stenosis (AS) and coronary artery disease, undergoing transcatheter aortic valve replacement (TAVR), to determine how AS affects 1) phasic coronary flow; 2) hyperemic coronary flow; and 3) the most common clinically used indices of coronary stenosis severity, instantaneous wave-free ratio and fractional flow reserve.Background A significant proportion of patients with severe aortic stenosis (AS) have concomitant coronary artery disease. The effect of the valve on coronary pressure, flow, and the established invasive clinical indices of stenosis severity have not been studied.Methods Twenty-eight patients (30 lesions, 50.0% men, mean age 82.1 ± 6.5 years) with severe AS and coronary artery disease were included. Intracoronary pressure and flow assessments were performed at rest and during hyperemia immediately before and after TAVR.Results Flow during the wave-free period of diastole did not change post-TAVR (29.78 ± 14.9 cm/s vs. 30.81 ± 19.6 cm/s, p = 0.64). Whole-cycle hyperemic flow increased significantly post-TAVR (33.44 ± 13.4 cm/s pre-TAVR vs. 40.33 ± 17.4 cm/s post-TAVR, p = 0.006); this was secondary to significant increases in systolic hyperemic flow post-TAVR (27.67 ± 12.1 cm/s pre-TAVR vs. 34.15 ± 17.5 cm/s post-TAVR, p = 0.02). Instantaneous wave-free ratio values did not change post-TAVR (0.88 ± 0.09 pre-TAVR vs. 0.88 ± 0.09 post-TAVR, p = 0.73), whereas fractional flow reserve decreased significantly post-TAVR (0.87 ± 0.08 pre-TAVR vs. 0.85 ± 0.09 post-TAVR, p = 0.001).Conclusions Systolic and hyperemic coronary flow increased significantly post-TAVR; consequently, hyperemic indices that include systole underestimated coronary stenosis severity in patients with severe AS. Flow during the wave-free period of diastole did not change pos
Ahmad Y, Götberg M, Cook C, et al., 2018, Coronary hemodynamics in patients with severe aortic stenosis and coronary Artery disease undergoing transcatheter aortic valve replacement: implications for clinical indices of coronary stenosis severity, JACC: Cardiovascular Interventions, Vol: 11, Pages: 2019-2031, ISSN: 1936-8798
OBJECTIVES: In this study, a systematic analysis was conducted of phasic intracoronary pressure and flow velocity in patients with severe aortic stenosis (AS) and coronary artery disease, undergoing transcatheter aortic valve replacement (TAVR), to determine how AS affects 1) phasic coronary flow; 2) hyperemic coronary flow; and 3) the most common clinically used indices of coronary stenosis severity, instantaneous wave-free ratio and fractional flow reserve. BACKGROUND: A significant proportion of patients with severe aortic stenosis (AS) have concomitant coronary artery disease. The effect of the valve on coronary pressure, flow, and the established invasive clinical indices of stenosis severity have not been studied. METHODS: Twenty-eight patients (30 lesions, 50.0% men, mean age 82.1 ± 6.5 years) with severe AS and coronary artery disease were included. Intracoronary pressure and flow assessments were performed at rest and during hyperemia immediately before and after TAVR. RESULTS: Flow during the wave-free period of diastole did not change post-TAVR (29.78 ± 14.9 cm/s vs. 30.81 ± 19.6 cm/s, p = 0.64). Whole-cycle hyperemic flow increased significantly post-TAVR (33.44 ± 13.4 cm/s pre-TAVR vs. 40.33 ± 17.4 cm/s post-TAVR, p = 0.006); this was secondary to significant increases in systolic hyperemic flow post-TAVR (27.67 ± 12.1 cm/s pre-TAVR vs. 34.15 ± 17.5 cm/s post-TAVR, p = 0.02). Instantaneous wave-free ratio values did not change post-TAVR (0.88 ± 0.09 pre-TAVR vs. 0.88 ± 0.09 post-TAVR, p = 0.73), whereas fractional flow reserve decreased significantly post-TAVR (0.87 ± 0.08 pre-TAVR vs. 0.85 ± 0.09 post-TAVR, p = 0.001). CONCLUSIONS: Systolic and hyperemic coronary flow increased significantly post-TAVR; consequently, hyperemic indices that include systole underestimated coronary stenosis severity in patients with severe AS. Flow during the wave-free per
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