CT Transit Time And Its Correlation To Cardiac Output Derived From Mr

Introduction: Pulmonary transit time (PTT), the time taken for contrast to travel from the left to right ventricle, can be used as a surrogate marker for cardiac output. There have been previous studies evaluating the prognostic significance of Magnetic Resonance (MR) and Computed Tomography (CT) PTT in heart failure patients. This study used dynamic CT images to determine the PTT and study its correlation with left and right ventricular ejection fraction and left and right cardiac output in COVID patients, with a known range of cardiac outputs. Method(s): 123 COVID-19 patients were retrospectively studied. A single contrast bolus timing scan was acquired with a 320-detector CT (Acquilion ONE, Canon). A single 2 mm slice was placed axially where left and right ventricle and descending aorta were visualised. Contrast administration and scan acquisition began at the same with 20 ml of Omnipaque with 40 ml saline flush at 5 ml/s. One image was acquired every second and the total scan time was 26 seconds. A circular ROI was placed in the centre left and right ventricle, the signal intensity was plotted over time for each of these regions. Matlab software was used to extract the peak contrast time between the right and left ventricles. MR cardiac images were acquired on a 3 T Prisma, which determined MR PTT, left and right ejection fraction (LVEF, RVEF) and left and right ventricle cardiac output (LVCO, RVCO). These values were already computed from a previous study where this data was taken from. Correlations were studied using the Pearson correlation method using Minitab software. Result(s): There was correlation between MR PTT and LVEF and RVEF, r = - 0.433 p<0.05 and r=-0.358 p<0.05 respectively. A correlation was also seen with CT PTT and LVEF (figure 1) and RVEF, r=-0.-345 p<0.05 and r=-0.2 p=0.029 respectively. A correlation was seen for MR PTT and LVCO and RVCO, r=-0.322 p<0.05 and r=-0.295 p<0.05 but not for CT PTT and LVCO and RVCO, r=-0.1 p=0.297 and r=-0.04 p=0.668 respectively. Conclusion(s): A correlation was seen between MR PTT and CT PTT for both LVEF and RVEF, but this was not seen for CT PTT and LVCO and RVCO. Further work is required to understand the limitations of the CT PTT and why it fails to correlate with these parameters. Limitations may include dynamic CT temporal resolution or due to poor image quality due to motion from breathing. Compared to previous studies there is agreement between the MR PTT and MR cardiac parameters. At this stage there is an indication that CT PTT could be a potential tool to estimate LVEF and RVEF. [Formula presented]Copyright © 2023

Prevention and early treatment of the long-term physical effects of COVID-19 in adults: design of a randomised controlled trial of resistance exercise-CISCO-21.

BACKGROUND: Coronavirus disease-19 (COVID-19) infection causes persistent health problems such as breathlessness, chest pain and fatigue, and therapies for the prevention and early treatment of post-COVID-19 syndromes are needed. Accordingly, we are investigating the effect of a resistance exercise intervention on exercise capacity and health status following COVID-19 infection. METHODS: A two-arm randomised, controlled clinical trial including 220 adults with a diagnosis of COVID-19 in the preceding 6 months. Participants will be classified according to clinical presentation: Group A, not hospitalised due to COVID but persisting symptoms for at least 4 weeks leading to medical review; Group B, discharged after an admission for COVID and with persistent symptoms for at least 4 weeks; or Group C, convalescing in hospital after an admission for COVID. Participants will be randomised to usual care or usual care plus a personalised and pragmatic resistance exercise intervention for 12 weeks. The primary outcome is the incremental shuttle walks test (ISWT) 3 months after randomisation with secondary outcomes including spirometry, grip strength, short performance physical battery (SPPB), frailty status, contacts with healthcare professionals, hospitalisation and questionnaires assessing health-related quality of life, physical activity, fatigue and dyspnoea. DISCUSSION: Ethical approval has been granted by the National Health Service (NHS) West of Scotland Research Ethics Committee (REC) (reference: GN20CA537) and recruitment is ongoing. Trial findings will be disseminated through patient and public forums, scientific conferences and journals. TRIAL REGISTRATION: ClinicialTrials.gov NCT04900961 . Prospectively registered on 25 May 2021.

Role of inpatient coronary CT angiography on clinical decision making during COVID- 19 pandemic

Background: The COVID-19 pandemic has had a profound effect on healthcare delivery. Here we describe the effect of repurposing of a research Computed Tomography scanner on clinical care of cardiology patients in an urban academic medical centre which did not have routine access to CCTA prior to the pandemic. Patients requiring invasive coronary angiography require transfer to a regional cardiac centre (no ICA available on site). Purpose: We investigated the effect of CCTA on i) diagnostic certainty ii) avoidance of clinician defined unnecessary invasive angiography in hospitalised patients. Methods: This was a prospective, longitudinal cohort study involving hospitalized patients admitted to an urban academic medical centre (catchment population 650 000) between March 29 and September 21, 2020. Routinely collected (usual care) data were gathered by clinicians who were members of the usual care medical team and ethics approval or explicit patient consent was not required. High-sensitivity Troponin-I was measured on admission and 3- and 6- hours after if mandated (Abbott Architect TnI assay). A 320-detector scanner (Aquilon ONE, Canon) was used. Intravenous metoprolol was used where required to control the heart rate (target 60 b.p.m.) and sublingual glyceryl trinitrate will be given to all patients immediately before the scan acquisition. Results: Forty-three patients underwent inpatient CCTA, mean age: 61 ± 13 years (range 30-88y), 54% female. The presenting complaint was typical chest pain in 28 (65%), atypical chest pain in 10 (23%), and a variety of symptoms in 5 (12%) including palpitations, syncope, breathlessness. Thirty-six (84%) of patients had a detectable TnI above the 99% centile. Median(IQR) peak TnI was 127 (33-635)ng/L. CCTA was carried out on average 1 day post request. CCTA resulted in an improvement in clinician diagnostic certainty (Initial review: 21% yes, 79% probable, post-CCTA review: 84% yes, 16% probable) in providing a diagnosis. 21 (49%) of invasive coronary angiograms were avoided due to CCTA, whilst an inpatient invasive coronary angiogram (ICA) was performed in 4(9%) due to CCTA demonstrating significant disease, and in 2(%) the ICA was changed from out-patient to in-patient. Three ICA tests were requested as OP due to CCTA findings. CCTA did not overestimate disease severity in this cohort. We saved 21 inter hospital transfers for ICA during this time period. Using NHS England cost tariffs, a cost saving of >£36,000 was made for using CCTA instead of ICA in these 21 patients who would have required ICA. Conclusion: Inpatient CCTA resulted in greater clinician diagnostic confidence, avoidance of unnecessary invasive angiograms and a significant cost saving. This also reduced the duration of patient stay, reducing the potential exposure of patients to COVID-19. (Table Presented).