Use of cardiac imaging in chronic coronary syndromes: the EURECA Imaging registry.

BACKGROUND: The prospective, multicentre EURECA registry assessed the use of imaging and adoption of the European Society of Cardiology (ESC) Guidelines (GL) in patients with chronic coronary syndromes (CCS). METHODS: Between May 2019 and March 2020, 5156 patients were recruited in 73 centres from 24 ESC member countries. The adoption of GL recommendations was evaluated according to clinical presentation and pre-test probability (PTP) of obstructive coronary artery disease (CAD). RESULTS: The mean age of the population was 64 ± 11 years, 60% of patients were males, 42% had PTP >15%, 27% had previous CAD, and ejection fraction was <50% in 5%. Exercise ECG was performed in 32% of patients, stress imaging as the first choice in 40%, and computed tomography coronary angiography (CTCA) in 22%. Invasive coronary angiography (ICA) was the first or downstream test in 17% and 11%, respectively. Obstructive CAD was documented in 24% of patients, inducible ischaemia in 19%, and 13% of patients underwent revascularization. In 44% of patients, the overall diagnostic process did not adopt the GL. In these patients, referral to stress imaging (21% vs. 58%; P < 0.001) or CTCA (17% vs. 30%; P < 0.001) was less frequent, while exercise ECG (43% vs. 22%; P < 0.001) and ICA (48% vs. 15%; P < 0.001) were more frequently performed. The adoption of GL was associated with fewer ICA, higher proportion of diagnosis of obstructive CAD (60% vs. 39%, P < 0.001) and revascularization (54% vs. 37%, P < 0.001), higher quality of life, fewer additional testing, and longer times to late revascularization. CONCLUSIONS: In patients with CCS, current clinical practice does not adopt GL recommendations on the use of diagnostic tests in a significant proportion of patients. When the diagnostic approach adopts GL recommendations, invasive procedures are less frequently used and the diagnostic yield and therapeutic utility are superior.

Cardiac contusions in the acute care setting: Historical background, evaluation and management.

INTRODUCTION: Albeit described since 1763, cardiac contusions is still an under-recognised clinical condition in the acute care setting. This evidence-based review aims to provide an overview of the topic by focusing on etiopathogenesis, classification and clinical presentation of patients with cardiac contusions, as well as on the diagnostic work-up and therapy options available for this subset population in the acute care setting. METHODS: A targeted research strategy was performed using PubMed, MEDLINE, Embase and Cochrane Central databases up to June 2022. The literature search was conducted using the following keywords (in Title and/or Abstract): ("cardiac" OR "heart" OR "myocardial") AND ("contusion"). All available high-quality resources written in English and containing information on epidemiology, etiopathogenesis, clinical findings, diagnosis and management of cardiac contusions were included in our research. RESULTS: Biochemical samples of cardiac troponins together with a 12­lead ECG appear to be sufficient screening tools in hemodynamically stable subjects, while cardiac ultrasound provides a further diagnostic clue for patients with hemodynamic instability or those more likely to have a significant cardiac contusion. CONCLUSIONS: The management of patients with suspected cardiac contusion remains a challenge in clinical practice. For this kind of patients a comprehensive diagnostic approach and a prompt emergency response are required, taking into consideration the degree of severity and clinical impairment of associated traumatic injuries.

Cardiac herniation: A practical review in the emergency setting.

INTRODUCTION: Albeit described since 1948, cardiac herniations still represent an under-recognized clinical entity in the general population, due to their difficult diagnostic detection and to a limited knowledge in clinical practice. This paper aims to provide an updated overview focusing on definition, clinical presentation and diagnostic work-up of cardiac herniations, as well as on further findings concerning prognoses and available therapeutic options. METHODS: This narrative review was performed by following the standard methods of the Cochrane Collaboration and the PRISMA statement. A Pubmed search was conducted using the following keywords (in Title and/or Abstract): ("cardiac" OR "heart") AND ("herniation" OR "hernia"). All available high quality resources containing information on epidemiology, etiopathogenesis, clinical findings, diagnostic tools and therapeutic strategies, were included in our search. RESULTS: Causative agents, location and the degree of haemodynamic impairment were found to play a pivotal role in defining the patient's natural history and prognostic outcomes, and in detecting potential associated clinical conditions which may significantly impact on first line decision-making strategy. CONCLUSIONS: Cardiac herniations remain a rare and life-threatening pathological injury, whose knowledge is still very limited in clinical practice. Clinicians should be aware of such a clinical entity and of its wide spectrum of clinical manifestations, particularly in high-risk subsets of patients, in order to provide the most appropriate decision-making strategy and timely therapeutic approach.

Lung distribution of gas and blood volume in critically ill COVID-19 patients: a quantitative dual-energy computed tomography study.

BACKGROUND: Critically ill COVID-19 patients have pathophysiological lung features characterized by perfusion abnormalities. However, to date no study has evaluated whether the changes in the distribution of pulmonary gas and blood volume are associated with the severity of gas-exchange impairment and the type of respiratory support (non-invasive versus invasive) in patients with severe COVID-19 pneumonia. METHODS: This was a single-center, retrospective cohort study conducted in a tertiary care hospital in Northern Italy during the first pandemic wave. Pulmonary gas and blood distribution was assessed using a technique for quantitative analysis of dual-energy computed tomography. Lung aeration loss (reflected by percentage of normally aerated lung tissue) and the extent of gas:blood volume mismatch (percentage of non-aerated, perfused lung tissue-shunt; aerated, non-perfused dead space; and non-aerated/non-perfused regions) were evaluated in critically ill COVID-19 patients with different clinical severity as reflected by the need for non-invasive or invasive respiratory support. RESULTS: Thirty-five patients admitted to the intensive care unit between February 29th and May 30th, 2020 were included. Patients requiring invasive versus non-invasive mechanical ventilation had both a lower percentage of normally aerated lung tissue (median [interquartile range] 33% [24-49%] vs. 63% [44-68%], p < 0.001); and a larger extent of gas:blood volume mismatch (43% [30-49%] vs. 25% [14-28%], p = 0.001), due to higher shunt (23% [15-32%] vs. 5% [2-16%], p = 0.001) and non-aerated/non perfused regions (5% [3-10%] vs. 1% [0-2%], p = 0.001). The PaO2/FiO2 ratio correlated positively with normally aerated tissue (ρ = 0.730, p < 0.001) and negatively with the extent of gas-blood volume mismatch (ρ = - 0.633, p < 0.001). CONCLUSIONS: In critically ill patients with severe COVID-19 pneumonia, the need for invasive mechanical ventilation and oxygenation impairment were associated with loss of aeration and the extent of gas:blood volume mismatch.

Computed tomography assessment of PEEP-induced alveolar recruitment in patients with severe COVID-19 pneumonia.

BACKGROUND: There is a paucity of data concerning the optimal ventilator management in patients with COVID-19 pneumonia; particularly, the optimal levels of positive-end expiratory pressure (PEEP) are unknown. We aimed to investigate the effects of two levels of PEEP on alveolar recruitment in critically ill patients with severe COVID-19 pneumonia. METHODS: A single-center cohort study was conducted in a 39-bed intensive care unit at a university-affiliated hospital in Genoa, Italy. Chest computed tomography (CT) was performed to quantify aeration at 8 and 16 cmH2O PEEP. The primary endpoint was the amount of alveolar recruitment, defined as the change in the non-aerated compartment at the two PEEP levels on CT scan. RESULTS: Forty-two patients were included in this analysis. Alveolar recruitment was median [interquartile range] 2.7 [0.7-4.5] % of lung weight and was not associated with excess lung weight, PaO2/FiO2 ratio, respiratory system compliance, inflammatory and thrombophilia markers. Patients in the upper quartile of recruitment (recruiters), compared to non-recruiters, had comparable clinical characteristics, lung weight and gas volume. Alveolar recruitment was not different in patients with lower versus higher respiratory system compliance. In a subgroup of 20 patients with available gas exchange data, increasing PEEP decreased respiratory system compliance (median difference, MD - 9 ml/cmH2O, 95% CI from - 12 to - 6 ml/cmH2O, p < 0.001) and the ventilatory ratio (MD - 0.1, 95% CI from - 0.3 to - 0.1, p = 0.003), increased PaO2 with FiO2 = 0.5 (MD 24 mmHg, 95% CI from 12 to 51 mmHg, p < 0.001), but did not change PaO2 with FiO2 = 1.0 (MD 7 mmHg, 95% CI from - 12 to 49 mmHg, p = 0.313). Moreover, alveolar recruitment was not correlated with improvement of oxygenation or venous admixture. CONCLUSIONS: In patients with severe COVID-19 pneumonia, higher PEEP resulted in limited alveolar recruitment. These findings suggest limiting PEEP strictly to the values necessary to maintain oxygenation, thus avoiding the use of higher PEEP levels.

SIRM-SIC appropriateness criteria for the use of Cardiac Computed Tomography. Part 1: Congenital heart diseases, primary prevention, risk assessment before surgery, suspected CAD in symptomatic patients, plaque and epicardial adipose tissue characterization, and functional assessment of stenosis.

In the past 20 years, Cardiac Computed Tomography (CCT) has become a pivotal technique for the noninvasive diagnostic work-up of coronary and cardiac diseases. Continuous technical and methodological improvements, combined with fast growing scientific evidence, have progressively expanded the clinical role of CCT. Recent large multicenter randomized clinical trials documented the high prognostic value of CCT and its capability to increase the cost-effectiveness of the management of patients with suspected CAD. In the meantime, CCT, initially perceived as a simple non-invasive technique for studying coronary anatomy, has transformed into a multiparametric "one-stop-shop" approach able to investigate the heart in a comprehensive way, including functional, structural and pathophysiological biomarkers. In this complex and revolutionary scenario, it is urgently needed to provide an updated guide for the appropriate use of CCT in different clinical settings. This manuscript, endorsed by the Italian Society of Medical and Interventional Radiology (SIRM) and by the Italian Society of Cardiology (SIC), represents the first of two consensus documents collecting the expert opinion of Radiologists and Cardiologists about current appropriate use of CCT.

Prognostic value of cardiac CT.

In the past decades, coronary computed tomography angiography (CCTA) has become a powerful tool in the management of coronary artery disease. The diagnostic and prognostic value of CCTA has been extensively demonstrated in both large observational studies and clinical trials among stable chest pain patients. The quantification of coronary artery calcium score (CACS) is a well-established predictor of cardiovascular morbidity and mortality in asymptomatic subjects. Besides CACS, the main strength of CCTA is the accurate assessment of the individual total atherosclerotic plaque burden, which holds important prognostic information. In addition, CCTA, by providing detailed information on coronary plaque morphology and composition with identification of specific high-risk plaque features, may further improve the risk stratification beyond the assessment of coronary stenosis. The development of new CCTA applications, such as stress myocardial CT perfusion and computational fluids dynamic applied to standard CCTA to derive CT-based fractional flow reserve (FFR) values have shown promising results to guide revascularization, potentially improving clinical outcomes in stable chest pain patients. In this review, starting from the role of CACS and moving beyond coronary stenosis, we evaluate the existing evidence of the prognostic effectiveness of the CCTA strategy in real-world clinical practice.

Comparison of coronary flow reserve estimated by dynamic radionuclide SPECT and multi-detector x-ray CT.

BACKGROUND: Recent technical advances in multi-detector computed tomography (MDCT) allow for assessment of coronary flow reserve (CFR). We compared regional CFR by dynamic SPECT and by dynamic MDCT in patients with suspected or known coronary artery disease (CAD). METHODS: Thirty-five patients, (29 males, mean age 69 years) with greater than average Framingham risk of CAD, underwent dipyridamole vasodilator stress imaging. CFR was estimated using dynamic SPECT and dynamic MDCT imaging in the same patients. Myocardial perfusion findings were correlated with obstructive CAD (≥50% luminal narrowing) on CT coronary angiography (CA). RESULTS: Mean CFR estimated by SPECT and MDCT in 595 myocardial segments was not different (1.51 ± 0.46 vs. 1.50 ± 0.37, p = NS). Correlation of segmental CFR by SPECT and MDCT was fair (r 2 = 0.39, p < 0.001). Bland-Altman analysis revealed that MDCT in comparison to SPECT systematically underestimated CFR in higher CFR ranges. By CTCA, 12 patients had normal CA, 11 had non-obstructive, and 12 had obstructive CAD. CFR by both techniques was significantly higher in territories of normal CA than in territories subtended by non-obstructive or obstructive CAD. SPECT CFR was also significantly different in territories subtended by non-obstructive and obstructive CAD, whereas MDCT CFR was not. CONCLUSION: Despite relative underestimation of high CFR values, MDCT CFR shows promise for assessing the pathophysiological significance of anatomic CAD.

Aberrant right subclavian artery (arteria lusoria) challenging 4-French homolateral transradial coronary catheterisation in adulthood.

We report a case of an accidental finding of an aberrant right subclavian artery diagnosed in an adult man during a 4-French coronary angiography performed by right transradial access, then confirmed by multi-slice computed tomography. Tips and tricks have been suggested to complete the 4-French procedure avoiding changing the vascular access.

Endovascular treatment with primary stenting of inferior cava vein torsion following orthotopic liver transplantation with modified piggyback technique.

PURPOSE: This study was undertaken to evaluate primary stenting in patients with inferior vena cava torsion after orthotopic liver transplantation performed with modified piggyback technique. MATERIALS AND METHODS: From November 2003 to October 2010, six patients developed clinical, laboratory and imaging findings suggestive of caval stenosis, after a mean period of 21 days from an orthotopic liver transplantation performed with modified piggyback technique. Vena cavography showed stenosis due to torsion of the inferior vena cava at the anastomoses and a significant caval venous pressure gradient. All patients were treated with primary stenting followed by in-stent angioplasty in three cases. RESULTS: In all patients, the stents were successfully positioned at the caval anastomosis and the venous gradient pressure fell from a mean value of 10 to 2 mmHg. Signs and symptoms resolved in all six patients. One patient died 3 months after stent placement due to biliary complications. No evidence of recurrence or complications was noted during the follow-up (mean 49 months). CONCLUSIONS: Primary stenting of inferior vena cava stenosis due to torsion of the anastomoses in patients receiving orthotopic liver transplantation with modified piggyback technique is a safe, effective and durable treatment.

Ischemia with non-obstructive coronary artery (INOCA): Non-invasive versus invasive techniques for diagnosis and the role of #FullPhysiology.

Ischemia with non-obstructive coronary arteries (INOCA) is an increasingly recognized entity. It encompasses different pathophysiological subtypes (i.e., endotypes), including coronary microvascular dysfunction (CMD), vasospastic angina (VSA) and mixed entities resulting from the variable combination of both. Diagnosing INOCA and precisely characterizing the endotype allows for accurate medical treatment and has proven prognostic implications. A breadth of diagnostic technique is available, ranging from non-invasive approaches to invasive coronary angiography adjuvated by functional assessment and provocative tests. This review summarizes the strength and limitations of these methodologies and provides the rationale for the routine referral for invasive angiography and functional assessment in this subset of patients.

Endovascular embolization of a third jejunal artery aneurysm: isolation technique using the Amplatzer vascular plug 4.

Aneurysm of the jejunal artery (JA) is very uncommon with few specific symptoms, but can be a lethal entity. When at risk to rupture, it must be treated expeditiously to avoid mortality. We report a case of a 76-year-old male patient that underwent contrast-enhanced multi-detector computed tomography (MDCT) which incidentally reveals a 12 mm saccular aneurysm of the third JA at the bifurcation of the first arcade. Patient underwent successful endovascular embolization using the isolation technique with the Amplatzer Vascular Plug 4. The patient's recovery was unremarkable and he was discharged on postoperative day 5. Follow-up MDCT reveals total exclusion of the saccular aneurysm of the third jejunal artery with patency of the distal branches.

Supra-renal aortic atheroma extent and composition predict acute kidney injury after transcatheter aortic valve replacement: A three-dimensional computed tomography study.

OBJECTIVE: Acute kidney injury (AKI) may complicate transcatheter aortic valve replacement (TAVR) and could be linked to atheroembolization associated with catheter manipulation in the supra-renal (SR) aorta. We sought to determine the impact of SR aortic atheroma burden (SR-AAB) and composition, as well as of the aortic valve calcium score (AV-CS), measured at pre-operative multislice computed tomography (PO-MSCT), on AKI-TAVR. METHODS: All TAVR-patients 3 January-2018 to December-2020 were included. A three-dimensional analysis of PO-MSCT was performed, calculating percentage SR-AAB (%SR-AAB) as [(absolute SR-AAB volume)*100/vessel volume]. Types of plaque were defined according to Hounsfield unit (HU) intensity ranges. Calcified plaque was subcategorized into 3 strata: low- (351-700 HU), mid- (701-1000 HU), and high­calcium (>1000 HU, termed 1 K-plaque). RESULTS: The study population included 222 patients [mean age 83.3 ± 5.7 years, 95 (42.8%) males], AKI-TAVR occurred in 67/222 (30.2%). Absolute SR-AAB (41.3 ± 16.4 cm3 vs. 32.5 ± 10.7 cm3,p < 0.001) and %SR-AAB (17.6 ± 5.1% vs. 13.9 ± 4.3%,p < 0.001) were significantly higher in patients developing AKI-TAVR. Patients who developed AKI-TAVR had higher mid­calcium (6.9 ± 3.8% vs. 4.2 ± 3.5%,p < 0.001) and 1 K-plaque (5.4 ± 3.7% vs. 2.4 ± 2.4%,p < 0.001) with no difference in AV-CS (p = 0.691). Adjusted multivariable logistic regression analysis showed that %SR-AAB [OR (x%increase): 1.12, 95%CI: 1.04-1.22,p = 0.006] and %SR-calcified plaque [OR (x%increase): 5.60, 95%CI: 2.50-13.36,p < 0.001] were associated with AKI-TAVR. Finally, 3-knots spline analyses identified %SR-AAB >15.0% and %SR-calcified plaque >7.0% as optimal thresholds to predict an increased risk of AKI-TAVR. CONCLUSIONS: Suprarenal aortic atheroma, when highly calcified, is associated with AKI-TAVR. Perioperative-MSCT assessment of aortic atherosclerosis may help in identification of patients at high-risk for AKI-TAVR, who could benefit from higher peri-operative surveillance.

Intravenous Contrast Material for Cardiac Computed Tomography: Results From the Open-label Multicenter, Multivendor Italian Registry of Contrast Material Use in Cardiac Computed Tomography.

PURPOSE: The Italian Registry of Contrast Material use in Cardiac Computed Tomography (iRCM-CCT) is a multicenter, multivendor, observational study on the use of contrast media (CM) in patients undergoing cardiac computed tomography (CCT). The aim of iRCM-CCT is to assess image quality and safety profile of intravenous CM compounds. MATERIALS AND METHODS: iRCM-CCT enrolled 1842 consecutive patients undergoing CCT (≥50 per site) at 20 cluster sites with the indication of suspected coronary artery disease. Demographic characteristics, CCT, and CM protocols, clinical indications, safety markers, radiation dose reports, qualitative (ie, poor vascular enhancement) and quantitative (ie, HU attenuation values) image parameters were recorded. A centralized coordinating center collected and assessed all image parameters. RESULTS: The cohort included 891 men and 951 women (age: 63±14 y, body mass index: 26±4 kg/m2) studied with ≥64 detector rows computed tomography scanners and different iodinated intravenous CM protocols and compounds (iodixanol, iopamidol, iohexol, iobitridol, iopromide, and iomeprol). The following vascular attenuation was reported: 504±147 HU in the aorta, 451±146 HU in the right coronary artery, 474±146 HU in the left main, 451±146 HU in the left anterior descending artery, and 441±149 HU in the circumflex artery. In 4% of cases the image quality was not satisfactory due to poor enhancement. The following adverse reactions to CM were recorded: 6 (0.3%) extravasations and 17 (0.9%) reactions (11 mild, 4 moderate, 2 severe). CONCLUSIONS: In a multicenter registry on CM use during CCT the prevalence of CM-related adverse reactions was very low. The appropriate use of CM is a major determinant of image quality.

Nonocclusive mesenteric ischemia in a dialysis patient with extensive vascular calcification.

We describe a case of nonocclusive mesenteric ischemia in a 37-year-old man with hemodialysis-dependent chronic kidney disease due to diabetes who was admitted to our hospital with abdominal pain. A plain radiograph of the abdomen showed distended loops of small bowel and gas in the hepatic portal vein. Multidetector computed tomography showed massive wall calcification of the superior mesenteric artery and its collaterals, pneumatosis intestinalis of a segment of the jejunum, and porto-mesenteric vein gas. Urgent laparotomy confirmed segmental necrosis of the jejunum, which was resected. Pathologic examination showed whole-layer necrosis of the resected bowel without arterial or venous thrombosis. Nonocclusive mesenteric ischemia is an increasingly recognized and potentially lethal complication in hemodialysis patients. In the present case, critical factors for the development of nonocclusive mesenteric ischemia may have included prolonged hypotension during hemodialysis treatments that reduced blood flow to the small bowel and massive vascular calcification that negatively affected compliance of the superior mesenteric artery and its branches.

Left and right ventricle assessment with Cardiac CT: validation study vs. Cardiac MR.

OBJECTIVES: To compare Magnetic Resonance (MR) and Computed Tomography (CT) for the assessment of left (LV) and right (RV) ventricular functional parameters. METHODS: Seventy nine patients underwent both Cardiac CT and Cardiac MR. Images were acquired using short axis (SAX) reconstructions for CT and 2D cine b-SSFP (balanced-steady state free precession) SAX sequence for MR, and evaluated using dedicated software. RESULTS: CT and MR images showed good agreement: LV EF (Ejection Fraction) (52 ± 14% for CT vs. 52 ± 14% for MR; r = 0.73; p > 0.05); RV EF (47 ± 12% for CT vs. 47 ± 12% for MR; r = 0.74; p > 0.05); LV EDV (End Diastolic Volume) (74 ± 21 ml/m² for CT vs. 76 ± 25 ml/m² for MR; r = 0.59; p > 0.05); RV EDV (84 ± 25 ml/m² for CT vs. 80 ± 23 ml/m² for MR; r = 0.58; p > 0.05); LV ESV (End Systolic Volume)(37 ± 19 ml/m² for CT vs. 38 ± 23 ml/m² for MR; r = 0.76; p > 0.05); RV ESV (46 ± 21 ml/m² for CT vs. 43 ± 18 ml/m² for MR; r = 0.70; p > 0.05). Intra- and inter-observer variability were good, and the performance of CT was maintained for different EF subgroups. CONCLUSIONS: Cardiac CT provides accurate and reproducible LV and RV volume parameters compared with MR, and can be considered as a reliable alternative for patients who are not suitable to undergo MR. KEY POINTS: • Cardiac-CT is able to provide Left and Right Ventricular function. • Cardiac-CT is accurate as MR for LV and RV volume assessment. • Cardiac-CT can provide accurate evaluation of coronary arteries and LV and RV function.

Perforated Meckel's diverticulitis on the mesenteric side: MDCT findings.

Meckel's diverticulum (MD) is the most common congenital anomaly of the gastro-intestinal tract (approximately 2% of population), and arises from improper closure and absorption of the omphalomesenteric duct. Very few cases of Meckel's diverticulitis on the mesenteric side have been reported in the surgical literature, and no reported cases have been documented on preoperative imaging. We report a 65-year-old woman presenting symptoms and signs of acute abdomen with an initial suspicion of acute appendicitis. MDCT imaging revealed a mesenteric abscess in the right lower quadrant at the level of the distal ileum as a complication of Meckel's diverticulitis on the mesenteric side. The patient recovered after a diverticulectomy without the need for a small bowel resection. This case demonstrates that MDCT is a fast imaging technique that may be helpful in the emergency setting for the preoperative diagnosis of an unusual complicated MD on the mesenteric side.

Prognostic Value of Coronary Calcium Score in Asymptomatic Individuals: A Systematic Review.

Despite updated guidelines and technological developments that allow for an accurate diagnosis, many asymptomatic individuals have a high risk of developing CAD or cardiac events. The CAC score can estimate a correct risk level for these subjects, which is clinically significant for adequate management of risk factors and obtaining personalized preventive therapy. This systematic review aims to assess the prognostic value of CAC score in asymptomatic individuals. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a systematic literature search was performed to identify original articles since 2010 that evaluated the prognostic value of CAC score in asymptomatic individuals. The quality of the included studies was assessed by the QUIPS tool. A total of 45 articles were selected. Many of these (25 studies) evaluated the prognostic value of CAC score in asymptomatic subjects. In comparison, others (20 studies) evaluated the association of CAC score with other clinical parameters and imaging modalities or the comparison with computed tomography coronary angiography (CTCA). Our findings showed that the CAC score provides valuable prognostic information for predicting CAD risk in asymptomatic individuals.

Early versus late intubation in COVID-19 patients failing helmet CPAP: A quantitative computed tomography study.

PURPOSE: To describe the effects of timing of intubation in COVID-19 patients that fail helmet continuous positive airway pressure (h-CPAP) on progression and severity of disease. METHODS: COVID-19 patients that failed h-CPAP, required intubation, and underwent chest computed tomography (CT) at two levels of positive end-expiratory pressure (PEEP, 8 and 16 cmH2O) were included in this retrospective study. Patients were divided in two groups (early versus late) based on the duration of h-CPAP before intubation. Endpoints included percentage of non-aerated lung tissue at PEEP of 8 cmH2O, respiratory system compliance and oxygenation. RESULTS: Fifty-two patients were included and classified in early (h-CPAP for ≤2 days, N = 26) and late groups (h-CPAP for >2 days, N = 26). Patients in the late compared to early intubation group presented: 1) lower respiratory system compliance (median difference, MD -7 mL/cmH2O, p = 0.044) and PaO2/FiO2 (MD -29 mmHg, p = 0.047), 2) higher percentage of non-aerated lung tissue (MD 7.2%, p = 0.023) and 3) similar lung recruitment increasing PEEP from 8 to 16 cmH2O (MD 0.1%, p = 0.964). CONCLUSIONS: In COVID-19 patients receiving h-CPAP, late intubation was associated with worse clinical presentation at ICU admission and more advanced disease. The possible detrimental effects of delaying intubation should be carefully considered in these patients.