Ventilator-Associated Pneumonia in Patients with COVID-19: A Systematic Review and Meta-Analysis.

The aim of this systematic review and meta-analysis was to estimate the pooled occurrence of ventilator-associated pneumonia (VAP) among patients admitted to an intensive care unit with COVID-19 and mortality of those who developed VAP. We performed a systematic search on PubMed, EMBASE and Web of Science from inception to 2nd March 2021 for nonrandomized studies specifically addressing VAP in adult patients with COVID-19 and reporting data on at least one primary outcome of interest. Random effect single-arm meta-analysis was performed for the occurrence of VAP and mortality (at the longest follow up) and ICU length of stay. Twenty studies were included in the systematic review and meta-analysis, for a total of 2611 patients with at least one episode of VAP. The pooled estimated occurrence of VAP was of 45.4% (95% C.I. 37.8-53.2%; 2611/5593 patients; I2 = 96%). The pooled estimated occurrence of mortality was 42.7% (95% C.I. 34-51.7%; 371/946 patients; I2 = 82%). The estimated summary estimated metric mean ICU LOS was 28.58 days (95% C.I. 21.4-35.8; I2 = 98%). Sensitivity analysis showed that patients with COVID-19 may have a higher risk of developing VAP than patients without COVID-19 (OR 3.24; 95% C.I. 2.2-4.7; P = 0.015; I2 = 67.7%; five studies with a comparison group).

CT Perfusion Versus Coronary CT Angiography in Patients With Suspected In-Stent Restenosis or CAD Progression.

OBJECTIVES: The goal of this study was to assess the diagnostic performance of coronary computed tomography angiography (CTA) alone, adenosine-stress myocardial perfusion assessed by computed tomography (CTP) alone, and coronary CTA + CTP by using a 16-cm Z-axis coverage scanner versus invasive coronary angiography (ICA) and fractional flow reserve (FFR) as the clinical standard. BACKGROUND: Diagnostic performance of coronary CTA for in-stent restenosis detection is still challenging. Recently, CTP showed additional diagnostic power over coronary CTA in patients with suspected coronary artery disease. However, few data are available on CTP performance in patients with previous stent implantation. METHODS: Consecutive stable patients with previous coronary stenting referred for ICA were enrolled. All patients underwent stress myocardial CTP and rest CTP + coronary CTA. Invasive FFR was performed during ICA when clinically indicated. The diagnostic rate and diagnostic accuracy of coronary CTA, CTP, and coronary CTA + CTP were evaluated in stent-, territory-, and patient-based analyses. RESULTS: In the 150 enrolled patients (132 men; mean age 65.1 ± 9.1 years), the CTP diagnostic rate was significantly higher than that of coronary CTA in all analyses (territory based [96.7% vs. 91.1%; p < 0.0001] and patient based [96% vs. 68%; p < 0.0001]). When ICA was used as gold standard, CTP diagnostic accuracy was significantly higher than that of coronary CTA in all analyses (territory based [92.1% vs. 85.5%, p < 0.03] and patient based [86.7% vs. 76.7%, p < 0.03]). The concordant coronary CTA + CTP assessment exhibited the highest diagnostic accuracy values versus ICA (95.8% in the territory-based analysis). The diagnostic accuracy of CTP was significantly higher than that of coronary CTA (75% vs. 30.5%; p < 0.001). The radiation exposure of coronary CTA + CTP was 4.15 ± 1.5 mSv. CONCLUSIONS: In patients with coronary stents, CTP significantly improved the diagnostic rate and accuracy of coronary CTA alone compared with both ICA and invasive FFR as gold standard.

Interpretability of coronary CT angiography performed with a novel whole-heart coverage high-definition CT scanner in 300 consecutive patients with coronary artery bypass grafts.

AIMS: Coronary CT angiography (CCTA) is an accurate non-invasive tool for the evaluation of coronary artery bypass graft (CABG). However, inability to sustain a long breath-hold, high heart rate (HR) and atrial fibrillation may affect image quality. Moreover, radiation exposure is still a matter of some concern. A scanner combining 0.23-mm spatial resolution, new iterative reconstruction and fast gantry rotation time has been recently introduced in the clinical field. The aims of our study were to evaluate interpretability, radiation exposure and diagnostic accuracy of CCTA performed with the latest generation of cardiac-CT scanners compared to invasive coronary angiography (ICA) in the assessment of bypass grafts, and non-grafted and post-anastomotic native coronary arteries. METHODS AND RESULTS: We prospectively enrolled 300 patients undergoing clinically indicated CCTA with a 16-cm z-axis coverage, 256-detector rows, and 0.28-sec gantry rotation time scanner. Coronary artery and graft interpretability, image quality and effective dose (ED) were assessed in all patients and diagnostic accuracy was evaluated in a subgroup of 100 patients who underwent ICA. Mean HR during the scan was 69.6 ±â€¯10.8. Sinus rhythm was present in 118 patients with HR < 75 bpm and in 112 patients with HR ≥ 75 bpm, while 70 patients had atrial fibrillation. CABG interpretability was 100%. Compared to ICA, CCTA was able to correctly detecting occlusions or significant stenoses of all CABG segments. Overall interpretability of native coronary segments was 95.6%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of coronary arteries were 98.3%, 97.4%, 93.1%, 99.3% and 96.5%, respectively. The diagnostic accuracy in a patient based analysis was 95.2%. Mean ED was 3.14 ±â€¯1.7 mSv. CONCLUSIONS: The novel whole-heart coverage CT scanner allows to evaluating CABG and native coronary arteries with excellent interpretability and low radiation exposure even in the presence of unfavorable heart rhythm.

Low-Dose Coronary CT Angiography in Patients with Atrial Fibrillation: Comparison of Image Quality and Radiation Exposure with Two Different Approaches.

RATIONALE AND OBJECTIVES: To evaluate image quality, coronary interpretability and radiation exposure of coronary CT angiography (CCTA) performed in patients with atrial fibrillation (AF) with the latest scanner generation, comparing two different technical approaches. A new scanner that combines a 0.23 mm spatial resolution, a new generation of iterative reconstruction, fast gantry rotation time and the intracycle motion-correction algorithm to improve the temporal resolution was recently introduced in the clinical field. MATERIALS AND METHODS: We enrolled 105 consecutive patients with chronic AF who performed CCTA with a whole-heart coverage high-definition CT scanner (16-cm z-axis coverage with 256 detector rows, 0.28 s gantry rotation time). Five of them were excluded for impaired renal function. Patients were randomized between a double acquisition protocol (50 patients, group 1) or a single acquisition protocol (50 patients, group 2). The image quality, coronary segment interpretability and effective dose (ED) of CCTA were assessed. RESULTS: The mean HR during the scan was 85.6±21 bpm in group 1 vs. 83.7±23 bpm in Group 2, respectively (p < ns). In group 2, overall image quality was high and comparable with that of group 1 (Likert scale =3.2 ± 1.4 vs. 3.3 ± 1.2, p = ns, in group 1 and 2, respectively). Coronary interpretability was high and similar between the two groups (97.5% and 97.1% in group 1 and 2, p = ns, respectively). Mean ED was significantly higher in group 1 than in group 2 (5.3 ± 1.8 mSv vs. 2.7 ± 0.7 mSv, p < 0.001). CONCLUSION: The novel whole-heart coverage CT scanner allows to perform CCTA with a single-acquisition protocol with high image quality and low radiation exposure in AF patients.

Rationale and design of advantage (additional diagnostic value of CT perfusion over coronary CT angiography in stented patients with suspected in-stent restenosis or coronary artery disease progression) prospective study.

BACKGROUND: Recent studies demonstrated a significant improvement in the diagnostic performance of coronary CT angiography (CCTA) for the evaluation of in-stent restenosis (ISR). However, coronary stent assessment is still challenging, especially because of beam-hardening artifacts due to metallic stent struts and high atherosclerotic burden of non-stented segments. Adenosine-stress myocardial perfusion assessed by CT (CTP) recently demonstrated to be a feasible and accurate tool for evaluating the functional significance of coronary stenoses in patients with suspected coronary artery disease (CAD). Yet, scarce data are available on the performance of CTP in patients with previous stent implantation. AIM OF THE STUDY: We aim to assess the diagnostic performance of CCTA alone, CTP alone and CCTA plus CTP performed with a new scanner generation using quantitative invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR) as standard of reference. METHODS: We will enroll 300 consecutive patients with previous stent implantation, referred for non-emergent and clinically indicated invasive coronary angiography (ICA) due to suspected ISR or progression of CAD in native coronary segments. All patients will be subjected to stress myocardial CTP and a rest CCTA. The first 150 subjects will undergo static CTP scan, while the following 150 patients will undergo dynamic CTP scan. Measurement of invasive FFR will be performed during ICA when clinically indicated. RESULTS: The primary study end points will be: 1) assessment of the diagnostic performance (diagnostic rate, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy) of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. ICA as standard of reference in a territory-based and patient-based analysis; 2) assessment of sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. invasive FFR as standard of reference in a territory-based analysis. CONCLUSIONS: The ADVANTAGE study aims to provide an answer to the intriguing question whether the combined anatomical and functional assessment with CCTA plus CTP may have higher diagnostic performance as compared to CCTA alone in identifying stented patients with significant ISR or CAD progression.

Impact of a New Adaptive Statistical Iterative Reconstruction (ASIR)-V Algorithm on Image Quality in Coronary Computed Tomography Angiography.

RATIONALE AND OBJECTIVES: A new postprocessing algorithm named adaptive statistical iterative reconstruction (ASIR)-V has been recently introduced. The aim of this article was to analyze the impact of ASIR-V algorithm on signal, noise, and image quality of coronary computed tomography angiography. MATERIALS AND METHODS: Fifty consecutive patients underwent clinically indicated coronary computed tomography angiography (Revolution CT; GE Healthcare, Milwaukee, WI). Images were reconstructed using filtered back projection and ASIR-V 0%, and a combination of filtered back projection and ASIR-V 20%-80% and ASIR-V 100%. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for left main coronary artery (LM), left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA) and were compared between the different postprocessing algorithms used. Similarly a four-point Likert image quality score of coronary segments was graded for each dataset and compared. A cutoff value of P < .05 was considered statistically significant. RESULTS: Compared to ASIR-V 0%, ASIR-V 100% demonstrated a significant reduction of image noise in all coronaries (P < .01). Compared to ASIR-V 0%, SNR was significantly higher with ASIR-V 60% in LM (P < .01), LAD (P < .05), LCX (P < .05), and RCA (P < .01). Compared to ASIR-V 0%, CNR for ASIR-V ≥60% was significantly improved in LM (P < .01), LAD (P < .05), and RCA (P < .01), whereas LCX demonstrated a significant improvement with ASIR-V ≥80%. ASIR-V 60% had significantly better Likert image quality scores compared to ASIR-V 0% in segment-, vessel-, and patient-based analyses (P < .01). CONCLUSIONS: Reconstruction with ASIR-V 60% provides the optimal balance between image noise, SNR, CNR, and image quality.

Image Quality, Overall Evaluability, and Effective Radiation Dose of Coronary Computed Tomography Angiography With Prospective Electrocardiographic Triggering Plus Intracycle Motion Correction Algorithm in Patients With a Heart Rate Over 65 Beats Per Minute.

PURPOSE: Recently, a new intracycle motion correction algorithm (MCA) was introduced to reduce motion artifacts from heart rate (HR) in coronary computed tomography angiography (cCTA). The aim of the study was to evaluate the image quality, overall evaluability, and effective radiation dose (ED) of cCTA with prospective electrocardiographic (ECG) triggering plus MCA as compared with standard protocol with retrospective ECG triggering in patients with HR≥65 bpm. MATERIALS AND METHODS: One hundred consecutive patients (67±10 y) scheduled for cCTA with 65