256 Impact of physiologically diffuse vs. focal pattern of coronary disease on quantitative flow reserve diagnostic accuracy

Aims Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) disagree in ∼20% of intermediate coronary lesions. The physiological pattern of disease has a significant influence on FFR-iFR discordance. However, if the pattern of disease (diffuse vs. focal) impacts on QFR accuracy and on its agreement with FFR and iFR remains unknown. Methods and results 194 unselected patients with 224 intermediate coronary lesions were investigated with iFR, FFR and QFR. The physiological pattern of disease was independently assessed with iFR Scout pullback in all the cases by two expert interventional cardiologists who were blinded to the clinical presentation, patient characteristics, coronary angiography and QFR results. A predominantly physiologically focal pattern was observed in 81 (36.2%) lesions, whereas a predominantly physiologically diffuse was observed in 143 (63.8%) cases. QFR demonstrated a significant correlation (r = 0.581, P < 0.001) and a substantial agreement with iFR, both in diffuse (AUC = 0.798) and in focal (AUC = 0.812) pattern of disease. Disagreement between QFR and iFR was observed in 51 (22.8%) lesions, consisting of iFR+/QFR − (64.7%) and iFR−/QFR + (35.3%). Notably, the physiological pattern of disease was the only variable significantly associated with iFR/QFR disagreement. In particular, coronary lesions with iFR+/QFR− demonstrated a significantly higher prevalence of predominantly physiologically diffuse pattern of disease compared with the subgroup with iFR−/QFR + [81.3% (26 of 32) vs. 55.6% (10 of 18); P = 0.012]. QFR virtual pullback demonstrated an excellent agreement (83.9%) with iFR Scout pullback in classifying the physiological pattern of disease. Conclusions QFR has a good diagnostic accuracy in assessing myocardial ischemia independently of the pattern of coronary disease. However, the physiological pattern of disease has an influence on the QFR/IFR disagreement, which occurs in ∼20% of the cases. The QFR virtual pullback correctly defined the physiological pattern of disease in the majority of the cases using the iFR pullback as reference.

Radiological pattern in ARDS patients: partitioned respiratory mechanics, gas exchange and lung recruitability

Background The ARDS is characterized by different degrees of impairment in oxygenation and distribution of the lung disease. Two radiological patterns have been described: a focal and a diffuse one. These two patterns could present significant differences both in gas exchange and in the response to a recruitment maneuver. At the present time, it is not known if the focal and the diffuse pattern could be characterized by a difference in the lung and chest wall mechanical characteristics. Our aims were to investigate, at two levels of PEEP, if focal vs. diffuse ARDS patterns could be characterized by different lung CT characteristics, partitioned respiratory mechanics and lung recruitability. Methods CT patterns were analyzed by two radiologists and were classified as focal or diffuse. The changes from 5 to 15 cmH2O in blood gas analysis and partitioned respiratory mechanics were analyzed. Lung CT scan was performed at 5 and 45 cmH2O of PEEP to evaluate lung recruitability. Results One-hundred and ten patients showed a diffuse pattern, while 58 showed a focal pattern. At 5 cmH2O of PEEP, the driving pressure and the elastance, both the respiratory system and of the lung, were significantly higher in the diffuse pattern compared to the focal (14 [11–16] vs 11 [9–15 cmH2O; 28 [23–34] vs 21 [17–27] cmH2O/L; 22 [17–28] vs 14 [12–19] cmH2O/L). By increasing PEEP, the driving pressure and the respiratory system elastance significantly decreased in diffuse pattern, while they increased or did not change in the focal pattern (Δ15-5: − 1 [− 2 to 1] vs 0 [− 1 to 2]; − 1 [− 4 to 2] vs 1 [− 2 to 5]). At 5 cmH2O of PEEP, the diffuse pattern had a lower lung gas (743 [537–984] vs 1222 [918–1974] mL) and higher lung weight (1618 [1388–2001] vs 1222 [1059–1394] g) compared to focal pattern. The lung recruitability was significantly higher in diffuse compared to focal pattern 21% [13–29] vs 11% [6–16]. Considering the median of lung recruitability of the whole population (16.1%), the recruiters were 65% and 22% in the diffuse and focal pattern, respectively. Conclusions An early identification of lung morphology can be useful to choose the ventilatory setting. A diffuse pattern has a better response to the increase of PEEP and to the recruitment maneuver.

A hybrid therapy for arrhythmogenic congestive cavity in a single ventricle

We describe a 15-year-old girl who underwent intraoperative catheter ablation for the ventricular tachycardia associated with Ebstein’s anomaly with functional pulmonary atresia and a small right ventricle (RV) after Fontan surgery. The computed tomography showed the dilated right atrium and RV due to the failure of RV plication. The activation mapping revealed that the ventricular tachycardia showed a focal pattern originating from the atrialized RV (aRV). With careful preparations, the procedure of catheter ablation combined with the adjustment of Starnes fenestration and plication of RV/atrialized RV was very effective for this patient.

Evidence-Based Data About Prevalence and Risk of Malignancy of Thyroid Incidentalomas Detected by Different PET Radiopharmaceuticals

Background: To date, several meta-analyses and systematic reviews have reported data about the prevalence and risk of malignancy of thyroid incidentalomas detected by different PET radiopharmaceuticals. Objective: This article aims to summarize the published evidence-based data about the prevalence and risk of malignancy of thyroid incidentalomas detected by different PET radiopharmaceuticals. Methods: A comprehensive computer literature search of systematic reviews and meta-analyses published up to July 2019 in PubMed/MEDLINE and Cochrane library databases regarding the prevalence and risk of malignancy of thyroid incidentalomas detected by different PET radiopharmaceuticals was carried out. Results: We have summarized the data about prevalence and risk of malignancy of thyroid incidentalomas detected by different PET radiopharmaceuticals (fluorine-18 fluorodeoxyglucose, radiolabelled choline and prostate-specific membrane antigen) taking into account 8 evidence-based articles. Conclusion: Evidence-based data demonstrated that thyroid incidentalomas detected by different PET radiopharmaceuticals are not infrequent and their risk of malignancy is not negligible, in particular if focal pattern is evident at PET, thus requiring further clinical and instrumental evaluation.

Acute Respiratory Distress Syndrome Phenotypes

The acute respiratory distress syndrome (ARDS) phenotype was first described over 50 years ago and since that time significant progress has been made in understanding the biologic processes underlying the syndrome. Despite this improved understanding, no pharmacologic therapies aimed at the underlying biology have been proven effective in ARDS. Increasingly, ARDS has been recognized as a heterogeneous syndrome characterized by subphenotypes with distinct clinical, radiographic, and biologic differences, distinct outcomes, and potentially distinct responses to therapy. The Berlin Definition of ARDS specifies three severity classifications: mild, moderate, and severe based on the PaO2 to FiO2 ratio. Two randomized controlled trials have demonstrated a potential benefit to prone positioning and neuromuscular blockade in moderate to severe phenotypes of ARDS only. Precipitating risk factor, direct versus indirect lung injury, and timing of ARDS onset can determine other clinical phenotypes of ARDS after admission. Radiographic phenotypes of ARDS have been described based on a diffuse versus focal pattern of infiltrates on chest imaging. Finally and most promisingly, biologic subphenotypes or endotypes have increasingly been identified using plasma biomarkers, genetics, and unbiased approaches such as latent class analysis. The potential of precision medicine lies in identifying novel therapeutics aimed at ARDS biology and the subpopulation within ARDS most likely to respond. In this review, we discuss the challenges and approaches to subphenotype ARDS into clinical, radiologic, severity, and biologic phenotypes with an eye toward the future of precision medicine in critical care.