Determination of the Optimal Measurement Point for Fractional Flow Reserve Derived From CTA Using Pressure Wire Assessment as Reference.

BACKGROUND. For clinical decision making, it was recently recommended that values of fractional flow reserve (FFR) derived from coronary CTA (FFRCT) be measured 1-2 cm distal to the stenosis, given the potential for overestimation of ischemia when FFRCT values at far distal segments are used. Supporting data are, however, lacking. OBJECTIVE. The purpose of the present study was to evaluate the diagnostic performance of FFRCT values measured 1-2 cm distal to the stenosis and at more distal locations relative to invasive FFR values. METHODS. FFRCT and invasive FFR values for 365 vessels in 253 patients identified from the Assessing Diagnostic Value of Noninvasive FFRCT in Coronary Care (ADVANCE) registry were prospectively assessed. FFRCT values were measured 1-2 cm distal to the stenosis and at the pressure wire position and far distal segments. The diagnostic accuracy of FFRCT was assessed on the basis of the ROC AUC. The AUC of FFRCT was calculated using FFRCT as an explanatory variable and an invasive FFR of 0.80 or less as the dichotomous dependent variable. RESULTS. The AUC of FFRCT values measured 1-2 cm distal to the stenosis (0.85; 95% CI, 0.80-0.88) was higher (p = .002) than that of FFRCT values measured at far distal segments (0.80; 95% CI, 0.76-0.84) and similar (p = .16) to that of FFRCT values measured at the pressure wire position (0.86; 95% CI, 0.81-0.89). FFRCT values measured 1-2 cm distal to the stenosis and at far distal segments had sensitivity of 87% versus 92% (p = .003), specificity of 73% versus 42% (p < .001), PPV of 75% versus 59% (p < .001), and NPV of 86% versus 85% (p = .72), respectively. Subgroup analyses of lesions of the left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery all showed improved specificity and PPV (all p < .005) for FFRCT values measured 1-2 cm distal to the stenosis compared with values measured at the pressure wire position. However, the AUC was higher for measurements obtained 1-2 cm distal to the stenosis versus those obtained at far distal segments, for left anterior descending coronary artery lesions (p < .001) but not for left circumflex coronary artery lesions (p = .27) or right coronary artery lesions (p = .91). CONCLUSION. The diagnostic performance of FFRCT values measured 1-2 cm distal to the stenosis was higher than that of FFRCT values measured at far distal segments and was similar to that of FFRCT values measured at the pressure wire position in evaluating ischemic status, particularly for left anterior descending coronary artery lesions. CLINICAL IMPACT. The present study supports recent recommendations from experts to use FFRCT measured 1-2 cm distal to the stenosis, rather than measurements obtained at far distal segments, in clinical decision making.

QFR Versus FFR Derived From Computed Tomography for Functional Assessment of Coronary Artery Stenosis.

OBJECTIVES: The aim of this study was to compare diagnostic performance between quantitative flow ratio (QFR) derived from coronary angiography and fractional flow reserve derived from computed tomography (FFRCT) using fractional flow reserve (FFR) as the reference standard. BACKGROUND: QFR and FFRCT are recently developed, less invasive techniques for functional assessment of coronary artery disease. METHODS: QFR, FFRCT, and FFR were measured in 152 patients (233 vessels) with stable coronary artery disease. RESULTS: QFR was highly correlated with FFR (r = 0.78; p < 0.001), whereas FFRCT was moderately correlated with FFR (r = 0.63; p < 0.001). Both QFR and FFRCT showed moderately good agreement with FFR, presenting small values of mean difference but large values of root mean squared deviation (FFR-QFR, 0.02 ± 0.09; FFR-FFRCT, 0.03 ± 0.11). The sensitivity, specificity, positive predictive value, and negative predictive value of QFR ≤0.80 for predicting FFR ≤0.80 were 90%, 82%, 81%, and 90%, respectively. Those of FFRCT ≤0.80 for predicting FFR ≤0.80 were 82%, 70%, 70%, and 82%, respectively. The diagnostic accuracy of QFR ≤0.80 for predicting FFR ≤0.80 was 85% (95% confidence interval [CI]: 81% to 89%), whereas that of FFRCT ≤0.80 for predicting FFR ≤0.80 was 76% (95% CI: 70% to 80%). CONCLUSIONS: QFR and FFRCT showed significant correlation with FFR. Mismatches between QFR and FFR and between FFRCT and FFR were frequent.

Pulmonary strongyloidiasis: assessment between manifestation and radiological findings in 16 severe strongyloidiasis cases.

BACKGROUND: Strongyloidiasis is a chronic parasitic infection caused by Strongyloides stercoralis. Severe cases such as, hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), can involve pulmonary manifestations. These manifestations frequently aid the diagnosis of strongyloidiasis. Here, we present the pulmonary manifestations and radiological findings of severe strongyloidiasis. METHODS: From January 2004 to December 2014, all patients diagnosed with severe strongyloidiasis at the University of the Ryukyus Hospital or affiliated hospitals in Okinawa, Japan, were included in this retrospective study. All diagnoses were confirmed by the microscopic or histopathological identification of larvae. Severe strongyloidiasis was defined by the presence of any of the following: 1) the identification of S. stercoralis from extra gastrointestinal specimens, 2) sepsis, 3) meningitis, 4) acute respiratory failure, or 5) respiratory tract hemorrhage. Patients were assigned to either HS or DS. Medical records were further reviewed to extract related clinical features and radiological findings. RESULTS: Sixteen severe strongyloidiasis cases were included. Of those, fifteen cases had pulmonary manifestations, eight had acute respiratory distress syndrome (ARDS) (53%), seven had enteric bacterial pneumonia (46%) and five had pulmonary hemorrhage (33%). Acute respiratory failure was a common indicator for pulmonary manifestation (87%). Chest X-ray findings frequently showed diffuse shadows (71%). Additionally, ileum gas was detected for ten of the sixteen cases in the upper abdomen during assessment with chest X-ray. While, chest CT findings frequently showed ground-glass opacity (GGO) in 89% of patients. Interlobular septal thickening was also frequently shown (67%), always accompanying GGO in upper lobes. CONCLUSIONS: In summary, our study described HS/DS cases with pulmonary manifestations including, ARDS, bacterial pneumonia and pulmonary hemorrhage. Chest X-ray findings in HS/DS cases frequently showed diffuse shadows, and the combination of GGO and interlobular septal thickening in chest CT was common in HS/DS, regardless of accompanying pulmonary manifestations. This CT finding suggests alveolar hemorrhage could be used as a potential marker indicating the transition from latent to symptomatic state. Respiratory specimens are especially useful for detecting larvae in cases of HS/DS.