Yuichi Higami

A Mixed Phenotype of Airway Wall Thickening and Emphysema Is Associated with Dyspnea and Hospitalization for Chronic Obstructive Pulmonary Disease

RATIONALE Quantitative computed tomography (CT) has been used to phenotype patients with chronic obstructive pulmonary disease (COPD). A mixed phenotype is defined as the presence of both airway wall thickening and emphysema on quantitative CT. Little is known about patients with COPD with the mixed phenotype. OBJECTIVES To propose a method of phenotyping COPD based on quantitative CT and to compare clinically relevant outcomes between patients with COPD with the mixed phenotype and those with other CT-based phenotypes. METHODS Each of 427 male smokers (187 without COPD, 240 with COPD) underwent a complete medical interview, pulmonary function testing, and whole-lung CT on the same day. The percentage of low-attenuation volume at the threshold of -950 Hounsfield units (%LAV) and the square root of wall area of a hypothetical airway with an internal perimeter of 10 mm (Pi10) were measured. Patients with COPD were classified into four distinct phenotypes based on the upper limits of normal for %LAV and Pi10, which were derived from the data of smokers without COPD by using quantile regression. MEASUREMENTS AND MAIN RESULTS Of 240 patients with COPD, 52 (21.7%) were classified as CT-normal phenotype, 39 (16.3%) as airway-dominant phenotype, 103 (42.9%) as emphysema-dominant phenotype, and 46 (19.2%) as mixed phenotype. Patients with COPD with the mixed phenotype were associated with more severe dyspnea than those with each of the remaining CT-based phenotypes (P < 0.01 for all comparisons). The number of hospitalizations for COPD exacerbations during the preceding year was 2.0 to 3.6 times higher in patients with the mixed phenotype than in those with each of the remaining CT-based phenotypes (P < 0.05 for all comparisons). Findings persisted after adjustment for age, pack-years of smoking, smoking status, body mass index, and FEV1. CONCLUSIONS Patients with COPD with the mixed phenotype are associated with more severe dyspnea and more frequent hospitalizations than those with each of the remaining CT-based phenotypes. Thus, patients with COPD with the mixed phenotype may need more attention and interventions.

Airway wall area derived from 3-dimensional computed tomography analysis differs among lung lobes in male smokers.

Background It is time-consuming to obtain the square root of airway wall area of the hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10), a comparable index of airway dimensions in chronic obstructive pulmonary disease (COPD), from all airways of the whole lungs using 3-dimensional computed tomography (CT) analysis. We hypothesized that √Aaw at Pi10 differs among the five lung lobes and √Aaw at Pi10 derived from one certain lung lobe has a high level of agreement with that derived from the whole lungs in smokers. Methods Pulmonary function tests and chest volumetric CTs were performed in 157 male smokers (102 COPD, 55 non-COPD). All visible bronchial segments from the 3rd to 5th generations were segmented and measured using commercially available 3-dimensional CT analysis software. √Aaw at Pi10 of each lung lobe was estimated from all measurable bronchial segments of that lobe. Results Using a mixed-effects model, √Aaw at Pi10 differed significantly among the five lung lobes (R2 = 0.78, P<0.0001). The Bland-Altman plots show that √Aaw at Pi10 derived from the right or left upper lobe had a high level of agreement with that derived from the whole lungs, while √Aaw at Pi10 derived from the right or left lower lobe did not. Conclusion In male smokers, CT-derived airway wall area differs among the five lung lobes, and airway wall area derived from the right or left upper lobe is representative of the whole lungs.

Pulmonary Tumor Thrombotic Microangiopathy Induced by Ureteral Carcinoma: A Necropsy Case Report

Background: Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal cancer-related pulmonary complication with rapidly progressing dyspnea and pulmonary hypertension that occasionally induces sudden death. We report the first case of PTTM induced by ureter carcinoma. Case Presentation: The patient was an 80-year-old Japanese female with chief complaints of dry cough and dyspnea. An echocardiogram revealed severe pulmonary hypertension. A chest radiograph showed ground glass opacity of bilateral lower lung field predominance, and an abdominal computed tomography scan revealed a left ureter mass suggestive of ureter carcinoma. The patient died of respiratory failure on the eighth day of hospitalization. Postmortem examination indicated that the primary lesion was a left ureter cancer with tumor microemboli extending to both lungs through the right side of the heart. The final diagnosis of this case was PTTM induced by ureter carcinoma. Conclusion: The pathogenesis and pathophysiology of PTTM remains obscure with no effective management available. In cases of rapidly progressing respiratory failure with pulmonary hypertension, it is necessary to consider PTTM in the differential diagnosis.

Acute cerebral arterial embolism following pemetrexed and carboplatin treatment in non-small-cell lung cancer: A case report.

Thromboembolism is a known vascular toxicity associated with tumor chemotherapy. The combination of pemetrexed and carboplatin has exhibited significant antitumor activity, with mild manageable toxicity in patients with advanced non-small-cell lung cancer (NSCLC), whereas cerebral arterial embolism has not been recognized as a side effect associated with this regimen. This is the case report of an unusual case of NSCLC, in which the patient suffered a left middle cerebral arterial embolism following chemotherapy. A 62-year-old non-smoking woman, diagnosed with stage IV lung adenocarcinoma, was administered pemetrexed and carboplatin as second-line therapy. On the day of the completion of the first regime cycle, the patient was readmitted to the emergency department with complaints of sudden-onset right hemiplegia and agitation. Brain magnetic resonance imaging and magnetic resonance angiography revealed an occlusion of the left middle cerebral artery (MCA) and no further chemotherapy was administered due to the deterioration in the performance status of the patient associated with right hemiplegia. Pemetrexed plus carboplatin is routinely used for the treatment of advanced NSCLC. The present case highlights the potential risk for development of embolism following pemetrexed-based chemotherapy. Further investigations are required to elucidate the mechanism through which these drugs may eventually cause neurovascular adverse events. Clinicians should be aware of the potential risk for development of cerebral arterial embolism following pemetrexed-based chemotherapy.

Increased Epicardial Adipose Tissue Is Associated with the Airway Dominant Phenotype of Chronic Obstructive Pulmonary Disease

Background Epicardial adipose tissue (EAT) has been shown to be a non-invasive marker that predicts the progression of cardiovascular disease (CVD). It has been reported that the EAT volume is increased in patients with chronic obstructive pulmonary disease (COPD). However, little is known about which phenotypes of COPD are associated with increased EAT. Methods One hundred and eighty smokers who were referred to the clinic were consecutively enrolled. A chest CT was used for the quantification of the emphysematous lesions, airway lesions, and EAT. These lesions were assessed as the percentage of low attenuation volume (LAV%), the square root of airway wall area of a hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10) and the EAT area, respectively. The same measurements were made on 225 Vietnamese COPD patients to replicate the results. Results Twenty-six of the referred patients did not have COPD, while 105 were diagnosed as having COPD based on a FEV1/FVC<0.70. The EAT area was significantly associated with age, BMI, FEV1 (%predicted), FEV1/FVC, self-reported hypertension, self-reported CVD, statin use, LAV%, and √Aaw at Pi10 in COPD patients. The multiple regression analyses showed that only BMI, self-reported CVD and √Aaw at Pi10 were independently associated with the EAT area (R2 = 0.51, p<0.0001). These results were replicated in the Vietnamese population. Conclusions The EAT area is independently associated with airway wall thickness. Because EAT is also an independent predictor of CVD risk, these data suggest a mechanistic link between the airway predominant form of COPD and CVD.