Emphysema on Thoracic CT and Exercise Ventilatory Inefficiency in Mild-to-Moderate COPD.

There is growing evidence that emphysema on thoracic computed tomography (CT) is associated with poor exercise tolerance in COPD patients with only mild-to-moderate airflow obstruction. We hypothesized that an excessive ventilatory response to exercise (ventilatory inefficiency) would underlie these abnormalities. In a prospective study, 19 patients (FEV1 = 82 ± 13%, 12 Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 1) and 26 controls underwent an incremental exercise test. Ventilatory inefficiency was assessed by the ventilation ([Formula: see text]E)/CO2 output ([Formula: see text]CO2) nadir. Pulmonary blood flow (PBF) in a submaximal test was calculated by inert gas rebreathing. Emphysema was quantified as % of attenuation areas below 950 HU. Patients typically presented with centrilobular emphysema (76.8 ± 10.1% of total emphysema) in the upper lobes (upper/total lung ratio = 0.82 ± 0.04). They had lower peak oxygen uptake ([Formula: see text]O2), higher [Formula: see text]E/[Formula: see text]CO2 nadir, and greater dyspnea scores than controls (p < 0.05). Lower peak [Formula: see text]O2 and worse dyspnea were found in patients with higher [Formula: see text]E/[Formula: see text]CO2 nadirs (≥30). Patients had blunted increases in PBF from rest to iso-[Formula: see text]O2 exercise (p < 0.05). Higher [Formula: see text]E/[Formula: see text]CO2 nadir in COPD was associated with emphysema severity (r = 0.63) which, in turn, was related to reduced lung diffusing capacity (r = -0.72) and blunted changes in PBF from rest to exercise (r = -0.69) (p < 0.01). Ventilation "wasted" in emphysematous areas is associated with impaired exercise ventilatory efficiency in mild-to-moderate COPD. Exercise ventilatory inefficiency links structure (emphysema) and function (DLCO) to a key clinical outcome (poor exercise tolerance) in COPD patients with only modest spirometric abnormalities.

Placental morphology and the prediction of underlying cardiovascular risk factors.

OBJECTIVE: Pre-eclampsia is associated with an increased risk of future cardiovascular disease. Maladaptive placentation or malperfusion, as well as predisposing cardiovascular or metabolic risk for endothelial dysfunction, contribute to the systemic inflammatory response that establishes the origins of the disease. The purpose of this study was to investigate the relationship between placental size and cardiovascular risk when assessed at six months postpartum in women who experienced pre-eclampsia. STUDY DESIGN: Maternal clinical and biochemical cardiovascular risk factors were used to categorize preeclamptic women into high vs. low lifetime cardiovascular disease risk profiles at six months postpartum. A multivariable logistic regression model was then used to identify the association between placental weight to birth weight ratio and high lifetime cardiovascular disease risk, adjusting for maternal age, pre-pregnancy BMI, and severity of pre-eclampsia. A p-value of < 0.05 was deemed statistically significant. RESULTS: 186/216 women with pre-eclampsia who attended the Maternal Health Clinic met inclusion criteria. No significant differences were observed for placental morphometric measurements between women who screened as having a high vs. low lifetime risk profile for cardiovascular disease at six months postpartum. However, using multivariable modelling that controlled for maternal age, pre-pregnancy body mass index, gestational age at delivery, and severity of pre-eclampsia, a low placenta to birth weight ratio (<15%) was associated with an increased odds of high lifetime cardiovascular disease risk (p < 0.009). CONCLUSION: The findings of the current study identify clinical measurements that can be collected at the time of delivery which may help identify specific women who may benefit most from postpartum cardiovascular risk screening and intervention.