Outcome measures of the 6 minute walk test: relationships with physiologic and computed tomography findings in patients with sarcoidosis.

BACKGROUND: We assessed the relationship between physiologic parameters, computed tomography patterns, 6 minute walk distance (6MWD) and the distance-saturation product [DSP; defined as the product of the 6MWD and the lowest oxygen saturation during the 6 minute walk test (6MWT)]. In addition, we investigated factors affecting 6MWD in patients with pulmonary sarcoidosis. METHODS: We performed a retrospective study of patient demographics, treatment, pulmonary function, 6MWT, echocardiography and computed tomography results. RESULTS: Fifty nine patients were included in this study. Their mean+standard deviation age was 47.5 years + 12.5 years, and 42 (71.2%) were female. Mean pulmonary function parameters for forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and total lung capacity (TLC) results, as percentages of predicted values, were 77.6 +/- 22.2, 77.1 +/- 22.8 and 78.7 +/- 16.1, respectively. Comparison of the DSP with distance walked revealed a significant correlation with factors underlying reduced 6MWD, including gender, pulmonary function indices, partial pressure of oxygen (PaO2), and Borg dyspnea score. Other factors were significantly associated with DSP but not distance; these included lung fibrosis (p = 0.02), pulmonary hypertension (p = 0.01) and systemic therapy (p = 0.04). Backward elimination stepwise multiple regression analysis revealed that gender, and FEV1 were independent predictors of 6MWD, but FEV1 was more strongly related when DSP applied [DSP, R2 = 0.53, p = 0.02; distance, R2 = 0.45, p < 0.0001]. CONCLUSION: Our findings reveal that, compared to 6MWD alone, the DSP is correlated with a greater number of factors associated with reduced 6MWT performance. Therefore, the DSP may be a useful indicator of functional status in patients with sarcoidosis. Additional large-scale studies are warranted to validate our findings.

Sarcoidosis-associated pulmonary hypertension: Clinical features and outcomes in Arab patients.

BACKGROUND: Pulmonary hypertension (PH) occurs in many patients with interstitial lung disease, including sarcoidosis. We explored the frequency, clinical characteristics and outcomes of PH in Arab patients diagnosed with pulmonary sarcoidosis. METHODS: A retrospective study in three tertiary hospitals was performed on 96 patients who underwent Doppler echocardiography. Demographic and clinical characteristics, physiological studies and computed tomography (CT) results were collected, and compared between patients with and without PH. RESULTS: Twenty (20.8%) patients were found to have PH. Patients with PH were more likely to be symptomatic (cough, P = 0.008; dyspnea, P = 0.04), to have an advanced radiographic stage (P = 0.001), and to be receiving systemic therapy (P = 0.001), compared to those without PH. Physiological data including pulmonary function test parameters, arterial blood gas levels and oxygen saturation at rest and after exercise were all significantly lower in patients with PH compared to those without PH. Comparison of CT patterns between patients with and without PH showed significant differences in the frequencies of ground-glass opacity (61.5 vs. 28.8%, P = 0.032) and fibrosis (76.9 vs. 44.2%, P = 0.035). In total, four patients died during the study period, including three with evidence of PH. CONCLUSIONS: The frequency of PH in the present study was 20.8%. Clinical, physiologic and radiographic characteristics appeared to differentiate patients with PH from those without PH. The presence of PH contributed to poor outcomes in patients with pulmonary sarcoidosis.

Clinical and functional outcomes in Middle Eastern patients with idiopathic pulmonary fibrosis.

BACKGROUND: Baseline clinical and physiological variables have been described as relevant predictors of survival among patients with idiopathic pulmonary fibrosis (IPF). However, substantial heterogeneity in both survival time and mortality has been observed with many of these predictive factors. The incidence and mortality rates of IPF vary from country to country, with race potentially contributing to such variations. OBJECTIVE: We sought to describe baseline clinical features to determine their predictive value among Middle Eastern patients diagnosed with IPF. METHODS: We retrospectively examined 61 patients diagnosed with IPF at a university hospital in Riyadh, Saudi Arabia. RESULTS: At presentation, most patients exhibited either dyspnea or cough. The median survival time for all patients was 92 months. Diminished survival was significantly associated with finger clubbing (P = 0.01). Factors not influencing survival were age, gender, percent predicted forced vital capacity, percent predicted forced expiratory volume in 1 s, percent predicted total lung capacity, percent predicted diffusion capacity of the lung for carbon monoxide and resting oxygen saturation. CONCLUSIONS: Finger clubbing is a significant predictive variable and was associated with a 5-fold increase in mortality. Other baseline demographic characteristics as well as pulmonary function tests were not predictive of prognosis in Middle Eastern patients with IPF. It appears that IPF patients of Middle Eastern descent have a longer median survival curve compared to other races.