Does 1-minute walk test predict results of 6-minute walk test in patients with idiopathic pulmonary fibrosis?

BACKGROUND: The six-minute walk test (6MWT) is a readily available tool used to evaluate functional capacity in patients with idiopathic pulmonary fibrosis (IPF). However, it is often logistically challenging to perform in the context of a busy clinical practice. We sought to investigate if the 1MWT distance (1MWD) predicts the 6MWT distance (6MWD), and if an abbreviated walk could accurately predict outcomes in IPF patients. METHODS: Baseline demographics and pulmonary function testing of IPF patients evaluated at a tertiary referral center between 2010 and 2017 were collected. 6MWT variables at baseline as well as 1 and 6 minutes were collected. Time to death, lung transplantation, or most recent follow-up was ascertained. RESULTS: There were 177 patients, the majority of whom (80%) were male. The mean age was 67 ± 9 years and mean FVC was 64 ± 18% predicted. Forty eight (27%) patients used oxygen supplementation during the 6MWT. The median 6MWD was 366 meters (IQR: 268-471) while the median 1MWD was 65 meters (IQR: 46-81). Stratified by the median, 89 patients were "High Walkers" based on the 6MWD ≥ 366m (HW6) and 88 patients were "Low Walkers" (LW6). HW6 had a higher FVC% (70 ± 15 vs 57 ± 18, p= 0.001), higher DLCO% (45 ± 12 vs 34 ± 14, p= 0.001) and higher 1MWD (83 ± 28 vs 47 ± 16, m p= 0.001). Median transplant-free survival was better in HW6 vs LW6 (27 ± 16 vs 22 ± 18 months, log rank p= 0.018). There was a strong correlation between the 1MWD and the 6MWD (r= 0.91, Spearman's correlation, p < 0.0001). Also, the transplant-free survival curves stratified by 1MWD were very similar to the curves for 6MWD, showing a lower survival in the LW1 cohort (log rank p= 0.009). CONCLUSION: The 1MWD obtained during the first minute of a 6MWD shows a strong correlation to total 6MWD and retains its ability to predict transplant-free survival. 1MWT may serve as a practical substitute for the more cumbersome 6MWT. Our findings require further validation prospectively in larger cohorts of IPF patients.

Impact of OSA on cardiovascular events after coronary artery bypass surgery.

BACKGROUND: The impact of OSA on new cardiovascular events in patients undergoing coronary artery bypass graft (CABG) surgery is poorly explored. METHODS: Consecutive patients referred for CABG underwent clinical evaluation and standard polysomnography in the preoperative period. CABG surgery data, including percentage of off-pump and on-pump CABG, number of grafts, and intraoperative complications, were collected. The primary end point was major adverse cardiac or cerebrovascular events (MACCEs) (combined events of all-cause death, myocardial infarction, repeated revascularization, and cerebrovascular events). Secondary end points included individual MACCEs, typical angina, and arrhythmias. Patients were evaluated at 30 days (short-term) and up to 6.1 years (long term) after CABG. RESULTS: We studied 67 patients (50 men; mean age, 58 ± 8 years; mean BMI, 28.5 ± 4.1 kg/m2). OSA (apnea-hypopnea index ≥ 15 events/h) was present in 56% of the population. The patients were followed for a mean of 4.5 years (range, 3.2-6.1 years). No differences were observed in the short-term follow-up. In contrast, MACCE (35% vs 16%, P = .02), new revascularization (19% vs 0%, P = .01), episodes of typical angina (30% vs 7%, P = .02), and atrial fibrillation (22% vs 0%, P = .0068) were more common in patients with than without OSA in the long-term follow-up. OSA was an independent factor associated with the occurrence of MACCE, repeated revascularization, typical angina, and atrial fibrillation in the multivariate analysis. CONCLUSIONS: OSA is independently associated with a higher rate of long-term cardiovascular events after CABG and may have prognostic and economic significance in CABG surgery.

Critical evaluation of screening questionnaires for obstructive sleep apnea in patients undergoing coronary artery bypass grafting and abdominal surgery.

BACKGROUND: Obstructive sleep apnea (OSA) is an independent risk factor for complications after surgery. However, OSA remains largely under recognized, and questionnaires designed to detect OSA have shown inconsistent results. Patients with cardiovascular diseases may not present with the typical symptoms of OSA. We therefore sought to compare the performance of screening questionnaires of patients referred for coronary artery bypass grafting (CABG) versus abdominal surgery (Abd surgery). METHODS: We studied 40 consecutive patients referred for CABG [29 men; age 56 ± 7 years; body mass index (BMI) 30 ± 4 kg/m(2)], and 41 referred to Abd Surgery matched for age, gender, and BMI (28 men; age 56 ± 8 years; BMI 29 ± 5 kg/m(2)). All patients were evaluated with validated questionnaires to predict OSA (STOP-Bang and Berlin), Epworth sleepiness scale (ESS) and full overnight polysomnography. RESULTS: The prevalence of OSA (apnea-hypopnea index ≥15 events/hour) in the CABG and Abd surgery groups was similar (52 and 41 %, respectively, p = 0.32). The Berlin questionnaire showed similar sensitivity (67 vs. 82 %, p = 0.17) but lower specificity in the CABG group (26 vs. 62 %, p = 0.02). The STOP-BANG questionnaire had a high sensitivity (90 vs. 94 %, p = 0.42) but low specificity (5 vs. 13 %, p = 0.25) in the CABG and Abd surgery groups, respectively. Patients referred for CABG slept less (323 [285-376] vs. 378 [308-415] minutes, p = 0.04) but had lower levels of daytime sleepiness than Abd surgery patients had (ESS, 6 ± 4 vs. 9 ± 5; p = 0.01, respectively). CONCLUSIONS: Presenting clinical characteristics of OSA are modulated by the population evaluated and may affect the performance of screening questionnaires.

A rare cause of hemoptysis: benign sugar (clear) cell tumor of the lung.

A case of benign sugar (clear) cell tumor of the lung with an unusual clinical presentation and its evaluation with computed tomography are reported. A 48-year-old man presented with one episode of hemoptysis. Chest radiographs revealed a round nodule in the lower left lung lobe, and fiberoptic bronchoscopy was normal. On the computed tomography scans, the nodule showed intense post-contrast enhancement (74.7 Hounsfield units). The patient underwent a left thoracotomy, and a segmentectomy was performed. Pathologic examination showed a benign sugar cell tumor of the lung. The patient is alive and has remained free of disease for the last 2 years. To the best of our knowledge, this is the first case report of sugar cell tumor located in lung parenchyma that presented with hemoptysis and the second report of the contrast-enhanced computed tomography findings in this neoplasm.