Six-Minute Walk Test as a Predictor of Diagnosis, Disease Severity, and Clinical Outcomes in Scleroderma-Associated Pulmonary Hypertension: The DIBOSA Study

BACKGROUND

Pulmonary hypertension (PH) is a common complication of scleroderma (SSc) and is a leading cause of morbidity and mortality.

OBJECTIVES

To explore the utility of the 6MWT in the prediction of SSc-PH and to assess its prognostic implications.

METHODS

A retrospective review of SSc patients from 2003 to 2013, with 6MWT and echocardiogram (n = 286), was conducted. Presence of PH was defined by right heart catheterization. Patients were randomized into development and validation cohorts. Using regression techniques, we developed a scoring system to predict the presence of SSc-PH and tested it in our validation cohort. Trends of mortality and disease severity were studied for incremental scores.

RESULTS

The DIBOSA scoring system includes DIstance walked in 6 min, BOrg dyspnea index, and SAturation of oxygen at 6 min. The DIBOSA score in the development cohort ranged from 0 to 3, resulting in an area of 0.858 (P < 0.0001) under the ROC curve. A score of 0 had a NPV of 100% and a score of 3 had a PPV of 86.58%. The validation cohort had an area under the ROC curve of 0.842. The DIBOSA score correlated with both pulmonary artery pressures and mortality. The 3-year survival rates for DIBOSA scores of 0, 1, 2, and 3 were 100, 100, 87.67, and 66.67%, respectively (HR = 3.92, P < 0.0001).

CONCLUSIONS

DIBOSA score is a sensitive tool for the prediction of SSc-PH. The DIBOSA score is a direct predictor of mortality in SSc-PH and strongly correlates with pulmonary pressures. 6MWT can be used to predict clinical outcomes in SSc-PH.

Saudi guidelines on the diagnosis and treatment of pulmonary hypertension: 2014 updates

The Saudi Association for Pulmonary Hypertension (previously called Saudi Advisory Group for Pulmonary Hypertension) has published the first Saudi Guidelines on Diagnosis and Treatment of Pulmonary Arterial Hypertension back in 2008.[1] That guideline was very detailed and extensive and reviewed most aspects of pulmonary hypertension (PH). One of the disadvantages of such detailed guidelines is the difficulty that some of the readers who just want to get a quick guidance or looking for a specific piece of information might face.

All efforts were made to develop this guideline in an easy-to-read form, making it very handy and helpful to clinicians dealing with PH patients to select the best management strategies for the typical patient suffering from a specific condition. This Guideline was designed to provide recommendations for problems frequently encountered by practicing clinicians involved in management of PH. This publication targets mainly adult and pediatric PH-treating physicians, but can also be used by other physicians interested in PH.

Updating clinical endpoint definitions

The 6-Minute Walk Distance (6-MWD) has been the most utilized endpoint for judging the efficacy of pulmonary arterial hypertension (PAH) therapy in clinical trials conducted over the past two decades. Despite its simplicity, widespread use in recent trials and overall prognostic value, the 6-MWD has often been criticized over the past several years and pleas from several PAH experts have emerged from the literature to find alternative endpoints that would be more reliable in reflecting the pulmonary vascular resistance as well as cardiac status in PAH and their response to therapy. A meeting of PAH experts and representatives from regulatory agencies and pharmaceutical companies was convened in early 2012 to discuss the validity of current as well as emerging valuable endpoints. The current work represents the proceedings of the conference.

Challenges in the diagnosis and management of Nocardia infections in lung transplant recipients

BACKGROUND

Nocardia infection occurs in 2.1-3.5% of lung transplant recipients, and may involve cavitary nodular pulmonary lesions, soft tissue infection, or other sites of dissemination. Nocardiosis can pose challenging clinical problems in the areas of diagnosis and treatment. Diagnostic delays may occur, and adverse reactions to therapy are common. This study reviews clinical and epidemiological aspects of nocardiosis in lung transplant recipients, with special attention to pitfalls in management. Clinicians should be alert for these possibilities in order to institute prompt therapy and to achieve successful outcomes.

METHODS

A retrospective cohort study was conducted of 577 lung transplant recipients from January 1991 to May 2007. Demographics, reason for transplant, recent rejection, time from transplantation, site of infection, hypogammaglobulinemia, and/or neutropenia shortly before onset, Pneumocystis jiroveci prophylaxis, Nocardia species, radiographic findings, extrapulmonary lesions, nature and duration of treatment, adverse reactions, and outcomes were recorded.

RESULT

Nocardia infection occurred in 1.9% (11/577). Mean onset was 14.3 months after transplant (range 1.5-39 months). N. asteroides was isolated in 55% (6/11). Emphysema was the most common reason for transplant (7/11, 64%). Six patients were receiving trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis at the time of diagnosis. Three patients had immune globulin G levels <400 mg/dL and 2 were neutropenic in the 3 months preceding diagnosis. Diagnosis was made by bronchoalveolar lavage (55%), skin abscess culture (18%), open lung biopsy (9%), pleural fluid (9%), and sputum culture (9%). Definitive diagnosis required a median of 9 days and a mean of 13.6 days (range 3-35 days) from the time of diagnostic sampling. Soft tissue lesions occurred in 3 and central nervous system involvement in 1 patient. Adverse reactions to therapy occurred in 9/10 (90%) of patients for whom information was available. Nocardia-related mortality occurred in 2/11 patients (18%).

CONCLUSIONS

Nocardiosis occurred in 1.9% of lung transplant recipients and was associated with a mean of nearly 2 weeks to diagnosis and frequent adverse effects on therapy. TMP-SMX prophylaxis on a thrice weekly basis did not prevent all episodes of nocardiosis. Despite utilization of protocol bronchoscopies with cultures for Nocardia, this organism remains a source of clinical complexity in the lung transplant population.

The effect of lung volume reduction surgery on chronic obstructive pulmonary disease exacerbations

RATIONALE

Lung volume reduction surgery (LVRS) has been demonstrated to provide a functional and mortality benefit to a select group of subjects with chronic obstructive pulmonary disease (COPD). The effect of LVRS on COPD exacerbations has not been as extensively studied, and whether improvement in postoperative lung function alters the risk of disease exacerbations is not known.

OBJECTIVES

To examine the effect, and mechanism of potential benefit, of LVRS on COPD exacerbations by comparing the medical and surgical cohorts of the National Emphysema Treatment Trial (NETT).

METHODS

A COPD exacerbation was defined using Centers for Medicare and Medicaid Services data and International Classification of Diseases, Ninth Revision, discharge diagnosis.

MEASUREMENTS AND MAIN RESULTS

There was no difference in exacerbation rate or time to first exacerbation between the medical and surgical cohorts during the year before study randomization (P = 0.58 and 0.85, respectively). Postrandomization, the surgical cohort experienced an approximate 30% reduction in exacerbation frequency (P = 0.0005). This effect was greatest in those subjects with the largest postoperative improvement in FEV(1) (P = 0.04) when controlling for changes in other spirometric measures of lung function, lung capacities, and room air arterial blood gas tensions. Finally, LVRS increased the time to first exacerbation in both those subjects with and those without a prior history of exacerbations (P = 0.0002 and P < 0.0001, respectively).

CONCLUSIONS

LVRS reduces the frequency of COPD exacerbations and increases the time to first exacerbation. One explanation for this benefit may be the postoperative improvement in lung function.