Hospital readmission in systemic sclerosis associated pulmonary hypertension: Results from the PHAROS registry

OBJECTIVE

To identify individual-level factors associated with hospital readmission among individuals with systemic sclerosis associated pulmonary hypertension (SSc-PH).

METHODS

Individuals enrolled in the Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma (PHAROS) registry contributed clinical data related to SSc-PH disease severity and hospital admissions. Readmission was defined as a subsequent hospitalization within 12 months of any hospital discharge. Characteristics were compared between individuals with and without readmissions using Fisher's exact test, Wilcoxon rank-sum test, or Kruskal Wallis test. Logistic regression was used to estimate associations between clinical predictors and likelihood of readmission.

RESULTS

Of 572 individuals with SSc-PH enrolled in PHAROS, 54% had ≥1 hospitalizations between 2005 and 2016. Among individuals ever-hospitalized, 34% had ≥1 readmission. Individuals with vs without readmissions had shorter median (IQR) time between index hospitalization date and next PHAROS visit (37 (3, 80) vs 81 (42, 136) days, p< 0.001). Index admissions related to PH or SSc (vs non-PH/SSc related) were associated with an increased odds of 12-month readmission (aOR 6.6 (95% CI 3.2, 13.6) and aOR 2.2 (95% CI 1.1, 4.5), respectively). Readmission was less likely among home oxygen users (vs non-users) (aOR 0.44; 95% CI 0.22, 0.89). Race, age, sex, disease duration, and disease subtype were not associated with readmission.

CONCLUSION

The strongest predictor for 12-month readmission was an index hospitalization reason related to PH. Home oxygen use was associated with lower odds of readmission. Future studies should determine whether testing for the need for home oxygen mediates the risk of readmission in SSc-PH.

Esophageal Dilation and Other Clinical Factors Associated with Pulmonary Function Decline in Patients with Systemic Sclerosis

OBJECTIVE

To identify clinical factors, including esophageal dilation on chest high-resolution computed tomography (HRCT), that are associated with pulmonary function decline in patients with systemic sclerosis (SSc).

METHODS

Patients fulfilled 2013 SSc criteria and had ≥1 HRCT and ≥2 pulmonary function tests (PFTs). According to published methods, widest esophageal diameter (WED) and radiographic interstitial lung disease (ILD) were assessed, and WED was dichotomized as dilated (≥19mm) vs. not dilated (<19mm). Clinically meaningful PFT decline was defined as %-predicted change in forced vital capacity (FVC) ≥5 and/or diffusion capacity for carbon monoxide (DLCO) ≥15. Linear mixed effect models were used to model PFT change over time.

RESULTS

138 SSc patients met study criteria: 100 (72%) had radiographic ILD; 49 (35%) demonstrated FVC decline (median follow-up 2.9y). Patients with Scl-70 autoantibodies had 5- year %-predicted FVC decline (-6.3; 95% CI -9.9, -2.8), while patients without Scl-70 autoantibodies demonstrated 5-year FVC stability (+1.78; 95% CI -0.6, 4.15). Esophageal diameter did not distinguish between those with vs. without FVC decline. Patients with esophageal dilation had statistically significant 5-year %-predicted DLCO decline (-5.6; 95% CI - 10.0, -1.2), but this decline was unlikely clinically significant. Similar results were observed in sub-analysis of patients with radiographic ILD.

CONCLUSION

In patients with SSc, Scl-70 positivity is a risk factor for %-predicted FVC decline at five years. Esophageal dilation on HRCT was associated with a minimal, non-clinically significant decline in DLCO and no change in FVC during 5-year follow-up. These results have prognostic implications for SSc-ILD patients with esophageal dilation.

Machine learning integration of scleroderma histology and gene expression identifies fibroblast polarisation as a hallmark of clinical severity and improvement

OBJECTIVE

We sought to determine histologic and gene expression features of clinical improvement in early diffuse cutaneous systemic sclerosis (dcSSc; scleroderma).

METHODS

Fifty-eight forearm biopsies were evaluated from 26 individuals with dcSSc in two clinical trials. Histologic/immunophenotypic assessments of global severity, alpha-smooth muscle actin (aSMA), CD34, collagen, inflammatory infiltrate, follicles and thickness were compared with gene expression and clinical data. Support vector machine learning was performed using scleroderma gene expression subset (normal-like, fibroproliferative, inflammatory) as classifiers and histology scores as inputs. Comparison of w-vector mean absolute weights was used to identify histologic features most predictive of gene expression subset. We then tested for differential gene expression according to histologic severity and compared those with clinical improvement (according to the Combined Response Index in Systemic Sclerosis).

RESULTS

aSMA was highest and CD34 lowest in samples with highest local Modified Rodnan Skin Score. CD34 and aSMA changed significantly from baseline to 52 weeks in clinical improvers. CD34 and aSMA were the strongest predictors of gene expression subset, with highest CD34 staining in the normal-like subset (p<0.001) and highest aSMA staining in the inflammatory subset (p=0.016). Analysis of gene expression according to CD34 and aSMA binarised scores identified a 47-gene fibroblast polarisation signature that decreases over time only in improvers (vs non-improvers). Pathway analysis of these genes identified gene expression signatures of inflammatory fibroblasts.

CONCLUSION

CD34 and aSMA stains describe distinct fibroblast polarisation states, are associated with gene expression subsets and clinical assessments, and may be useful biomarkers of clinical severity and improvement in dcSSc.

Thirty-day hospital readmission in systemic sclerosis associated pulmonary hypertension: A nationwide study

OBJECTIVE

To identify risk-factors for 30-day hospital readmission in systemic sclerosis pulmonary hypertension (SSc-PH) and to compare trends and characteristics of 30-day readmissions in SSc-PH versus non-SSc pulmonary arterial hypertension (non-SSc PAH).

METHODS

In this retrospective study, we identified SSc-PH and non-SSc PAH hospitalizations using ICD-9 codes within the Healthcare Cost and Utilization Project-National Readmission Database. Thirty-day readmission rates were calculated between 2010 and 2015. Characteristics were compared using chi-square, Wilcoxon rank-sum, or two-sample t-tests between (A) SSc-PH patients with versus without readmission and (B) patients with ≥1 readmission with SSc-PH versus non-SSc PAH. Adjusted logistic regression models were generated for readmission in SSc-PH.

RESULTS

4,846 of 22,420 (22%) with SSc-PH and 10,573 of 49,254 (21%) with non-SSc PAH had ≥1 30-day readmission. Between 2010-2015, readmission rate decreased in non-SSc PAH (23% to 20%; p<0.001) and was unchanged in SSc-PH (23% to 23%; p = 0.77). In SSc-PH, independent predictors of 30-day readmission include male sex, age <60, Medicare or Medicaid, higher Charlson/Deyo comorbidity index, and congestive heart failure (CHF). A higher proportion of patients with SSc-PH (vs. non-SSc PAH) died during index hospitalizations (p = 0.001) and readmissions (p <0.001). Readmitted patients with SSc-PH (vs. non-SSc PAH) were younger and less often had CHF. In SSc-PH, the most common readmission primary diagnosis was infection, followed by respiratory and heart failure.

CONCLUSION

In SSc-PH, 30-day readmission is frequent, and in-hospital deaths occur at a higher rate compared to those with non-SSc PAH. This study identifies factors that may characterize those with SSc-PH at highest risk for readmission.

Assessment of skin disease in scleroderma: Practices and opinions of investigators studying scleroderma

BACKGROUND

The modified Rodnan skin score is a common primary outcome measurement tool in clinical trials of systemic sclerosis (scleroderma). However, it is unknown how often physicians perform the modified Rodnan skin score in clinical practice or what precise approach is most often used when assessing each of the 17 sites included in the modified Rodnan skin score (i.e. "maximizing," "averaging," "representative area"). This study assessed the experiences, perceptions, training, and practices of individuals studying scleroderma with regard to modified Rodnan skin score.

METHODS

An invitation with an online survey link was sent electronically to 282 individuals who are part of the Scleroderma Clinical Trials Consortium. The 46-item survey included three sections: participant demographics, modified Rodnan skin score background/training, and modified Rodnan skin score assessment practices. The survey was accessible for 5 weeks (October-November 2019).

RESULTS

The response rate was 41% (116 of 282 individuals). The majority of participants perform the modified Rodnan skin score in clinical care (>99%) and practice at academic institutions (90%) in North America (41%) or Europe (40%). Nearly all participants felt that the modified Rodnan skin score is either "somewhat important" (43%) or "essential" (56%) to the care of patients with systemic sclerosis. In total, 91% of participants reported having received modified Rodnan skin score training. The majority (60%) of those who had not received training were interested in receiving modified Rodnan skin score training, and 39% of participants felt either "uncomfortable" or only "somewhat comfortable" performing the modified Rodnan skin score. The modified Rodnan skin score approach varied: 44% used "maximizing," 28% used "averaging," and 18% used "representative area."

CONCLUSION

A majority of participants feel that the modified Rodnan skin score is "essential" to the care of patients with systemic sclerosis; however, the method used to measure modified Rodnan skin score varies greatly among systemic sclerosis investigators. These results indicate a continued role of modified Rodnan skin score for care and research in systemic sclerosis, support ongoing efforts to increase opportunities for modified Rodnan skin score training, and highlight a potential need to harmonize the technical approach to measuring the modified Rodnan skin score.

Complementary therapies for patients with systemic sclerosis

Patients with systemic sclerosis often seek information regarding complementary and nutrition-based therapy. Some study results have shown that vitamins D and E, probiotics, turmeric, l-arginine, essential fatty acids, broccoli, biofeedback, and acupuncture may be beneficial in systemic sclerosis care. However, large randomized clinical trials have not been conducted. This review summarizes current data regarding various complementary therapies in systemic sclerosis and concludes with recommendations.

Performance of Forced Vital Capacity and Lung Diffusion Cutpoints for Associated Radiographic Interstitial Lung Disease in Systemic Sclerosis

OBJECTIVE

Forced vital capacity (FVC) and DLCO are used for screening of systemic sclerosis-associated interstitial lung disease (SSc-ILD). The study purpose was to determine the sensitivity, specificity, and negative predictive value (NPV) (proportion of true negative screening tests) of FVC and DLCO thresholds for SSc-ILD on chest high-resolution computed tomography (HRCT) scans.

METHODS

Patients fulfilling American College of Rheumatology 2013 SSc criteria with a chest HRCT scan and pulmonary function tests (PFT) were studied. A thoracic radiologist quantified radiographic ILD. Optimal FVC and DLCO % predicted thresholds for ILD were identified using receiver-operating characteristic curves. The FVC and DLCO combinations with greatest sensitivity and specificity were also determined. Subanalysis was performed in patients with positive Scl-70 autoantibodies.

RESULTS

The study included 265 patients. Of 188 (71%) with radiographic ILD, 59 (31%) had "normal" FVC (≥ 80% predicted), and 65 out of 151 (43%) had "normal" DLCO (≥ 60% predicted). FVC < 80% (sensitivity 0.69, specificity 0.73), and DLCO < 62% (sensitivity 0.60, specificity 0.70) were optimal thresholds for radiographic SSc-ILD. All FVC and DLCO threshold combinations evaluated had NPV < 0.70. The NPV for radiographic ILD for FVC < 80% was lower in patients with positive Scl-70 autoantibody (NPV = 0.05) compared to negative Scl-70 autoantibody (NPV = 0.57).

CONCLUSION

Radiographic ILD is prevalent in SSc despite "normal" PFT. No % predicted FVC or DLCO threshold combinations yielded high NPV for SSc-ILD screening. "Normal" FVC and DLCO in patients with SSc, especially those with positive Scl-70 autoantibodies, should not obviate consideration of HRCT for ILD evaluation.

Multiple myeloma diagnosed secondary to analysis of a lytic bone lesion encountered during Mohs micrographic surgery

An 89-year-old man underwent Mohs micrographic surgery for treatment of a squamous cell carcinoma of the scalp. A lytic bone lesion was found that led to the diagnosis of multiple myeloma.

Navigating complex labyrinths: optimal paths from chemical waves

The properties of excitable media are exploited to find minimum-length paths in complex labyrinths. Optimal pathways are experimentally determined by the collection of time-lapse position information on chemical waves propagating through mazes prepared with the Belousov-Zhabotinsky reaction. The corresponding velocity fields provide maps of optimal paths from every point in an image grid to a particular target point. Collisions of waves that were temporarily separated by obstacles mark boundary lines between Significantly different paths with the same absolute distance. The pathfinding algorithm is tested in very complex mazes with a simple reaction-diffusion model.

Experimental and theoretical studies of feedback stabilization of propagating wave segments

Experimental and theoretical studies of the excitability boundary for spiral wave behavior are presented. The boundary is defined by unstable wave segments, which are stabilized by using a negative-feedback control algorithm. A kinematic description of the constant-size, constant-shape wave segments is presented.

Spatial symmetry breaking in the Belousov-Zhabotinsky reaction with light-induced remote communication

Domains containing spiral waves form on a stationary background in a photosensitive Belousov-Zhabotinsky reaction with light-induced alternating nonlocal feedback. Complex behavior of colliding and splitting wave fragments is found with feedback radii comparable to the spiral wavelength. A linear stability analysis of the uniform stationary states in an Oregonator model reveals a spatial symmetry breaking instability. Numerical simulations show behavior in agreement with that found experimentally and also predict a variety of other new patterns.

Wave propagation in subexcitable media with periodically modulated excitability

Wave propagation in a photosensitive, subexcitable Belousov-Zhabotinsky medium is made possible by periodic modulation of a homogeneous illumination field. The propagation can be understood in terms of an interplay between the radial expansion of the wave and the motion of its free ends as the excitability varies periodically. This description leads to a simple kinematic analysis that provides insights into the initial conditions and forcing parameters giving rise to sustained wave propagation.

Self-segregation of competitive chaotic populations

The dynamical behavior of species competing for a common resource is studied with a reaction-diffusion system based on cubic autocatalysis. Randomly seeded populations self-segregate to form a complex network of domains separated by distinct interfaces. For chaotic populations in one-dimensional media, the interfaces exhibit irregular motions on long time scales. In two-dimensional media, the interface motions are governed by curvature-induced drift.

Coherent structure analysis of spatiotemporal chaos

We introduce a measure to quantify spatiotemporal turbulence in extended systems. It is based on the statistical analysis of a coherent structure decomposition of the evolving system. Applied to a cellular excitable medium and a reaction-diffusion model describing the oxidation of CO on Pt(100), it reveals power-law scaling of the size distribution of coherent space-time structures for the state of spiral turbulence. The coherent structure decomposition is also used to define an entropy measure, which sharply increases in these systems at the transition to turbulence.

Uncertain destination dynamics

Certain dynamical systems exhibit a sensitivity to initial conditions in which the asymptotic state is selected from an infinite number of possible states. The phase space of such systems is foliated with "attractors," each of which is associated with a particular set of initial conditions. The associated uncertain destination dynamics can be analyzed by an appropriate reduction of the full system to a subsystem that explicitly yields the dynamics.

Noise sustained waves in subexcitable media: From chemical waves to brain waves

We discuss a novel type of spatiotemporal pattern that can be observed in subexcitable media when coupled to a thermal environment. These patterns have been recently observed in several different types of systems: a subexcitable photosensitive Belousov-Zhabotinsky reaction, hippocampal slices of rat brains, and astrocyte syncytium. In this paper, we introduce the basic concepts of subexcitable media, describe recent experimental observations in chemistry and neurophysiology, and put these observation into context with computer simulations. (c) 1998 American Institute of Physics.

Anisotropy and Spiral Organizing Centers in Patterned Excitable Media

Chemical wave behavior in a patterned Belousov-Zhabotinsky system prepared by printing the catalyst of the reaction on membranes with an ink jet printer is described. Cellular inhomogeneities give rise to global anisotropy in wave propagation, with specific local patterns resulting in hexagonal, diamond, and pentagonal geometries. Spiral wave sources appear spontaneously and serve as organizing centers of the surrounding wave activity. The experimental methodology offers flexibility for studies of excitable media with made-to-order spatial inhomogeneities.