Bayesian semiparametric joint modeling of longitudinal explanatory variables of mixed types and a binary outcome.

Many prospective biomedical studies collect longitudinal clinical and lifestyle data that are both continuous and discrete. In some studies, there is interest in the association between a binary outcome and the values of these longitudinal measurements at a specific time point. A common problem in these studies is inconsistency in timing of measurements and missing follow-ups which can lead to few measurements at the time of interest. Some methods have been developed to address this problem, but are only applicable to continuous measurements. To address this limitation, we propose a new class of joint models for a binary outcome and longitudinal explanatory variables of mixed types. The longitudinal model uses a latent normal random variable construction with regression splines to model time-dependent trends in mean with a Dirichlet Process prior assigned to random effects to relax distribution assumptions. We also standardize timing of the explanatory variables by relating the binary outcome to imputed longitudinal values at a set time point. The proposed model is evaluated through simulation studies and applied to data from a cancer survivor study of participants in the Women's Health Initiative.

Imaging-Based Risk Stratification for Recurrence Risk in Women with a History of Peripartum Cardiomyopathy.

OBJECTIVE: Peripartum cardiomyopathy (PPCM) affects 1:1,000 U.S. pregnancies, and while many recover from the disease, the risk of recurrence in subsequent pregnancy (SSP) is high. This study aims to evaluate the utility of left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) to predict the risk of recurrence of PPCM in SSP. STUDY DESIGN: We retrospectively evaluated outcomes in women with a history of PPCM and SSP at a large-volume cardioobstetrics program (2008-2019). RESULTS: There were 18 women who had incident PPCM and pursued SSP. Of 24 pregnancies in these women, 8 (33%) were complicated by the development of recurrent PPCM. LVEF ≥ 52% or GLS ≤ -16 was associated with a low risk of recurrent PPCM. CONCLUSION: Approximately one-third of women with PPCM developed recurrent PPCM in SSP. LVEF and GLS on prepregnancy echocardiography may predict the risk of recurrence. Additional studies evaluating risk for recurrence are required to better understand which women are the safest to consider SSP. KEY POINTS: · Peripartum cardiomyopathy affects 1:1000 US pregnancies.. · Approximately one third of women with a history of peripartum cardiomyopathy developed recurrent disease in a subsequent pregnancy.. · A left ventricular ejection fraction ≥52% or global longitudinal strain ≤-16 on echocardiogram is associated with a low risk of recurrence..

Correlation of echocardiographic probability of pulmonary hypertension with maternal outcomes in pregnant women with elevated right ventricular systolic pressure.

INTRODUCTION: The use of echocardiography to evaluate the probability for pulmonary hypertension (PH) in pregnant women has not been reported or correlated with outcomes. We hypothesized that in women with elevated right ventricular systolic pressure (RVSP) on echocardiography first identified during pregnancy, those with low probability for PH would have fewer major adverse cardiac events (MACE). METHODS: We performed a retrospective cohort study of pregnant women with RVSP >35 mm Hg on echocardiogram first identified during pregnancy. Women were classified as intermediate-high probability for PH (HP) or low probability for PH (LP) based on simplified European Society of Cardiology echocardiographic criteria. Maternal cardiac, obstetric, and fetal outcomes were assessed. RESULTS: A total of 77 women met inclusion criteria (mean age 30 ± 5 years), with 45 (58%) classified as HP and 32 (42%) as LP. There were 21 (27%) women who experienced MACE, more commonly in the HP cohort (HP 18 (40%) women vs. LP 3 (9%) women, P = .01). The echocardiographic criteria for intermediate-high probability of PH identified women at risk for MACE with 85% sensitivity and 52% specificity. The negative predictive value for MACE in women meeting low echocardiographic probability for PH criteria was 91%. CONCLUSIONS: In women with elevated RVSP on echocardiography first identified during pregnancy, those with low echocardiographic PH probability are at significantly lower risk for MACE during pregnancy, though the risk is not eliminated. This may be useful to risk stratify pregnant women with suspected PH, guiding tertiary care referral and invasive catheterization.

Bayesian semiparametric joint modeling of a count outcome and inconveniently timed longitudinal predictors.

The Women's Health Initiative (WHI) Life and Longevity After Cancer (LILAC) study is an excellent resource for studying the quality of life following breast cancer treatment. At study entry, women were asked about new symptoms that appeared following their initial cancer treatment. In this article, we were interested in using regression modeling to estimate associations of clinical and lifestyle factors at cancer diagnosis (independent variables) with the number of new symptoms (dependent variable). Although clinical and lifestyle data were collected longitudinally, few measurements were obtained at diagnosis or at a consistent timepoint prior to diagnosis, which complicates the analysis. Furthermore, parametric count models, such as the Poisson and negative binomial, do not fit the symptom data well. Thus, motivated by the issues encountered in LILAC, we propose two Bayesian joint models for longitudinal data and a count outcome. Our two models differ according to the assumption on the outcome distribution: one uses a negative binomial (NB) distribution and the other a nonparametric rounded mixture of Gaussians (RMG). The mean of each count distribution is dependent on imputed values of continuous, binary, and ordinal variables at a time point of interest (e.g. diagnosis). To facilitate imputation, longitudinal variables are modeled jointly using a linear mixed model for a latent underlying normal random variable, and a Dirichlet process prior is assigned to the random subject-specific effects to relax distribution assumptions. In simulation studies, the RMG joint model exhibited superior power and predictive accuracy over the NB model when the data were not NB. The RMG joint model also outperformed an RMG model containing predictors imputed using the last value carried forward, which generated estimates that were biased toward the null. We used our models to examine the relationship between sleep health at diagnosis and the number of new symptoms following breast cancer treatment in LILAC.

Maternal and fetal outcomes in pregnant women with pulmonary hypertension: The impact of left heart disease.

Background: Pulmonary hypertension (PH) due to left heart disease (World Health Organization (WHO) Group 2 PH) is the largest PH subgroup, however most reports of PH in pregnancy focus on patients with pulmonary arterial hypertension (WHO Group 1 PH). We evaluated pregnancy outcomes across WHO PH subgroups. Methods: We performed a retrospective single center cohort study of maternal and fetal outcomes in pregnant women with PH (2004-2018). Results: We analyzed outcomes of 70 pregnancies in 70 women with PH (30 ± 6 years-old), classified as WHO Group 1 PH (12 (17%)), Group 2 PH (45 (64%)), Group 3 PH (4 (6%)) and Group 5 PH (9 (13%)). Although no peripartum death occurred, 3 (4.3%) women with WHO Group 2 PH had late mortality (7 ± 4 months post- partum). Additionally, 33 major adverse cardiac events occurred in 26 (37%) women, preterm birth occurred in 32 (49%), and post-partum hemorrhage in 10 (14%), such that only 24 (37%) women completed a viable pregnancy free of an adverse cardiac, obstetric or fetal/neonatal event. Major adverse cardiac events were predominantly due to heart failure (24 (73%)), occurring only in WHO Groups 1 and 2 PH (3 (25%) women vs. 17 (38%), p = 0.07), and significantly associated with pre-eclampsia, left ventricular ejection fraction ≤45%, maternal diabetes, and systemic hypertension. Conclusions: WHO Group 2 PH carries similar risk for maternal cardiovascular events when compared to women with WHO Group 1 PH. Further studies evaluating maternal risk in this cohort are needed.

Hospital Trends of Acute Pancreatitis During the Coronavirus Disease 2019 Pandemic.

OBJECTIVE: The coronavirus disease 2019 pandemic led to changes in individuals' behaviors and healthcare delivery. We examined the impact of these changes on the rates and clinical course of acute pancreatitis (AP). METHODS: Hospitalizations for AP from March 1 through August 31 in 2019 (baseline group) and the same period in 2020 (pandemic group) were retrospectively reviewed. Univariate and multivariate analyses were used for demographics and outcomes. RESULTS: Two hundred eighty subjects (315 admissions) were identified in 2019 and 237 subjects (264 admissions) in 2020. Subjects in the pandemic group were more likely to have systemic inflammatory response syndrome (40% vs 25%, P < 0.01), pancreatic necrosis (14% vs 10%, P = 0.03), and persistent organ failure (17% vs 9%, P = 0.01) compared with prepandemic. There was no difference in etiology of AP. A multivariable model indicates that increased comorbidities, prior pancreatitis, pancreatic necrosis, and prescription of opiates at discharge were associated with 30-day readmissions during the pandemic. CONCLUSIONS: Fewer patients were admitted for AP during the pandemic, suggesting that patients with milder symptoms avoided hospital interaction. Practices followed during the pandemic, especially avoidance of hospitalization and improved efficiency of hospital management, may reduce the burden of pancreatitis care in the future.

Investigating the Genetic Profile of the Amyotrophic Lateral Sclerosis/Frontotemporal Dementia (ALS-FTD) Continuum in Patients of Diverse Race, Ethnicity and Ancestry.

Preliminary evidence suggests that commonly used genetic tests may be less likely to identify a genetic etiology for ALS-FTD in patients of underrepresented race, ethnicity, and ancestry (REA), as compared to European REA. Patients of underrepresented REA may therefore be less likely to receive accurate and specific genetic counseling information and less likely to have access to gene-targeted therapies currently in clinical trials. We compiled outcome data from 1911 ALS-FTD patients tested at a commercial laboratory over a seven-year period for C9orf72 hexanucleotide repeat expansion (HRE) alone or C9orf72 and multigene sequencing panel testing. We compared the incidence of pathogenic (P), likely pathogenic (LP), and uncertain variants in C9orf72 and other ALS-FTD genes, as well as age at testing, in patients of different REA. The diagnostic rate in patients of European REA (377/1595, 23.64%) was significantly higher than in patients of underrepresented REA (44/316, 13.92%) (p < 0.001). Patients of European REA were more likely to have the C9orf72 HRE (21.3%) than patients of underrepresented REA (10.4%) (p < 0.001). The overall distribution of positive test outcomes in all tested genes was significantly different between the two groups, with relatively more P and LP variants in genes other than C9orf72 identified in patients of underrepresented REA. The incidence of uncertain test outcomes was not significantly different between patients of European and underrepresented REA. Patients with positive test outcomes were more likely to be younger than those with negative or uncertain outcomes. Although C9orf72 HRE assay has been advocated as the first, and in some cases, only genetic test offered to patients with ALS-FTD in the clinical setting, this practice may result in the reduced ascertainment of genetic ALS-FTD in patients of diverse REA.