Normal Ranges of Right Atrial Strain: A Systematic Review and Meta-Analysis.

BACKGROUND: Standard measures for the clinical assessment of right atrial (RA) function are lacking. OBJECTIVES: In this systematic review and meta-analysis, the authors sought to report a reference range for RA deformation parameters in healthy subjects and to identify factors that contribute to reported variations. METHODS: The authors conducted a comprehensive search of MEDLINE; MEDLINE In-Process & Other Non-Indexed Citations; Embase; Scopus; and the Cochrane Central Register of Controlled Trials from database inception through October 2021. Studies were included if they reported RA strain or strain rate (SR) using 2-dimensional speckle-tracking echocardiography in healthy volunteers or apparently healthy control patients. Data were extracted by 1 reviewer and then reviewed by 2 independent reviewers. Conflicts were resolved through consensus. Data were combined using the method developed by Siegel and adjusted using the restricted maximum likelihood random-effects model. The normal range was defined as the 95% CI of the mean. Heterogeneity was assessed by the Cochran Q-statistic and the inconsistency index (I2). The quality of the included studies and publication bias were assessed. Effects of clinical variables were sought in a metaregression. RESULTS: The search identified 4,111 subjects from 21 studies. The average RA reservoir strain was 44% (95% CI: 25%-63%), contractile strain was 17% (95% CI: 2%-32%), and conduit strain was 18% (95% CI: 7%-28%), with significant between-study heterogeneity and inconsistency. The systolic SR was 2.1 s-1 (95% CI: 0.9-3.4 s-1), early-diastolic SR was -2.0 s-1 (95% CI: -3.3 to -0.8 s-1), and late-diastolic SR was -1.9 s-1 (95% CI: -2.4 to -1.3 s-1), with nonsignificant heterogeneity and inconsistency. Ranges remained wide in healthy volunteers. The metaregression identified only age as significantly associated with systolic SR and no other significant determinants of variation among normal ranges of strain. CONCLUSIONS: There are wide reference ranges for RA deformation, and these may limit the utility of this test in clinical practice.

Circulating collagen biomarkers as indicators of disease severity in pulmonary arterial hypertension.

OBJECTIVES: The goal of this study was to determine if biomarkers of collagen metabolism in PAH identify patients with worse disease and higher risk of death. BACKGROUND: The relationship between circulating markers of collagen metabolism, degree of disease severity, and outcome in pulmonary arterial hypertension (PAH) is unknown. METHODS: Patients with stable idiopathic, anorexigen-associated, and hereditary PAH were prospectively enrolled. Levels of the following collagen biomarkers were measured: N-terminal pro-peptide of type III procollagen (PIIINP), C-terminal telopeptide of collagen type I (CITP), matrix metalloproteinase (MMP)-9, and tissue inhibitor of metalloproteinase (TIMP)-1. Patients were divided into mild, moderate, and severe PAH groups. Data were compared between tertiles of each biomarker. Pearson correlation and Spearman rank coefficient analyses were performed. Data on time to death or transplantation were examined by Kaplan-Meier survival curves. RESULTS: Circulating levels of PIIINP, CITP, MMP-9, and TIMP-1 were higher in the PAH group (n = 68) as compared with age- and sex-matched healthy controls (n = 37) (p < 0.001 for each). PIIINP levels increased with the severity of disease (p = 0.002). PIIINP tertile data indicated that with increasing levels, 6-min walk distance and cardiac index decreased, World Health Organization functional classification worsened, and resting heart rate increased. A significant correlation existed between PIIINP levels and worsening World Health Organization functional classification (rs = 0.320; p < 0.01), and there was a negative correlation between cardiac index and 6-min walk distance (r = -0.304 and r = -0.362, respectively; p < 0.05). PIIINP tertiles showed a trend toward worse outcome in patients with higher tertiles (lung transplant or death) (p = 0.07; log-rank test). CONCLUSIONS: Markers of collagen metabolism were associated with worse disease in patients with PAH.

Rhodococcus equi pneumonia in a renal transplant patient: a case report and review of literature.

Immunocompromised patients are susceptible to many pathogens, including those that are predominantly problems in veterinary medicine. We report a case of a 42-yr-old white male who presented 19 months post-cadaveric renal transplant (for IgA nephropathy) with a 5 d history of nausea, vomiting, abdominal cramping and diarrhea. Admission chest X-ray revealed a suspicious mass lesion in the left lower lobe. Computed tomography (CT) guided biopsy of the lesion showed a large zone of CD68 +ve histiocytes in a non-caseating granuloma. Gram stain revealed multiple gram-positive rods within the histiocytes, which were eventually identified as R. equi. After 4 months of therapy with fluoroquinolones (Avelox) and Azithromycin a repeat CT showed complete resolution of the lesion. We reviewed the literature with special focus on the clinical features, challenges in diagnosis, and treatment of this rare infection (especially in the transplant patients who are also on immunosuppressive therapy).