Cardiac Catheterization and Hemodynamics in a Multicenter Cohort of Children with Pulmonary Hypertension.

Rationale: Hemodynamic assessments direct care among children with pulmonary hypertension, yet the use of cardiac catheterization is highly variable, which could impact patient care and research. Objectives: We analyzed hemodynamic findings from right heart catheterization (RHC) and left heart catheterization and acute vasodilator testing (AVT) and the safety of catheterization in children with World Symposium on Pulmonary Hypertension (WSPH) group 1 and 3 subtypes in a large multicenter North American cohort. Methods: Of 1,475 children enrolled in the Pediatric Pulmonary Hypertension Network Registry (2014-2020), there were 1,383 group 1 and 3 patients, of whom 671 (48.5%) underwent RHC at diagnosis and were included for analysis. Results: Compared with those without diagnostic RHC, these children were older, less likely to be an infant or preterm, more often female, treated with targeted pulmonary hypertension medications at diagnosis, and had advanced World Health Organization functional class. Catheterization was performed without a difference in complication rates between WSPH groups. Pulmonary capillary wedge pressure was well correlated with left ventricular end-diastolic pressure and left atrial pressures. Results of AVT using three different methods were comparable; positive AVT results were observed in 8.0-11.8% of subjects, did not differ between WSPH groups 1 and 3, and were not associated with freedom from the composite endpoint of lung transplantation or death during follow-up. Conclusions: In a large pediatric pulmonary hypertension cohort, diagnostic RHC with or without left heart catheterization in WSPH group 1 and 3 patients was performed safely at experienced pediatric pulmonary hypertension centers. Hemodynamic differences were noted between group 1 and 3 subjects. Higher mean pulmonary arterial pressure and mean pulmonary arterial pressure/mean systemic arterial pressure ratio were associated with a higher risk of death/transplantation. Findings suggest overall safety and potential value of RHC as a standard diagnostic approach to guide pulmonary hypertension management in children.

Trochanteric bursitis: refuting the myth of inflammation.

BACKGROUND AND OBJECTIVES: Greater trochanteric (GT) bursitis is a common cause of hip pain. Previously, the etiology of the trochanteric pain syndrome was thought to be caused by inflammation of the subgluteus maximus bursa (i.e., bursitis). Recently, MRI and ultrasound studies have brought into serious doubt the idea that bursitis is the etiology for trochanteric pain. To our knowledge, no histologic study of GT bursitis has been reported to date. The purpose of this study is to evaluate the histopathology of patients with and without the clinical syndrome of GT bursitis to assess for the presence of bursal inflammation. DESIGN AND METHODS: This is a prospective, case-controlled, blinded study of the histopathologic features of controls and patients with GT bursitis. We recruited patients who required total hip arthroplasty (THA) for rheumatoid or osteoarthritis. Inclusion criteria for the study consisted of the following: needing THA as standard of care; THA secondary to OA or RA; age greater than 18; and minimal risk for surgery by the American Heart Association Criteria. We excluded anyone who received a GT bursa injection 9 months before surgery. Eligible participants were then stratified as cases or controls using the 1985 clinical criteria for GT bursitis. The harvesting of the bursa required no modification of the surgical procedure. The specimens were then examined by 2 independent pathologists who were blinded as to the patients' clinical status. RESULTS: Six bursal specimens were evaluated by 2 blinded surgical pathologists revealing primarily fibroadipose tissue with no signs of acute or chronic inflammation. There were 3 bursas in the control group and 2 specimens with clinical GT bursitis. No significant differences were found between the specimens of the 2 groups. CONCLUSIONS: The results of this small prospective observational histologic study, along with recent MRI and ultrasound studies on the topic, strongly suggest that there is no etiologic role of bursal inflammation in the trochanteric pain syndrome.