Strengths and limitations
Our study has some limitations. Our patients were recruited at a referral hospital, which may represent a population bias in terms of disease prevalence and severity. Despite this, our population had a significant cohort without PH and had various degrees of pulmonary hypertension. There was, however, only a small number of patients with moderate PH, potentially affecting our ability to see significantly different measurements between the moderate and severe PH categories. Additionally, we included a small cohort of patients with PH and with biopsies evaluated postmortem to determine the presence and percentage of fibrosis associated with an increase in systolic pulmonary artery pressure. We did not have strain values in these patients. Accordingly, while fibrosis has been associated with reduced echocardiographic derived strain, we consider the relationship between pathology-derived fibrosis and reduced strain as a measurement of decreased RV function and possibly of fibrosis as exploratory. Finally, the assessment at follow-up to evaluate possible adverse outcomes is left as an area of opportunity for further research.