Feasibility of 2-dimensional speckle tracking echocardiography strain analysis of the right ventricle with trans-thoracic echocardiography in intensive care: a literature review and meta-analysis.

OBJECTIVES: To identify variables that affect the feasibility of 2-dimensional right ventricular speckle tracking echocardiography (RV-STE) in the intensive care unit.

BACKGROUND: Trans-thoracic echocardiography (TTE) of the right ventricle is challenging. RV-STE is a novel echocardiography method thought to measure global RV function more fully than conventional TTE parameters. The feasibility of RV-STE in ICU populations has not been well described, and variables influencing RV-STE in ICU have not been investigated. This study aimed to address this.

METHODS: A literature review using Ovid MEDLINE(R) was undertaken. We performed meta-analysis with subgroup analysis of; RV-STE type (RV free-wall [RVFWLS] versus RV global longitudinal strain [RVGLS]), study design (prospective versus retrospective), coronavirus disease-19 (COVID-19) study or not, and strain software used. This was followed by meta-regression of proportion of invasive mechanical ventilation (IMV), with and without COVID-19 studies as a co-variate.

RESULTS: Eleven relevant studies from the literature search were identified, reporting an overall feasibility of RV-STE of 83.3% (95%CI 74.6-89.4%). Prospective study design was associated with higher feasibility compared with retrospective studies (p = 0.02). There were no statistical differences on univariate analysis between RVFWLS versus RVGLS, COVID-19 study or not, or strain software used. Meta-regression with COVID-19 study as a covariate demonstrated that higher proportions of IMV were significantly associated with worse feasibility (p = 0.04), as were COVID-19 studies (p < 0.01).

CONCLUSIONS: We have identified three variables associated with poor feasibility; retrospective study design, COVID-19 studies, and proportion of IMV. A prospective study design should be viewed as gold standard to maximise RV-STE feasibility.