Cardiovascular magnetic resonance-assessed fast global longitudinal strain parameters add diagnostic and prognostic insights in right ventricular volume and pressure loading disease conditions

Abstract

Background: Parameters of myocardial deformation may provide improved insights into right ventricular (RV) dysfunction. We quantified RV longitudinal myocardial function using a fast, semi-automated method and investigated its diagnostic and prognostic values in patients with repaired tetralogy of Fallot (rTOF) and pulmonary arterial hypertension (PAH), who respectively exemplify patients with RV volume and pressure overload conditions.

Methods: The study enrolled 150 patients (rTOF, n = 75; PAH, n = 75) and 75 healthy controls. RV parameters of interest were fast global longitudinal strain (GLS) and strain rates during systole (GLSRs), early diastole (GLSRe) and late diastole (GLSRa), obtained by tracking the distance from the medial and lateral tricuspid valve insertions to the RV epicardial apex on cine cardiovascular magnetic resonance (CMR).

Results: The RV fast GLS exhibited good agreement with strain values obtained by conventional feature tracking approach (bias - 4.9%, error limits (± 2·standard deviation) ± 4.3%) with fast GLS achieving greater reproducibility and requiring reduced analysis time. Mean RV fast GLS was reduced in PAH and rTOF groups compared to healthy controls (PAH < rTOF < healthy controls: 15.1 ± 4.9 < 19.3 ± 2.4 < 24.4 ± 3.0%, all P < 0.001 in pairwise comparisons). In rTOF patients, RV fast GLS was significantly associated with metabolic equivalents, peak oxygen consumption (PVO2) and percentage of predicted PVO2 achieved during cardiopulmonary exercise testing. Lower RV fast GLS was associated with subnormal exercise capacity in rTOF (area under the curve (AUC) = 0.822, sensitivity = 72%, specificity = 91%, cut-off = 19.3%). In PAH patients, reduced RV fast GLS was associated with RV decompensated hemodynamics (AUC = 0.717, sensitivity = 75%, specificity = 58%, cut-off = 14.6%) and higher risk of clinical worsening (AUC = 0.808, sensitivity = 79%, specificity = 70 %, cut-off = 16.0%).

Conclusions: Quantitative RV fast strain and strain rate parameters assessed from CMR identify abnormalities of RV function in rTOF and PAH and are predictive of exercise capacity, RV decompensation and clinical risks in these patients. Trial registry Clinicaltrials.gov: NCT03217240.

Keywords: Cardiovascular magnetic resonance; Pressure overload; Right ventricular function; Strain; Volume overload.

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1

Top Semi-automatic tracking of tricuspid annular insertions and right ventricular (RV) epicardial apex, Bottom The strain of each wall (RV septal and free wall) was calculated using the presented strain formula. RV fast global longitudinal strain (FGLS) and peak strain rates (FGLSRs, FGLSRe, and FGLSRa) were extracted from the strain and strain rate curves

Fig. 2

Correlation and Bland-Altman plots (1st row) between RV fast GLS and RV GLS, (2nd row) between RV fast GLSRs and RV GLSRs, (3rd row) between RV fast GLSRe and RV GLSRe, and (4th row) between RV fast GLSRa and RV GLSRa. In correlation plots, solid line and dash lines denote Passing-Bablok non-parametric regression line and 95 % confidence interval, respectively

Fig. 3

Correlation between right ventricular (RV) fast global longitudinal strain (FGLS) and RV ejection fraction (RVEF) (r = 0.71) in the entire subject cohort

Fig. 4

Right ventricular (RV) fast global longitudinal strain (FGLS) and strain rates (FGLSRs, FGLSRe, and FGLSRa) in a rTOF patients with normal and subnormal exercise capacity, b compensated pulmonary arterial hypertension (PAH-C) and decompensated pulmonary arterial hypertension (PAH-D), c PAH with low, intermediate and high risks of clinical worsening. *Significant difference compared to those with normal exercise capacity/PAH-C/low risk; #Significant difference compared to those with intermediate risk

Fig. 5

Linear relationship of right ventricular (RV) fast global longitudinal strain (FGLS) to a Percent of predicted peak oxygen consumption (% Predicted PVO2) (r = 0.58) and b peak oxygen consumption (PVO2) (r = 0.41) in rTOF patients

Fig. 6

Utility of right ventricular (RV) fast global longitudinal strain (FGLS), conventional RV GLS and RV ejection fraction (RVEF) to discriminate a subnormal exercise capacity in rTOF patients, b RV decompensation in PAH patients, c intermediate and high risks of clinical worsening in PAH patients