Long-term changes of right ventricular myocardial deformation and remodeling studied by cardiac magnetic resonance imaging in patients with chronic thromboembolic pulmonary hypertension following pulmonary thromboendarterectomy

BACKGROUND: Right ventricular (RV) afterload in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is associated with reduced myocardial contractility and ventriculoarterial coupling. The impact of increased afterload on RV myocardial deformation was assessed by comparing the characteristics of CTEPH patients to healthy controls at baseline, and by comparing characteristics of CTEPH patients before and 12 months after pulmonary endarterectomy (PEA).

METHODS: Cardiac deformation and function of CTEPH patients (n = 20) and healthy controls (n = 20) were assessed by cardiac magnetic resonance (CMR). CTEPH patients were also examined with right heart catheterization before and 12 months after PEA.

RESULTS: PEA resulted in significant improvement of invasive hemodynamics and normalization of RV hypertrophy and right atrial, RV and left ventricular dimensions and volumes. RV ejection fraction improved from 30 ± 13% at baseline to 44 ± 10% at 12 months (p < 0.0001) but remained decreased compared with control subjects (54 ± 4%, p < 0.05). RV global circumferential strain (GCS) normalized 12 months after PEA, but RV global longitudinal strain (GLS) remained significantly lower in CTEPH patients than controls (baseline -12.9 ± 3.3% vs. -16.5 ± 3.6% at 12 months p < 0.01, vs. controls -19.3 ± 3.2%, p < 0.05). RV mass changes were significantly correlated with RV-ejection fraction, RV-GLS, and RV-GCS. RV-pulmonary arterial coupling with the volume method improved at 12 months (0.49 ± 0.30 vs. 0.84 ± 0.31, p < 0.0005), but remained significantly reduced compared with healthy controls (1.19 ± 0.20, p < 0.0005).

CONCLUSION: RV global longitudinal and circumferential myocardial three-dimensional strain by CMR improved significantly in CTEPH patients 12 months after PEA. Improvements in myocardial deformation were associated with regression of RV hypertrophy and decrease in pulmonary artery pressure.