Decreased biventricular longitudinal strain in patients with systemic sclerosis is mainly caused by pulmonary hypertension and not by systemic sclerosis per se.

PURPOSE: Patients with pulmonary arterial hypertension (PAH) due to systemic sclerosis (SSc) have high mortality. Left ventricular (LV) peak global longitudinal strain (GLS) is decreased in SSc. It is unknown whether low GLS is due to SSc or PAH. Therefore, our primary aim was to evaluate both LV and right ventricular free wall GLS (RVFW GLS) in SSc, with and without PAH, using cardiac magnetic resonance with feature tracking. Secondary aim was to relate GLS to invasive mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR).

METHODS

Thirty-eight patients with SSc, 19 patients with SSc-PAH and 19 healthy controls for comparison, were included. Endocardial and epicardial borders were delineated in cine images (short-axis stack and three long-axis views) for volumetric and strain calculations.

RESULTS

Systemic sclerosis-PAH had lower LV and RVFW GLS than SSc (LV: P = 0·01, RV: P<0·001) and controls (LV: P = 0·02; RV: P<0·001), with no difference between SSc and controls. LV strain correlated with mPAP (R = 0·42, P = 0·03) and PVR (R = 0·52, P = 0·006). RVFW GLS correlated with mPAP (R = 0·68, P<0·001) and PVR (R = 0·59, P = 0·001). ROC curves for predicting PAH had AUC 0·73 for LV strain (P = 0·003) and 0·86 for RVFW GLS (P<0·001).

CONCLUSIONS

Lower GLS is mainly determined by increased pulmonary pressure and not by SSc per se. Low LV and RVFW GLS are indicative of increased mPAP and PVR, which opens for improved non-invasive methods to select patients eligible for right heart catheterization and to monitor the effects of PAH therapy.