Systemic sclerosis-related pulmonary hypertension (SSc-PH) is a common complication of SSc associated with accelerated mortality. We hypothesized that cardiac axis deviation may indicate abnormalities in cardiac function allowing for prognostication of disease severity and mortality.
This was a retrospective study where electrocardiograms (ECGs) were reviewed for cardiac axis deviation and their association with echocardiography and cardiopulmonary hemodynamics on right heart catheterization. The primary outcome observed was all-cause mortality from the time of PH diagnosis.
ECGs were reviewed from 169 patients with SSc-PH. Right axis deviation (RAD) and left axis deviation (LAD) occurred in 28.4% and 30.8% of patients with SSc-PH, respectively. Compared to those without, patients with RAD exhibited predominantly right-sided cardiac disease on echocardiography and increased PH severity by cardiopulmonary hemodynamics including a greater mean pulmonary artery pressure (42.0 ± 12.5 mm Hg vs. 29.8 ± 7.0 mm Hg) and pulmonary vascular resistance (645.6 ± 443.2 dyn·s/cm
RAD and LAD reflect structural cardiac abnormalities and are associated with poor prognosis in patients with SSc-PH. These findings support the importance of electrocardiography, an inexpensive, widely available non-invasive test, in risk stratification.