Rapid Fire Abstracts
Bharath Ambale Venkatesh, PhD
Research Faculty, Instructor
Johns Hopkins University
Ghazal Zandieh, MD
Postdoctoral fellow
Johns hopkins medicine
Hoda Mombeini, MD
Post doctoral research fellow
johns hopkins university
Shadi Afyouni, MD
Postdoctoral fellow
Johns Hopkins medicine
Steven Hsu, MD
Professor
johns hopkins university
Stephen Mathai, MD
Professor
johns hopkins university
Paul Hassoun, MD
Professor
johns hopkins university
Monica Mukherjee, MD
Professor
johns hopkins university
Stefan L. Zimmermann, MD
Professor
Johns Hopkins University School of Medicine
John Hopkins
Bharath Ambale-Venkatesh, PhD
Physicist
The John Hopkins Hospital
Right heart adaptation to emerging pulmonary arterial hypertension (PAH) largely determines outcomes. While numerous studies focus on right ventricular (RV) remodeling, few explore the contribution of right atrial (RA) function across PAH subtypes.
Research Questions and
Aims: We assessed the prognostic utility of RA and RV ejection fraction (EF) and strain in systemic sclerosis (SSc) patients with and without PAH, and idiopathic pulmonary arterial hypertension (IPAH) patients using CMR.
Methods:
We included patients with SSc (n=49) and IPAH (n=13) from the Johns Hopkins Pulmonary Hypertension clinical, with both right heart catheterization (RHC) and CMR. RA and RV strain were calculated using 4-chamber long-axis images using Circle CVI 42 (Figure 1). RV EF was calculated from a stack of short-axis images while RA EF was calculated using a 4-chamber long-axis. The contours were detected automatically using artificial intelligence and then tracked through the cardiac cycle. These were then corrected by the user if needed. Maximum RA and RV longitudinal strain were computed as the percentage change in deformation between systole and diastole, with deformation representing the relative change in longitudinal length during the cardiac cycle. Multivariable Cox regression models adjusting for age, gender, and body-mass index were used to assess the association between right-sided function metrics with mortality.
Results:
Of 49 SSc patients (33 had PAH, and 16 were without). The mean age of the population was 57±13 years, and 89% were women. RV strain was lowest in the IPAH group (-16.1±5.8), followed by SSc-PAH (-19.5±6), and highest in the SSc without PAH (-23.8±6.5) group (p < 0.01). RA strain was lowest in the IPAH group (23.2±9.5), followed by SSc-PAH (28.3±10.1), and highest in the SSc without PAH (36.0±14.5) group (p < 0.05). RA EF did not differ between the SSc-PAH and IPAH groups. However, RVEF was lowest in the IPAH group (39.4±10.7), followed by SSc-PAH (46.6±11.6), and highest in the SSc without PAH (56.7±8.1) group (p < 0.001). RAEF was not significantly correlated to mean pulmonary artery pressure from RHC (p=0.06), but worsening RV strain (r=0.43, p< 0.001), RV EF (r=-0.41, p< 0.001), and RA strain ((r=-0.38, p< 0.01) were all associated. Over a median follow-up of 2.73 years, 17 deaths occurred. Cox regression analysis showed RA strain > 20.8% (corresponding to the 25th percentile) significantly predicted survival (HR: 0.20, confidence interval: 0.06-0.67, p< 0.01) after adjustments for age, sex, and body mass index. This association was also independent of adjustment for SSc vs IPAH, mean pulmonary artery pressure, and pulmonary vascular resistance calculated from RHC. RVEF, RAEF, and RV strain were not associated with outcomes (Table 1).
Conclusion:
We found diminished RA strain in SSc-PAH and IPAH as compared to those without PAH. Reduced RA strain was also associated with higher PA pressures, and was predictive of mortality. RA strain from CMR might be a potentially useful marker in those with varying etiologies of PAH.
