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Cystatin C, a novel marker of renal function, is associated with left heart failure and cardiovascular mortality. We tested the hypothesis that cystatin C accurately predicts pulmonary artery pressure and right ventricular (RV) function in pulmonary arterial hypertension (PAH).
Using a prospective study, 15 subjects with right heart catheterization-proven PAH and 10 age-matched controls underwent same-day echocardiography, cardiac MRI (CMR), and phlebotomy for cystatin C, brain natriuretic peptide (BNP), and creatinine. CMR was used to calculate RV ejection fraction (RVEF), end diastolic volume (RVEDV), end systolic volume (RVESV), and mass. Echocardiography was used to estimate RV systolic pressure (RSVP) and assess RV diastolic function using tricuspid valve (TV) e’ velocity. Glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease Study equation.
All PAH subjects were either idiopathic (N=13) or connective-tissue disease associated (N=2). There was no significant difference in age (PAH 63 ± 8 years vs. control 58 ± 9 years) or GFR (PAH 75 ± 26 mL/min/1.73 m2vs. control 89 ± 13 mL/min/1.73 m2). RVSP in PAH subjects was significantly elevated vs. controls (58 ± 17 mmHg vs. 26 ± 8 mmHg, p < .001). Cystatin C levels positively correlated with RVSP (r 0.6, p .002), RVEDV (r 0.7, p .0001), RVESV (.69, p < .001), and RV mass (r .67, p < .001) and negatively correlated with TV e’ (r .59, p .003). All correlations with BNP were inferior to cystatin C including RVSP (r 0.48, p .02), RVEDV (r 0.48, p .01), RVESV (.44, p .03), RV mass (r .49, p .01), and TV e’ (r .3, p .12).
Cystatin C levels accurately predict pulmonary pressure, RV function, and RV morphology independent of renal function. Furthermore, cystatin C outperforms BNP, the traditional PAH biomarker. Cystatin C may represent a novel biomarker for PAH diagnosis and monitoring.
Poster Sessions, Expo North
Monday, March 11, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Pulmonary Hypertension: Pre-Clinical, Clinical, Biomarkers
Abstract Category: 27. Pulmonary Hypertension
Presentation Number: 1294-148
- 2013 American College of Cardiology Foundation