Abstract 10179: Myocardial T1 in Nonischemic Dilated Cardiomyopathy is Related to Circulating Procollagen Type 1 Carboxyterminal Peptide and Predicts Reverse Remodeling by Spironolactone Therapy
Introduction: Pathologic collagen remodeling and fibrosis are prominent features of nonischemic dilated cardiomyopathy (NIDCM) and heart failure (HF). Circulating levels of collagen markers, such as procollagen type I carboxyterminal peptide (PICP), are elevated in HF. Spironolactone improves LV systolic function in association with decreased PICP. Cardiac magnetic resonance (CMR) T1 is emerging as an estimate of myocardial tissue fibrosis in HF. We assessed the hypothesis that CMR T1 imaging is related to circulating PICP and predictive of LV functional response to treatment with the mineralocorticoid antagonist, spironolactone.[[Unable to Display Character:
Methods: Twelve patients with NIDCM and HF on stable beta blocker and ACE inhibitor/ARB medication were studied using CMR and collagen markers, before and after 6-24 months of treatment with spironolactone. Changes in LV structure and function were analyzed, and 10 minute-post gadolinium contrast myocardial T1 values were determined using a standard Look Locker sequence and MRMap software. PICP was determined by ELISA for 11/12 patients.
Results: Baseline mean PICP was elevated at 57,557 pg/mL (SD 29,269), and CMR T1 was inversely related to baseline PICP (P=0.02). After 6-24 months of medical therapy, the LV ejection fraction improved and the end-systolic volume index (LVESV/m2) decreased in all patients (both P=0.002). The baseline CMR T1 was inversely related to the post-treatment percent reduction in LVESV/m2 (P=0.02), but baseline PICP was not (P=0.21).
Conclusions: Spironolactone added to standard HF medication improved LV function, consistent with other clinical studies. While PICP did correlate with fibrosis by CMR T1, we found that CMR T1, and not PICP, was quantitatively related to the reduction in LVESV/m2 in patients treated with spironolactone. Thus, CMR T1 may have a role in identifying patients with the greatest likelihood of reverse remodeling from mineralocorticoid receptor blockade.
- © 2013 by American Heart Association, Inc.