Abstract 1979: Association of Renal Dysfunction, Myocardial Fibrosis and Survival in Patients with Severe Left Ventricular Dysfunction: A Delayed Hyperenhancement MRI Study
Background: Both renal dysfunction and severe left ventricular (LV) systolic dysfunction lead to reduced survival. Delayed hyperenhancement magnetic resonance imaging (DHE-MRI) accurately detects myocardial fibrosis (scar), seen commonly in patients with severe left ventricular (LV) dysfunction. We sought to determine the association of myocardial scar and renal dysfunction on survival in patients with severe LV dysfunction.
Methods: We studied 176 consecutive patients (61 ± 13 years, 73 % men) with severe LV systolic dysfunction (mean ejection fraction (24 ± 8 %) who underwent DHE-MRI (Siemens 1.5 T scanner, Erlangen, Germany) from 2005–6. Myocardial scar was determined visually on DHE-MR images, using custom software (Siemens Research), and defined as intensity >2 standard deviation above viable myocardium. Clinical and laboratory information, along with all-cause mortality, were recorded. Glomerular filtration rate (GFR, ml/min/1.73 m2) was calculated using the following formula: 186 × (serum creatinine−1.154) × (age−0.203) × 1.212 (if black) × 0.742 (if female). We divided patients into 4 groups:
GFR > 60, no scar (n = 28)
GFR > 60 with scar (n = 85)
GFR ≤ 60, no scar (n = 9) and
GFR ≤ 60 with scar (n = 53).
Results: There were 24 deaths in the group and 14 patients (65 %) had myocardial scar. Mean GFR was 70 ± 29 and 62 (35 %) patients had at-least moderate renal dysfunction (GFR < 60). Frequency of myocardial scar was higher in patients with GFR ≤ 60 vs. those with GFR > 60 (92 % vs. 79 %, p = 0.02). On multiple regression (including GFR, myocardial scar, coronary artery disease, hypertension, diabetes and coronary bypass), GFR and myocardial scar were associated with mortality (both p value < 0.05, overall model p value < 0.001). There were no deaths in group 1, 7 in group 2, 3 in group 3 and 14 in group 4 (p < 0.001). One year survival was significantly worse for groups 2, 3 and 4, compared to group 1 (log rank p value < 0.001).
Conclusion: Renal dysfunction is associated with a higher frequency of myocardial fibrosis in patients with severe LV dysfunction. Presence of renal dysfunction, myocardial fibrosis or both is associated with worse survival in such patients. The mechanistic association between renal dysfunction and myocardial fibrosis needs to be further defined.