Redefinition of uremic cardiomyopathy by contrast-enhanced cardiac magnetic resonance imaging

Abstract

Patients with end stage renal failure (ESRF) have an increased risk of premature cardiovascular disease. Left ventricular (LV) abnormalities, so called 'uremic cardiomyopathy', are associated with poorer outcome. Cardiac magnetic resonance imaging (CMR) accurately defines LV dimensions and identifies underlying myocardial pathology. We studied the relationship between LV function and myocardial pathology in ESRF patients with CMR. A total of 134 patients with ESRF underwent CMR. LV function was assessed with further images acquired after gadolinium-diethylentriaminepentaacetic acid (DTPA). The presence of myocardial fibrosis was indicated by late gadolinium enhancement (LGE). Two main myocardial pathologies were identified. A total of 19 patients (14.2%) displayed 'subendocardial LGE' representing myocardial infarction, which was associated with conventional cardiovascular risk factors including a history of ischemic heart disease (IHD) (P < 0.001), hypercholesterolemia (P < 0.05), and diabetes (P < 0.01). Patients with subendocardial LGE had greater LV mass (P < 0.05), LV dilation (P < 0.01), and LV systolic dysfunction (P < 0.001) compared to patients with no evidence of LGE. The second pattern, 'diffuse LGE', seen in 19 patients (14.2%) appeared to represent regional areas of diffuse myocardial fibrosis. Diffuse LGE was associated with greater LV mass compared to patients without LGE (P < 0.01) but not systolic dysfunction. In total, 28.4% of all patients exhibited evidence of myocardial fibrosis demonstrated by LGE. In contrast to published literature describing three forms of uremic cardiomyopathy - left ventricular hypertrophy (LVH), dilation, and systolic dysfunction, we have shown that LVH is the predominant cardiomyopathy specific to uremia, while LV dilation and systolic dysfunction are due to underlying (possibly silent) ischemic heart disease.

Determinants of Left Ventricular Mass and Hypertrophy in Hemodialysis Patients Assessed by Cardiac Magnetic Resonance Imaging

“…Since 2002 (10,11,13), we have used CMR as part of the standard assessment of patients for renal transplantation. The renal transplant unit at the Western Infirmary (Glasgow, Scotland, UK) provides transplant services to a population of 2.8 million people in the west of Scotland.…”

“…This technique has been established as the most accurate noninvasive method of assessing ventricular dimensions in patients, including those with stage 5 chronic kidney disease (10,11). In particular, measurements obtained by echocardiography tend to overestimate LVMI, particularly at higher values, when compared with CMR (12).…”

Cardiovascular Problems on Hemodialysis

“…It is characterized by a composite of inappropriate ventricular hypertrophy, marked interstitial fibrosis, microvessel disease with thickening of intramyocardial arteries, and capillary deficit (11). In a small biopsy controlled study, it was shown that cardiac fibrosis was a predictor of death (12). Cardiac fibrosis (causing arrhythmia as a result of reentry circuits) as well as diastolic malfunction (the result of reduced compliance [11]) are the most important causes of cardiac death and potentially future therapeutic targets.…”

Proof of concept study: Improvement of echocardiographic parameters after renal sympathetic denervation in CKD refractory hypertensive patients - diastolic function

“…In addition, among participants with more advanced kidney disease on dialysis, magnetic resonance imaging (MRI) with contrast demonstrates a diffuse pattern image with gadolinium uptake suggestive of fibrosis and non-ischemic cardiomyopathy [5]. Nowadays, the ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e′ ratio) is used for the evaluation of left ventricular filling pressure, and it has been used as a marker to diagnose diastolic heart failure (HF) [6,7].…”