NT-proBNP can be used to detect right ventricular systolic dysfunction in pulmonary hypertension.

Right ventricular systolic dysfunction (RVSD) at baseline (pre-treatment) predicts early death in patients with pulmonary hypertension (PH). However, RVSD can only be detected reliably by prohibitively invasive or expensive techniques. N-terminal B-type natriuretic peptide concentration ([NT-proBNP]) correlates with RV function in PH; however, an [NT-proBNP] threshold that indicates RVSD in individual patients has not previously been determined. Twenty-five patients with PH (pulmonary arterial hypertension (n = 19) or chronic thromboembolic PH (n = 6)) underwent cardiovascular magnetic resonance (CMR) imaging and NT-proBNP measurement at baseline. [NT-proBNP] was correlated against RV dimensions and ejection fraction (RVEF) measured directly by CMR imaging. The ability of NT-proBNP to detect RVSD (defined as a CMR-derived RVEF >2 SDS below control values) was tested and predictors of [NT-proBNP] identified. [NT-proBNP] correlated negatively with RVEF. RVSD was present in nine out of 25 patients. An [NT-proBNP] threshold of 1,685 pg.mL(-1) was sensitive (100%) and specific (94%) in detecting RVSD. RVEF and RV mass index independently predicted [NT-proBNP]. In pulmonary hypertension, a baseline N-terminal B-type natriuretic peptide concentration of >1,685 ng.L(-1) suggests right ventricular systolic dysfunction, and thus an increased risk of early death. N-terminal B-type natriuretic peptide could prove useful as an objective, noninvasive means of identifying patients with pulmonary hypertension who have right ventricular systolic dysfunction at presentation.

Vascular function in patients with end-stage renal disease and/or coronary artery disease: a cardiac magnetic resonance imaging study.

Decreased arterial compliance in end-stage renal disease (ESRD) is associated with increased cardiovascular risk. Our aim was to examine aortic compliance in patients with ESRD using cardiac magnetic resonance imaging (MRI) and to compare these with patients with advanced atherosclerotic disease who are known to be at high cardiovascular risk. We examined a total of 83 subjects matched for age: 24 had ESRD and were on dialysis therapy for 3+/-6 years, 24 had severe coronary artery disease (CAD), 11 had both ESRD and CAD (4+/-5 years on dialysis therapy), and 24 healthy subjects with no evidence of CAD. Vascular and cardiac function was assessed using cardiac MRI. Aortic compliance was significantly reduced in patients with CAD compared to control subjects (11.3+/-6.3 ml x 10(-3)/mm Hg vs 15.6+/-6.0 ml x 10(-3)/mm Hg, P=0.009). Patients with ESRD also exhibited significantly reduced aortic compliance compared to healthy controls (12.4+/-5.8 ml x 10(-3)/mm Hg vs 15.6+/-6.0 ml 10(-3)/mm Hg, P=0.012), whereas there was no significant difference in aortic compliance between patients with CAD and ESRD. Even in the absence of symptomatic CAD, patients with ESRD have significantly reduced aortic compliance compared to normal subjects. Patients with ESRD have equivalent aortic compliance to patients with advanced CAD. These findings suggest that a significantly reduced aortic compliance is one of many mechanisms promoting premature cardiovascular events in patients with ESRD compared to age-matched controls from the general population.

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

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.