15 research outputs found
Meta-analysis of B-type natriuretic peptide's ability to identify stress induced myocardial ischemia
MRI of the left atrium at 3T:Evaluation of measurement reproducibility in healthy volunteers and patients with cardiovascular disease
Background Left ventricular (LV) function has traditionally been the focus for cardiac magnetic resonance imaging (MRI) investigations, but similar methods can also be applied to the left atrium (LA). Previous studies elsewhere have almost entirely involved the use of 1.5T systems, but 3T MRI can provide faster data acquisition with thinner image slices, and may be more suitable for quantifying the structure and function of the LA. Purpose To evaluate 3T-MRI for LA volume assessments in: (i) healthy volunteers (HV); (ii) patients with LV-hypertrophy and ischemia (LVHI); and (iii) patients with LV-hypertrophy and diabetes (LVHD). Material and Methods Participants were imaged using a balanced steady-state free precession sequence. Healthy volunteers were scanned twice and patients were scanned on one occasion. Volumes were segmented by two observers, and coefficients of repeatability (CoR) were derived. Results For LA volumes (indexed to body surface area), CoRs were in the range of 1.3–4.6 mL/m2. The LVHI patients had enlarged LA volumes (diastolic, 46.4 mL/m2; systolic, 25.9 mL/m2) and reduced ejection fraction (EF) (44.9%) relative to the HV (diastolic, 39.0 mL/m2; systolic, 17.8 mL/m2; EF, 54.5%) and LVHD groups (diastolic, 41.4 mL/m2; systolic, 20.2 mL/m2; EF, 50.7%). LA volumes were moderately correlated with LV mass in the HV group (R2 = 0.59 for LA end-systolic volume), but became weaker (R2 ≤ 0.17) for patient groups. Conclusion 3T-MRI derived LA volume measurements are simple and repeatable, and can elicit clear differences between LVHI patients and HVs. These MRI endpoints provide scope for improved radiological interpretation of LA structure and function, and the high degree of repeatability validates their use for longitudinal investigations where precision work is essential. </jats:sec
Allopurinol reduces left ventricular mass in patients with type ii diabetes and left ventricular hypertrophy
ObjectivesThis study sought to ascertain whether high-dose allopurinol causes regression of left ventricular mass (LVM) in patients with type 2 diabetes mellitus (T2DM).BackgroundLeft ventricular hypertrophy (LVH) is common in T2DM and contributes to patients' high cardiovascular (CV) event rate. Oxidative stress (OS) has been implicated in LVH development, and allopurinol has been previously shown to reduce vascular OS. We therefore investigated whether allopurinol causes regression of LVH in patients with T2DM.MethodsWe conducted a randomized, double-blind, placebo-controlled study of 66 optimally-treated T2DM patients with echocardiographic evidence of LVH. Allopurinol, 600 mg/day, or placebo was given over the study period of 9 months. The primary outcome was reduction in LVM as calculated by cardiac magnetic resonance imaging at baseline and at 9 months' follow-up. Secondary endpoints were change in flow-mediated dilation and augmentation index.ResultsAllopurinol significantly reduced absolute LVM (−2.65 ± 5.91 g vs. placebo group +1.21 ± 5.10 g [p = 0.012]) and LVM indexed to body surface area (−1.32 ± 2.84 g/m2 vs. placebo group +0.65 ± 3.07 g/m2 [p = 0.017]). No significant changes were seen in either flow-mediated dilation or augmentation index.ConclusionsAllopurinol causes regression of LVM in patients with T2DM and LVH. Regression of LVH has been shown previously to improve CV mortality and morbidity. Therefore, allopurinol therapy may become useful to reduce CV events in T2DM patients with LVH. (Allopurinol in Patients with Diabetes and LVH; UKCRN 8766
MRI of the left atrium at 3T: evaluation of measurement reproducibility in healthy volunteers and patients with cardiovascular disease
High-Dose Allopurinol reduces left ventricular mass in patients with ischemic heart disease
ObjectivesThis study sought to ascertain if high-dose allopurinol regresses left ventricular mass (LVM) in patients with ischemic heart disease (IHD).BackgroundLV hypertrophy (LVH) is common in patients with IHD including normotensive patients. Allopurinol, a xanthine oxidase inhibitor, has been shown to reduce LV afterload in IHD and may therefore also regress LVH.MethodsA randomized, double-blind, placebo-controlled, parallel group study was conducted in 66 patients with IHD and LVH, comparing 600 mg/day allopurinol versus placebo therapy for 9 months. The primary outcome measure was change in LVM, assessed by cardiac magnetic resonance imaging (CMR). Secondary outcome measures were changes in LV volumes by CMR, changes in endothelial function by flow-mediated dilation (FMD), and arterial stiffness by applanation tonometry.ResultsCompared to placebo, allopurinol significantly reduced LVM (allopurinol −5.2 ± 5.8 g vs. placebo −1.3 ± 4.48 g; p = 0.007) and LVM index (LVMI) (allopurinol −2.2 ± 2.78 g/m2 vs. placebo −0.53 ± 2.5 g/m2; p = 0.023). The absolute mean difference between groups for change in LVM and LVMI was −3.89 g (95% confidence interval: −1.1 to −6.7) and −1.67 g/m2 (95% confidence interval: −0.23 to −3.1), respectively. Allopurinol also reduced LV end-systolic volume (allopurinol −2.81 ± 7.8 mls vs. placebo +1.3 ± 7.22 mls; p = 0.047), improved FMD (allopurinol +0.82 ± 1.8% vs. placebo −0.69 ± 2.8%; p = 0.017) and augmentation index (allopurinol −2.8 ± 5.1% vs. placebo +0.9 ± 7%; p = 0.02).ConclusionsHigh-dose allopurinol regresses LVH, reduces LV end-systolic volume, and improves endothelial function in patients with IHD and LVH. This raises the possibility that allopurinol might reduce future cardiovascular events and mortality in these patients. (Does a Drug Allopurinol Reduce Heart Muscle Mass and Improve Blood Vessel Function in Patients With Normal Blood Pressure and Stable Angina?; ISRCTN73579730