Adverse myocardial effects of B-vitamin therapy in subjects with chronic kidney disease and hyperhomocysteinaemia.

BACKGROUND & AIMS: Hyperhomocysteinaemia (HHCY), a common finding in patients with chronic kidney disease (CKD), has been shown to contribute to adverse cardiac remodelling and failure. We hypothesised that in human subjects with CKD, HHCY would be associated with myocardial dysfunction, and that homocysteine (HCY)-lowering therapy would improve myocardial remodelling and heart-failure (HF) outcomes. METHODS AND RESULTS: Post hoc analysis of the Homocysteinemia in Kidney and End Stage Renal Disease (HOST) trial (n=2056) was performed to determine if HCY-lowering therapy with high dose B vitamins affects HF outcomes in patients with CKD. In addition, effects on myocardial remodelling were assessed in a subgroup of 220 trial subjects who had transthoracic echocardiograms done before study randomisation and during the course of the study as part of their routine clinical care. HF outcomes were not significantly affected by treatment compared to the placebo. HCY levels were inversely correlated with diastolic function (R=-0.21; p=0.038). Vitamin therapy resulted in a significant increase in left atrial size (+0.15±0.8 cm vs. -0.13±0.07 cm; p=0.0095). No other echocardiographic parameters were significantly associated with baseline HCY levels or changes with vitamin therapy. CONCLUSION: HHCY is associated with diastolic dysfunction in patients with CKD. However, B-vitamin therapy did not improve HF outcomes despite lowering of plasma HCY levels, and was associated with an increase in left atrial size, which is a surrogate for worsening left ventricular diastolic dysfunction. These findings suggest that high-dose B vitamin therapy may be harmful in patients with CKD.

Retrospective look at change in brain natriuretic peptide values in ambulatory patients with chronic heart failure.

BACKGROUND: There is significant interest in the role of B-type natriuretic peptide (BNP) guided therapy for outpatient congestive heart failure (CHF) patients. The objective of this study was to see if the percentage change in BNP levels can predict CHF hospitalisations or death. METHODS: We retrospectively reviewed the records of CHF patients who had BNP levels drawn on two clinic visits. Patients were divided into two groups, those with a 70% or greater increase in the BNP values and those in whom the BNP value either decreased or did not increase by 70%. Primary outcome measured was the need for hospitalisation for CHF or death within 6 months of the second clinic visit. RESULTS: One hundred and fourteen (114) paired BNP measurements were included in the analysis. Of these, 26 had > 70% increase in BNP while 88 did not. Hospitalisations for CHF or death at 6 months were significantly higher in the former group than the latter (p = 0.04). On multivariate regression analysis significant change in BNP remained a predictor of adverse outcomes. CONCLUSIONS: In stable outpatients with CHF, > 70% increase in BNP is an independent risk factor for CHF hospitalisations or death at 6 months.