Angiotensin converting enzyme inhibition for cardiac hypertrophy in patients with end-stage renal disease: what is the evidence?

Cardiovascular Autonomic Dysfunction in Chronic Kidney Disease: a Comprehensive Review

Cardiovascular autonomic dysfunction is a major complication of chronic kidney disease (CKD), likely contributing to the high incidence of cardiovascular mortality in this patient population. In addition to adrenergic overdrive in affected individuals, clinical and experimental evidence now strongly indicates the presence of impaired reflex control of both sympathetic and parasympathetic outflow to the heart and vasculature. Although the principal underlying mechanisms are not completely understood, potential involvements of altered baroreceptor, cardiopulmonary, and chemoreceptor reflex function, along with factors including but not limited to increased renin-angiotensin-aldosterone system activity, activation of the renal afferents and cardiovascular structural remodeling have been suggested. This review therefore analyzes potential mechanisms underpinning autonomic imbalance in CKD, covers results accumulated thus far on cardiovascular autonomic function studies in clinical and experimental renal failure, discusses the role of current interventional and therapeutic strategies in ameliorating autonomic deficits associated with chronic renal dysfunction, and identifies gaps in our knowledge of neural mechanisms driving cardiovascular disease in CKD.

Cardiovascular effects of angiotensin converting enzyme inhibition or angiotensin receptor blockade in hemodialysis: a meta-analysis

BACKGROUND AND OBJECTIVES

Cardiovascular (CV) disease causes significant morbidity and mortality among the hemodialysis (HD) population. This meta-analysis was performed to determine whether angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) reduce fatal and nonfatal CV events and left ventricular (LV) mass in patients receiving HD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Studies were identified by searching electronic databases, bibliographies, and conference proceedings. Two reviewers independently selected randomized controlled trials using ACEIs or ARBs compared with control among patients receiving HD. Studies were independently assessed for inclusion, quality, and data extraction. Random-effects models were used to estimate the pooled relative risk (RR) for CV outcomes and the weighted mean difference (WMD) for pooled change-from-baseline comparisons for LV mass for ACEI or ARB treated patients compared with control.

RESULTS

Compared with control, the RR of CV events associated with ACEI or ARB use was 0.66 [95% confidence interval (CI) 0.35 to 1.25; P = 0.20]. ACEI or ARB use resulted in a statistically significant reduction in LV mass, with a WMD of 15.4 g/m(2) (95% CI 7.4 to 23.3; P < 0.001).

CONCLUSIONS

Treatment with an ACEI or ARB reduced LV mass in patients receiving HD. However, their use was not associated with a statistically significant reduction in the risk of fatal and nonfatal CV events. Larger, high-quality trials in the HD population are required to determine if the effects of ACEI or ARB therapy on LV mass translate into decreased CV morbidity and mortality.

Effect of ramipril on left ventricular mass in normotensive hemodialysis patients

BACKGROUND

Normotensive hemodialysis patients may still have left ventricular hypertrophy in the absence of significant pressure or volume overload. We examined the hypothesis that treatment with an angiotensin-converting enzyme inhibitor could be beneficial in the reversal of left ventricular hypertrophy in these patients.

METHODS

Forty-six normotensive patients with end-stage renal disease on regular hemodialysis therapy were randomly assigned to administration of ramipril, 2.5 mg 3 times/wk, or placebo for 1 year. Left ventricular mass index and parameters of cardiovascular structure and function were evaluated noninvasively by means of echocardiography and arterial tonometry at baseline, 6 and 12 months after treatment, and 1 month after washout.

RESULTS

In the ramipril group, blood pressure decreased significantly at 6 and 12 months after treatment. There were no significant within-group or between-group differences in left ventricular mass index at entry, 6 and 12 months after treatment, and 1 month after washout. There were no significant differences in left atrial dimension, left ventricular size and wall thickness, left ventricular ejection fraction, aortic dimension, intima-media thickness, elastic modulus and augmentation index of the common carotid artery, and aortic pulse wave velocity between the ramipril and placebo groups at entry, 6 and 12 months after treatment, and 1 month after washout.

CONCLUSION

A 12-month treatment with ramipril did not cause significant regression of left ventricular hypertrophy in normotensive hemodialysis patients. Results may suggest that the renin-angiotensin system has little role in the pathogenesis of mild left ventricular hypertrophy in these patients.