Left ventricular mass monitoring in the follow-up of dialysis patients: prognostic value of left ventricular hypertrophy progression.

BACKGROUND: Regression of left ventricular hypertrophy (LVH) in the setting of a well-planned intervention study has been associated with longer survival in hemodialysis patients. Whether changes in left ventricular mass (LVM) in clinical practice predict survival and cardiovascular events in these patients is still unknown. METHODS: In a prospective study in 161 hemodialysis patients we tested the prognostic value of changes in LVM on survival and incident cardiovascular events. Echocardiography was performed twice, 18 +/- 2 SD months apart. Changes in LVM occurring between the first and the second echocardiographic study were then used to predict mortality and cardiovascular events during the ensuing 29 +/- 13 months. The prognostic value of LVM changes was tested in a multivariate Cox's model with LVM index (LVMI) [expressed as LVM/height(2.71)], included as a covariate to control for regression to the mean. RESULTS: The rate of increase of LVMI was significantly (P= 0.029) higher in patients with incident cardiovascular events than in those without such events. Accordingly, cardiovascular event-free survival in patients with changes in LVMI below the 25th percentile was significantly (P= 0.004) higher than in those with changes above the 75th percentile. In a multiple Cox regression analysis, including age, diabetes, smoking, homocysteine, 1 g/m(2.7)/month increase in LVMI was associated with a 62% increase in the incident risk of fatal and nonfatal cardiovascular events [hazard ratio 1.62 (95% CI 1.13-2.33), P= 0.009]. CONCLUSION: Changes in LVMI have an independent prognostic value for cardiovascular events and provide scientific support to the use of repeated echocardiographic studies for monitoring cardiovascular risk in dialysis patients.

Prognostic value of echocardiographic indicators of left ventricular systolic function in asymptomatic dialysis patients.

Patients with end-stage renal disease (ESRD) are at high risk for heart failure, but the prevalence and the prognostic value of asymptomatic systolic dysfunction in these patients are unknown. In this prospective cohort study, the authors have therefore assessed by echocardiography the prevalence and the prognostic value of systolic function as estimated by ejection fraction (EF), fractional shortening at endocardial level (endoFS), and at midwall (mwFS), in a cohort of 254 asymptomatic dialysis patients. Systolic dysfunction had a prevalence rate of 26% by endoFS and of 48% by mwFS. During the follow-up period, 125 patients had one or more fatal and nonfatal CV events. On multivariate COX regression analysis, the three LV systolic function indicators were independently associated with incident fatal and nonfatal CV events, and there were no differences in the predictive power of these indicators (P > 0.30). The prediction power of LV function indicators was largely independent of traditional and novel risk factors in ESRD such as C-reactive protein and asymmetric dimethyl arginine (ADMA). ADMA was significantly related with LV function indicators as well as with mortality and incident CV events, but these links were much reduced (P = NS) in models including LV function indicators. Of note, the risk of CV events was minimal in patients with normal LV mass and function, intermediate in patients with either LVH or systolic dysfunction, and maximal in patients displaying both alterations. The study of myocardial contractility by echocardiography provides prognostic information independently of LV mass and other risk factors in ESRD. Risk stratification by simple systolic function parameters may prove useful in secondary prevention strategies in these patients.

Heart valve calcifications, survival, and cardiovascular risk in hemodialysis patients.

BACKGROUND: Cardiovascular (CV) calcifications constitute a strong risk marker, and recent studies in continuous ambulatory peritoneal dialysis patients have associated valvular calcifications to inflammation, mortality, and CV events. The prognostic value of cardiac valve calcifications and their relationship with left ventricular hypertrophy and background cardiovascular risk in hemodialysis patients is still unknown. METHODS: The prognostic value of heart valve calcifications (detected by echocardiography) for all-cause and CV death was tested in a cohort of 202 hemodialysis (HD) patients. RESULTS: Forty-seven patients had 1 or more calcified valves. Background CV complications were more frequent (P = 0.001) and left ventricular hypertrophy was more severe (P < 0.001) in patients with calcified valves than in those without this alteration. During the follow-up period (44 +/- 23 months), 96 patients died, 66 patients (69%) of CV causes. Valve calcifications were significantly associated with all-cause (P = 0.02) and CV mortality (P < or = 0.001). However, in statistical models adjusting for traditional and nontraditional CV risk factors and background CV complications and left ventricular mass index (LVMI), the relationship between calcified valves and incident all-cause and CV mortality was not significant. CONCLUSION: In HD patients, cardiac valve calcifications predict all-cause and CV mortality in unadjusted analyses, but these associations are not evident in models adjusting for background CV complications, LVMI, and other risk factors. Cardiac valve calcifications do not provide an independent contribution in the prediction of death and CV mortality.

Prognostic impact of the indexation of left ventricular mass in patients undergoing dialysis.

Left ventricular hypertrophy (LVH) is exceedingly frequent in patients undergoing dialysis. Cardiac mass is proportional to body size, but the influence of various indexing methods has not been studied in patients with end-stage renal disease. The issue is important because malnutrition and volume expansion would both tend to distort the estimate of LV mass (LVM) in these patients. In a cohort of 254 patients, the prognostic impact on all-cause mortality and cardiovascular outcomes of LVH values, calculated according to two established methods of indexing, either body surface area (BSA) or height(2.7), was assessed prospectively. When LVM was analyzed as a categorical variable, the height(2.7)-based method identified a larger number of patients with LVH than the corresponding BSA-based method. One hundred and thirty-seven fatal and nonfatal cardiovascular events occurred during the follow-up period. Overall, 90 patients died, 51 of cardiovascular causes. In separate Cox models, both the LVM/height(2.7) and the LVM/BSA index independently predicted total and cardiovascular mortality (P < 0.001). However, the height(2.7)-based method coherently produced a closer-fitting model (P < or = 0.02) than did the BSA-based method. The height(2.7) index was also important for the subcategorization of patients according to the presence of concentric or eccentric LVH because the prognostic value of such subcategorization was apparent only when the height(2.7)-based criterion was applied. In conclusion, LVM is a strong and independent predictor of survival and cardiovascular events in patients undergoing dialysis. The indexing of LVM by height(2.7) provides more powerful prediction of mortality and cardiovascular outcomes than the BSA-based method, and the use of this index appears to be appropriate in patients undergoing dialysis.

Cardiac natriuretic peptides are related to left ventricular mass and function and predict mortality in dialysis patients.

This study was designed to investigate the relationship among brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) and left ventricular mass (LVM), ejection fraction, and LV geometry in a large cohort of dialysis patients without heart failure (n = 246) and to test the prediction power of these peptides for total and cardiovascular mortality. In separate multivariate models of LVM, BNP and ANP were the strongest independent correlates of the LVM index. In these models, the predictive power of BNP was slightly stronger than that of ANP. Both natriuretic peptides also were the strongest independent predictors of ejection fraction, and again BNP was a slightly better predictor of ejection fraction than ANP. In separate multivariate Cox models, the relative risk of death was significantly higher in patients of the third tertile of the distribution of BNP and ANP than in those of the first tertile (BNP, 7.14 [95% confidence interval (CI), 2.83 to 18.01, P = 0.00001]; ANP, 4.22 [95% CI, 1.79 to 9.92, P = 0.001]), and a similar difference was found for cardiovascular death (BNP, 6.72 [95% CI, 2.44 to 18.54, P = 0.0002]; ANP, 3.80 [95% CI, 1.44 to 10.03, P = 0.007]). BNP but not ANP remained as an independent predictor of death in a Cox's model including LVM and ejection fraction. Cardiac natriuretic peptides are linked independently to LVM and function in dialysis patients and predict overall and cardiovascular mortality. The measurement of the plasma concentration of BNP and ANP may be useful for risk stratification in these patients.