Tissue Doppler-derived E/e' ratio as a parameter for assessing diastolic heart failure and as a predictor of mortality in patients with chronic kidney disease

Abstract

Background/aims: Diastolic dysfunction occurs frequently in patients with chronic kidney disease (CKD) and is associated with heart failure (HF) or mortality. We investigated whether the ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e' ratio), estimated using tissue Doppler imaging, has prognostic value for cardiovascular morbidity and all-cause mortality in patients with CKD.

Methods: For 186 patients with CKD of stages III to V, we obtained echocardiograms with tissue Doppler imaging. A 5-year follow-up of 136 patients was performed based on hospital records and telephone interviews. The enrolled patients (79 males and 57 females) were categorized into the following CKD subgroups: stage III (n = 25); stage IV (n = 22); and stage V (n = 89).

Results: The average follow-up period was 30.45 months and the mean age of the patients was 61.13 years. The mortality rate after 5 years was 60.0%. The causes of death were: sepsis, 21.9%; HF, 16.2%; and sudden death, 15.2%. Age (p = 0.000), increased C-reactive protein level (p = 0.018), and increased E/e' ratio (p = 0.048) were found to correlate with mortality. Age (p = 0.000), decreased ejection fraction (p = 0.003), and increased E/e' ratio (p = 0.045) correlated with cardiovascular event.

Conclusions: The E/e' ratio can predict mortality and cardiovascular events in patients with CKD who have diastolic dysfunction.

Keywords: Chronic kidney disease; Diastolic heart failure; Echocardiography, Doppler; Mortality.

Figure 1

Causes of death for all patients during follow-up period. The most common cause of death is sepsis (n = 23, 16.91%), followed by congestive heart failure (CHF) (n = 17, 12.5%) and sudden death (n = 16, 11.76%). ICH, intracerebral hemorrhage; GI, gastrointestinal.

Figure 2

Kaplan-Meier curves for patient survival. In the Kaplan-Meier analysis, the survival rate for patients in the E/e' ratio group > 15 is lower than that for patients in the E/e' ratio group < 15 (p = 0.037). E, early diastolic mitral inflow velocity; e', early diastolic mitral annulus velocity.

Figure 3

Kaplan-Meier curves for cumulative cardiovascular events. In the Kaplan-Meier analysis, the cumulative risk of cardiovascular events is higher in the group with E/e' ratio > 15 than in the group with E/e' ratio < 15 (p = 0.007). E, early diastolic mitral inflow velocity; E', early diastolic mitral annulus velocity.

Figure 4

Kaplan-Meier curves for cardiovascular mortality. In the analysis performed by the Kaplan-Meier method, the death due to cardiovascular diseases the E/e' ratio group higher than 15 occurred more than lower group (p = 0.005). E, early diastolic mitral inflow velocity; e', early diastolic mitral annulus velocity.

Figure 5

Receiver operating characteristic (ROC) curves of E/e' ratios for (A) mortality rates and (B) cardiovascular events. In the ROC curve for mortality, when the E/e' ratio is 14.4, the sensitivity is 62.9% and the specificity is 72.2% (A). Concerning the incidence of cardiovascular disease, when the E/e' ratio is 13.08, the sensitivity is 63.2% and the specificity is 68.2% (B). E, early diastolic mitral inflow velocity; e', early diastolic mitral annulus velocity.