Diastolic dysfunction and mortality in severe sepsis and septic shock

Abstract

Aims: Systolic dysfunction in septic shock is well recognized and, paradoxically, predicts better outcome. In contrast, diastolic dysfunction is often ignored and its role in determining early mortality from sepsis has not been adequately investigated.

Methods and results: A cohort of 262 intensive care unit patients with severe sepsis or septic shock underwent two echocardiography examinations early in the course of their disease. All clinical, laboratory, and survival data were prospectively collected. Ninety-five (36%) patients died in the hospital. Reduced mitral annular e'-wave was the strongest predictor of mortality, even after adjusting for the APACHE-II score, low urine output, low left ventricular stroke volume index, and lowest oxygen saturation, the other independent predictors of mortality (Cox's proportional hazards: Wald = 21.5, 16.3, 9.91, 7.0 and 6.6, P< 0.0001, <0.0001, 0.002, 0.008, and 0.010, respectively). Patients with systolic dysfunction only (left ventricular ejection fraction ≤50%), diastolic dysfunction only (e'-wave <8 cm/s), or combined systolic and diastolic dysfunction (9.1, 40.4, and 14.1% of the patients, respectively) had higher mortality than those with no diastolic or systolic dysfunction (hazard ratio = 2.9, 6.0, 6.2, P= 0.035, <0.0001, <0.0001, respectively) and had significantly higher serum levels of high-sensitivity troponin-T and N-terminal pro-B-type natriuretic peptide (NT-proBNP). High-sensitivity troponin-T was only minimally elevated, whereas serum levels of NT-proBNP were markedly elevated [median (inter-quartile range): 0.07 (0.02-0.17) ng/mL and 5762 (1001-15 962) pg/mL, respectively], though both predicted mortality even after adjusting for highest creatinine levels (Wald = 5.8, 21.4 and 2.3, P= 0.015, <0.001 and 0.13).

Conclusion: Diastolic dysfunction is common and is a major predictor of mortality in severe sepsis and septic shock.

Figures

Figure 1

Kaplan–Meier survival curves of all patients divided into quartiles according to early-diastolic mitral annular peak velocity (e′ wave) (A), the ratio of early diastolic mitral inflow velocity to peak early mitral annular velocity (E/e′ ratio) (B), left-ventricular stroke-volume index (C) or to terciles according to early-to-late diastolic mitral inflow velocities. The displayed P-values represent groups with significant difference from the first quartile or tercile by Log-rank test. The numbers on the survival curves represent the number of patients remained after 5, 10, and 20 months of follow-up.

Figure 2

Kaplan–Meier survival curves of the patients divided into four groups: (A) normal systolic or diastolic function; (B) systolic dysfunction only (LVEF <50%); (C) diastolic dysfunction only (e′-wave <8 cm/s); (D) combined systolic and diastolic dysfunction (LVEF <50% and e′-wave <8 cm/s). The numbers on the survival curves represent the number of patients remained after 5, 10, and 20 months of follow-up.

Figure 3

Mean ± SD of log-transformed NT-proBNP and high-sensitivity troponin-T in each one of the four groups: (A) normal systolic or diastolic dysfunction (LVEF ≥50%, e′-wave ≥8 cm/s); (B) systolic dysfunction only (LVEF <50%); (C) diastolic dysfunction only (e′-wave <8 cm/s); (D) combined systolic and diastolic dysfunction.