Diastolic dysfunction has major impact on sepsis mortality
MedWire News: Diastolic function is common in patients with severe sepsis or septic shock and is a strong predictor of mortality, a study shows.
"Although most clinical and investigational efforts in critically ill patients are focused at cardiac systolic function and the majority of cardiovascular monitoring instruments provide data almost exclusively on cardiac output and pressures, the present study shows that diastolic function is at least as important as systolic function and plays a major role in determining outcome, which should not be overlooked," say the researchers.
Of the 262 patients with severe sepsis or septic shock included in the study, 26% died in the intensive care unit, 36% died in hospital, and a further 7% died after discharge, during follow-up lasting an average of 13.5 months.
Giora Landesberg (Hadassah-Hebrew University Medical Center, Jerusalem, Israel) and team used septal e'-wave to represent diastolic dysfunction, as this was the only tissue Doppler imaging (TDI) variable to independently predict mortality, after adjustment for other TDI variables. Isolated diastolic dysfunction, defined as e'-wave below 8 cm/s, was present in 40.4% of patients. Diastolic dysfunction in combination with systolic dysfunction (left ventricular ejection fraction ≤50%) was present in 14.1%, and 9.1% had isolated systolic dysfunction.
Patients with diastolic dysfunction were 2.9-fold more likely to die than were patients with normal cardiac function, and this was the strongest independent predictor for mortality among all clinical and echocardiographic variables, the team reports in the European Heart Journal.
Patients with isolated systolic dysfunction also had poorer survival than those with normal cardiac function, but they were less likely to die than were those with diastolic dysfunction.
Other independent predictors of mortality, in order of importance, were high Acute Physiology and Chronic Health Evaluation (APACHE) II score, low urine output, low left ventricular stroke volume index, and lowest arterial oxygen saturation.
The researchers note that "fluid loading is one of the mainstays in the haemodynamic management of sepsis to increase cardiac output," but add that it "may also be particularly hazardous in septic patients with microvascular dysfunction and increased vascular permeability by causing interstitial oedema with subsequent tissue hypoxia, organ dysfunction, and death."
They say: "It is not surprising therefore that the 'right' amount of fluid resuscitation is frequently debated in septic patients and echocardiography may have an important role in assessing cardiac load and cardiac response to fluids in this setting."
Landesberg et al note that diastolic dysfunction was associated with age, hypertension, diabetes, and history of ischemic heart disease, suggesting that diastolic dysfunction may have pre-existed in many of their patients, but suggest that sepsis could trigger or aggravate the condition and that this should be explored in future studies. "Additional studies are also needed to show what therapeutic interventions might improve diastolic function and survival in septic patients," they add.
By Eleanor McDermid