CHICAGO — Tissue Doppler imaging of the heart may be a way to safely and noninvasively screen asymptomatic people who are at risk of dying from heart failure, according to results from a pilot study.
Participants in the study who fell into the lowest tertile of left ventricular motion had a 2.6-fold increased risk of dying over the next 5 years, compared with patients who had the highest level of ventricular wall motion, in an analysis that controlled for age and gender, Dr. Rasmus Mogelvang said at the annual meeting of the American College of Cardiology.
The finding suggested tissue Doppler imaging (TDI) may be effective for early detection of heart failure and an increased risk of death from heart failure, but the data collected so far are preliminary and did not allow Dr. Mogelvang, a cardiologist at Gentofte Hospital in Copenhagen, and his associates to calculate a threshold value for increased risk.
“Before we can start to use this in daily practice, we need to set cut-off values,” he said.
The investigators used TDI data collected on 1,100 apparently healthy people enrolled in the Copenhagen City Heart Study, with an average age of about 60 years. They all underwent ventricular assessment using both TDI and conventional echocardiography, and were then followed for an average of 5.1 years. During follow-up, 90 people died.
Three TDI measurements were made for each subject: s', which corresponds to left ventricular wall motion at peak systole; e', which is wall motion between systole and diastole; and a', wall speed at end diastole. In general, people with slower ventricular wall motion also had worse survival. Wall-motion speed is also linked with age; older people have reduced wall-motion speed.
In a series of multivariate analyses that adjusted for baseline differences in age and gender, a combined wall-speed assessment that included readings for s', e', and a' was the best correlate of survival, Dr. Mogelvang reported. In absolute terms, 5-year survival was about 96% in people in the tertile with the greatest wall motion, about 92% in those in the middle tertile, and about 85% in those in the tertile with the lowest level of wall motion.
The combined TDI value, which integrated s', e', and a', was a powerful predictor of survival even in people who had normal ventricular function based on their conventional echocardiogram, he said.