Impact of Diastolic Function Parameters on the Risk for Left Atrial Appendage Thrombus in Patients with Nonvalvular...

In patients with nonvalvular atrial fibrillation (NVAF), the impact of left ventricular diastolic function on the risk for left atrial appendage (LAA) thrombus has not been prospectively studied.

At two academic medical centers, patients with NVAF were prospectively enrolled to undergo investigational transthoracic echocardiography immediately before clinically indicated transesophageal echocardiography. Mitral inflow E velocity and tissue Doppler septal and lateral mitral annulus velocities (e') were measured, and E/e' ratios were calculated.

Among 266 subjects (mean age, 65 years; 32% women), 17 (6.4%) had LAA thrombus. Patients with LAA thrombus had a higher mean CHA2DS2-VASc score (4.6 ± 1.7 vs 3.0 ± 1.8, P < .001), a higher mean lateral E/e' ratio (19.4 ± 10.1 vs 10.2 ± 5.6, P < .001), and a lower mean lateral e' velocity (7.0 ± 3.2 vs 10.4 ± 3.7 cm/sec, P = .001). There was a good discriminative capacity for E/e' (area under the curve, 0.83; P < .001) and e' velocity (area under the curve, 0.76; P = .001). None of the patients with normal E/e' ratios or normal e' velocities had LAA thrombus. Both E/e' (odds ratio, 1.13 per point; 95% CI, 1.06-1.20; P < .001) and e' velocity (odds ratio, 0.76 per 1 cm/sec; 95% CI, 0.63-0.92; P = .005) provided independent and incremental predictive value beyond the CHA2DS2-VASc score; however, E/e' provided greater incremental value than e' velocity (P = .036). Analyses using septal and averaged E/e' and septal e' velocity yielded similar results. Diastolic function parameters were also associated with the presence and intensity of left atrial spontaneous echo contrast, a precursor of LAA thrombus.

This prospective and concomitant evaluation of diastolic function and LAA thrombus in patients with NVAF demonstrates that E/e' ratio and e' velocity are associated with LAA thrombus, independent of CHA2DS2-VASc score, and may play a role in identifying patients at low risk for LAA thrombus. These data suggest that diastolic function assessment may improve stroke prediction in patients with NVAF.