Is echocardiography valid and reproducible in patients with atrial fibrillation? a systematic review

Aims: Echocardiography is vital in the routine assessment and management of atrial fibrillation (AF). We performed a systematic review of the validity and reproducibility of echocardiographic left ventricular systolic and diastolic function in AF, and optimal acquisition methods. Methods: Online databases were searched for studies in patients with AF at the time of echocardiography (1960 to August 2015), prospectively registered with PROSPERO (CRD42015025297). Results: The systematic review included 32 studies from 3,066 search results (1,968 patients with AF). Average age was 67 years, 33% were women, mean LVEF 53% (±10%) and average E/e’ 11.7 (±2.7). Data on the validity and reproducibility of systolic indices were extremely limited. In contrast, diastolic parameters demonstrated correlation with invasive filling pressure and adequate reproducibility: E/e’ (n=444) r= 0.47 to 0.79; IVRT (n=177) r= -0.70 to -0.95; E/Vp (n=55) r= 0.63 and 0.65; pulmonary vein diastolic flow (n=67) r= -0.80 and -0.91. Elevated E/e’ (>15) was associated with functional capacity, quality of life and impaired prognosis. For optimal acquisition in AF patients, cardiac cycles with controlled heart rate (<100 beats/minute) and similar preceding and pre-preceding RR intervals are required. Cardiac cycle length and equivalence were more important that the number of beats averaged. Conclusions: With careful selection of appropriate cardiac cycles, echocardiography is a valid tool to identify diastolic dysfunction in AF, and E/e’ is an independent marker of clinical status and adverse prognosis. However, data on systolic function was extremely limited and requires further prospective study and assessment of variability in clinical practice.