Characterization of cardiac mechanics and incident atrial fibrillation in participants of the Cardiovascular Health Study

Abstract

BACKGROUND. Left atrial (LA) and left ventricular (LV) remodeling are associated with atrial fibrillation (AF). The prospective associations of impairment in cardiac mechanical function, as assessed by speckle-tracking echocardiography, with incident AF are less clear. METHODS. In the Cardiovascular Health Study, a community-based cohort of older adults, participants free of AF with echocardiograms of adequate quality for speckle tracking were included. We evaluated the associations of indices of cardiac mechanics (LA reservoir strain, LV longitudinal strain, and LV early diastolic strain rate) with incident AF. RESULTS. Of 4341 participants with strain imaging, participants with lower LA reservoir strain were older, had more cardiometabolic risk factors, and had lower renal function at baseline. Over a median follow-up of 10 years, 497 (11.4%) participants developed AF. Compared with the highest quartile of LA reservoir strain, the lowest quartile of LA reservoir strain was associated with higher risk of AF after covariate adjustment, including LA volume and LV longitudinal strain (Hazard Ratio [HR], 1.80; 95% CI, 1.31-2.45; P < 0.001). The association of LA reservoir strain and AF was stronger in subgroups with higher blood pressure, NT-proBNP, and LA volumes. There were no associations of LV longitudinal strain and LV early diastolic strain rate with incident AF after adjustment for LA reservoir strain. CONCLUSION. Lower LA reservoir strain was associated with incident AF, independent of LV mechanics, and with stronger associations in high-risk subgroups. These findings suggest that LA mechanical dysfunction precedes the development of AF. Therapies targeting LA mechanical dysfunction may prevent progression to AF.

Optimizing indices of atrial fibrillation susceptibility and burden to evaluate atrial fibrillation severity, risk and outcomes

“…In recent years, great developments on clinical imagery, such as LA strain-derived quantification of LA function, could fill the gap between biological knowledge and clinical care of the arrhythmia. The role of LA strain in AF is promising since there is increasing evidence that LA strain could be used as a valid predictor of AF occurrence and recurrence, 51 and potentially as a predictor of thromboembolic events. Additionally, LA strain may finely characterize the tissue composition including fibrosis, fat accumulation, and pave the way for the search of new biomarkers in high-risk patients.…”

“…As a marker of pre-clinical atrial dysfunction, LA strain strongly predicted new-onset AF, independently of traditional LA measurements and clinical risk factors. 51 …”

Atrial fibrillation and atrial cardiomyopathies

“…Reduced LA reservoir strain has been associated with higher risk of incidence of AF, independent of measures of LA size; this marker has additionally been associated with heart failure with preserved ejection fraction and has been shown to correlate with elevated LV filling pressures during exercise. [46][47][48][49][50] Furthermore, subjects with brief paroxysmal AF, defined as episodes <30 s, had lower LA reservoir function than patients without AF history; these measurements were obtained during sinus rhythm. 51 Replicated in many studies, it is becoming clear that atrial mechanics remain abnormal, even during periods of sinus rhythm, in patients with a history of AF, thus suggesting that subclinical atrial myopathy may precede the presentation of clinical AF.…”

“…LA strain allows for investigation of LA reservoir function or the ability of the LA to stretch during ventricular systole and concomitant atrial filling. Reduced LA reservoir strain has been associated with higher risk of incidence of AF, independent of measures of LA size; this marker has additionally been associated with heart failure with preserved ejection fraction and has been shown to correlate with elevated LV filling pressures during exercise 46–50 . Furthermore, subjects with brief paroxysmal AF, defined as episodes <30 s, had lower LA reservoir function than patients without AF history; these measurements were obtained during sinus rhythm 51 .…”

Left atrial booster-pump function as a predictive parameter for atrial fibrillation in patients with severely dilated left atrium

“…Speckletracking echocardiography (STE) is a non-Doppler echocardiographic method to quantify atrial deformation by calculating both the atrial longitudinal strain and strain rate of atrial segments and has been proposed as a non-invasive technique to assess atrial fibrosis (8,9). The influences of strain and strain rate on patients with AF were described previously (10). However, the LA mechanics in patients with severely enlarged left atrium without AF have not been well evaluated yet.…”