This article is more than 5 years old. Information may no longer be current.
Left atrial deformation on imaging indicative of stroke risk in AF patients
Reduced left atrial reservoir function, as indicated by tissue-tracking cardiac magnetic resonance imaging, may aid in the early detection of patients with atrial fibrillation at risk for stroke, according to results published in the Journal of the American Heart Association.
The single-center, retrospective cross-sectional study included data collected from 169 patients (mean age 59 years, 74% men) with a history of AF who underwent preablation cardiac magnetic resonance (CMR) imaging. All participants were in sinus rhythm at the time of CMR. The researchers used tissue-tracking CMR to measure left atrial volume, emptying fraction, strain and strain rate in all patients.
Compared with patients without a history of stroke or transient ischemic attack, 18 patients with history of stroke or TIA had significantly greater minimum left atrial volume (35.1 ± 15.8 mL/m2 vs. 24.6 ± 10.7 mL/m2; P < .001) and maximum left atrial volume (52.2 ± 16.2 mL/m2 vs. 44.2 ± 12.9 mL/m2; P = .024).
Total emptying fraction (34.6 ± 13.5% vs. 45.6 ± 11.8%; P < .001), left atrial maximum strain (19.4 ± 9.2% vs. 28.6 ± 10.6%; P < .001), pre-atrial contraction strain (10.1 ± 6.6% vs. 15 ± 7.1%; P = .01) and absolute values of left atrial strain rate (0.81 ± 0.37 1/s vs. 1.15 ± 0.47 1/s; P = .005 for left ventricular systole and –0.78 ± 0.41 1/s vs. –1.12 ± 0.62; P = .03 for early diastole) were significantly lower in these 18 patients.
Left atrial reservoir function was significantly associated with risk for stroke or TIA on multivariable analysis, including the total emptying fraction (OR = 0.94; 95% CI, 0.89-0.99), left atrial maximum strain (OR = 0.91; 95% CI, 0.84-0.97) and left atrial strain rate during left ventricular systole (OR = 0.17; 95% CI, 0.02-0.94).
“Our research suggests that certain features of the heart’s upper left chamber that are easily seen on heart MRI could be the smoking gun we need to tell apart low-risk from high-risk patients,” Hiroshi Ashikaga, MD, PhD, assistant professor of medicine and biomedical engineering at the Johns Hopkins University School of Medicine, said in a press release. “Maybe when it comes to stroke and [AF], we’ve been chasing the wrong guy all along. Maybe AF itself is not the real culprit and dysfunction of the left atrium is … It’s a possibility we have to consider, and will in an upcoming study.” – by Adam Taliercio
Disclosure: The researchers report no relevant financial disclosures.