CHICAGO — Atrial fibrillation-associated morbidity and mortality are on the increase, and a new study pointed out the critical need for improved surveillance and prevention strategies to reduce the condition which can lead to strokes.
The report in The Journal of Interventional Cardiac Electrophysiology argued that specific echocardiographic parameters that can predict future onset of AF within three months are needed.1
To help achieve that, researchers from the University of Illinois Chicago and the Jesse Brown VAMC in Chicago compared 20 patients with AF, identified through ICD-9 diagnosis code, were compared with a control group of 20 age- and sex-matched patients selected from the same clinic population but without a diagnosis of AF.
The study team reviewed transthoracic echocardiograms (TTE) obtained within 90 days prior to first documented AF episode (study group) or obtained closest to first clinic visit (control). The two groups had similar baseline characteristics, including age, BMI, presence of hypertension, hyperlipidemia, diabetes, and heart failure.
Results indicated that most closely associated with AF compared to the control group were:
- Increased left atrial (LA) size (end systolic major axis in 2-chamber view: AF 4.62±0.03 vs control 3.79±0.21, P =0.03),
- Increased mitral inflow (E/A ratio: AF 1.35±0.15 vs control 1.06±0.07, P =0.04), and
- Reduced LA global longitudinal strain (AF -2.69±0.26 vs control – 3.59±0.31, P =0.04)
Based on predictive models developed through multivariate logistic regression, researchers determined that a combination of imaging and traditional clinical risk factors was the best AF prediction model with AUC (area under the curve) of 0.94. They pointed out that the AUC “greatly exceeds the current best predictors published.”
From the parameters, the study team developed the SMASH2 scoring system for 90- day AF risk estimation.
“Risk factors for AF and early features of atrial cardiomyopathy including male sex, hypertension, LA enlargement, reduced mitral inflow and reduced LA strain are powerful predictors of AF onset within 90 days and may be used to prognosticate future AF risk,” the authors wrote.
AF is the most common cardiac arrhythmia worldwide, affecting as many as 70 million people. In the United States, an estimated 6 million patients are being treated for AF. The VA has cared for as many as a million AF patients in the past decade.
The condition is associated with increased mortality and morbidity, including congestive heart failure, coronary heart disease, and ischemic stroke, the risk of which increases by five-fold with AF, according to recent VA research.
Darlington AM, Rodriguez Ziccardi MC, Konda S, Gonzalez-Gonzalez FJ, Nazir NT, McCauley MD. Left atrial echocardiographic parameters predict the onset of atrial fibrillation: the SMASH2 scoring system. J Interv Card Electrophysiol. 2022 May 17. doi: 10.1007/s10840-022-01243-8. Epub ahead of print. PMID: 35579783.