Left Atrial Strain to Predict Postoperative Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting.

BACKGROUND: Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery being associated with poorer outcomes. Revealing before the operation of left atrial subtle structural/functional abnormalities may help to identify patients at increased risk of POAF. We investigated the role of left atrial strain parameters by preoperative speckle tracking echocardiography as independent predictors of POAF in patients undergoing coronary artery bypass graft. METHODS: Consecutive patients undergoing isolated coronary artery bypass graft were prospectively enrolled at three Italian centers. All patients underwent transthoracic echocardiography before the operation. The occurrence of POAF up to discharge was monitored. RESULTS: Overall, a total of 310 patients were included. POAF was demonstrated in 103 patients (33%). At receiver operating characteristic curve analysis, lower global peak atrial longitudinal strain (PALS) values significantly predicted the risk of POAF (area under the curve, 0.74; P<0.001). The optimal cutoff value for the arrhythmia prediction was a global PALS value <28%, with a specificity of 86% and a sensitivity of 36%. The incidence of POAF was 51% in patients with global PALS <28% versus 14% in those with PALS ≥28% (P<0.001), with a POAF-free survival at Kaplan-Meier analysis of 45.4% and 85.7%, respectively (P<0.001). At multivariate analysis, a global PALS <28% carried a 3.6-fold higher risk of POAF (hazard ratio, 3.6 [95% CI, 2.2-5.9]; P<0.001). The risk increase was even higher when PALS <28% was associated with age ≥70 years (adjusted hazard ratio, 11.2 [4.7-26.6], P<0.001). CONCLUSIONS: A presurgery global PALS <28% is a specific parameter to stratify patients at increased risk of POAF after coronary artery bypass graft. This assessment can be useful to identify patients at higher arrhythmic risk in whom perioperative preventive strategies and stricter monitoring aimed at early diagnosing and treating POAF may be applied.

Predictive Value of Left Atrial and Ventricular Strain for the Detection of Atrial Fibrillation in Patients With Cryptogenic Stroke.

Background and Aims: Cryptogenic stroke (CS) is associated with a high rate of recurrences and adverse outcomes at long-term follow-up, especially due to its unknown etiology that often leads to ineffective secondary prevention. Asymptomatic atrial fibrillation (AF) could play an important pathophysiological role. Some studies have pointed to left atrial (LA) and left ventricular (LV) systolic and diastolic dysfunction as surrogate markers of AF. The aim of the study is to evaluate the relationship between echocardiographic parameters of LA and LV function, and the occurrence of AF revealed by continuous ECG monitoring in a cohort of patients with CS. Methods: Single-center prospective cohort study. Seventy-two patients with CS with insertable cardiac monitors (ICM) underwent transthoracic echocardiography (TTE). TTE was focused on LA and LV function, including both standard and longitudinal strain-derived parameters. All detected AF episodes lasting more than 2 min were considered. Results: Continuous ECG monitoring revealed subclinical AF in 23 patients (32%) at an average of 6.5 months after ICM implantation. Many echocardiographic parameters, indicating LA volume and LV systolic/diastolic function, were significantly associated with the occurrence of AF, suggesting the worst atrial function in the AF group. Furthermore, multivariable regression analysis revealed that peak atrial contraction strain and left ventricular strain were independently associated with AF (adjusted OR = 0.72, CI 95% 0.48-0.90, p = 0.005, and adjusted OR = 0.69, CI 95% 0.46-0.95, p = 0.041, respectively). Conclusion: In patients with CS, LA and LV strain analysis add predictive value for the occurrence of AF over clinical and morpho-functional echocardiographic parameters. Impaired booster pump strain and LV longitudinal strain are strong and independent predictors of AF.