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

Predictive value of left and right atrial strain for the detection of device-detected atrial fibrillation in patients with cryptogenic stroke and implantable cardiac monitor

BACKGROUND AND OBJECTIVE

Device-detected atrial fibrillation (DDAF) is frequently identified using implantable cardiac monitors (ICMs) following cryptogenic stroke (CS). While left atrium (LA) echocardiographic parameters have been linked to DDAF risk, right atrial (RA) parameters remain underexplored. This study aimed to assess the relationship between speckle-tracking echocardiography parameters and the occurrence of DDAF detected via ICM in patients with CS.

METHODS

We retrospectively analyzed consecutive CS patients who received an ICM at our institution. All underwent transthoracic echocardiography to evaluate LA, RA, left and right ventricle (LV, RV) function using standard and strain-derived parameters. The primary endpoint was the first DDAF episode lasting >6 min recorded by ICM.

RESULTS

Between May 2013 and July 2022, 204 patients (82 % males, median age 69 years) received an ICM. Over a median follow-up of 15.3 months [interquartile range: 7.4-23.5], DDAF was detected in 96 patients (47.0 %). LA peak longitudinal strain (adjusted-hazard ratio [HR] 0.87, 95 %CI 0.84-0.89, p < 0.001), peak conduit strain (adjusted-HR 1.17, 95 %CI 1.13-1.22, p < 0.001), and peak contraction strain (adjusted-HR 1.17, 95 % CI 1.11-1.22, p < 0.001) significantly predicted DDAF. RA peak longitudinal strain (adjusted-HR 0.89, 95 % CI 0.83-0.95, p < 0.001) and peak contraction strain (adjusted-HR 1.39, 95 % CI 1.26-1.53, p < 0.001) were also predictive, but peak conduit strain was not (p = 0.103). No significant associations were found for LV or RV parameters.

CONCLUSIONS

LA and RA strain analyses are valuable for predicting DDAF detection following CS and can aid in risk stratification before ICM insertion.

Computer-Assisted Electrocardiogram Analysis Improves Risk Assessment of Underlying Atrial Fibrillation in Cryptogenic Stroke

Background

The detection of underlying paroxysmal atrial fibrillation (AF) in patients with cryptogenic stroke (CS) can be challenging, and there is great interest in finding predictors of its hidden presence. The recent development of sophisticated software has enhanced the diagnostic and prognostic performance of the 12-lead electrocardiogram (ECG). Our aim was to assess the additional role of a computer-assisted ECG analysis in identifying predictors of AF in patients with CS.

Methods

Sixty-seven patients with ischemic stroke or high-risk transient ischemic attack of unknown etiology were prospectively studied. Their 12-lead digitized ECG was analyzed with dedicated software, quantifying 468 morphological variables. The main clinical, biochemical, and echocardiographic variables were also collected. At discharge, patients were monitored with a wearable Holter for 15 days, and the primary outcome was the detection of AF.

Results

The median age was 80 (interquartile range (IQR): 73 - 84) and AF was detected in 21 patients (31.3%). After preselecting significant ECG variables from the univariate analysis, a multivariate regression including other significant clinical, biochemical and echocardiographic predictors of AF was performed. Among the automatically analyzed ECG parameters, the amplitude of the R wave in V1 (V1_ramp) was significantly associated with the outcome. The best model to predict AF was composed of age, N-terminal B-type natriuretic peptide (NT-proBNP), left atrial reservoir strain (LASr) and V1_ramp. This model showed good discrimination capacity (corrected Somer's Dxy: 0.907, Brier's B: 0.079, area under the curve (AUC): 0.941) and performed better than the same model without the ECG variable (Somer's Dxy: 0.827, Brier's B: 0.119, AUC: 0.896).

Conclusions

The addition of computer-assisted ECG analysis can help stratify the risk of AF in the challenging clinical setting of CS.

The prognostic and diagnostic significance of echocardiographic parameters on acute ischemic stroke

OBJECTIVE

To comprehensively explore the prognostic significance of transthoracic echocardiography (TTE) and three-dimensional speckle-tracking echocardiography (3D STE) parameters in AIS and their role in distinguishing cardioembolic stroke.

METHODS

301 acute ischemic stroke (AIS) patients were enrolled. TTE and 3D STE were employed to evaluate cardiac function and structure, also left atrial strain. Patients were categorized into two groups based on functional outcome at discharge and 3 months post-stroke, respectively. Models combining variables related to unfavorable outcome were established, and their predictive efficacy was assessed using receiver operating characteristic (ROC) curves. Additionally, AIS patients were stratified into cardioembolic and non-cardioembolic stroke groups. Logistic regression identified predictors for cardioembolic stroke, and ROC curves assessed their diagnostic performance.

RESULTS

We found that a decrease in early diastolic peak velocity of the mitral valve (E value) was independently associated with adverse outcomes at both discharge (P = 0.014, OR = 0.126, 95% CI 0.024-0.657) and 3 months post-stroke in AIS patients (P = 0.004, OR = 0.054, 95% CI 0.007-0.403). Adding E value significantly improved predictive ability for adverse outcome at discharge and 3 months post-onset (0.807 vs. 0.794; 0.834 vs. 0.815). Moreover, left atrial diameter (LAD) [area under the curve (AUC) = 0.705] was the most valuable TTE parameter, and left atrial reservoir circumferential strain (LASr-c) (AUC = 0.766) was the most valuable STE parameter, even among all echocardiographic parameters for prediction of cardioembolic stroke.

CONCLUSIONS

This study indicates reduced E value was associated with unfavorable outcome at discharge and 3 months post-onset of AIS patients. LAD, especially LASr-c exhibited optimal diagnostic performance on cardioembolic stroke.

Atrial Imaging and Cardiac Rhythm in Cryptogenic Embolic Stroke: The ARIES Study

BACKGROUND

Unknown cardioembolic sources are frequent causes of cryptogenic stroke. We analyzed the risk of atrial fibrillation (AF) or high burden of ectopic atrial activity (HBEA) in patients with cryptogenic stroke, assessing atrial function and 1-year outcomes.

METHODS AND RESULTS

The ARIES (Atrial Imaging and Cardiac Rhythm in Cryptogenic Embolic Stroke) study is an observational study including patients with cryptogenic stroke. We analyzed the frequency of AF and HBEA (>3000 atrial ectopic beats/day or >2 bursts or atrial tachycardia between 3 beats and ≤30 seconds) in two 30-day Holter-ECGs, comparing advanced echocardiography signs of left atrial (LA) dysfunction according to rhythm: AF, HBEA, and normal sinus rhythm. We also evaluated 1-year stroke recurrence and mortality. The study included 109 patients; 35 (32.1%) patients had AF, 27 (24.8%) HBEA, and 47 (43.1%) normal sinus rhythm. Compared with those with normal sinus rhythm, patients with AF presented higher 2-dimensional and 3-dimensional LA indexed volumes (38.8±11.2 versus 27.3±11.8 mL/m2, and 50.6±17.2 versus 34.0±15.4 mL/m2, respectively, P<0.001), lower 3-dimensional LA ejection fraction (50±14.6 versus 62.7±11.8, P=0.001), LA reservoir strain (22.0±8.6 versus 30.4±10.5, P<0.001), and LA contraction strain (10.5±8.18 versus 17.1±7.5, P<0.001), remaining significant in multivariate analysis. Patients with HBEA showed higher LA indexed volumes and lower LA reservoir strain than patients with normal sinus rhythm only in univariate analysis. There were no differences in ischemic recurrence or mortality among the groups.

CONCLUSIONS

Patients with cryptogenic stroke showed a high incidence of AF and HBEA. AF is strongly related to LA volume, LA function, and LA reservoir and contraction strain, whereas HBEA showed milder structural changes. Advanced LA echocardiography could help patient selection for long-term ECG monitoring in suspected cardiac sources.

Altered left atrial metrics in patients with cryptogenic stroke: A systematic review and meta-analysis

BACKGROUND

There is no defined cause for cryptogenic stroke/embolic stroke of undetermined source (CS-ESUS). As atrial fibrillation (AF) develops in a significant proportion of these patients, it has been suggested that left atrial (LA) myopathy may predispose to CS-ESUS. We investigated alterations in echocardiographic measures of LA size and function in patients with CS-ESUS.

METHODS

A systematic literature review and meta-analysis was performed. PubMed, EMBASE, Cochrane Library, Web of Science and SCOPUS were searched for articles published between 1 January 1990 and 10 February 2023. All observational studies of adult CS-ESUS patients with LA volume or function measurements performed by transthoracic echocardiogram were included. Individual random effects meta-analyses were performed on LA measurements in the CS-ESUS patients using subgroup analysis of comparator groups.

RESULTS

We included 29 articles with 3927 CS-ESUS patients. Analysis of weighted mean differences showed CS-ESUS patients had altered LA structure and function parameters, with a larger maximum indexed LA volume, reduced LA emptying fraction and/or LA reservoir strain, compared to healthy controls and noncardioembolic stroke patients. Conversely, CS-ESUS patients had a smaller left atrium with better function, compared to cardioembolic stroke patients and CS-ESUS patients who subsequently developed atrial fibrillation.

CONCLUSIONS

LA volume and function are altered in CS-ESUS patients compared to healthy controls and other stroke aetiologies. An underlying atrial myopathy in a subset of CS-ESUS patients may be involved in both thrombogenesis and dysrhythmia (specifically AF). While LA functional assessment is not currently recommended following stroke, it may offer an opportunity for recurrent stroke risk stratification.

Pathophysiology and clinical relevance of atrial myopathy

Atrial myopathy is a condition that consists of electrical, structural, contractile, and autonomic remodeling of the atria and is the substrate for development of atrial fibrillation, the most common arrhythmia. Pathophysiologic mechanisms driving atrial myopathy are inflammation, oxidative stress, atrial stretch, and neurohormonal signals, e.g., angiotensin-II and aldosterone. These mechanisms initiate the structural and functional remodeling of the atrial myocardium. Novel therapeutic strategies are being developed that target the pathophysiologic mechanisms of atrial myopathy. In this review, we will discuss the pathophysiology of atrial myopathy, as well as diagnostic and therapeutic strategies.

Towards a new classification of atrial fibrillation detected after a stroke or a transient ischaemic attack

Globally, up to 1·5 million individuals with ischaemic stroke or transient ischaemic attack can be newly diagnosed with atrial fibrillation per year. In the past decade, evidence has accumulated supporting the notion that atrial fibrillation first detected after a stroke or transient ischaemic attack differs from atrial fibrillation known before the occurrence of as stroke. Atrial fibrillation detected after stroke is associated with a lower prevalence of risk factors, cardiovascular comorbidities, and atrial cardiomyopathy than atrial fibrillation known before stroke occurrence. These differences might explain why it is associated with a lower risk of recurrence of ischaemic stroke than known atrial fibrillation. Patients with ischaemic stroke or transient ischaemic attack can be classified in three categories: no atrial fibrillation, known atrial fibrillation before stroke occurrence, and atrial fibrillation detected after stroke. This classification could harmonise future research in the field and help to understand the role of prolonged cardiac monitoring for secondary stroke prevention with application of a personalised risk-based approach to the selection of patients for anticoagulation.

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.

Atrial strain and occult atrial fibrillation in cryptogenic stroke patients: a systematic review and meta-analysis

BACKGROUND

Cryptogenic stroke (CS) remains a significant cause of morbidity. Failure to identify the underlying pathology increases the rate of recurrence. Atrial fibrillation (AF) seems to be responsible for a substantial proportion of CS. Thus, there is an unmet need to identify and properly treat those with silent AF.

PURPOSE

To investigate the association between left atrial strain and newly diagnosed AF in CS patients.

OBJECTIVES

We searched major electronic databases for articles assessing the relationship between either peak left atrial longitudinal (PALS) or peak contractile (PACS) strain-quantified using speckle tracking echocardiography-and the incidence of occult AF during the diagnostic work-up of CS patients.

RESULTS

Eleven studies (two thousand and eighty-one patients) were analyzed. Incidence of occult AF was 19%. Both PALS and PACS were significantly lower in patients with newly diagnosed AF (MD - 8.6%, 95%CI - 10.7 to - 6.4, I2 86.4% and MD - 5.5, 95%CI - 6.8 to - 4.2, I2 80.8%). According to the diagnostic accuracy meta-analysis, PALS < 20% present 71% (95%CI 47-87%) sensitivity and 71% (95%CI 60-81%) specificity for the diagnosis of occult AF, assuming a prevalence of 20%. The corresponding values for PACS < 11% are 83% (95%CI 57-94%) and 78% (95%CI 56-91%).

CONCLUSION

Both PALS and PACS are significantly lower in patients with CS and silent AF. It seems that the cut-off values mentioned above could help physicians in identifying patients who may benefit more from prolonged rhythm monitoring. More studies are needed to confirm these findings.

Probability of Cardioembolic vs. Atherothrombotic Pathogenesis of Cryptogenic Strokes in Older Patients

Some clinical, laboratory, ECG, and echocardiographic parameters could provide useful indications to assess the probability of cardioembolism or atherothrombosis in cryptogenic strokes. We retrospectively examined 290 patients with ischemic stroke aged ≥60 years, divided into 3 groups: strokes originating from large artery atherothrombosis (n = 92), cardioembolic strokes caused by paroxysmal atrial fibrillation (n = 88) and cryptogenic strokes (n = 110). In addition to echocardiographic and routine clinical-laboratory variables, neutrophil:lymphocyte ratio, red blood cell distribution width, mean platelet volume, P wave and PR interval duration and biphasic inferior P waves, both on admission and after 7 to 10 days, were also considered. By multiple logistic regression, cardioembolic strokes were compared with large artery atherothrombosis strokes, and beta coefficients were rounded to produce a scoring system. Late PR interval ≥188 ms, left atrium ≥4 cm, left ventricular end-diastolic volume <65 ml, and posterior circulation syndrome were associated with paroxysmal atrial fibrillation (positive scores). In contrast, male gender, hypercholesterolemia, and initial platelet count ≥290 × 10⁹/L were associated with atherothrombosis of large arteries (negative scores). The algebraic sum of these scores produced values indicative of cardioembolism if >0 (positive predictive value 89.1%), or of atherothrombosis, if ≤0 (positive predictive value 72.5%). The area under the receiver operating characteristic curve was 0.85. Among cryptogenic strokes, 41.5% had a score >0 (probable atrial fibrillation) and 58.5% had a score ≤0 (possible atherothrombosis). In conclusion, a scoring system based on electrocardiogram, laboratory, clinical and echocardiographic parameters can provide useful guidance for further investigations and secondary prevention in older patients with cryptogenic stroke.

A Bibliometric Analysis of Cardioembolic Stroke From 2012 to 2022

Cardioembolic stroke, a subtype of ischemic stroke with the worst prognosis, is quietly threatening public health. We aimed to visualize the development trend and hotspots of research on cardioembolic stroke. A total of 2886 papers about cardioembolic stroke published from 2012 to 2022 were retrieved in the Web of Science Core Collection (WoSCC) database. Further, we performed a bibliometric analysis of these publications, such as generating cooperation maps, co-citation analysis of journals and references, and cluster analysis of keywords. According to the results, cardioembolic stroke research faces many clinical challenges. We obtained the knowledge maps of countries/institutions, authors, journals with high publications and citations, and representative references in this field. Studies about optimal prevention strategies for cardioembolic stroke, identification of cardioembolism in cryptogenic stroke, and prophylactic anticoagulation for patients with embolic stroke of undetermined source (ESUS) or at high risk of left ventricle (LV) thrombus are in the spotlight.