The research, led by Chiara Giordano and Giacomo Gamberini of the University of Milan together with senior author Stefano Carugo and a team spanning the Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, focused on a measurement called the Left Atrial Volumetric–Mechanical Coupling Index, abbreviated LACI-VM. The index is elegantly simple: it is calculated by dividing the left atrial volume index—the size of the heart’s upper left chamber adjusted for body surface area—by a′, the late diastolic mitral annular velocity measured with Doppler tissue imaging. That denominator reflects how well the atrium contracts during its mechanical squeeze. A large atrium that still contracts vigorously produces a modest ratio; a large, sluggish atrium produces a high one. In other words, LACI-VM fuses two complementary dimensions of atrial disease into a single number obtainable from any standard transthoracic echo.

The rationale is rooted in the biology of atrial cardiomyopathy. When the left atrium is chronically exposed to high filling pressures, hypertension, or aging-related fibrosis, it enlarges and its muscle fibers are progressively replaced by scar tissue. Electrical conduction through this remodeled chamber becomes slow and heterogeneous, creating the substrate for the reentrant circuits that drive atrial fibrillation. Structural dilation alone, captured by the left atrial volume index, has long been known to predict AF detection after cryptogenic stroke. Mechanical dysfunction, assessable through atrial strain or annular velocities, adds independent information. By combining both, LACI-VM aims to capture the full anatomical and functional footprint of an atrium that is primed to fibrillate.

The Milanese team applied this concept to 285 consecutive patients admitted with an embolic stroke or transient ischemic attack of undetermined source. All underwent transthoracic echocardiography during the index hospitalization, including measurement of LACI-VM and of the related Left Atrioventricular Coupling Index, or LACI, which is defined as the ratio of left atrial end-diastolic volume to left ventricular end-diastolic volume and reflects atrioventricular uncoupling. The patients, whose median age was 71 years and of whom 43 percent were women, were then followed for new-onset atrial fibrillation. Over a median follow-up of 10.9 months, AF appeared in 24 patients, or 8.4 percent of the cohort—and, critically, 62 percent of those events occurred within the first year, underscoring how early the arrhythmia tends to declare itself after a cerebral embolic event.

The statistical results were striking. LACI-VM was significantly higher in patients who went on to develop atrial fibrillation, and after multivariable adjustment for confounders it remained independently associated with incident AF, with a hazard ratio of 6.64 and a confidence interval of 1.34 to 59.88, reaching a p-value of 0.041. A hazard ratio approaching seven means that patients with an impaired coupling index faced roughly a six- to seven-fold higher rate of AF detection than their counterparts with preserved values, a magnitude of effect rarely seen for a single echocardiographic parameter. By contrast, the purely volumetric LACI showed only a non-significant overall association, with a hazard ratio of 2.28 and a p-value of 0.09, and its predictive power appeared confined to events occurring within the first twelve months. The comparison suggests that atrial mechanical performance, not merely chamber size, carries the prognostic signal that matters for unmasking occult AF.

Perhaps the most clinically actionable finding emerged when the researchers combined LACI-VM with an assessment of left ventricular filling pressures, expressed as the E/e′ ratio—the ratio of early transmitral flow velocity to early diastolic mitral annular velocity. Patients whose LACI-VM remained below 2.5 and whose E/e′ was 10 or lower experienced an AF incidence of only about 2 percent, identifying a genuinely low-risk subgroup in whom intensive, invasive rhythm monitoring may be safely deferred. At the opposite extreme, when both the coupling index was elevated at 2.5 or above and filling pressures were elevated above 10, the AF risk climbed to roughly 20 percent—a tenfold difference between the two phenotypes. This layered approach transforms a single ultrasound number into a practical decision tool: one echo study, performed during the index admission, can separate stroke survivors who need implantable loop recorders from those who can be managed with conventional, less burdensome surveillance.

The implications reach into one of the most contested corners of stroke medicine. Randomized trials such as CRYSTAL-AF and FIND-AF, which used implantable or prolonged monitoring, established that occult atrial fibrillation is common after cryptogenic stroke, detecting it in a meaningful fraction of patients over months to years. Yet prolonged monitoring is costly, and debates persist about how intensively every ESUS patient should be screened, whether oral anticoagulation benefits all detected subgroups, and how to weigh the burden of devices against the risk of recurrent embolism. European Society of Cardiology consensus statements have repeatedly called for better tools to stratify patients. An index that costs nothing beyond an echocardiogram already being performed fits that need precisely, potentially concentrating expensive monitoring resources on the patients most likely to benefit.

The study also builds on a growing literature. LACI-VM was first proposed as a predictor of outcomes in heart failure with reduced ejection fraction, and subsequent work has linked atrioventricular coupling indices to cardiovascular events in the Multi-Ethnic Study of Atherosclerosis, to new-onset AF in hypertrophic cardiomyopathy, and to heart failure and AF in the general population. Earlier investigations specifically in ESUS populations reported that the volumetric-mechanical coupling index associated with AF detection, and the Milan group itself had previously shown that peak atrial longitudinal strain can catch atrial fibrillation in sinus-rhythm patients admitted for cerebral ischemic events. The present analysis extends this line by demonstrating independent prediction in a dedicated ESUS and TIA cohort and by pairing the index with filling pressures to define a truly low-risk stratum.

Certain caveats temper the enthusiasm. The investigation was retrospective and conducted at a single center, and the confidence interval around the hazard ratio is wide, reflecting the modest number of endpoint events; larger, prospective, multicenter validation will be needed before the index enters guidelines. The follow-up duration of roughly eleven months captures the early window in which most events occurred but may miss later arrhythmia emergence. Still, the direction of the evidence is coherent with atrial physiology, the measurement is reproducible with standard techniques endorsed by the American Society of Echocardiography and the European Association of Cardiovascular Imaging, and the effect sizes are large enough to be clinically meaningful even in a small cohort.

For patients and clinicians alike, the message is compelling. A stroke whose cause remains invisible may not be invisible to the heart itself: the left atrium often carries the fingerprints of the arrhythmia that launched the clot. By reading those fingerprints through a simple ratio of atrial size to atrial squeeze, obtained from an ultrasound exam already part of routine care, physicians may soon be able to tailor rhythm monitoring with far greater precision—intensifying surveillance for the one in five patients at highest risk while sparing the many at genuinely low risk from unnecessary devices and prolonged uncertainty. In a field where every undetected episode of atrial fibrillation represents a potential second, potentially devastating stroke, a cheap, fast, and widely available predictor is exactly the kind of advance that could change practice.

Subject of Research: Prediction of early new-onset atrial fibrillation after embolic stroke or TIA of undetermined source using echocardiographic left atrial volumetric–mechanical coupling indices

Article Title: Echocardiography-derived Left Atrial Volumetric–Mechanical Coupling Index predicts early new-onset atrial fibrillation after embolic stroke/transient ischemic attack of undetermined source

Article References: Giordano, C., Gamberini, G., Faggiano, A., Garau, L., Conti, G., D’Andria, P. F., Moda, F., Mallardi, G., Saviano, M., Bonato, S., Ghione, I., Lanfranconi, S., Gherbesi, E., Santangelo, G., Ruscica, M., Bursi, F., & Carugo, S. (2026). Echocardiography-derived Left Atrial Volumetric–Mechanical Coupling Index predicts early new-onset atrial fibrillation after embolic stroke/transient ischemic attack of undetermined source. Clinical Research in Cardiology. https://doi.org/10.1007/s00392-026-03041-y

Image Credits: AI Generated

DOI: 10.1007/s00392-026-03041-y

Keywords: atrial fibrillation, embolic stroke of undetermined source, echocardiography, left atrium, LACI-VM, left atrioventricular coupling index, transient ischemic attack, rhythm monitoring, implantable loop recorder, atrial cardiomyopathy, E/e′ ratio, stroke prevention

The numbers behind the headline finding are sobering. Across the studies that compared patients with central retinal artery occlusion against matched controls free of ocular events and stroke at baseline, 14.26 percent of eye-occlusion patients developed atrial fibrillation during follow-up, compared with 8.32 percent of controls. Expressed as a pooled odds ratio using a random-effects model, that translates to a 47 percent increase in the odds of developing the arrhythmia (OR 1.47, 95 percent confidence interval 1.18 to 1.83; p = 0.0006), with remarkably low heterogeneity between studies (I squared of just 1 percent). The secondary outcome was even more alarming: new-onset ischemic stroke occurred in 13.8 percent of eye-occlusion patients versus 6.7 percent of controls, a more than twofold elevation in risk (OR 2.10, 95 percent CI 1.57 to 2.82; p < 0.00001, with zero heterogeneity). In total, 115 cases of new-onset atrial fibrillation were recorded during a median follow-up of 34 months.

Perhaps the most provocative result is the comparison with cerebral stroke itself. When the researchers contrasted new-onset atrial fibrillation after central retinal artery occlusion with new-onset atrial fibrillation after ischemic stroke in other brain territories, the difference vanished: the pooled odds ratio of 0.80 (95 percent CI 0.40 to 1.61; p = 0.54) indicates that the eye event carries essentially the same arrhythmic risk as a stroke. Continuous monitoring with implantable loop recorders revealed cumulative atrial fibrillation incidence of 33.4 percent at 12 months and 49.6 percent at 24 months after the ocular event, figures that closely mirror the 33.6 percent and 43.2 percent seen at the same time points in the ischemic stroke cohort. On this evidence, the authors argue, central retinal artery occlusion should be regarded as a stroke equivalent, a red flag that demands the same intensive cardiac work-up that neurologists already apply after cryptogenic stroke or transient ischemic attack.

The pathophysiological logic supporting this association is straightforward. Central retinal artery occlusion occurs when a sudden vascular blockage cuts off perfusion to the retina, triggering rapid ischemic cellular damage and typically an acute, painless decrease or complete loss of monocular vision. In its non-arteritic form, which accounted for all patients in the included studies, the occlusion is usually embolic in origin, with clots travelling from the ipsilateral internal carotid artery, the aortic arch or, crucially, the heart itself, where atrial fibrillation can generate thrombi in the fibrillating atria. The eye and the brain share the same upstream risk factors, including hypertension, hyperlipidemia, diabetes mellitus, coronary artery disease and smoking, and the CRAO cohort in this analysis carried a heavy comorbidity burden: 54 percent had hypertension, 29 percent hyperlipidemia and 26 percent diabetes. Adding weight to a shared thromboembolic mechanism, prior MRI studies cited in the paper found silent cerebral ischemia in 24 to 34.2 percent of patients at the time of acute presentation with monocular visual loss.

One of the study’s most consequential findings concerns timing, and it exposes what the authors describe as a substantial monitoring gap in current clinical practice. New-onset atrial fibrillation after the ocular event follows a bimodal pattern. Early-onset cases appear within days, detected at a mean of just 0.1 months, or about three days, after the event by short-term Holter monitoring. But the bulk of cases emerge far later: under continuous surveillance with implantable loop recorders, cumulative incidence climbs steadily to nearly half of all patients by two years. Standard 30-day monitoring protocols, the analysis concludes, would miss approximately 70 percent of the atrial fibrillation cases eventually diagnosed within two years, and only about one in seven patients ultimately found to have the arrhythmia is captured within the first month. In other words, the conventional short window of cardiac surveillance is profoundly insufficient for this population, leaving the majority of cardiovascular threats effectively off-camera.

The stakes of missing that window are high. Within an acute window of roughly six weeks, 7.4 percent of patients in one included study experienced a symptomatic new-onset ischemic stroke after the ocular event, and registry data spanning 10 to 12 years of follow-up indicate that long-term stroke risk peaks during the first four years. Recurrent ischemic events may even occur before atrial fibrillation is ever identified, which means that a patient can suffer a second, potentially devastating embolic event while the underlying rhythm disorder remains undetected. Because there is currently no evidence-based acute treatment that consistently improves visual outcomes in central retinal artery occlusion, with options such as ocular massage, hyperbaric oxygen, thrombolysis and antithrombotic therapy showing inconsistent results, the authors emphasize that the most valuable intervention may lie not in rescuing the eye but in protecting the brain through structured cardiovascular evaluation and secondary prevention.

Translating these findings into practice, the researchers propose that central retinal artery occlusion without an identified cause should be managed much like cryptogenic stroke, the diagnostic paradigm established by landmark trials such as CRYSTAL AF and EMBRACE. That means urgent, ideally same-day cardiovascular evaluation, serial electrocardiograms, and extended rhythm surveillance using implantable loop recorders or insertable cardiac monitors capable of capturing the delayed-onset, paroxysmal episodes that intermittent monitoring misses. Ophthalmological work-up with fundoscopy, dilated examination, optical coherence tomography and fluorescein angiography remains essential to characterize the retinal ischemia, but the authors stress that interdisciplinary cooperation between eye specialists, neurologists and electrophysiologists is vital. Where atrial fibrillation is confirmed, anticoagulation should be strongly considered to mitigate the risk of future embolic events, although the authors caution that blanket anticoagulation for all eye-occlusion patients remains premature in the absence of prospective randomized evidence and must be individualized through careful risk-benefit assessment.

The study is not without limitations, and the authors are candid about them. The pooled estimate for new-onset atrial fibrillation rests on only two studies, and the seven included investigations differed substantially in follow-up duration, which ranged from seven-day clinical trial surveillance to 15-year nationwide registry follow-up, and in detection methodology, spanning administrative ICD-9 and ICD-10 codes, intermittent Holter monitoring of 24 hours to 7 days, and continuous implantable loop recorders that flag episodes of two minutes or longer. Because implantable devices detect far higher atrial fibrillation rates than claims data or short-term electrocardiography, methodological differences likely explain much of the variation in reported prevalence, and the limited number of studies precluded subgroup analyses. The predominance of retrospective and registry-based designs heightens susceptibility to selection bias, residual confounding and coding inaccuracies, and subclinical or previously undiagnosed arrhythmia could not be fully excluded. Whether atrial fibrillation identified after the ocular event is truly new, previously silent, or an incidental finding remains uncertain, and the authors frame their cardioembolic interpretation as hypothesis generating.

Even with those caveats, the central message is difficult to ignore. Quality assessment using the Newcastle-Ottawa Scale scored most included studies at seven points or higher, funnel plot analysis revealed no evidence of publication bias, and the consistency of the stroke findings across cohorts with zero heterogeneity lends credibility to the core conclusion. For clinicians, the implication is that a patient presenting with a pale retina and a cherry-red spot should trigger not only an urgent eye evaluation but a cardiac investigation equivalent to that performed after a cerebral stroke. For the public, the message is starker still: sudden, painless vision loss in one eye is never just an eye problem. It may be the first and only warning that the heart’s upper chambers are silently throwing clots, and that a disabling stroke could be next. Recognizing the eye event as a cardiovascular emergency, and monitoring the heart long after the initial crisis has passed, could mean the difference between a patient who loses sight in one eye and one who loses much more.

Subject of Research: Association of central retinal artery occlusion with new-onset atrial fibrillation and ischemic stroke risk

Article Title: Central retinal artery occlusion: meta-analysis of the risk of new-onset atrial fibrillation and ischemic stroke

Article References: Gupta, P., Anjos, R., Miguel, A., Bekoju, P., Panthi, R. C., Salangsang, J., Lioutas, V. A., Hilbert, S., Seewöster, T., Bode, K., Bollmann, A., & Nedios, S. (2026). Central retinal artery occlusion: meta-analysis of the risk of new-onset atrial fibrillation and ischemic stroke. Clinical Research in Cardiology. https://doi.org/10.1007/s00392-026-03012-3

Image Credits: AI Generated

DOI: 10.1007/s00392-026-03012-3

Keywords: central retinal artery occlusion, atrial fibrillation, ischemic stroke, meta-analysis, cardiac monitoring, implantable loop recorder, anticoagulation, cryptogenic stroke, retinal ischemia, stroke prevention, cardiology, ophthalmology