Cardiac thrombi detected by CT in patients with acute ischemic stroke: A substudy of Mind the Heart

Abstract

Background: Cardiac thrombi are a major risk factor for ischemic stroke, but are rarely diagnosed in the acute phase. We examined characteristics and functional outcome of patients with ischemic stroke and a concomitant cardiac thrombus detected on cardiac CT performed in the acute phase. Patients and Methods: We used data from “Mind the Heart,” a prospective cohort study in which consecutive adult patients with acute ischemic stroke underwent prospective ECG-gated cardiac CT during their acute stroke imaging protocol. We compared characteristics, functional outcome (modified Rankin scale) and stroke recurrence rate at 90 days of patients with a cardiac thrombus on CT (defined as filling defect <100 Hounsfield Units) to those without a cardiac thrombus. Results: Among 452 included patients, cardiac CT detected 41 thrombi in 38 (8%) patients. Thrombi were most often located in the left atrial appendage (31/38 [82%]). Patients with a cardiac thrombus more frequently had intracranial occlusions in multiple vascular territories (5% vs 0.5%, p = 0.04) and a higher baseline NIHSS score (17 [IQR 6–22] vs 5 [IQR 2–3], p < 0.001) compared to patients without a cardiac thrombus. In 13/38 (34%) patients with a cardiac thrombus, no atrial fibrillation was detected. A cardiac thrombus was associated with worse functional outcome (adjusted common odds ratio 3.18 95%CI 1.68–6.00). Recurrence rate was not significantly different (8% vs 4%, aOR 1.50 (0.39–5.82). Discussion and Conclusion: Cardiac CT detected a cardiac thrombus in one in every 12 patients with acute ischemic stroke, and these patients had more severe deficits, multivessel occlusions, and a worse functional outcome.

Presence of Residual Cardiac Thrombus Predicts Poor Outcome in Cardioembolic Stroke After Reperfusion Therapy

“… 19 Similarly, Rinkel et al performed ECG‐gated cardiac CT in patients with acute ischemic stroke and identified cardiac thrombus in 8% of them, and this rate increased to 24% (35/143) in patients with cardioembolic stroke. 8 In our study, we focused on patients with acute cardioembolic stroke after reperfusion therapy and used 2‐phase cardiac CT to differentiate thrombus from slow flow effects. We observed a residual cardiac thrombus in 31% of patients and circulatory stasis in 22% of patients with cardioembolic stroke after reperfusion therapy.…”

“…Interestingly, prior anticoagulant therapy was identified as another risk factor for residual cardiac thrombi in our study, which is consistent with the findings of 2 other studies. 8 , 19 This paradox could be partially explained by subtherapeutic international normalized ratio levels in patients treated with vitamin K antagonists. 8 , 19 On the other hand, patients with persistent AF are more likely to be detected during routine clinical assessments compared with those with paroxysmal AF.…”

“… 8 , 19 This paradox could be partially explained by subtherapeutic international normalized ratio levels in patients treated with vitamin K antagonists. 8 , 19 On the other hand, patients with persistent AF are more likely to be detected during routine clinical assessments compared with those with paroxysmal AF. While the former group is more likely to receive early anticoagulation therapy due to early detection, the persistent presence of cardiac arrhythmia also increases the risk of forming cardiac thrombi and experiencing ischemic events.…”

“…Cardiac thrombi are frequently found in the left atrial appendage (in cases of AF) or left ventricle (in cases of myocardial infarction), 6 often leading to multivessel occlusions and severe neurological deficits in all stroke subtypes. 8 While transesophageal echocardiography is considered the gold standard for imaging intracardiac thrombi, 9 , 10 it is relatively invasive, may require sedation, and is not routinely performed in the acute stage of ischemic stroke. Cardiac computed tomography (CT), particularly with a 2‐phase protocol, is a suitable first‐line screening method for detecting cardiac thrombi and circulatory stasis.…”

Non–ECG-gated cardiac CT angiography in acute stroke is feasible and detects sources of embolism

“…12 Specifically, cardiac thrombus was detected in 8% of patients. 24 cCTA was performed as a separate study immediately after neuroimaging, with a median increased total scan time of 6 min. 12 We chose non–ECG-gated cCTA, as it is seamlessly incorporated into current protocols and potentially prevents treatment delays.…”