Prehospital Stroke Triage: A Modeling Study on the Impact of Triage Tools in Different Regions.

BACKGROUND AND PURPOSE: Direct transportation to a thrombectomy-capable intervention center is beneficial for patients with ischemic stroke due to large vessel occlusion (LVO), but can delay intravenous thrombolytics (IVT). The aim of this modeling study was to estimate the effect of prehospital triage strategies on treatment delays and overtriage in different regions. METHODS: We used data from two prospective cohort studies in the Netherlands: the Leiden Prehospital Stroke Study and the PRESTO study. We included stroke code patients within 6 h from symptom onset. We modeled outcomes of Rapid Arterial oCclusion Evaluation (RACE) scale triage and triage with a personalized decision tool, using drip-and-ship as reference. Main outcomes were overtriage (stroke code patients incorrectly triaged to an intervention center), reduced delay to endovascular thrombectomy (EVT), and delay to IVT. RESULTS: We included 1798 stroke code patients from four ambulance regions. Per region, overtriage ranged from 1-13% (RACE triage) and 3-15% (personalized tool). Reduction of delay to EVT varied by region between 24 ± 5 min (n = 6) to 78 ± 3 (n = 2), while IVT delay increased with 5 (n = 5) to 15 min (n = 21) for non-LVO patients. The personalized tool reduced delay to EVT for more patients (25 ± 4 min [n = 8] to 49 ± 13 [n = 5]), while delaying IVT with 3-14 min (8-24 patients). In region C, most EVT patients were treated faster (reduction of delay to EVT 31 ± 6 min (n = 35), with RACE triage and the personalized tool. CONCLUSIONS: In this modeling study, we showed that prehospital triage reduced time to EVT without disproportionate IVT delay, compared to a drip-and-ship strategy. The effect of triage strategies and the associated overtriage varied between regions. Implementation of prehospital triage should therefore be considered on a regional level.

Comparison of eight prehospital stroke scales to detect intracranial large-vessel occlusion in suspected stroke (PRESTO): a prospective observational study.

BACKGROUND: Due to the time-sensitive effect of endovascular treatment, rapid prehospital identification of large-vessel occlusion in individuals with suspected stroke is essential to optimise outcome. Interhospital transfers are an important cause of delay of endovascular treatment. Prehospital stroke scales have been proposed to select patients with large-vessel occlusion for direct transport to an endovascular-capable intervention centre. We aimed to prospectively validate eight prehospital stroke scales in the field. METHODS: We did a multicentre, prospective, observational cohort study of adults with suspected stroke (aged ≥18 years) who were transported by ambulance to one of eight hospitals in southwest Netherlands. Suspected stroke was defined by a positive Face-Arm-Speech-Time (FAST) test. We included individuals with blood glucose of at least 2·5 mmol/L. People who presented more than 6 h after symptom onset were excluded from the analysis. After structured training, paramedics used a mobile app to assess items from eight prehospital stroke scales: Rapid Arterial oCclusion Evaluation (RACE), Los Angeles Motor Scale (LAMS), Cincinnati Stroke Triage Assessment Tool (C-STAT), Gaze-Face-Arm-Speech-Time (G-FAST), Prehospital Acute Stroke Severity (PASS), Cincinnati Prehospital Stroke Scale (CPSS), Conveniently-Grasped Field Assessment Stroke Triage (CG-FAST), and the FAST-PLUS (Face-Arm-Speech-Time plus severe arm or leg motor deficit) test. The primary outcome was the clinical diagnosis of ischaemic stroke with a proximal intracranial large-vessel occlusion in the anterior circulation (aLVO) on CT angiography. Baseline neuroimaging was centrally assessed by neuroradiologists to validate the true occlusion status. Prehospital stroke scale performance was expressed as the area under the receiver operating characteristic curve (AUC) and was compared with National Institutes of Health Stroke Scale (NIHSS) scores assessed by clinicians at the emergency department. This study was registered at the Netherlands Trial Register, NL7387. FINDINGS: Between Aug 13, 2018, and Sept 2, 2019, 1039 people (median age 72 years [IQR 61-81]) with suspected stroke were identified by paramedics, of whom 120 (12%) were diagnosed with aLVO. Of all prehospital stroke scales, the AUC for RACE was highest (0·83, 95% CI 0·79-0·86), followed by the AUC for G-FAST (0·80, 0·76-0·84), CG-FAST (0·80, 0·76-0·84), LAMS (0·79, 0·75-0·83), CPSS (0·79, 0·75-0·83), PASS (0·76, 0·72-0·80), C-STAT (0·75, 0·71-0·80), and FAST-PLUS (0·72, 0·67-0·76). The NIHSS as assessed by a clinician in the emergency department did somewhat better than the prehospital stroke scales with an AUC of 0·86 (95% CI 0·83-0·89). INTERPRETATION: Prehospital stroke scales detect aLVO with acceptable-to-good accuracy. RACE, G-FAST, and CG-FAST are the best performing prehospital stroke scales out of the eight scales tested and approach the performance of the clinician-assessed NIHSS. Further studies are needed to investigate whether use of these scales in regional transportation strategies can optimise outcomes of patients with ischaemic stroke. FUNDING: BeterKeten Collaboration and Theia Foundation (Zilveren Kruis).

Accuracy of CTA evaluations in daily clinical practice for large and medium vessel occlusion detection in suspected stroke patients.

INTRODUCTION: Early detection of large vessel occlusion (LVO) is essential to facilitate fast endovascular treatment. CT angiography (CTA) is used to detect LVO in suspected stroke patients. We aimed to assess the accuracy of CTA evaluations in daily clinical practice in a large cohort of suspected stroke patients. PATIENTS AND METHODS: We used data from the PRESTO study, a multicenter prospective observational cohort study that included suspected stroke patients between August 2018 and September 2019. Baseline CTAs were re-evaluated by an imaging core laboratory and compared to the local assessment. LVO was defined as an occlusion of the intracranial internal carotid artery, M1 segment, or basilar artery. Medium vessel occlusion (MeVO) was defined as an A1, A2, or M2 occlusion. We calculated the accuracy, sensitivity, and specificity to detect LVO and LVO+MeVO, using the core laboratory evaluation as reference standard. RESULTS: We included 656 patients. The core laboratory detected 89 LVOs and 74 MeVOs in 155 patients. Local observers missed 6 LVOs (7%) and 28 MeVOs (38%), of which 23 M2 occlusions. Accuracy of LVO detection was 99% (95% CI: 98-100%), sensitivity 93% (95% CI: 86-97%), and specificity 100% (95% CI: 99-100%). Accuracy of LVO+MeVO detection was 95% (95% CI: 93-96%), sensitivity 79% (95% CI: 72-85%), and specificity 99% (95% CI: 98-100%). DISCUSSION AND CONCLUSION: CTA evaluations in daily clinical practice are highly accurate and LVOs are adequately recognized. The detection of MeVOs seems more challenging. The evolving EVT possibilities emphasize the need to improve CTA evaluations in the acute setting.

Exercise and myocardial injury in hypertrophic cardiomyopathy.

OBJECTIVE: Troponin and high signal intensity on T2-weighted (HighT2) cardiovascular magnetic resonance imaging (CMRi) are both markers of myocardial injury in hypertrophic cardiomyopathy (HCM). The interplay between exercise and disease development remains uncertain in HCM. We sought to assess the occurrence of postexercise troponin rises and its determinants. METHODS: Multicentre project on patients with HCM and mutation carriers without hypertrophy (controls). Participants performed a symptom limited bicycle test with hs-cTnT assessment pre-exercise and 6 hours postexercise. Pre-exercise CMRi was performed in patients with HCM to assess measures of hypertrophy and myocardial injury. Depending on baseline troponin (< or >13 ng/L), a rise was defined as a >50% or >20% increase, respectively. RESULTS: Troponin rises occurred in 18% (23/127) of patients with HCM and 4% (2/53) in mutation carriers (p=0.01). Comparing patients with HCM with and without a postexercise troponin rise, maximum heart rates (157±19 vs 143±23, p=0.004) and maximal wall thickness (20 mm vs 17 mm, p=0.023) were higher in the former, as was the presence of late gadolinium enhancement (85% vs 57%, p=0.02). HighT2 was seen in 65% (13/20) and 19% (15/79), respectively (p<0.001). HighT2 was the only independent predictor of troponin rise (adjusted odds ratio 7.9; 95% CI 2.7 to 23.3; p<0.001). CONCLUSIONS: Postexercise troponin rises were seen in about 20% of patients with HCM, almost five times more frequent than in mutation carriers. HighT2 on CMRi may identify a group of particularly vulnerable patients, supporting the concept that HighT2 reflects an active disease state, prone to additional injury after a short episode of high oxygen demand.

Association between Lifelong Physical Activity and Disease Characteristics in HCM.

PURPOSE: Hypertrophic cardiomyopathy (HCM) is characterized by inappropriate left ventricular (LV) wall thickness. Adaptations to exercise can occasionally mimic certain HCM characteristics. However, it is unclear whether physical activity affects HCM genotype expression and disease characteristics. Consequently, we compared lifelong physical activity volumes between HCM gene carriers with and without HCM phenotype, and compared disease characteristics among tertiles of physical activity in phenotypic HCM patients. METHODS: We enrolled n = 22 genotype positive/phenotype negative (G+/P-) HCM gene carriers, n = 44 genotype positive/phenotype positive (G+/P+) HCM patients, and n = 36 genotype negative/phenotype positive (G-/P+) HCM patients. Lifelong physical activity was recorded using a questionnaire and quantified as metabolic equivalent of task hours per week. RESULTS: We included 102 participants (51 ± 16 yr, 49% male). Lifelong physical activity volumes were not different between G+/P+ and G+/P- subjects (16 [10-29] vs 14 [6-26] metabolic equivalent of task-hours per week, P = 0.33). Among phenotypic HCM patients, there was no difference in LV wall thickness, mass, and late gadolinium enhancement across physical activity tertiles. Patients with the highest reported physical activity volumes were younger at the time of diagnosis (tertile 1: 52 ± 14 yr, tertile 2: 49 ± 15 yr, tertile 3: 41 ± 18 yr; P = 0.03), and more often had a history of nonsustained ventricular tachycardia (4% vs 30% vs 30%, P = 0.03). CONCLUSIONS: Lifelong physical activity volumes are not associated with genotype-to-phenotype transition in HCM gene carriers. We also found no difference in LV wall thickness across physical activity tertiles. However, the most active HCM patients were younger at the time of diagnosis and had a higher arrhythmic burden. These observations warrant further exploration of the role of exercise in HCM disease development.

Prediction of Extensive Myocardial Fibrosis in Nonhigh Risk Patients With Hypertrophic Cardiomyopathy.

In nonhigh risk patients with hypertrophic cardiomyopathy (HC), the presence of extensive late gadolinium enhancement (LGEext) at cardiovascular magnetic resonance (CMR) imaging has been proposed as a risk modifier in the decision process for implantable cardioverter defibrillator implantation. With a pretest risk of about 10%, a strategy that alters the likelihood of LGEext could markedly affect efficacious CMR imaging. Our aim was to study the potential of clinical variables and biomarkers to predict LGEext. In 98 HC patients without any clear indication for implantable cardioverter defibrillator implantation, we determined the discriminative values of a set of clinical variables and a panel of biomarkers (hs-cTnT, NTproBNP, GDF-15, and Gal-3, CICP) for LGEext, that is, LGE ≥15% of the left ventricular mass. LGEext was present in 10% (10/98) of patients. The clinical prediction model contained a history of nonsustained ventricular tachycardia, maximal wall thickness and reduced systolic function (c-statistic: 0.868, p <0.001). Of all biomarkers, only hs-cTnT was associated with LGEext, in addition to the improved clinical model of diagnostic accuracy (p = 0.04). A biomarker-only strategy allowed the exclusion of LGEext in half of the cohort, in case of a hs-cTnT concentration less than the optimal cutoff (Youden index; 8 ng/L-sensitivity 100%, specificity 54%). In conclusion, in this nonhigh risk HC cohort, the pretest likelihood of LGEext can be altered using clinical variables and the addition of hs-cTnT. The promising findings with the use of hs-cTnT only call for new initiatives to study its impact on efficacious CMR imaging in a larger HC population, either with or without additional use of clinical variables.

High T2-weighted signal intensity for risk prediction of sudden cardiac death in hypertrophic cardiomyopathy.

In search of improved risk stratification in hypertrophic cardiomyopathy (HCM), CMR imaging has been implicated as a potential tool for prediction of sudden cardiac death (SCD). In follow-up of the promising results with extensive late gadolinium enhancement (LGE), high signal-intensity on T2-weighted imaging (HighT2) has become subject of interest given its association with markers of adverse disease progression, such as LGE, elevated troponin and non-sustained ventricular tachycardia. In lack of follow-up cohorts, we initiated an exploratory study on the association between HighT2 and the internationally defined risk categories of SCD. In a cohort of 109 HCM patients from a multicenter study on CMR imaging and biomarkers, we estimated the 5-year SCD risk (HCM Risk-SCD model). Patients were categorized as low (< 4%), intermediate (≥ 4-<6%) or high (≥ 6%) risk. In addition, risk categorization according to the ACC/AHA guidelines was performed. HighT2 was present in 27% (29/109). Patients with HighT2 were more often at an intermediate-high risk of SCD according to the European (28 vs. 10%, p = .032) and American guidelines (41 vs. 18%, p = .010) compared to those without HighT2. The estimated 5-year SCD risk of our cohort was 1.9% (IQR 1.3-2.9%), and projected SCD rates were higher in patients with than without HighT2 (2.8 vs. 1.8%, p = .002). In conclusion, HCM patients with HighT2 were more likely to be intermediate-high risk, with projected SCD rates that were 1.5 fold higher than in patients without HighT2. These pilot findings call for corroborative studies with more intermediate-high risk HCM patients and clinical follow-up to assess whether HighT2 may have additional value to current risk stratification.

High T2-weighted signal intensity is associated with elevated troponin T in hypertrophic cardiomyopathy.

OBJECTIVE: Areas of high signal intensity (HighT2) on T2-weighted cardiovascular magnetic resonance (CMR) imaging have been demonstrated in hypertrophic cardiomyopathy (HCM). It has been hypothesised that HighT2 may indicate active tissue injury in HCM. In this context, we studied HighT2 in relation to cardiac troponin. METHODS: Outpatient HCM patients without a history of coronary artery disease underwent CMR imaging at 1.5 T using T2-weighted, cine and late gadolinium enhancement (LGE) imaging to assess HighT2, left ventricular (LV) function, LV mass and the presence and extent of LGE. Highly sensitive cardiac troponin T (hs-cTnT) was assessed as a marker of injury, with hs-cTnT ≥14 and >3 ng/L defined as an elevated and detectable troponin. RESULTS: HighT2 was present in 28% of patients (28/101). An elevated hs-cTnT was present in 54% of patients with HighT2 (15/28) compared with 14% of patients without HighT2 (10/73) (p<0.001). Hs-cTnT was detectable in 96% of patients with HighT2 (27/28) compared with 66% of patients without HighT2 (48/73) (p=0.002). In case of an undetectable hs-cTnT, HighT2 was only seen in 4% (1/26). In addition, the extent of HighT2 was related with increasing hs-cTnT concentrations (Spearman's ρ: 0.42, p<0.001). CONCLUSIONS: In this CMR study of patients with HCM, we observed HighT2 in a quarter of patients, and demonstrated that HighT2 was associated with an elevated hs-cTnT. This observation, combined with the very high negative predictive value of an undetectable hs-cTnT for HighT2, provides supportive evidence for the hypothesis that HighT2 is indicative of recently sustained myocyte injury.

[Diagnostic imaging in dementia: use of imaging modalities in Dutch memory clinics]. / Beeldvormende diagnostiek bij dementie: inventarisatie van de praktijk binnen de Nederlandse geheugenklinieken.

PURPOSE: To evaluate the use of MRI and CT in the diagnostic work-up of dementia in Dutch memory clinics, and to analyse the rationale for choosing each modality. MATERIALS AND METHODS: A digital survey was sent by e-mail to all medical specialists (n=235) working at a memory clinic in the Netherlands. RESULTS: The survey was completed by 64% (151). 85% of the respondents were geriatricians, 13% neurologists and 2% other, working at a total of 69 clinics. 40% variably orders CT or MRI, 37% orders MRI, 19% CT, and 4% CT plus MRI. Primary factors influencing this choice are: MRI contraindications, physical limitations, age, vascular or oncological medical history, and waiting time. With CT, 87% indicates information is lacking: vascular disease/white matter lesions, (hippocampal) atrophy, and specific pathologies (metastases, amyloid angiopathy). Furthermore, respondents prefer MRI because they can assess the images more easily themselves. Only 50% of respondents indicate that CT protocol dictates coronal reconstructions. Additionally, these reconstructions are not provided consistently. Rating-scales are used to describe images in 5%. In 75% assessment is not uniform. CONCLUSION: MRI is preferred over CT in diagnostic imaging of dementia, in accordance with existing guidelines. However, these guidelines are mostly out-dated and modern multislice CT potential is relatively unknown among geriatricians. In memory clinics, multislice CT could offer a well suitable imaging alternative, but only if multiplanar reconstructions are performed consistently. Furthermore, radiology reports need to be improved by using more standardized assessment.

Relation of highly sensitive cardiac troponin T in hypertrophic cardiomyopathy to left ventricular mass and cardiovascular risk.

Elevated cardiac troponin can be seen in patients with left ventricular (LV) hypertrophy and in asymptomatic subjects with a high a priori risk of cardiovascular disease (CVD). In hypertrophic cardiomyopathy (HC) troponin can be detected as well, but little is known about the contribution of LV mass, on the one hand, and the long-term risk of CVD, on the other. In an observational single-center study of 62 patients with HC, without a history of CVD, we assessed the Framingham Heart 10-year risk score (FH10yrs), LV mass index (LVMI) using magnetic resonance imaging, and highly sensitive cardiac troponin T (hs-cTnT). Hs-cTnT (>3 ng/L) was detectable in 74% of patients (46 of 62). Hs-cTnT was elevated in 26% (16 of 62) of patients (ninety-ninth percentile reference limit of 14 ng/L or more). From 3 to 14 ng/L, patients were older, more often had hypertension, and the FH10yrs was higher. Hs-cTnT correlated positively with LVMI (p<0.001) and maximal wall thickness (p<0.001). In addition, LVMI and hypertension were independently associated with increasing hs-cTnT concentrations in linear regression. Using multivariate binary logistic regression, both LVMI and FH10yrs were independently associated with detectable hs-cTnT levels. In contrast, only LVMI was associated with elevated hs-cTnT levels. In conclusion, hs-cTnT was detectable in 3 quarters and elevated in a quarter of our patients with HC. Although detectable hs-cTnT is associated with both LV mass and CVD risk, elevated hs-cTnT relates to LV mass only. This indicates that hypertrophy more than the risk of CVD seems the most important drive for hs-cTnT to occur in these patients.

Value of routine chest radiography in the medical screening of internationally adopted children.

AIM: To assess the value of the routine chest radiography as part of the medical evaluation of newly arrived, internationally adopted children. METHODS: We evaluated the use of routine chest radiography (CXR) in the medical screening of 1598 internationally adopted children. RESULTS: CXR showed abnormalities in 128 cases: 38 of these findings were already known and/or consistent with obvious clinical signs or symptoms, and 54 had no clinical relevance. In two patients, CXR raised the suspicion of tuberculosis. CONCLUSION: The routine use of CXR in the screening of internationally adopted children rarely yields new, clinically relevant, information and should be performed on indication only.

Sonography as the primary screening method in evaluating blunt abdominal trauma.

PURPOSE: The radiological evaluation of patients with blunt abdominal trauma can be done with either ultrasound (US) or computed tomography (CT) with strategies varying considerably among institutions. We evaluated the efficacy of our current strategy in which US is used at our hospital as the primary screening tool for patients with blunt abdominal trauma. METHODS: We retrospectively analysed all patients admitted to our hospital with possible blunt abdominal trauma who underwent abdominal US, abdominal CT and/or a laparotomy during the initial trauma assessment from 1998 until 2002 (n = 1149). RESULTS: Nine-hundred sixty-one of the 1149 patients had a negative US, of which 922 were true negative, resulting in a negative predictive value of 96%. A CT of the abdomen was performed in 7%. In 1.7% there was delayed diagnosis with no significant additional morbidity. Fourteen of the 103 laparotomies (14%) were non-therapeutic; in 5 of these cases the patients underwent non-therapeutic laparotomy despite the performance of a CT. Seven were emergency operations. CONCLUSIONS: In our practice, the use of US for the evaluation of acute blunt abdominal trauma is adequate, with a high negative predictive value, a small number of delayed diagnoses, and an acceptable rate of non-therapeutic laparotomies.

MR urography for the preoperative evaluation of living renal donors.

The purpose of this study was to assess the image quality and diagnostic value of MR urography in detecting abnormalities of the urinary collecting system relevant for the preoperative evaluation of living renal donors. Study subjects were selected from the existing intravenous urography (IVU) reports: 18 consecutive patients with a duplication or another abnormality of the collecting system and 20 consecutive patients with normal anatomy. They underwent a respiratory-triggered 3D T2-weighted fast spin-echo acquisition after oral administration of furosemide, without and with abdominal compression. The MR images were evaluated by two independent blinded observers. The IVU was used as the standard of reference. Image quality of the MR urograms with compression was overall better than those without compression, and the former were regarded as adequate for the evaluation of small filling defects and deformities of the pelvis and calyces in 76-81% of the kidneys and 74-79% of the patients. Both observers correctly diagnosed all 13 kidneys with a partial or complete duplication. The image quality of MR urography was inadequate to evaluate the calyces and pelvis for small filling defects or deformities in approximately 25% of the patients; however, the technique was accurate in the detection of abnormalities of the urinary collecting system relevant for the preoperative evaluation of living renal donors.

Optimal scan delay in spiral CT for the diagnosis of acute pulmonary embolism.

PURPOSE: The purpose of this work was to assess whether easily obtained clinical parameters can predict optimal scan delay for contrast-enhanced spiral CT of pulmonary arteries and to compare image quality between individualized contrast timing versus a fixed scan delay. METHOD: We used an individualized delay in 85 patients by measuring the contrast transit time through the pulmonary circulation (Group A) and assessed the correlation between transit time and clinical parameters. In 56 patients (Group B), we used a 20 s fixed scan delay. The CT examinations of both groups were compared with regard to image quality. RESULTS: Contrast transit times (mean 10.5 s, range 4-26 s) did not correlate significantly with heart rate, blood pressure, body length, weight, body surface area, or cardiac function. Although contrast transit times were significantly related to gender and age, only 14.8% of the variation could be explained by these clinical parameters. Data of 57 patients in Group A and 50 patients in Group B were available for analysis. Image quality was not significantly different between Groups A and B, which was good, moderate, and poor in 61, 32, and 7% in Group A and 60, 34, and 6% in Group B, respectively (p = 1.0). CONCLUSION: One cannot predict individual scan delay from easily obtainable clinical parameters. Fortunately, a 20 s fixed scan delay provides equal image quality as individualized contrast timing.