Age-dependent yield of screening for undetected atrial fibrillation in stroke patients: the Find-AF study.

Diagnosis of paroxysmal atrial fibrillation (AF) in stroke patients is challenging, but highly clinically relevant. The percentage of stroke patients with permanent AF increases with age, but limited data are available for the age-dependent yield of paroxysmal AF by Holter monitoring. Patients with acute cerebral ischemia were included into the prospective observational Find-AF study. Patients free from AF at presentation received 7 day Holter monitoring. We calculated the percentage of otherwise undetected paroxysmal AF and the number needed to screen for age groups under 60 years, and in 5 year clusters from the age of 60 up to 85 and older. 272 patients were included, 43 (15.8 %) had AF at admission, 33 patients with paroxysmal AF were identified by 7 day Holter (n = 29) or medical history (n = 4).The yield of 7 day Holter ECG clearly increased with older age (p = 0.004): <60 years: 5 %, 60-64 years: 5 %, 65-69 years: 7 %, 70-74 years: 11 %, 75-79 years: 13 %, 80-84 years: 25 %, ≥ 85 years: 39 %. The number needed to screen (NNS) to find one patient with paroxysmal AF decreased with age: ≤ 60 years: 18, 60-64 years: 20, 65-69 years: 14, 70-74 years: 9, 75-79 years: 8, 80-84 years: 4, ≥ 85 years: 3, respectively. In patients <65 years, all AF cases were detected by Holter ECG. The percentage of paroxysmal AF in stroke patients increases with age. The 7 day Holter ECG is most efficient in elderly patients.

High-sensitivity troponin assay improves prediction of cardiovascular risk in patients with cerebral ischaemia.

BACKGROUND AND PURPOSE: Clinical scores are recommended for predicting cardiovascular risk in patients with cerebral ischaemia to inform secondary prevention. Blood biomarkers may improve prediction beyond clinical scores. METHODS: Within the observational Find-AF trial (ISRCTN46104198), 197 patients >18 years of age with cerebral ischaemia and without atrial fibrillation had blood sampled at baseline. The predictive value of five biomarkers for a combined vascular endpoint (acute coronary syndrome, stroke, cardiovascular death) and all-cause mortality was determined, alone and in addition to the Essen Stroke Risk Score (ESRS), Stroke Prognostic Instrument 2 (SPI-2) and National Institutes of Health Stroke Scale (NIH-SS). RESULTS: There were 23 vascular events (11.7%) and 13 deaths (6.6%) to 1 year follow-up. In multivariate analyses of all markers, only high-sensitivity troponin T (hsTropT) remained independently predictive for vascular events (p=0.045) and all-cause mortality (p=0.004). hsTropT was higher in patients with a vascular event (median 12.7 ng/ml vs 5.1 ng/ml), and patients with hsTropT above the median of 6.15 ng/ml had vascular events more frequently (HR 3.86, p=0.008). For prediction of vascular events as well as all-cause mortality, hsTropT significantly improved multivariate Cox regression models with ESRS, SPI-2 or NIH-SS. The c-statistic increased non-significantly from 0.695 (ESRS) or 0.710 (hsTropT) to 0.747 (ESRS+hsTropT) and from 0.699 (SPI-2) to 0.763 (SPI-2+hsTropT). No patient with a low-risk ESRS and an hsTropT below the median had a vascular event or died. CONCLUSIONS: hsTropT predicts vascular events and all-cause mortality in patients with acute cerebral ischaemia and improves prediction beyond established clinical scores.

Natriuretic peptides for the detection of paroxysmal atrial fibrillation in patients with cerebral ischemia--the Find-AF study.

BACKGROUND AND PURPOSE: Diagnosis of paroxysmal atrial fibrillation (AF) can be challenging, but it is highly relevant in patients presenting with sinus rhythm and acute cerebral ischemia. We aimed to evaluate prospectively whether natriuretic peptide levels and kinetics identify patients with paroxysmal AF. METHODS: Patients with acute cerebral ischemia were included into the prospective observational Find-AF study. N-terminal pro brain-type natriuretic peptide (NT-proBNP), brain-type natriuretic peptide (BNP) and N-terminal pro atrial-type natriuretic peptide (NT-proANP) plasma levels were measured on admission, after 6 and 24 hours. Patients free from AF at presentation received 7 day Holter monitoring. We prospectively hypothesized that patients presenting in sinus rhythm with NT-proBNP>median were more likely to have paroxysmal AF than patients with NT-proBNPmedian (239 pg/ml), 17.9% had paroxysmal AF in contrast to 7.4% with NT-proBNP<239 pg/ml (p = 0.025). The ratio of early (0 h) to late (24 h) plasma levels of NT-proBNP showed no difference between both groups. For the detection of paroxysmal atrial fibrillation, BNP, NT-proBNP and NT-proANP at admission had an area under the curve in ROC analysis of 0.747 (0.663-0.831), 0.638 (0.531-0.744) and 0.663 (0.566-0.761), respectively. In multivariate analysis, BNP was the only biomarker to be independently predictive for paroxysmal atrial fibrillation. CONCLUSIONS: BNP is independently predictive of paroxysmal AF detected by prolonged ECG monitoring in patients with cerebral ischemia and may be used to effectively select patients for prolonged Holter monitoring.

Clinical impact and predictors of carotid artery in-stent restenosis.

To assess the incidence and clinical significance as well as predictors of in-stent restenosis (ISR) after carotid artery stenting (CAS) diagnosed with serial duplex sonography investigations. We analyzed 215 CAS procedures that had clinical and serial carotid duplex ultrasound investigations. The incidence of in-stent restenosis (ISR) and periprocedural as well as long-term clinical complications were recorded. The influence of an ISR on clinical complication was analyzed using Kaplan-Meier curves and clinical risk factors for the development of an ISR with multivariate logistic regression. During a median follow-up time of 33.4 months (interquartile range 15.3-53.7) an ISR of ≥70% was detected in 12 (6.1%) of 215 arteries (mean age of 68.1 ± 9.8 years, 71.6% male). The combined stroke and death rate during long-term follow-up was significantly higher in the group with an ISR [odds ratio (OR): 3.59, 95% confidence interval (CI): 1.50-8.59, p = 0.004]. After applying multivariate logistic regression analysis contralateral carotid occlusion (OR 10.11, 95% CI 2.06-49.63, p = 0.004), carotid endarterectomy (CEA) restenosis (OR 8.87, 95% CI 1.68-46.84, p = 0.010) and postprocedural carotid duplex ultrasound with a PSV ≥120 cm/s (OR 6.33, 95% CI 1.27-31.44, p = 0.024) were independent predictors of ISR. ISR after CAS during long-term follow-up is associated with a higher proportion of clinical complications. A close follow-up is suggested especially in those patients with the aforementioned independent predictors of an ISR. Against the background of a lacking established treatment of ISR, these findings should be taken into account when offering CAS as a treatment alternative to CEA.

Growth-differentiation factor-15 and functional outcome after acute ischemic stroke.

Blood biomarkers may improve the performance in predicting early stroke outcome beyond well-established clinical factors. We investigated the value of growth-differentiation factor-15 (GDF-15) to predict functional outcome after 90 days in a prospectively collected patient cohort with symptoms of acute ischemic stroke. Two hundred eighty-one patients with symptoms of acute ischemic stroke were prospectively investigated. Serial blood samples for GDF-15 analysis were obtained after the admission of the patient, after 6 and 24 h. Primary outcome was the dichotomized modified ranking scale (MRS) 90 days after the initial clinical event. Within the final study population (264 patients, mean age 70.3 ± 12.7 years, 55.3% male), National Institutes of Health Stroke Scale (NIH-SS) [odds ratio (OR) 1.269, 95% confidence interval (CI) 1.141-1.412, p < 0.001] and initial GDF-15 levels (OR 1.029, 95% CI 1.007-1.053, p = 0.011) were independently associated with a MRS ≥ 2 after day 90 after multiple regression analysis. Growth-differentiation factor-15 levels increase with higher NIH-SS-tertiles (p = 0.005). Receiver-operator characteristic curves demonstrated a discriminatory accuracy to predict unfavourable stroke outcome of 0.629 (95% CI 0.558-0.699), 0.753 (95% CI 0.693-812) and 0.774 (95% CI 0.717-0.832) for GDF-15, NIH-SS and the combination of these variables. The additional use of GDF-15 to NIH-SS ameliorates the model with a net reclassification index of 0.044 (p = 0.541) and integrated discrimination improvement of 0.034 (p = 0.443). Growth-differentiation factor-15 as an acute stroke biomarker independently predicts unfavourable functional 90 day stroke outcome. Discriminatory value in addition to NIH-SS is only modestly distinct.

Transthoracic echocardiography to rule out paroxysmal atrial fibrillation as a cause of stroke or transient ischemic attack.

BACKGROUND AND PURPOSE: We assessed whether echocardiography can predict paroxysmal atrial fibrillation (PAF) in patients with cerebral ischemia presenting in sinus rhythm. METHODS: Within the prospective Find-AF cohort, 193 consecutive patients with cerebral ischemia and sinus rhythm on presentation had evaluation of echocardiographic parameters of left atrial size and function. PAF was diagnosed by 7-day Holter monitoring. RESULTS: In 26 patients with PAF, late diastolic Doppler (A) and tissue Doppler (a') velocities were lower whereas left atrial diameter, left atrial volume index (LAVI), LAVI/A, and LAVI/a' were larger (P<0.05 for all) than they were in 167 patients without PAF. In multivariate models A, a', LAVI/A, and LAVI/a' predicted the presence of PAF. Area under the receiver operating characteristic curve to diagnose PAF was highest for LAVI/a' (0.813 [0.738; 0.889]). A previously suggested cut-off of LAVI/a'<2.3 had 92% sensitivity, 55.8% specificity, and 98% negative predictive value for PAF. CONCLUSIONS: LAVI/a'<2.3 can effectively rule out PAF in patients with cerebral ischemia.

Inflammation and in-stent restenosis: the role of serum markers and stent characteristics in carotid artery stenting.

BACKGROUND: Carotid angioplasty and stenting (CAS) may currently be recommended especially in younger patients with a high-grade carotid artery stenosis. However, evidence is accumulating that in-stent restenosis (ISR) could be an important factor endangering the long-term efficacy of CAS. The aim of this study was to investigate the influence of inflammatory serum markers and procedure-related factors on ISR as diagnosed with duplex sonography. METHODS: We analyzed 210 CAS procedures in 194 patients which were done at a single university hospital between May 2003 and June 2010. Periprocedural C-reactive protein (CRP) and leukocyte count as well as stent design and geometry, and other periprocedural factors were analyzed with respect to the occurrence of an ISR as diagnosed with serial carotid duplex ultrasound investigations during clinical long-term follow-up. RESULTS: Over a median of 33.4 months follow-up (IQR: 14.9-53.7) of 210 procedures (mean age of 67.9±9.7 years, 71.9% male, 71.0% symptomatic) an ISR of ≥70% was detected in 5.7% after a median of 8.6 months (IQR: 3.4-17.3). After multiple regression analysis, leukocyte count after CAS-intervention (odds ratio (OR): 1.31, 95% confidence interval (CI): 1.02-1.69; p = 0.036), as well as stent length and width were associated with the development of an ISR during follow-up (OR: 1.25, 95% CI: 1.05-1.65, p = 0.022 and OR: 0.28, 95% CI: 0.09-0.84, p = 0.010). CONCLUSIONS: The majority of ISR during long-term follow-up after CAS occur within the first year. ISR is associated with periinterventional inflammation markers and influenced by certain stent characteristics such as stent length and width. Our findings support the assumption that stent geometry leading to vessel injury as well as periprocedural inflammation during CAS plays a pivotal role in the development of carotid artery ISR.

Enhanced detection of paroxysmal atrial fibrillation by early and prolonged continuous holter monitoring in patients with cerebral ischemia presenting in sinus rhythm.

BACKGROUND AND PURPOSE: Diagnosis of paroxysmal atrial fibrillation is difficult but highly relevant in patients presenting with cerebral ischemia yet free from atrial fibrillation on admission. Early initiation and prolongation of continuous Holter monitoring may improve diagnostic yield compared with the standard of care including a 24-hour Holter recording. METHODS: In the observational Find-AF trial (ISRCTN 46104198), consecutive patients presenting with symptoms of cerebral ischemia were included. Patients free from atrial fibrillation at presentation received 7-day Holter monitoring. RESULTS: Two hundred eighty-one patients were prospectively included. Forty-four (15.7%) had atrial fibrillation documented by routine electrocardiogram on admission. All remaining patients received Holter monitors at a median of 5.5 hours after presentation. In those 224 patients who received Holter monitors but had no previously known paroxysmal atrial fibrillation, the detection rate with early and prolonged (7 days) Holter monitoring (12.5%) was significantly higher than for any 24-hour (mean of 7 intervals: 4.8%, P = 0.015) or any 48-hour monitoring interval (mean of 6 intervals: 6.4%, P = 0.023). Of those 28 patients with new atrial fibrillation on Holter monitoring, 15 (6.7%) had been discharged without therapeutic anticoagulation after routine clinical care (ie, with data from 24-hour Holter monitoring only). Detection rates were 43.8% or 6.3% for short supraventricular runs of ≥ 10 beats or prolonged episodes (> 5 hours) of atrial fibrillation, respectively. Diagnostic yield appeared to be only slightly and not significantly increased during the first 3 days after the index event. CONCLUSIONS: Prolongation of Holter monitoring in patients with symptoms of cerebral ischemic events increases the rate of detection of paroxysmal atrial fibrillation up to Day 7, leading to a relevant change in therapy in a substantial number of patients. Early initiation of monitoring does not appear to be crucial. Hence, prolonged Holter monitoring (≥ 7 days) should be considered for all patients with unexplained cerebral ischemia.