Excessive supraventricular ectopic activity is indicative of paroxysmal atrial fibrillation in patients with cerebral ischemia.

BACKGROUND: Detecting paroxysmal atrial fibrillation (PAF) in patients with cerebral ischemia is challenging. Frequent premature atrial complexes (PAC/h) and the longest supraventricular run on 24-h-Holter (SV-run(24 h)), summarised as excessive supraventricular ectopic activity (ESVEA), may help selecting patients for extended ECG-monitoring, especially in combination with echocardiographic marker LAVI/a' (left atrial volume index/late diastolic tissue Doppler velocity). METHODS: Retrospective analysis from the prospective monocentric observational trial Find-AF (ISRCTN-46104198). Patients with acute stroke or TIA were enrolled at the University Hospital Göttingen, Germany. Those with sinus rhythm at presentation received 7-day Holter-monitoring. ESVEA was quantified in one 24-hour interval free from PAF. Echocardiographic parameters were assessed prospectively. RESULTS: PAF was detected in 23/208 patients (11.1%). The median was 4 [IQR 1; 22] for PAC/h and 5 [IQR 0; 9] for SV-run(24 h). PAF was more prevalent in patients with ESVEA: 19.6% vs. 2.8% for PAC/h >4 vs. ≤ 4 (p<0.001); 17.0% vs. 4.9% for SV-run(24 h >5) vs. ≤ 5 beats (p = 0.003). Patients with PAF showed more supraventricular ectopic activity: 29 PAC/h [IQR 9; 143] vs. 4 PAC/h [1]; [14] and longest SV-run(24 h = 10) [5]; [21] vs. 0 [0; 8] beats (both p<0.001). Both markers discriminated between the PAF- and the Non-PAF-group (area under receiver-operator-characteristics-curve 0.763 [95% CI 0.667; 0.858] and 0.716 [0.600; 0.832]). In multivariate analyses log(PAC/h) and log(SV-run(24 h)) were independently indicative of PAF. In Patients with PAC/h ≤ 4 and normal LAVI/a' PAF was excluded, whereas those with PAC/h >4 and abnormal LAVI/a' showed high PAF-rates. CONCLUSIONS: ESVEA discriminated PAF from non-PAF beyond clinical factors including LAVI/a' in patients with cerebral ischemia. Normal LAVI/a'+PAC/h ≤ 4 ruled out PAF, while prevalence was high in those with abnormal LAVI/a'+PAC/h >4.

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.

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.