P109: Characterizing spontaneous improvements in vasovagal syncope

Introduction: Syncope is responsible for up to 5% of emergency department visits. Vasovagal syncope (VVS) is the most common subtype and can have significant quality of life implications as it is often recurrent. Clinicians treating VVS have limited treatment options available to them and often struggle with prognostication. The aim of our study was to identify patient-specific determinants of VVS improvement or cessation. Methods: Patients (pts) from the Prevention of Syncope Trials (POST) 1 and 2 were included in this study. All patients had VVS according to tilt table testing or a diagnostic point score. Patients had fainted ≥1 time in the previous year and all were followed for up to 1 year after enrollment. Data are presented as median (IQR). Complete responders (CR) did not faint in follow-up; partial responders (PR) fainted ≥1/year less than prior year but did not stop; and non-responders (NR) did not improve or stop. Results: There were 392 patients: 126 males, median age 34 (23,50) who had fainted for 10 (3,22) years and followed for a median of 363 (148,376) days. There were 225 CR (57%), 120 PR (31%) and 47 NR (12%). PR subjects were younger: 27 (24,33) years compared to CR (36 (32,42)) years and NR (36 (29,47)) years (p<0.05). Receiver operator characteristic analysis showed age predicted PR (AUC=0.62). Lifetime fainting frequency was 0.67 (0.14,2.00) faints per year, increasing to 4 (2,10) faints in the pre-year and decreasing to 0 (0,1.9) faints in the post-year (p<0.0001). Pts had similar syncope frequency in the distant past (PR, 1.14 faints/year; CR, 0.68 faints/year; NR, 0.58 faints/year) but PR pts worsened markedly prior to enrollment. PR subjects fainted much more in the prior year: 10 (6,18) faints compared CR (3 (2,3) faints, p<0.0001) and NR (2 (2,4) faints, p<0.05). Receiver operator characteristic analysis showed prior year faints predicted PR well (AUC=0.81). There was no significant interaction with treatment (metoprolol in POST 1, fludrocortisone in POST 2). Conclusion: After specialist consultation, 57% of VVS patients stop fainting and 31% improve incompletely without a significant treatment effect. Patients who will improve incompletely can be accurately selected based on younger age and more frequent syncope. Older patients with less frequent syncope are 83% likely to stop fainting. These findings will help counsel pts and select candidates for medical therapy.

O Papel da Hemoglobina A1c no Rastreio de Intolerância à Glicose e da Diabetes Tipo 2 em Crianças e Adolescentes Obesos

<strong>Introduction:</strong> In 2012, an international expert committee in diabetes wrote in favor of screening adult and paediatric patients for glucose intolerance and type 2 diabetes using glycated haemoglobin. The aim of this study was to evaluate glycated haemoglobin utility as a screening tool in a young obese mainly Caucasian population.<br /><strong>Material and Methods:</strong> Children [(n = 266), body mass index z-score 3.35 ± 0.59, 90% Caucasian 90%, 55% female, median age 12.3 (range: 8.9 - 17.6) years old] recently referred to a tertiary hospital-based obesity clinic underwent a routine oral glicose tolerance test and glycated haemoglobin measurement. Exclusion criteria: abnormal forms of haemoglobin and conditions linked to increased erythrocyte turnover.<br /><strong>Results:</strong> The oral glicose tolerance test diagnosed 13 (4.9%) subjects as prediabetic but none as diabetic. According to glycated haemoglobin, 32 would be prediabetic (29 false positives) and one would be diabetic (when he was only glucose intolerant). On the other hand, 10 prediabetic patients would not have been identified (false negatives). Glycated haemoglobin receiver operator characteristic analysis area under the curve was 0.59 (CI 95% 0.40 - 0.78), confirming its reduced capacity to identify prediabetes. Better results were achieved when calculating receiver operator characteristic analysis area under the curve for fasting glucose (0.76;<br />CI 95% 0.66 - 0.87), homeostasis model assessment for insulin resistance (0.77; CI 95% 0.64 - 0.90) and triglycerides:HDL cholesterol ratio (0.81; CI 95% 0.66 - 0.96).<br /><strong>Discussion:</strong> In Paediatric populations, especially when mainly Caucasian, glycated haemoglobin does not seem to be a useful<br />screening tool for prediabetes.<br /><strong>Conclusion:</strong> For this reason, it would appear premature to advise it as a diagnostic tool until significantly more data is available. Homeostasis model assessment for insulin resistance and triglycerides: HDL cholesterol have higher precision and can be calculated using a fasting blood sample.