Blood-biomarkers and devices for atrial fibrillation screening: Lessons learned from the AFRICAT (Atrial Fibrillation Research In CATalonia) study.

BACKGROUND AND OBJECTIVE: AFRICAT is a prospective cohort study intending to develop an atrial fibrillation (AF) screening program through the combination of blood markers, rhythm detection devices, and long-term monitoring in our community. In particular, we aimed to validate the use of NT-proBNP, and identify new blood biomarkers associated with AF. Also, we aimed to compare AF detection using various wearables and long-term Holter monitoring. METHODS: 359 subjects aged 65-75 years with hypertension and diabetes were included in two phases: Phase I (n = 100) and Phase II (n = 259). AF diagnosis was performed by baseline 12-lead ECG, 4 weeks of Holter monitoring (NuuboTM), and/or medical history. An aptamer array including 1310 proteins was measured in the blood of 26 patients. Candidates were selected according to p-value, logFC and biological function to be tested in verification and validation phases. Several screening devices were tested and compared: AliveCor, Watch BP, MyDiagnostick and Fibricheck. RESULTS: AF was present in 34 subjects (9.47%). The aptamer array revealed 41 proteins with differential expression in AF individuals. TIMP-2 and ST-2 were the most promising candidates in the verification analysis, but none of them was further validated. NT-proBNP (log-transformed) (OR = 1.934; p<0.001) was the only independent biomarker to detect AF in the whole cohort. Compared to an ECG, WatchBP had the highest sensitivity (84.6%) and AUC (0.895 [0.780-1]), while MyDiagnostick showed the highest specificity (97.10%). CONCLUSION: The inclusion and monitoring of a cohort of primary care patients for AF detection, together with the testing of biomarkers and screening devices provided useful lessons about AF screening in our community. An AF screening strategy using rhythm detection devices and short monitoring periods among high-risk patients with high NT-proBNP levels could be feasible.

Calidad de la medida de la presión arterial en la asistencia habitual / Quality of blood pressure measurement in routine care

Fundamento y objetivos: la medida de la presión arterial es uno de los procedimientos más utilizados en la asistencia, lo que se relaciona con la elevada prevalencia de la hipertensión arterial. Una medición inexacta genera un problema importante, pues pocos mmHg de error sistemático aumentan o disminuyen artificialmente más de un 50% su diagnóstico y más de un 40% su grado de control. Asimismo, la medición correcta habitualmente muestra más hipertensos con presión arterial dentro del rango objetivo. El presente estudio se realizó para evaluar la calidad de la medida en la práctica habitual. Método: estudio observacional transversal en instituciones asistenciales mientras el personal realizaba el cuidado habitual. Lo observado se contrastó con los requisitos para una buena medida analizando 36 variables agrupadas en tres dimensiones: estructura (ambiente, equipamiento), proceso (interrogatorio, paciente, observador) y resultado. Se consideró correcta cada dimensión cuando tenía ³75% de variables apropiadas en cada medida. Resultados: en las 302 medidas analizadas hubo porcentaje correcto de 100% en estructura, 5% en proceso y 47% en resultado. El hecho de redondear a 0 (llevar a la decena entera más próxima el valor de la medida en mmHg) y el interrogatorio insuficiente fueron los errores más frecuentes, seguidos de colocar el estetoscopio debajo del brazalete y la realización de una única medida cuando el valor inicial fue ³140/90 mmHg. Conclusiones: se detectaron frecuentes fallas en la medida de la presión arterial en la práctica habitual relacionadas a mala técnica de medición, lo que tiene gran trascendencia en el manejo crónico de la HA, ya que la precisión de la medida es esencial, pues tanto su diagnóstico como su tratamiento requieren disponer de cifras apropiadas.

Background and objective: the measurement of blood pressure is one of the most used procedures in clinical practice, what is related to the high prevalence of arterial hypertension. An inaccurate measurement generates a significant problem, because few mmHg of systematic error artificially increase or decrease 50% its diagnosis and 40% its degree of control. Also, correct measurement usually shows more hypertensives with blood pressure within the target range. The present study was carried out to evaluate the quality of the blood pressure measure in the usual practice. Method: observational cross-sectional study in health institutions while the staff performed the usual care. The observations were contrasted with the requirements for a correct measure, by analyzing 36 variables grouped in three dimensions: structure (environment, equipment), process (interview, patient, observer) and result. The dimension was considered correct when it had ³75% of appropriate variables in each measure. Results: in the 302 measures analyzed there was a correct percentage of 100% in structure, 5% in process and 47% in result. Rounding to zero and insufficient patient interview were the most frequent errors, followed by placing the stethoscope under the cuff and performing a single measurement when the initial value was ³140/90 mmHg. Conclusions: failures were detected in the measurement of blood pressure in the usual practice related to poor measurement technique. In chronic treatment of arterial hypertension, the accuracy of the measurement is essential since both its diagnosis and its management require adequate blood pressure values.