Protocol for a multicentre and prospective follow-up cohort study of early detection of atrial fibrillation, silent stroke and cognitive impairment in high-risk primary care patients: the PREFA-TE study

BACKGROUND

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia. Future estimations suggest an increase in global burden of AF greater than 60% by 2050. Numerous studies provide growing evidence that AF is not only associated with stroke but also with cognitive impairment and dementia.

AIM

The main goal is to assess the impact of the combined use of cardiac rhythm monitoring devices, echocardiography, biomarkers and neuroimaging on the early diagnosis of AF, silent strokes and cognitive decline, in subjects at high risk of AF.

METHODS AND ANALYSIS

Two-year follow-up of a cohort of individuals aged 65-85 years at high risk for AF, with no prior diagnosis of either stroke or dementia. The study involves baseline echocardiography, biomarkers, and neuroimaging, yearly cardiac monitoring, and semiannual clinical assessments. Different parameters from these tests will be analysed as independent variables. Throughout the study period, primary outcomes: new diagnoses of AF, stroke and cognitive impairment, along with any clinical and therapeutic changes, will be registered. A first descriptive and bivariate statistical analysis, appropriate to the types of variables, will be done. The information obtained from the data analysis will encompass adjusted risk estimates along with 95% confidence intervals. Event risk predictions will rely on multivariate Cox proportional hazards regression models. The predictive value of the model will be evaluated through the utilisation of receiver operating characteristic curves for area under the curve calculation. Additionally, time-to-event analysis will be performed using Kaplan-Meier curves.

ETHICS AND DISSEMINATION

This study protocol has been reviewed and approved by the Independent Ethics Committee of the Foundation University Institute for Primary Health Care Research-IDIAP Jordi Gol (expedient file 22/090-P). The authors plan to disseminate the study results to the general public through various scientific events. Publication in open-access journals and presentations at scientific congresses, seminars and meetings is also foreseen.

TRIAL REGISTRATION NUMBER

NCT05772806.

[Treatment setting, symptomatology, clinical course, severity degree and case-fatality rate in 536 adults over 50 years with laboratory-confirmed COVID-19 in Tarragona, Spain, March-June 2020.]

OBJECTIVE

Population-based clinical data on COVID-19 is scarce. This study analyzed distinct clinical characteristics of COVID-19 and relationships with lethality among adults.

METHODS

Retrospective cohort that included all population ≥50 years with a laboratory-confirmed COVID-19 in Tarragona, Spain, during 01/03/2020-30/06/2020. Treatment setting (outpatient/hospital/nursing-home), pre-existing comorbidities, signs/symptoms, clinical course, severity and lethality (death from any cause in-hospital or within the first 30-day after the diagnosis) were determined. Chi squared and Fisher's test were used to compare percentages.

RESULTS

Of the 536 overall cases (mean age: 74 years; 43.8% male), 150 (28%) were outpatient, 179 (33.4%) were hospitalised and 207 (38.6%) happened in nursing-home/social-health centres. The most prevalent symptoms were fever (57.9%), cough (49.8%), dyspnea (41.5%), general discomfort (36.2%), fatigue (24.4%), diarrhea (19.6%), myalgias (17.3%), headache (14.6%), confusion/lethargy (14.6%), thoracic pain (10%), anosmia (9.8%), disgeusia/ageusia (8.1%) and sore throat (7.7%). Global lethality was 23.1% (1.7% in 50-64 years vs 25.5% in 65-79 years vs 38.7% in ≥80 years, p<0.001; 26.8% in men vs 20.3% in women, p=0.075; 3.3% in outpatient vs 29.6% in hospitalised vs 31.9% in nursing-home/social-health centres, p<0.001). By symptomatology, maximum lethality was observed among patients with confusion/lethargy (77.6%) and minimum among those with ageusia/disgeusia (4.8%), anosmia (3.9%) or myalgias (1.1%). By pre-existing comorbidities, greater lethality happened among patients with neurologic (36.7%), renal (35.4%) and cardiac disease (35.3%).

CONCLUSIONS

There was a relatively great lethality of COVID-19 among the general population ≥50 years across the first epidemic wave in the study setting. Increasing age, male sex, nursing-home residence and several signs/symptoms and comorbidities were associated with higher mortality.