Clinical Profile and One Year Outcome of Atrial Fibrillation- A Prospective Cohort Study

Abstract

Introduction: Atrial Fibrillation (AF) is the most common arrhythmia in clinical practice and imposes a great burden on health care resources. There is limited data regarding the impact of AF in our population. Aim: To estimate the mortality and Major adverse Cardiovascular events {(MACE)- Acute Coronary Syndrome (ACS), Stroke, Cardiac death} in AF patients in a tertiary care centre in South India. Materials and Methods: This prospective cohort study included all patients >18 years with newly diagnosed or previously documented evidence of AF in Electrocardiography (ECG). Transient reversible causes and critically ill patients were excluded. Total of 346 patients were recruited and prospectively, followed-up at 1, 3, 6 and 12 months for development of MACE, anticoagulation status, Prothrombin Time (PT), International Normalised Ratio (INR) and major bleeding events. Baseline data including clinical parameters, comorbidities and appropriate investigations such as ECG and Echocardiogram (ECHO) parameters were collected with a structured questionnaire and analysed at one year using appropriate statistical tests. Results: Average age was 60.5 years (SD 11.5 years) and majority (74.6%) were between 50-75 years. Females were more (59.5% vs 40.5%). Most common AF risk factor was Hypertension (44.5%) followed by Rheumatic Heart Disease (RHD) in 27.2% of AF patients. AF was classified as permanent in 42.2%, persistent in 23.1% and paroxysmal in 34.7%. Valvular AF was present in 26.6% and non-valvular AF in 73.4%. At one year, 17 patients were lost to follow-up. CHA2DS2VASc score of ≥2 was present in 65.1%. During one year follow-up the MACE rate was 26.7% (ischemic stroke in 9.4%, ACS in 2.7% and cardiac mortality in 14.6 %). Mean time in Therapeutic Range (TTR) was 28.12%. TTR >60% (good control) was present in only 9.2%. Conclusion: AF continues to be a significant arrhythmia causing substantial morbidity and mortality. Non-valvular AF was thrice as common as valvular AF. Though 3/4th of the patients were on oral anticoagulants, <10% had their INR under good control which contributed to the higher events. To improve the outcomes in AF patients, treatment of risk factors and optimal anticoagulation plays a crucial role.