This application relates to the technical field of medical research and clinical experiments, and provides an experimental method for clinical research of targeting molecules based on an atrial fibrillation warning system. The method includes: continuously monitoring dynamic electrocardiograms of a patient using an atrial fibrillation warning system; when the atrial fibrillation warning system issues an alert indicating imminent atrial fibrillation, immediately collecting blood or other clinical information of the patient; collecting blood or other clinical information of the patient when the patient has not experienced atrial fibrillation and the atrial fibrillation warning system has not issued an alert, to serve as control data; comparing biological indicators during atrial fibrillation occurrence and non-occurrence, and analyzing potential triggering factors and targeting molecules; and based on the identified targeting molecules, conducting targeted treatment research to validate effectiveness of the targeting molecules.

In various embodiments, the present disclosure provides methods reducing the risk of cardiovascular events in a subject on statin therapy and having atrial fibrillation and/or flutter by administering to the subject a pharmaceutical composition comprising about 1 g to about 4 g of eicosapentaenoic acid ethyl ester or a derivative thereof.

Disclosed are compositions and methods for determining aberrant cardiac function or a predisposition to aberrant cardiac function, said method comprising detecting a fragment of II spectrin associated with aberrant cardiac function or a predisposition to aberrant cardiac function in a sample derived from a subject, wherein the detection is indicative of aberrant cardiac function in the subject.