Relationship between platelet mass index and postoperative atrial fibrillation after elective coronary artery bypass surgery: a retrospective study

Background Atrial fibrillation (AF) is the most common complication after cardiac surgery. The pathogenesis of postoperative atrial fibrillation (POAF) is multifactorial and one of the known factors is inflammation. Platelet mass index (PMI) is an indicator of platelet activation and a better inflammatory marker than mean platelet volume (MPV). In this retrospective study, we investigated the relationship between POAF and PMI. Methods The study included 848 consecutive patients (655 male and 193 female) who had elective isolated coronary artery by-pass grafting (CABG) or combined CABG and valvular surgery. Platelet count and MPV were measured from preoperative blood samples to calculate PMI. Post-operative atrial fibrillation was defined as irregular and fibrillatory P waves occurring 48–96 h after cardiac surgery and lasting at least 30 s. The PMI values in patients who developed POAF were compared with those in patients who did not develop POAF. Results Patients who developed POAF had higher PMI values (2549.3 ± 1077.1) when compared with patients in sinus rhythm (2248.1 ± 683.4; p