Postpericardiotomy syndrome (PPS) is a common complication after cardiac surgery. In most cases it develops within two to three weeks after the surgery and the typical symptoms include dyspnea, chest pain, and fever. An immunological mechanism is suspected as the cause of the disease. The disease process is usually self-limiting. Even though PPS occasionally requires invasive interventions, the prognosis of the disease is considered to be benign. This thesis investigated the incidence of clinically significant PPS, the risk factors for the disease, and the effect of operation type on the occurrence of the disease. Furthermore, the mortality of PPS patients was investigated.

The results suggest that although the course of PPS is mostly benign, PPS requiring invasive interventions is associated with increased mortality. The syndrome had no significant impact on the occurrence of atrial fibrillation, cerebrovascular events, or bleeding episodes. The results also demonstrate that the incidence of clinically significant PPS is markedly lower compared to the diagnoses included in previous studies concerning the medical treatment of the disease. The use of red blood cell units, female sex, and younger age were identified as predisposing factors for PPS. Valve procedures and especially aortic procedures represented higher occurrence of the disease when compared to coronary artery bypass surgery. Moreover, PPS was less common in patients with diabetes.

The results demonstrate that the majority of the PPS diagnoses included in recent studies are clinically irrelevant. The knowledge concerning the predisposing factors, such as younger age, female sex, and specific operation types, may be useful for the targeting of prophylactic methods. In contrast with the previous conception, PPS requiring the evacuation of pericardial or pleural effusion is associated with higher mortality. The results suggest that PPS patients requiring invasive interventions are in the need of more intensive follow-up and treatment.