POSTMYOCARDIAL INFARCTION SYNDROME: INPATIENT CONTEMPORARY FEATURES OF A FORGOTTEN CONDITION IN THE POST PERCUTANEOUS CORONARY INTERVENTION ERA.

Background: Postmyocardial Infarction Syndrome (PMIS), also called Dressler syndrome or Post-pericardiotomy Syndrome, refers to a heterogeneous group of autoimmune-mediated conditions of pericardial, epicardial and myocardial inflammation following myocardial infarction. Generally considered to be rare in the reperfusion era, the features and risk factors of PMIS are less well characterized in the contemporary era. This study aims to better characterize PMIS in the United States in recent years.

Methods: Data from the National Inpatient Sample between 2012 and 2016 was queried for this study. The NIS is the largest all-payer inpatient care database in the United States. Patients with ICD 9/10 codes 412/I25.2, respectively, were identified as having a previous diagnosis of myocardial infarction (MI). First, a univariate analysis was performed to study differences in clinical characteristics between patients with prior MI who developed PMIS (identified by ICD9/10 codes 411.0/ I24.1, respectively) versus patients with prior MI who did not develop PMIS. A multivariate logistic regression model was then constructed to determine which of the clinical and demographic characteristics were significantly associated with the occurrence of PMIS.

Results: In total, 559 patients were identified with PMIS. Among patients with prior MI, patients with PMIS were more likely to be younger (63.0 ± 14.2 vs. 70.0 ±13.1, OR = 0.96, 95% CI = 0.96- 0.97, p <0.01), to have hyperlipidemia (OR = 1.37, 95% CI = 1.23-1.65, p < 0.01), history of PCI (OR = 1.37, 95% CI = 1.15-1.63, p<0.01), history of CABG (OR =1.61, 95% CI = 1.32-1.97, p<0.01), cardiogenic shock (OR = 9.63, 95% CI = 1.22- 76.00, p =0.03), acute HF (OR = 1.90, CI = 1.30 - 2.80, p < 0.01) and less likely to have diabetes (OR = 0.73, CI = 0.61- 0.87, p< 0.01) and chronic kidney disease (OR = 0.57, CI = 0.46 -0.71, p< 0.01) compared to patients with prior MI but without PMIS (n = 1,516,669).

Conclusions: To the best of our knowledge, this is the largest contemporary study on the incidence, demographic characteristics and inpatient clinical features of PMIS in the United States. Though generally having a good prognosis, PMIS is a major contributor to post-MI comorbidity, including longer hospital stays, more readmissions, and tamponade. In response to a recent editorial by Pattakos, et al published in the Journal of the American Heart Association “Post-pericardiotomy Syndrome: Beware or just Be Aware,” our study attempts to bring more awareness to this seemingly forgotten syndrome.