The Course of Ischemic Mitral Regurgitation in Acute Myocardial Infarction After Primary Percutaneous Coronary Intervention: From Emergency Room to Long-Term Follow-Up

Abstract

Background: Previously published evidence on ischemic mitral regurgitation (IMR) and its adverse prognosis after myocardial infarction has been based on the severity of IMR in the subacute or chronic period of myocardial infarction. However, the state of IMR can vary from the early stage to the chronic stage as a result of various responses of myocardium after primary percutaneous coronary intervention (PCI).

Methods and results: Standard echocardiography was serially performed in 546 consecutive patients with first-onset acute myocardial infarction (1) immediately after their arrival (pre-PCI), (2) before discharge (early post-PCI), and (3) 6 to 8 months after PCI (late post-PCI). The course of IMR after primary PCI and the prognostic impact of the IMR in each phase were investigated. IMR was found in 193/546 (35%) patients at the emergency room. In the acute phase after PCI, IMR improved in 63 patients. IMR worsened in 78 patients despite successful PCI. Shorter onset-to-reperfusion time and nontotal occlusion before PCI were the independent predictors of early improvement of IMR. In the chronic phase, IMR improved in 79 patients and worsened in 36 patients. Lower peak creatine kinase-myocardial band was an independent predictor of late improvement of IMR. IMR before PCI worsened 30-day prognosis (P=0.02), and persistent IMR in the chronic phase worsened long-term prognosis (P=0.04) after primary PCI.

Conclusions: Degrees of IMR changed in the early and chronic phase after primary PCI for acute myocardial infarction. IMR on arrival and persistent IMR in the chronic phase worsened short-term and long-term prognosis after acute myocardial infarction, respectively.

Keywords: acute coronary syndrome; echocardiography; mitral regurgitation; percutaneous coronary intervention; prognosis.