Postdischarge ischemic events in patients with recent MI tied to higher mortality: JAMA

SWEDEN: Post-discharge ischemia episodes were more frequent and linked to a higher death rate in patients with recent myocardial infarction (MI) than bleeding episodes, states a study published in JAMA Network.

In patients with acute myocardial infarction, antithrombotic therapy is utilized to lower the risk of further ischemic episodes. These drugs reduce the risk of ischemia events but raise the risk of bleeding.

"Based on the patient's risk of ischemia and bleeding episodes, antithrombotic medication after myocardial infarction should be tailored to their specific needs. Regarding the respective prognostic significance of the two different types of occurrences, more research is needed", the researchers wrote.

The authors aimed to determine if the relative mortality rate for the 2 types of outcomes has changed over the past 20 years and to evaluate the relationship between ischemic and bleeding events and death in patients with a recent MI.

For this purpose, in Sweden, from 2012 to 2017, cohort research based on national registries was carried out. Between July 2021 and May 2022, data was examined. The analysis comprised MI patients who received antithrombotic medication and were released from the hospital alive. Up to a year following discharge, the likelihood of a first ischemic event or bleeding event as well as the mortality risk were evaluated. The adjusted hazard ratios (aHRs) for 1-year mortality after an ischemia and bleeding incident vs. no event, and after an ischemic vs. bleeding event, were calculated using Cox proportional hazards regression models. For patients discharged in 1997–2000, 2001–2011, and 2012–2017, adjusted HRs for mortality following ischemic vs. bleeding episodes were evaluated.

Key results of the study:

• Out of 86 736 patients, 4039 people had their first ischemic incident (5.7 per 100 person-years) and 3399 had their first bleeding episode (4.8 per 100 person-years).
• Following an ischemic incident, the mortality rate was 46.2 per 100 person-years, while following a bleeding event, it was 27.1 per 100 person-years.
• The aHR for death at 1 year compared to no event was 4.16 after an ischemic incident and 3.43 after a bleeding episode.
• When the two types of events were examined, the aHR for an ischemic vs. bleeding incident was 1.27.
• In 1997-2000, 2001-2011, and 2012-2017, there was no statistically significant distinction between an ischemia and a bleeding event's aHR.

Despite the fact that attempts to tailor the length and severity of antithrombotic therapy after MI normally give equal weight to ischemic and bleeding episodes, the accompanying mortality risk may be greater for ischemic occurrences, concluded the authors.

REFERENCE

Simonsson M, Alfredsson J, Szummer K, Jernberg T, Ueda P. Association of Ischemic and Bleeding Events With Mortality Among Patients in Sweden With Recent Acute Myocardial Infarction Receiving Antithrombotic Therapy. JAMA Netw Open. 2022;5(8):e2220030. doi:10.1001/jamanetworkopen.2022.20030