Although there is an established link between type 2 myocardial infarction (T2MI) and elevated rates of cardiovascular events, less is known about the connection between T2MI and heart failure—which this new study investigated.
There is a great need for preventive strategies against heart failure–related events among patients with a history of type 2 myocardial infarction (T2MI), among whom approximately 20% will face hospital readmission for heart failure in the year following a T2MI, reports a new study from investigators at Massachusetts General Hospital (MGH).
These findings appeared recently in Journal of the American Heart Association.
Knowing there is a 60% 5-year mortality rate among individuals who suffer a T2MI, as well as that there is a close relationship between T2MI and heart failure—which is underexplored, the authors note—they investigated this relationship among a cohort of patients with a T2MI at MGH between October 2017 and May 2018, as identified by International Classification of Diseases, Tenth Revision, code I21.A1.
“As recognition of T2MI has increased, emerging data have demonstrated that this form of MI is common and may even be more prevalent than type 1 MI,” the authors wrote. “Moreover, as hospitals transition to high‐sensitivity cardiac troponin assays, the incidence of T2MI is anticipated to further increase.”
In cases of diagnostic uncertainty, to indicate myocardial injury, the following levels were used:
Among the 359 patients included in the authors’ retrospective single-center analysis, 51.3% (n = 184) had a history of heart failure. Of the 97.8% (n = 180) with ejection fraction data on file, most (59.4%) had heart failure with preserved ejection fraction (HFpEF); 30.0% had heart failure with reduced ejection fraction (HFrEF) and 10.6%, heart failure with midrange ejection fraction (HFmEF).
T2MI was found to be most commonly precipitated by acute heart failure (20.9%), and among this group, ejection fraction was a mean (SD) of 53.0% (16.8%) and 21.3% of the diagnoses were de novo in nature.
Data were also available on 80.5% of patients who were alive at discharge following hospitalization for a T2MI. Among this group, acute heart failure necessitated at least 1 readmission before 30 days in 5.5%, before 180 days in 17.3%, and by 1 year in 22.1%. The highest rehospitalization rate, however, was seen among patients who had a history of T2MI and comorbid prevalent or new heart failure vs those with T2MI but no heart failure: 34.2% vs 7.0%.
The authors’ analysis also found:
Overall, the authors believe their data indicate a high risk of heart failure–related hospitalizations following T2MI and myocardial injury and that this requires screening for the latter “to guide future risk of incident heart failure.”
“There is a complex intersection between T2MI and heart failure, and approximately 1 in 5 patients with T2MI will be readmitted for HF within 1 year of their index event,” they concluded. “Efforts to improve primary and secondary prevention of heart failure events after a T2MI are needed.”
McCarthy CP, Jones-O’Connor M, Olshan DS, et al. The intersection of type 2 myocardial infarction and heart failure. J Am Heart Assoc. Published online August 21, 2021. doi:10.1161/JAHA.121.020849