Background Type 2 myocardial infarction (T2MI) is common and associated with high cardiovascular event rates. However, the relationship between T2MI and heart failure (HF) is uncertain. Methods and Results We identified patients with T2MI at a large tertiary hospital between October 2017 and May 2018. Patient characteristics, causes of T2MI, and subsequent HF hospitalizations were determined by physician chart review. We identified 359 patients with T2MI over the study period; 184 patients had a history of HF. Among patients with ejection fraction (EF) assessment (N=180), the majority had preserved EF (N=107; 59.4%), followed by reduced EF (N=54; 30.0%), and mid-range EF (N=19; 10.6%). Acute HF was the most common cause of T2MI (20.9%). Of those whose T2MI was precipitated by HF (N=75), the mean EF was 53.0±16.8% and 16 (21.3%) were de novo diagnoses of HF. Among patients with T2MI who were discharged alive with available follow-up (N=289), 5.5% were hospitalized with acute HF within 30 days, 17.3% within 180 days, and 22.1% within 1 year. In subgroup analyses, among patients with T2MI with prevalent or new HF (N=161), the rate of HF hospitalization at 1 year was 34.2%, considerably higher than those with T2MI and no HF diagnosis at discharge (7.0%; N=9/128). Conclusions Index presentations of HF or worsening chronic HF represent the most common causes of T2MI. ≈1 in 5 patients with T2MI will be readmitted for HF within 1 year of their event. Strategies to prevent HF events after a T2MI are needed.
Keywords: heart failure; outcomes; type 2 myocardial infarction.