Patients who experienced Type 2 myocardial infarction were older and more likely to have comorbidities and risk factors than those who experienced Type 1.
Patients who experience Type 2 myocardial infarction are at higher risk for additional cardiovascular events and death than patients who experience Type 1 myocardial infarction (MI), according to a new analysis from the DCRI.
The analysis, which the DCRI’s Chiara Melloni, MD, presented as an oral abstract Saturday at the American Heart Association Scientific Sessions 2019 in Philadelphia, examined data from three completed DCRI-led trials to shed new light on the differences between patients who experience Type 1 MI and those who experience Type 2 MI.
All three trials—TRACER, which involved patients with acute coronary syndrome; EUCLID, which studied peripheral artery disease; and EXSCEL, which examined patients with Type 2 diabetes—had been adjudicated by the DCRI’s Clinical Events Classification (CEC) group, for which Melloni acts as a faculty adjudicator. This allowed the study team to have access to all the cardiovascular events that had been reported and adjudicated in the three trials and stored in the CEC databases.
Although Type 2 MI was initially defined in 2007, it remains difficult to diagnose because of the heterogeneity of the patient population that experiences it, as well as the different cardiac markers, assays, and cut-off used, said Melloni. While Type 1 MI is caused by a plaque rupture and has clear symptoms, Type 2 MI, which is characterized by a mismatch between oxygen demand and supply in the coronary vessel, is rarer and can be associated with many different comorbidities.
The analysis examined and compared baseline characteristics of patients enrolled in their respective trials based on the type of MI they experienced after inclusion in the study. Patients who experienced a Type 2 MI during the trial tended to be older and were more likely to have comorbidities and CV risk factors—overall, the Type 2 MI group was a sicker population than the Type 1 group.
The study team also examined outcomes of patients who experienced an MI during a trial. When followed from a year after their initial MI, patients with Type 2 MI were at a higher risk for subsequent MIs or death than their Type 1 counterparts.
One of the key messages of the analysis, Melloni said, was that the results held true regardless of the level of the cardiac troponin released in the blood. The rise and fall of troponin levels are used to ascertain whether a patient has experienced MI, and the peak level of troponin was collected for each patient. Even if patients with Type 2 MI experienced relatively lower levels of troponin leak during the time of their first MI compared with type 1 MI patients, they were at higher risk for negative outcomes than patients with Type 1 who had the same levels of troponin leak.
Other DCRI contributors to this analysis include Karen Alexander, MD; Angie Wu, MS; Schuyler Jones, MD; Rajendra Mehta, MD; David Kong, MD; Thomas Povsic, MD; Manesh Patel, MD; Sana Al-Khatib, MD; and Renato Lopes, MD, PhD. Matt Wilson and Marsha Marquess, who both work on the CEC team, were also instrumental in helping the study team identify which trials could provide the most suitable datasets to perform this analysis.