Incident Type 2 Myocardial Infarction in a Cohort of Patients Undergoing Coronary or Peripheral Arterial Angiography

Despite growing recognition of type 2 myocardial infarction (T2MI; related to supply/demand mismatch), little is known about its risk factors or its association with outcome.

A single-center cohort of patients undergoing coronary or peripheral angiography with or without intervention was prospectively enrolled and followed for incident type 1 and T2MI, and major adverse cardiovascular events (MACE, a composite of all-cause death, nonfatal myocardial infarction [MI], heart failure, stroke, transient ischemic attack, peripheral arterial complication, and cardiac arrhythmia), as well. T2MI was adjudicated using criteria from the Third Universal Definition of MI. Baseline characteristics, blood samples, and angiography information were obtained. Major end points subsequent to first MI were assessed using landmark analyses to compare the rates of first events only where everyone with a prior history of any MACE before MI were censored and adjusted for follow-up times. Cox proportional hazard models were used for time-to-event analyses with age and sex forced into all models and additional covariates evaluated by using the stepwise option for the selection.

One thousand two hundred fifty-one patients were enrolled and followed for a median of 3.4 years. Of these patients, 152 (12.2%) had T2MI during follow-up; T2MI was frequently recurrent. Multivariable predictors of T2MI were older age, lower systolic blood pressure, history of coronary artery disease, heart failure, chronic obstructive pulmonary disease, diabetes mellitus, nitrate use, and elevated concentrations of glucose, N-terminal pro-B type natriuretic peptide, and cystatin C. Patients with T2MI had higher rates of subsequent adverse events than those without T2MI (per 100 person-years: MACE, 53.7 versus 21.1, P<0.001; all-cause death, 23.3 versus 3.3, P<0.001; cardiovascular death, 17.5 versus 2.6, P<0.001; heart failure events, 22.4 versus 7.4, P<0.001); these rates are similar to those seen in patients with type 1 MI. Incident diagnosis of T2MI strongly predicted risk for subsequent MACE (adjusted hazard ratio, 1.90; 95% confidence interval, 1.46-2.48; P<0.001), all-cause death (adjusted hazard ratio, 2.96; 95% confidence interval, 2.01-4.36; P<0.001), and cardiovascular death (adjusted hazard ratio, 2.16; 95% confidence interval, 1.36-3.43; P=0.001).

T2MI is common and associated with poor prognosis. Studies evaluating treatment strategies for management of T2MI are needed.

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00842868.