AMI triggered by coronary atherosclerosis vs spasm more likely to result in complications

Major adverse cardiac events (MACEs) tend to occur more frequently in patients with acute myocardial infarction (AMI) caused by coronary artery atherosclerosis (CAA) than by coronary artery spasm (CAS), a recent study has found.

Researchers enrolled 36,797 AMI patients, of whom 36,313 had CAA-AMI (mean age, 63.1±12.7 years; 73.0 percent male) and 484 had CAS-AMI (mean age, 55.4±12.4 years; 69.0 percent male). MACE was set as the primary outcome and was defined as the composite of total death, nonfatal MI and repeat revascularization.

The incidence rate of MACEs after 2 years of follow-up was significantly lower in the CAS-AMI than in the CAA-AMI group (7.1 percent vs 11.2 percent; log-rank p=0.007).

Disaggregation according to endpoint components however showed that the incidences of total death (5.6 percent vs 6.4 percent; log-rank p=0.503) and nonfatal MI (0.9 percent vs 1.5 percent; log-rank p=0.594) did not significantly differ between the CAS-AMI and CAA-AMI patients. The same was true for 30-day total (4.6 percent vs 4.5 percent; p=0.941) and cardiac (4.1 percent vs 4.3 percent; p=0.901) death.

The significant difference in the primary composite endpoint was driven primarily by repeat revascularization, which was significantly more common in the CAA-AMI group (4.2 percent vs 0.4 percent; log-rank p<0.001).

Multivariate logistic regression analysis identified the following as significant predictors of 2-year total mortality in CAA-AMI patients: aborted cardiac arrest, ST-segment elevation MI, diabetes mellitus and current smoking, among other variables.