Spontaneous coronary artery dissection (SCAD) is a rare cause of acute myocardial infarction (AMI). We sought to compare the results on in-hospital mortality and 30-day readmission rates among patients with AMI-SCAD vs AMI due to other causes (AMI-non-SCAD).

Risk-standardized in-hospital mortality (rIMR) and risk-standardized 30-day readmission ratios (rRAR) were calculated using the minimum dataset of the Spanish National Health System (2016-2019).

A total of 806 episodes of AMI-SCAD were compared with 119 425 episodes of AMI–non-SCAD. Patients with AMI-SCAD were younger and more frequently female than those with AMI–non-SCAD. Crude in-hospital mortality was lower (3% vs 7.6%; P<.001) and rIMR higher (7.6±1.7% vs 7.4±1.7%; P=.019) in AMI-SCAD. However, after propensity score adjustment (806 pairs), the mortality rate was similar in the 2 groups (AdjOR, 1.15; 95%CI, 0.61-2,2; P=.653). Crude 30-day readmission rates were also similar in the 2 groups (4.6% vs 5%, P=.67) whereas rRAR were lower (4.7±1% vs 4.8%±1%; P=.015) in patients with AMI-SCAD. Again, after propensity score adjustment (715 pairs) readmission rates were similar in the 2 groups (AdjOR, 1.14; 95%CI, 0.67–1.98; P=.603).

In-hospital mortality and readmission rates are similar in patients with AMI-SCAD and AMI–non-SCAD when adjusted for the differences in baseline characteristics. These findings underscore the need to optimize the management, treatment, and clinical follow-up of patients with SCAD.