Risk factors, therapeutic approaches, and in-hospital outcomes in Mexicans with ST-elevation acute myocardial infarction: the RENASICA II multicenter registry.

Background: Ischemic heart disease is a growing health problem in Latin America. We aimed to analyze risk factors, acute management, and short-term outcome of Mexicans with ST-elevation myocardial infarction (STEMI).

Hypothesis: Modifiable risk factors are associated with the occurrence of STEMI in Mexicans, and potentially preventable acute complications are responsible for most short-term deaths.

Methods: Among 8600 patients enrolled in Registro Nacional de los Síndromes Coronarios Agudos II (RENASICA II) with a suspected acute coronary syndrome, we analyzed 4555 patients (56%; age 21-100 y) with confirmed STEMI who presented within 24 hours from symptoms' onset.

Results: Smoking (66%), hypertension (50%), and diabetes (43%) were the main risk factors. Most patients (74%) presented with Killip class I (class IV in 4%). Anterior-located STEMI occurred in 56% of cases, and posterior-inferior in 40% of cases. Significant Q waves were present in 43%, right bundle branch block in 7%, left bundle branch block in 5%, first-degree atrioventricular block in 2%, and high-degree atrioventricular block in 2%. A total of 1685 (37%) patients received fibrinolytic therapy (streptokinase, 82%; alteplase, 17%; tenecteplase, 1%), with 31% of patients receiving therapy in <2 hours, 36% in 2-4 hours, 19% in 4-6 hours, and 15% in >6 hours. Thirty percent of patients received either percutaneous coronary intervention or coronary artery bypass grafting during hospitalization. Major adverse cardiovascular events were recurrent ischemia (12%), reinfarction (4%), cardiogenic shock (4%), and stroke (1%). The main predictors of 30-day mortality (10%) in multivariate analysis were age ≥65 years (odds ratio [OR]: 2.47, 95% confidence interval [CI]: 1.94-3.13), Killip class IV (OR: 10.60, 95% CI: 6.09-18.40), and cardiogenic shock (OR: 18.76, 95% CI: 10.60-33.20).

Conclusions: Largely modifiable risk factors and preventable short-term complications are responsible for most STEMI cases and outcomes in this Mexican population.