Inhaled bronchodilators and acute myocardial infarction: a nested case-control study.

We investigated the association between the use of inhaled bronchodilators and the risk of AMI. A nested case-control study using the nationwide insurance claims database was conducted. Overall, 11,054 AMI cases and 47,815 matched (up to 1:5) controls were identified from 1,036,119 subjects without acute major cardiovascular events in the past year. Long-acting and short-acting β-agonists (LABAs and SABAs) were associated with increase in the risk of AMI, although an inhaled corticosteroid combined with a long-acting β-agonist was not. Long-acting muscarinic antagonists (LAMAs) in a dry powder inhaler (DPI) were significantly associated with reduced risk of AMI, while LAMAs in a soft mist inhaler (SMI) didn't decrease the risk of it. In hypertensive or diabetic patients, LAMAs in a DPI were associated with reduced risk of AMI, but LABAs were associated with increased risk. Among the β-blocker users, the reduction of AMI risk by LAMAs was the most significant. In conclusions, inhaled β-agonists were associated with increase in the risk of AMI, while LABAs accompanied by ICSs were not associated with increase in the risk of AMI. LAMAs in a DPI use were associated with lower risk of AMI.