Pneumonia is uncommon high among patients with acute myocardial infarction (AMI), which increases adverse clinical events and prolongs the hospital stay. Inspiratory muscle training (IMT) is able to improve inspiratory muscle strength and prevent pneumonia in patients undergoing cardiac surgery including coronary artery bypass grafting. Thus, the investigators design the study mainly aim to evaluate the 30 days IMT for the change of inspiratory muscle strength, and also to observe its potentially effect on reducing pneumonia, in participants who accepted primary percutaneous coronary intervention (PCI) and at a high risk of pneumonia.

This is a single center, prospective, randomized controlled study. All participants will be followed up until 30 days after randomized.

Inclusion Criteria:

• age ≥ 18 years, patients with AMI undergoing primary PCI, admitted to cardiac intensive care unit and at a high pneumonia risk [2 or more of the following parameters are regarded as high risk for pneumonia: 1. Age > 55 years, 2. Diabetes mellitus, 3. Smoking at present, 4. Chronic kidney disease: estimated glomerular filtration rate < 60 mL/min/1.73m2, 5. Forced expiratory volume in the first second of expiration (FEV1) < 80% predicted and FEV1/forced vital capacity (FVC) < 70% predicted]
• be able to understand and agree with informed consent

Exclusion Criteria:

• a history of cerebrovascular accident
• treat with immunosuppressive medication for 30 days before
• neuromuscular disorder
• cardiovascular instability (such as aortic dissection or unstable hemodynamics)
• a history of Coronary Artery Bypass Grafting (CABG)
• expected survival is less than 6 months due to noncardiogenic disease
• participated in other drugs and devices studies within 30 days
• confirmed as ventricular aneurysm
• other conditions not suit for the study after the discussion among the researchers (eg: poor compliance, unable to cooperate for the training)