Trial of Caffeine to Alleviate Dyspnea Related to Ticagrelor

• Age ≥ 18 years
• Recent acute coronary syndrome with ongoing ticagrelor treatment
• Stabilized clinical condition with no plans of additional revascularization
• Dyspnea with onset after start of ticagrelor treatment
• Willingness to abstain from caffeine intake (e.g. coffee, tea, cola-type beverages; other foods, nutritional supplements or medications containing caffeine) for the duration of the study
• Provision of signed informed consent form

Exclusion Criteria:

• Chronic obstructive pulmonary disease, asthma or other known pulmonary disease requiring daily medical therapy
• Obstructive sleep apnea syndrome requiring therapy
• Ongoing signs and symptoms of heart failure*, or evidence of moderately to severely reduced left ventricular (LV) function
• Renal failure, glomerular filtration rate (GFR) \<30 or on dialysis
• Pregnancy or lactation
• Known allergy to ticagrelor, or caffeine, or known intolerance of caffeine
• Ongoing treatment with any of the following: quinolone antibiotics, fluvoxamine, phenylpropanolamine, carbamazepine, clozapine, lithium, non-steroidal anti-inflammatory drugs (NSAIDs); or any drug containing theophylline or caffeine.
• Any condition that seriously increases the risk of non-compliance or loss of follow-up