Pulmonary Function Tests in Patients on Ticagrelor and Clopidogrel: A Comparative Study

Introduction: Acute coronary syndrome (ACS) can be defined as any group of clinical symptoms consistent with acute myocardial ischemia. This may include unstable angina (UA), non-ST-segment elevation and ST-segment elevation myocardial infarction. Antiplatelet therapy is an essential part of management of patients with acute coronary syndrome and may consist of aspirin (irreversibly inhibiting cyclooxygenase 1), clopidogrel (P2Y12 adenosine diphosphate receptor blocker), newer P2Y12 ADP Inhibitors (Prasugrel & Ticagrelor) and GP IIb/IIIa Inhibitors. There are studies which have reported that there is increased risk of dyspnea in patients of acute coronary syndrome who have been on Ticagrelor (The Platelet Inhibition and Patient Outcomes (PLATO) trial) due to which Ticagrelor was being avoided in patients who had history of COPD. We conducted this comparative study to compare effects of Ticagrelor and clopidogrel on pulmonary functions of patients with CAD. Materials and Methods: This was a comparative study which a total 120 patients with acute coronary syndrome were enrolled depending upon a predefined inclusion and exclusion criteria. The study was conducted in the department of medicine in a tertiary care medical college. A detailed clinical history was taken and through clinical examination was done in all the cases. Demographic details were noted in all the cases. Out of these total 120 patients 60 patients each were randomized to ticagrelor (90 mg twice daily) (Group A) and clopidogrel (75 mg once daily) (Group B). After a continuous therapy of 1-month pulmonary function tests (Pulse oximetry (SpO2), spirometry FEV1, FVC, FEF25-75) were repeated. Pulmonary function tests in Group A and Group B were compared. For statistical purposes P value less than 0.05 was taken as statistically significant. Results: Out of 120 patients there were 80 (66.67%) males and 40 (33.33%) females with a M:F ratio of 1:0.5. The gender difference in both the groups was statistically not significant (P>0.05). The mean age of the patients in group A and group B was found to be 61.56 +/-3.98 and 62.41 +/-3.40 respectively. Hypertension, dyslipidemia and diabetes mellitus were the most common co-morbid conditions in patients with CAD. Mean FEV1 values, FEV1/FVC ratio, FEF25-75 % and SPO2 levels were found to be comparable in both the groups with no statistically significant difference. Conclusion: Ticagrelor does not appear to be any adverse effect on pulmonary function tests as compared to clopidogrel in patients with CAD and hence appears to be preferable as compared to clopidogrel due to considerable reduction in cardiovascular death, myocardial infarction and stroke.