Elective PCI were included in the study. Patients were randomized into two different groups. One group took ASA 80 mg once daily and clopidogrel 75 mg once a day, and the other one took ASA 80 mg once a day and ticagrelor 90 mg twice a day. After six months of close follow-up, patients were asked to give a score to their dyspnea and asked about the major advance cardiovascular events ( MACE)

Clinical data of this Randomized Clinical Trial (RCT) study was gathered from patients referred to Prof. Kojuri cardiovascular clinic (Shiraz, Iran, Email: kojurij@yahoo.com , webpage: http://kojuriclinic.com/ ) from October 2022 to March 2023. The inclusion criterion was experiencing elective percutaneous coronary intervention (PCI). Patients diagnosed with hypersensitivity to either ticagrelor or clopidogrel or the ones having any other contraindications such as active pathological bleeding, were excluded from the study. Patients who consumed anticoagulants in the course of their medical therapy were also excluded.

Basic clinical information of all patients such as diabetes mellitus (diagnosed based on ADA 2018 criteria [23]), hypertension (defined as systolic blood pressure > 130 mmHg or diastolic blood > 80 mmHg based on 2017 ACC/AHA hypertension guideline [24]), dyslipidemia, anemia (defined according to 1968 Who definition [25]), asthma (diagnosed based on 2007 NAEPP criteria [26]) , chronic obstructive pulmonary disease (diagnosed according to 2020 GOLD criteria [27]), and atrial fibrillation (AF) were recorded. Furthermore, other clinical data such as body mass index (normal; 18.5 to 24.9, overweight; 25 to 29.9 and obesity; higher than 30), left ventricle ejection fracture (LVEF), and heart failure (classified based on 2001 ACC/AHA heart failure classification [28]), history of using tobacco within the past 3 months, and past drug history were also recorded. Major bleeding was defined according to the Thrombolysis in Myocardial Infarction (TIMI) criteria: intracranial bleeding, hemorrhage with a hemoglobin decrease of at least 5 g/dL, or fatal bleeding that caused death within 7 days [29].

Patients were asked to give a score to their dyspnea based on the 10 point Likert scale before undergoing PCI. Score 1-3 were considered mild, score 4-7 were considered moderate, and score 7-10 were considered severe. Patients were randomized using the Block randomization method with block size=4 into two different groups. One group took acetylsalicylic acid (ASA) 80 mg once daily and clopidogrel 75 mg that is produced by Sanofi company available in market as Plavix once a day, and the other one took ASA 80 mg once a day and ticagrelor 90 mg that is produced by Abidi company available in market as Brilavus twice a day.

The patients were completely informed about the advantages and disadvantages of the study, and inform consents were taken from participants. Patients who desired not to participate were excluded from the study. Participants were told to take their medications regularly, and they were also encouraged to call us immediately if they faced any medical problem for further investigation.

After six months of close follow-up, patients were asked to give a score to their dyspnea happened after PCI, based on the 10 point Likert scale. They were also asked about having dyspnea on exertion, paroxysmal nocturnal dyspnea (PND), any bleeding such as GI bleeding, and occurrence of major adverse cardiovascular event (MACE; defined as acute coronary syndrome (ACS), stroke, revascularization, hospitalization due to heart failure, and cardiac death.) [29] We followed the patients by using their phone numbers which were obtained at the beginning of the study.

For statistical analyses we used IBM SPSS software version 25. Independent-sample t tests and one-way ANOVA were used for parametric variables. The Mann-Whitney U test and Kruskal-Wallis test were used for nonparametric data. Values of p <0.05 were considered significant.

The study protocol was based on Helsinky declaration, all patients were filled the written consent, The study protocol was approved by Ethical committee of Shiraz University of medical sciences under the number of IR.SUMS.MED.REC.1401.351.

Inclusion Criteria:

• Experiencing elective percutaneous coronary intervention (PCI).

Exclusion Criteria:

• Patients diagnosed with hypersensitivity to either ticagrelor or clopidogrel
• Active pathological bleeding
• Patients who consumed anticoagulants in the course of their medical therapy

no data will be available to public