Patients in this prospective cohort study were selected if they had a history of PCI more than 1 year previously. 405 patients were divided based on their preferences to fasting and non fasting and after 1 month of fasting major adverse cardiovascular events were measured

Between 18 March 2019 and 18 April 2020, patients seen at Professor Kojuri Cardiovascular Clinic in Shiraz, Iran (email:kojurij@yahoo.com, webpage: http://kojuriclinic.com) for their annual check-up were selected. We explained the research project to them, and volunteers were selected. Patients were assigned to the fasting or non-fasting group according to their preference. All volunteers were informed about the details of this research, and provided their written informed consent. Patients who declined to participate in the study were excluded.

Patients were instructed how to divide their medication across the two daily meals before dawn and after sunset during the month of Ramadan. We informed patients to immediately stop fasting and consult the clinic if they experienced any signs of cardiovascular disease, including shortness of breath, chest pain, or palpitations. At the end of Ramadan, patients were contacted by telephone and asked about their symptoms, including chest pain and dyspnea, hospitalization, and MACE. The MACE were defined as acute myocardial infarction, hospitalization due to congestive heart failure, new-onset atrial fibrillation, stroke, or cardiac arrest [19, 20]. Symptomatic patients were referred to the clinic for cardiovascular examination.

The study was double-blinded. To blind the researchers, the clinic secretary contacted the patients and asked them not to specify their group (fasting or non-fasting), and then passed the phone to the researcher. We used alphabetical order in each group to blind the statisticians. Patients who fasted during Ramadan were designated with the letter X, and patients who did not fast during Ramadan were designated with the letter Y.

For statistical analyses we used IBM SPSS software version 25. We used the chi-squared test to compare categorical variables and Student's t-test to compare the mean values of continuous variables. The Mann-Whitney U test and Kruskal-Wallis test were used for nonparametric variables.

Inclusion Criteria:

• history of PCI, and a minimum of 1 year between angioplasty and enrollment in this study

Exclusion Criteria:

• Heart failure (ejection fraction <50 %)
• Advanced kidney failure (glomerular filtration rate <60 mL/min
• Unsuccessful revascularization
• Coronary artery bypass graft
• Liver cirrhosis
• Any acute conditions such as infection
• Needed repetitive treatment
• Diabetes who were on insulin treatment

triple blind