Effect of Sildenafil on Ischemic Cardiac Clinical and paraclinical manifestations in patients with Coronary Slow Flow Phenomenon : a randomized controlled clinical trial

Determination of the effect of sildenafil on the clinical manifestations of myocardial ischemia in patients with coronary slow flow

Clinical trial with control group, with parallel groups, three-way blind, randomized, phase 2 on 20 patients

10 patients with slow coronary blood flow in Afshar Hospital in Yazd will be prescribed sildenafil for 3 months and we will study the effects of this drug on improving patients' heart symptoms and changes in their ETT

Inclusion criteria: Definitive diagnosis of CSFP on coronary angiography ;Clinical signs of ischemia include typical angina pectoris or dyspnea. Exclusion criteria: Patients with myocardial infarction or PCI or CABG or valve replacement or repair; Patients with Obstructive CAD (stenosis greater than 40%); Patients with hepatic or renal insufficiency or CVA or COPD or Cancer or acute infectious disease such as Covid 19; Patients older than 70 years or less than 30 years; Patients with low systolic blood pressure (less than 90 mmHg); Patients with severe uncontrolled hypertension (more than 180/100); Patients with aneurysm or ectasia or no-reflow or spasm or dissection or systolic heart failure or valvular disease; Patients with LVEF less than 50%

Patients will be given sildenafil, starting with 25 mg twice daily and continued for up to 4 weeks if tolerated, then increasing the dose to 50 mg twice daily until the end of the study. In the other half of the patients in the control group, as in the intervention group, instead of sildenafil tablets, placebo is prescribed at the same intervals.

Clinical symptoms,ETT changes,readmission rate

Randomization will be done based on the quadruple block method.The letters A and B will be used to assign the drug and the placebo. Until the drug is assigned, it will not be clear which A and B belong to the drug or the placebo. Only one person (the main executor) is aware. For concealment, the person who performs the randomization and specifies the following arrangements (AABB ,ABAB, ABBA, BBAA, BABA, BAAB) will be different from the person delivering the drug to the patient.For randomization, random order of 4 is noted and each block is placed in a sealed envelope. After registering all the patients, each patient is given a code. After the blocks are randomized, the randomized sequences are numbered sequentially. The person who allocates the drug assigns the prepared drugs to the patient after opening each envelope.

A person who is aware of the assignment of the letters A and B to a drug or placebo is only the first executor and project manager. Other people who do randomization and drug allocation and examination and evaluation of patient outcomes and statistical analysis are different people and do not know which letter is assigned to the drug or placebo.The drugs are available to the dispenser in the same form in completely similar packages, and the patient himself is also unaware that he is receiving the drug or placebo. The drug packages are unnamed and are only in boxes A and B. The dispenser and the doctor are not aware of the contents of boxes A and B.