Effect of oral tablet nebivolol on improving the inner lining of blood vessels

INTERVENTION: Intervention1: Nebivolol 5 mg: Tablet Nebivolol 5 mg od will be given for a period of 4 weeks along with routine anti ischaemic therapy Control Intervention1: Metoprolol: Metoprolol 50 mg will be given for a period of 4 weeks along with other routine anti ischaemic therapy CONDITION: Patients with endothelial dysfunction and coronary artery disease PRIMARY OUTCOME: Improvement of endothelial dysfunction as measured by flow mediated dilatation‐‐‐‐‐‐Timepoint: Baseline and after four weeks of therapy SECONDARY OUTCOME: MDA, oxidant status, ICAM‐‐‐‐‐‐Timepoint: baseline and after four weeks INCLUSION CRITERIA: INCLUSION CRITERIA: 1. Age ‐ 18‐75 years 2. Either sex 3. Angiographically proven coronary artery stenosis with >50% block in atleast one of the major arteries or History of acute coronary syndrome 4. Known case of Hypertension