A 78 year old male is admitted with chest pain. His ECG shows widespread ST depression in all leads except aVR which shows ST elevation. Whilst in ER, he passes melaena and on fuher questioning, gave history of altered bowel habit, weight loss and dark stools for 2-3 months. O/E he is pale, pulse rate is 115 bpm and BP is 80/50 mmHg. Blood tests demonstrate a hemoglobin of 3.6g/l and a high-sensitivity troponin of 140ng/l. What is the best initial management?