 Discussion ABAD comprises approximately 30 of all aortic dissection cases. In contrast with type A aortic dissection, patients with type B dissection are tend to be older, have higher rates of atherosclerosis. Initial goals for acute aortic dissection management are directed at control of blood pressure and heart rate, which subsequently limiting propagation of the false lumen by controlling aortic shear stress. Whilst medical management has demonstrated an in-hospital mortality rate less than 10, post-discharge the acute type B aortic disease continues to evolve eventually resulting in complicated type B disease. Moreover, complicated acute type B aortic dissection shows even more striking mortality as high as 30, particularly in the elderly. Poor control of blood pressure was believed to be one of the main reasons for the progress of the type B aortic dissection into complications or even the laceration extended to the ascending aorta. Dalsart and colleague demonstrated that a systolic blood pressure more than 130 mmHg was associated with a bigger aortic enlargement in type B aortic dissection P0.02 . In another study of 25 years follow-up in 252 patients who received repair of acute type A aortic dissection, patients who maintained a systolic blood pressure 120 mm Hg had improved freedom from reoperation, compared to those target blood pressure 120-140 mm Hg or 140 mm Hg. Hence, most guidelines recommended a reasonable initial target for systolic blood pressure is between 100 and 120 mm Hg. However, this target is based on the hypothesis that all the end-organs blood supply is not compromised. Data from International Registry of Acute Aortic Dissection IRAD has shown that approximately one quarter of patients presenting with acute type B aortic dissection are followed into complicated category, including malperfusion of spinal arteries leading to paresis, and paraplegia or malperfusion of visceral arteries leading to abdominal pain. Thus, how to balance the decrease of blood pressure to the lowest amount and maintain adequate end-organ perfusion is a challenge. Given vast majority patients with type B aortic dissection had a history of hypertension, a too lower target of blood pressure may comprise the cerebral perfusion or complicated organ perfusion, which consequently caused stroke or other morbidity such as ischemic intestinal necrosis. On the other hand, a much strict blood pressure target and sometimes constrain on the patients daily activities may aggravate patients worry, which inversely increased increase the blood pressure. Unfortunately, there is no empirical data or trials to guide the optimal blood pressure target setting for various patients. Hence, the study was designed to bridge the gap. 