Blood Pressure Targets and Clinical Outcomes in Patients with Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES The optimal blood pressure (BP) target in patients with a history of acute myocardial infarction (MI) remains as a subject of debate. The 'J curve phenomenon' has been suggested as a target for BP control, however, it is unclear whether this phenomenon can be applied to MI patients. We analyzed patients with acute MI and investigated whether the 'J curve phenomenon' exists in this population. SUBJECTS AND METHODS Data were obtained from a nationwide prospective Korea Acute Myocardial Infarction Registry, which included 10337 patients with acute MI who underwent percutaneous coronary intervention (PCI) between 2011 and 2014. The patients were divided into quintiles according to systolic blood pressure (SBP) and diastolic blood pressure (DBP), which were measured during a two-year clinical follow up. Two-year cumulative incidence of major adverse cardiac events (MACE) was analyzed among the groups. RESULTS MACE was defined as a composite of cardiac death, need for recurrent revascularization (repeated PCI or coronary arterial bypass graft due to recurrent anginal symptoms or reoccurrence of MI), ischemic cerebrovascular accident, and need for hospitalization due to heart failure. During the two-year follow up, the total cumulative incidence of MACE was 9.7% (n=1005). BP-MACE analysis showed a U-shaped curve for both SBP and DBP, with the lowest MACE rate in quintiles with an average SBP of 112.2 mmHg and DBP of 73.3 mmHg. On Cox regression analysis, the U-shaped relation was statistically significant. CONCLUSION In patients with acute MI, a 'U curve phenomenon' was observed when assessing patient BP control versus MACE rate.