REN and myocardial infarction: However, they reported independent predictive factors of 12-month mortality being age, systolic blood pressure, acute myocardial infarction, LVEF, renal function, Killip class, N-terminal-pro-B-type natriuretic level and use of renin-angiotensin receptor blockers (RAB) use, and concluded that their observation was an apparent paradox due to confounding factors.