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Johnson DB, Foster RE, Barilla F, Blackwell GG, Roney M, Stanley AW Jr, Kirk K, Orr RA, van der Geest RJ, Reiber JH, Dell'Italia LJ.Johnson DB, et al.J Am Coll Cardiol. 1997 Jan;29(1):49-54. doi: 10.1016/s0735-1097(96)00451-2.J Am Coll Cardiol. 1997.PMID: 8996294Free article.Clinical Trial.