Savage et al. November 1987 Amarlcan Haart Journal ment of acute myocardial ischemia following percutaneous transluminal coronary angioplasty: role of the intra-aortic balloon pump. J Thorac Cardiovasc Surg 1984;87:332-9. 24. Hinohara T, Simpson JB, Phillips HR, et al. Transluminal catheter reperfusion: a new technique to reestablish blood flow after coronary occlusion during percutaneous translumi- nal coronary angioplasty. Am J Cardiol 1986;57:683-6. 25. Timmis AD, Crick JCP, Griffin B, Sowton E. Arterial blood infusion for myocardial protection during PTCA (abstr). J Am Co11 Cardiol 1986;7:105A. 26. McAuley BJ, Sehnon M, Sheehan DJ, Simpson JB. Coronary angioplasty of high-risk patients in a combined catheteriza- tion laboratory-operating room setting (abstr). Circulation 1985;72(suppl):217. High-risk 8 ot#ps of 8 wtth non-Q wave myumrdial and severity of ST s To determine the significance of the direction of ST segment deviation on admission of patients who evolved non-0 wave myocardial infarction (Ml), 97 pattents with initial ST segment depression were compared to 207 patlents with inltlal ST segment elevation. Patients with ST segment depression developed smaller Infarcts than those with ST segment elevation (creatine kinase MB isoenryme 8.2 vs 13.3 gmEq/m”, p < 0.002), but had a lower left ventricular ejectfon fraction on admission (44% vs 51%, p < O.OOl), more in-hospital complications, and a higher cumulative l-year mortality (29% vs 1 l%, p < 0.001) that could be accounted for by an excess of adverse baseline characteristics. Although a severity index (combining magnitude and extent of the initial ST segment devlation) was not useful for discriminating prognosis of patients with non-0 wave MI who presented with ST segment depression, it was useful in identifying a subgroup of patients with ST segment elevation with an adverse prognosis. The poor outcome of patients with non-Q wave Ml presenting with either ST segment depression or severe ST segment elevation on admission suggests that patients in these subgroups should receive close surveillance and should possibly be considered for aggressive therapy. (AM HEART J 1987;114:1110.) Stefan N. Willich, M.D., Peter H. Stone, M.D., James E. Muller, M.D., Geoffrey H. Tofler, M.D., James Crowder, M.P.H., Corette Parker, M.S.P.H., John D. Rutherford, M.D., Zoltan G. Turi, M.D., Thomas Robertson, M.D., Eugene Passamani, M.D., Eugene Braunwald, M.D., and the MILIS Study Group. Boston, Mass. The descriptive classification of myocardial infarc- tion (MI) as “Q wave” or “non-Q wave” infarction according to the development of a Q wave on the surface ECG has replaced the previous classification From the Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School; and Cooperating Institutions of the Multicenter Investigation of the Limitation of Infarct Size (MIL- IS). Based on research performed by the MILIS Group pursuant to contracts NOl-HV-7-2940, 7-2941, 7-2942, and 7-2979, with the National Heart, Lung, and Blood Institute, National Institutes of Health, United States Department of Health and Human Services. Received for publication May 7, 1987; accepted June 15, 1987. Reprint requests: Peter H. Stone, M.D., Harvard Medical School, 164 Longwood Ave., Boston, MA 02115. of “transmural” or “nontransmural” MI, since the latter terminology implied knowledge of the patho- logic anatomy.1~2 The outcome of patients with non-Q wave MI has been studied extensively.3-1o Short-term morbidity and mortality are significant- ly lower among patients with non-Q wave than for those with Q wave MI, but some studies4p5 indicate that recurrent MI, especially fatal MI, may be higher in the follow-up period among patients with non-Q wave MI. Other studies6 have observed, how- ever, that although patients with non-Q wave MI have a more benign in-hospital course compared to patients with Q wave MI, the mortality among hospital survivors in both group of patients is the same. Since the prognosis associated with MIS cate- 1110