Trans-fatty acid patterns in patients with demonstrated coronary artery disease

are also likely to be mistaken and superimposed with other isomers and perhaps with 16:109c. Again, the overall conclusions of the study In 1993, one of us published in are not ticcted, but the reported levyour Journal the article “Tram-Fatty els will not be comparable with levAcid Patternsin Patientswith Angio- els for similar fatty acids to be graphically Documented Coronary reported in the future by other sciArtery Disease.“’ The research was entists using more advancedsepambased on samples analyzed several tion techniques. We recommend that more reyears ago on a 60 m capillary column. Recent research, particularly search efforts be directed to deterby Ratnayake et a12*”has been able mine prevalent, optimal, or desirable to better separateand identify a large levels of trans-fatty acids in human number of isomers of fatty acids plasma and adipose tissue. with 18 carbons and 1 to 3 double E.N. Sgud, MD, PhD bonds. Ratnayake et al4 showed that Boston, 4lassachusetts 18:2A9c,l3t (9c,l31 -octadecadienoic WAN. Rahnyake, PhD acid) is the most common trans-fatOttawa, Canada ty acid among the 18 carbon, 2 dou30 June 1994 ble-bond fatty acids in foods. It is reasonable to assume that it would 1. Siguel ES. Lennan KH. Trans-fatty acid patterns in patients wifh angiogmphically documented corebe less abundant in plasma than sin- nary artery disease. Am J Cordial 1993:71:916-920. gle trans-fatty acids. Research by 2 Ratnayake W.MN. Beare-Rogers JL. Problems of C,, cir and tram fatty acidr of margarine Ratnayake (unpublished data) sug- onanalyzing the SP-2340 capillary column. J Chromarogr Sci geststhat this is the case,and that in l%Q28:633439. most columns, such as those usedby 3. Ratnayake WMN, Pelletier G. Positional and geoisomers of linoleic acid in oartiallv hvdmSiguel and Lerman, the single and metrical genated oils. J Am Oil Chem Sac 19&;69:9<-11% double trans-fatty acids elute almost 4. Katnayake WMN, Hollywood R. O’Grady E. Pel. at the same time. We therefore pro- l&x G.-Fatty acids in some common food items in pose that what was reported as the Canada. J Am G/l Nufr lS93:l2:6SlA6o. double tram of linoleic acid is likely to be mostly a single trans, perhapswith a small component of dou- Exercise-Induced Precordial ST ble trans. This changedoesnot affect Depression in Prior Inferior the conclusion becausethere is a high Myocardial Infarction correlation in plasma among indiI read with interest the article by vidual measuresof 18:206 and tram (unpublisheddata,E.N. Siguel).How- Khoury et all on exercise-induced ever, it is important to realize that precordial ST depression in prior many researchers have mistakenly inferior wall myocardial infarction identified the isomers in foods and (IMI). However, I disagreewith their plasma.Identification is very difficult concluding remark that “the presbecause there are ~20 compounds ence of [exercise-induced] ST-segthat appear in a narrow region be- ment depressionin leads VI to \(4 or tween 18:lw9 and 18:2w6. Inci- VI to VP in asymptomatic patients dentally, many measuresof 16:lw7t [with prior IMI] may not be an indication for invasive evaluation.” Letters (from the United States) concerning a parWhen their patients were stratified ticular article in The American Journal of Caron the basis of their criteria, as many diology@ must be received within 2 months of as 17 (11 group A and 6 group C the article’s publication. and should be limited patients) of 35 IMI patients (49%) (with rare exceptions) to 2 double-spaced type with anterior reversible defect on the written pages. Two copies must be submitted. Trans-Fatty Acid Patterns in Patients with Demonstrated Coronary Artery Disease

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THE AMERICAN JOURNAL OF CARDIOLOGY@

VOL. 75

FEB 15, 1995

thallium-201 exercise test were considered erroneously to be ineligible for invasive evaluation. It would be difficult to determine the further therapeutic strategy for such patients based solely on the electrocardiographic (ECG) findings reported by Khoury et al.’ Several years ago, I also published a similar type of study. In that rcport,2 I described a difference in precordial ST-segment depression between those with and without left anterior descending (LAD) artery diseaseon the electrocardiogram in prior IMI patients; the presence of ST-segment depression in lead V, and horizontal or downsloping STsegment depression was greater in IMI patients with than without LAD disease. In prior IMl patients without LAD disease, the type of precordial ST depressionobserved during exerciseECG testing was mainly a slow, uprising pattern. The incidence of ST-segment depression in V, or V, did not differ between the 2 groups. The study concluded that exercise ECG testing was of limited use for evaluating prior IMI patients with or without multivessel disease comparedwith exercisethallium-201 testing.2 Even though more precise ECG evaluation may somehow improve diagnostic accuracy,the exercise ECG test does not seem to be suitable for determining the indication for invasive evaluation in prior IMI patients with exercise-induced precordial ST-segment depression. Hajime

Kataoka,

MD

Oita, Japan 30 June 1994 1. Khouy Z. Keren A. Stem S. Correlation of CXCT&e-induced ST depression in orecordial clectmc:ardiognphic leads aftir inferior wall acute myocardial infarction with thallium-201 stress scintigraphy, coronary angiography. and two-dimensional echouardiography. Am J Cardiol 1994:73:X6.%871. 2. Kataoka It, Ohkubo T. Nakamura K, Hashimoto S. Exercise-induced prwordial ST-segment dqixssion in prior inferior myocardial infarction with single-vessel disease: wirh special reference 10 i& mechanisms and distinction from multi-vessel disease. Ini J Cardiol 1988:1X:223-241.