rapid atrial rate had more severe myocardial damage,greater microvascular reperfusion injury, and a largerinfarct size despite early restoration of TIMI flowgrade 3, as reported previously. These patients mighthave had severe microvasular damage and subse-quently less myocardial salvage, as suggested by lessresolution of complete ST-segment elevation afterreperfusion. Therefore, our previous finding1 of nodifference in infarct size between patients with andwithout CAVB probably resulted from summing ofsmall infarct sizes in patients with a slow atrial rateand large infarct size in those with a rapid atrial rate.

Although early CAVB in patients with inferiorAMI is related to a more extensive area at risk, theclinical features of this condition depend on theatrial rate during CAVB, suggesting that thepathogenesis of CAVB with a slow atrial rate dif-fers from that of CAVB with a rapid atrial rate.

1. Kimura K, Kosuge M, Ishikawa T, Shimizu M, Hongo Y, Sugiyama M,Tochikubo O, Umemura S. Comparison of results of early reperfusion in patientswith inferior wall acute myocardial infarction with and without complete atrio-ventricular block. Am J Cardiol 1999;84:731–733.2. The TIMI Study Group. The thrombolysis in myocardial infarction (TIMI)trial: phase I findings. N Engl J Med 1985;312:932–936.3. Rentrop KP, Cohen M, Blanke H, Philips RA. Change in collateral channelfilling immediately after controlled coronary artery occlusion by an angioplastyballoon in human subjects. J Am Coll Cardiol 1985;5:587–592.4. Wong CK, Freedman B, Bautovich G, Bailey BP, Bernstein L, Kelly D.Mechanism and significance of precordial ST-segment depression during inferior

wall acute myocardial infarction associated with severe narrowing of the domi-nant right coronary artery. Am J Cardiol 1993;71:1025–1030.5. Lopez-Sendon J, Coma-Canella I, Alcasena S, Seoane J, Gamallo C. Electro-cardiographic findings in acute right ventricular infarction: sensitivity and spec-ificity of electrocardiographic alterations of right precordial leads V4R, V3R, V1,V2, and V3. J Am Coll Cardiol 1985;6:1273–1279.6. Zehender M, Kasper W, Kauder E, Schonthaler M, Geibel A, Olschewski M, JustH. Right ventricular infarction as an independent predictor of prognosis after acuteinferior myocardial infarction. N Engl J Med 1993;328:981–988.7. Wehrens XHT, Doevendans PA, Ophuis TJO, Wellens HJJ. A comparison ofelectrocardiographic changes during reperfusion of acute myocardial infarctionby thrombolysis or percutaneous transluminal coronary angioplasty. Am Heart J2000;139:430–436.8. Van’t Hof AW, Liem A, de Boer M, Zijlstra F, for the Zwolle MyocardialInfarction Study Group. Clinical value of 12-lead electrocardiogram after suc-cessful reperfusion therapy for acute myocardial infarction. Lancet 1997;350:615–619.9. Selvester RH, Wagner GS, Hindman NB. The Selvester QRS scoring systemfor estimationg myocardial infarct size. The development and application of thesystem. Arch Intern Med 1985;145:1877–1881.10. Berger PB, Ruocco NA, Ryan TJ, Frederick MM, Jacob AK, Faxon DP, andthe Thrombolysis in Myocardial Infarction (TIMI) Investigators. Incidensce andprognostic implications of heart block complicating inferior myocardial infarc-tion treated with thrombolytic therapy: results from IMI II. J Am Coll Cardiol1992;20:533–540.11. Harpaz D, Behar S, Gottlieb S, Boyko V, Kishon Y, Eldar M, for the SPRINTStudy Group and Israeli Thrombolytic Survey Group. Complete atrioventricularblock complicating acute myocardial infarction in the thrombolytic era. J Am CollCardiol 1999;34:1721–1728.12. Berger PB, Ryan T. Inferior myocardial infarction high-risk subgroups.Circulation 1990;81:401–411.13. Bates ER. Revisiting reperfusion therapy in inferior myocardial infarction.J Am Coll Cardiol 1997;30:334–342.14. Sclarovsky S, Strasberg B, Hirshberg A, Arditi A, Lewin RF, Agmon J.Advanced early and late atrioventricular block in acute myocardial infarction. AmHeart J 1984;108:19–24.15. Wilbur SL, Marchlinski FE. Adenosine as an antiarrhythmic agent. Am JCardiol 1997;79:30–37.

Usefulness of Multislice Spiral Computed TomographyAngiography for Determination of Coronary

Artery Stenoses

Andreas Knez, MD, Christoph R. Becker, MD, Alexander Leber, MD,Bernd Ohnesorge, PhD, Alexander Becker, MD, Carl White, MD, Ralph Haberl, MD,

Maximilian F. Reiser, MD, and Gerhard Steinbeck, MD

In the United States 1,291,000 inpatient diagnosticcardiac catheterizations were performed in 1998.1

The replacement of even a fraction of these proce-dures with noninvasive imaging modalities wouldconstitute an important advance in the care of patientswith suspected coronary artery disease. Electron-beamcomputed tomography (EBCT)2,3 and magnetic reso-nance angiography4 have both been proposed for non-invasive coronary arterial imaging, but only EBCTachieved clinical satisfactory results. Recently, withthe introduction of multislice spiral computed tomog-

raphy (MSCT), these modalities have been challengedby an additional new method for the noninvasiveassessment of coronary artery stenoses.5 This studyevaluates the diagnostic accuracy of MSCT angiogra-phy in determining mid- to high-grade coronary arterystenoses (�50% lumen diameter narrowing in angiog-raphy) and occlusions compared with conventionalangiography.

• • •Forty-four patients (38 men and 6 women) with no

history of coronary stenting, previous coronary arterybypass grafting, arrhythmias, renal failure, and con-traindications to the administration of contrast agentswere enrolled in this study. Patient characteristics andreasons for diagnostic angiography are summarized inTable 1. All patients gave written consent according toinstitutional guidelines.

MSCT angiography was performed using a MSCT(Somatom Plus4VZ, Siemens, Germany) with dedi-

From the Departments of Cardiology, Clinical Radiology, Ludwig-Maximilians-University, Munich, Germany; Siemens Medical Systems,Forchheim, Germany; and Division of Cardiology, University of Min-nesota, Minneapolis, Minnesota. Dr. Knez’s address is: Department ofInternal Medicine I, Ludwig-Maximilians-University Munich, KlinikumGrosshadern, Marchioninistrasse 15, D - 81377 Munich, Germany.E-mail: knez@med1.med.uni-muenchen.de. Manuscript received May11, 2001; revised manuscript received and accepted July 18, 2001.

1191©2001 by Excerpta Medica, Inc. All rights reserved. 0002-9149/01/$–see front matterThe American Journal of Cardiology Vol. 88 November 15, 2001 PII S0002-9149(01)02060-4

cated cardiac reconstruction software. The scannerallows the simultaneous acquisition of 4 axial slicesduring the spiral scan (rotation time, 500 ms; tablespeed, 3 mm/s) with digital recording of the electro-cardiographic tracing. MSCT technology has previ-ously been described in detail.6,7 For administration ofcontrast material, an 18-gauge needle was placed inthe right antecubital vein. The patient was placed inthe scanner and the circulation time was determinedusing a test bolus to optimize contrast enhancementduring angiography. Scanning was initiated 1 cm be-low the carina to the base of the heart during contin-uous administration of 140 ml of nonionic contrastmedia (Ultravist 300, Schering, Germany). The wholeheart was scanned in 37 � 5 seconds during a singlebreath-hold. After the scan, the raw data and electro-cardiographic tracing were used to reconstruct axialslices in diastole. To obtain nearly motion free cardiacimages, the optimal trigger point of 400 to 550 msbefore the R wave was used for retrospective imagegating. Effective acquisition time, slice thickness, andreconstruction increment were 250 ms, 1.25 mm, and0.5 mm, respectively, resulting in 220 reconstructedaxial slices for the entire heart.

All axial images were sent to an external worksta-tion (Insight, NeoImagery, City of Industry, Califor-nia) and analyzed by an independent experienced

reader (AL), using 9 predetermined segments from theAmerican Heart Association coronary segment mod-el.8 Nonevaluated segments were primarily smallerdistal segments. Cross-sectional images were screenedfor artifacts caused by motion and for coronary calci-fication sufficient (in the readers opinion) to preludestenosis assessment. The investigators rated the leftmain coronary artery (segment 5), the proximal andmiddle segments of the left anterior descending artery(segments 6, 7, and half of segment 8), the left cir-cumflex artery (segments 11 and 13), and the right

coronary artery (segments 1, 2, and3) as being occluded or having astenosis �50% reduction in diame-ter. In addition 3-dimensional post-processing was applied to better vi-sualize the coronary arteries amongthe other contrast enhanced struc-tures (Figures 1 and 2). The severityof stenoses was based on visual esti-mation of both the axial cross sec-tions and the 3-dimensional recon-structions. Average postprocessingtime was 5 to 10 minutes.

The conventional angiogramserved as the gold standard. The di-agnostic accuracy of MSCT angiog-raphy was expressed as sensitivity,specificity, and positive and negativepredictive value. In all patients, con-ventional coronary angiography wasperformed using the transfemoralJudkins approach in 3 projections(right anterior oblique 30°, right an-terior oblique 15°, left anterior

oblique 45°) and, if necessary, in additional planes.All angiograms were recorded digitally and inter-preted by a single experienced reader (AK) who wasindependent of the MSCT scan reader (AL).

In all patients, MSCT angiography and conven-tional angiography were performed within 2 � 1 dayswithout any complications. One patient was excludedfrom evaluation because of the inability to hold hisbreath. In the remaining 43 patients, 358 of 387 seg-ments (94%) were considered assessable with MSCTangiography. Table 2 summarizes the causes for non-assessability. The major causes were motion artifacts(18 segments), most frequently in the midpart of theright coronary artery. In all of these cases heart ratewas �70 beats/min. At conventional angiography 13patients had no significant coronary stenosis, 14 had1-vessel, 9 had 2-vessel, and 7 patients 3-vessel dis-ease. Table 3 shows the relation between the angio-graphic status of the coronary arteries and results ofMSCT angiography in assessable segments. The over-all sensitivity of MSCT angiography for detectingstenoses �50% (Figure 1) and occlusions was calcu-lated as 78% (39 of 59). All 5 false-negative deter-mined occlusions were located in segments with an-giographically documented collateral vessels (Figure2). Blending with overlying vessels (n � 3) and cal-cified plaques (n � 3) was another cause of false-

TABLE 1 Patient Characteristics

PatientsMen

(n � 38)Women(n � 6)

Age (yrs) 58 � 6 62 � 10Body mass index (kg/m2) 25 � 3 26 � 3Heart rate (beats/min) 65 � 7 64 � 4� blockers 20 2Negative chronotropic drugs 3 1Suspected coronary disease 18 2Stable angina pectoris 17 2Valvular heart disease 2 1Cardiomyopathy 2 0

FIGURE 1. High-grade stenosis of the left anterior descending (LAD) artery (arrows),which compromises D1 according to MSCT angiography (panel A, 3-dimensional re-construction with volume rendering) and conventional angiography (panel B). Ao �aorta ascendens; LCx � left circumflex artery; Tp � truncus pulmonalis.

1192 THE AMERICAN JOURNAL OF CARDIOLOGY� VOL. 88 NOVEMBER 15, 2001

negative interpretations. In 301 of 308 segments, cor-onary artery disease could be correctly excluded withMSCT angiography, yielding a specificity of 98%.These results correspond to a positive predictive valueof 84%, negative predictive value of 96%, and diag-nostic accuracy of 94%. Compared with conventionalangiography in assessable segments, MSCT angiogra-phy correctly determined the absence of coronaryartery disease in 11 of 13 patients (85%), 1-vesseldisease in 10 of 14 (71%), 2-vessel disease in 6 of 9(67%) and 3-vessel disease in 5 of 7 (71%) patients.With conventional angiography, 12 significant steno-ses were found in excluded segments of the AmericanHeart Association 9 segment model (segment 4 � 3,distal segment 8 � 2, segment 9 � 2, segment 12 �4, segment 14 � 1). Stenoses of �50% were presentin an additional 5 technically nonassessable segments.

• • •This study demonstrates that MSCT angiography is

a promising and safe new imaging modality for thenoninvasive visualization of coronary arteries in as-sessable segments. Sensitivity and specificity in deter-mining significant lesions were in the range of EBCTangiography.3,9,10 In most cases, it allows assessmentof the proximal and midsegments of all 3 major arter-ies and, in addition, the distal segment (segment 3) ofthe right coronary artery. It permits high accuracy inthe exclusion of coronary artery disease and determi-nation of stenoses of 50% to 99%, but is limited in the

diagnosis of collateralized totallyobstructed vessels. Also side-branches, distal segments, and ves-sels with a lumen diameter of �2mm have to be excluded from anal-ysis. One major limitation of MSCTangiography is the somewhat im-paired temporal resolution resultingfrom its 250-ms acquisition time. Inpatients with heart rates �70 beats/min, this leads to artifacts, especiallyin the left circumflex (n � 4) andright coronary (n � 12) arteries, dueto the greater diastolic motion thatoccurs with the left anterior de-scending artery. This limitation isusually offset using a retrospectiveelectrocardiographic-trigger tech-nique, which allows the reconstruc-

tion of cross-sectional images at any desired timepoint within the RR interval and thus permits optimi-zation of axial image reconstruction. This approachseems to compensate for the longer exposure time(250 ms) than that with prospectively triggered EBCT(100 ms), and is independent of mistriggering (a con-sequence of premature beats) and changing heart ratesof patients during scanning, both of which can causeartifacts during EBCT angiography. Similar to EBCT,coronary arteries with a vessel diameter �2.0 mmcannot be accurately visualized because of limitedspatial resolution, which can lead to false-positive andnegative results (8 patients in our study). Five oc-cluded vessels were also missclassified. In all casescoronary angiography showed extensive collateralvessels. With MSCT angiography, it was not possibleto differentiate between anterograde or retrograde fill-ing of totally occluded vessels. This is a significantlimitation in this qualitative analysis. Interpretation ofheavy calcified segments with MSCT is also not pos-sible, and these segments must be excluded fromevaluation. Recently, Achenbach et al11 and Niemannet al.12 reported a sensitivity of 91% and 81% indetecting significant lesions with contrast-enhancedMSCT in interpretable coronary arteries. As opposedto our study, they found only 68% to 73% evaluablecoronary arteries. This discrepancy may be related tothe disregard of patients’ heart rates or application ofa nonoptimized acquisition protocol and image recon-struction algorithm. To achieve optimal image quality,heart rates �60 beats/min are required. Therefore, �blockers or other negative chronotropic drugs shouldbe administered before the computed tomographic in-vestigation whenever possible to reduce heart rate. Toreduce motion artifacts, shorter radiation exposuretimes are necessary. This may be realized in the nearfuture with faster gantry rotation and alternative re-construction algorithms.

Another cause for concern is the high radiation doseof 8 to 11 milli-Sievert (mSV) required for MSCT an-giography study. This results from continuous acquisi-tion of 4 axial slices during entire the cardiac cycle, whenonly diastolic image data are used. Pilot studies have

FIGURE 2. Misclassification of an angiographically occluded right coronary artery (ar-rows) with MSCT angiography. LV � left ventricle, coronary calcium (arrowhead); RV� right ventricle; other abbreviation as in Figure 1.

TABLE 2 Reasons for Poor Image Quality

Coronary Artery

LeftMain

LeftAnterior

DescendingLeft

Circumflex Right

Coronary artery movement 0 2 4 12Calcification 0 4 0 0Poor distal opacification 0 0 2 1Small vessel diameter 0 0 2 0Breathing artifact 0 0 0 2Total 0 6 8 15

BRIEF REPORTS 1193

been performed using reduced voltage and acquisition ofimages only in diastole. A 50% reduction in radiationdose may be expected without compromise in imagequality.

Thus, MSCT angiography is a rapidly develop-ing new imaging modality for visualizing the prox-imal and midsegments of the coronary arteries.Further technical advances to improve diagnosticaccuracy and clinical usefulness are expected in thenear future.

1. American Heart Association. 2001 Heart and Stroke Statistical Update. Dallas,TX: American Heart Association, 2001.2. Achenbach S, Moshage W, Ropers D, Nossen J, Daniel W. Value of electron-beam computed tomography for the noninvasive detection of high-grade coronaryartery stenosis and occlusion. N Engl J Med 1998;339:1964–1971.3. Rensing BJ, Bongaerts A, van Geuns RJ, Rensing BJ, Bongaerts A. Intrave-nous coronary angiography by electron beam computed tomography. Circulation1998;98:2509–2512.4. Sandstede JJ, Pabst T, Beer M, Geis N, Kenn W, Neubauer S, Hahn D.Three-dimensional MR coronary angiography using navigator technique com-pared with conventional coronary angiography. AJR Am J Roentgenol 1999;172:135–139.

5. Knez A, Becker CR, Ohnesorge B, Haberl R, Reiser M, Steinbeck G. Nonin-vasive detetction of coronary artery stenosis by multislice helical computedtomography. Circulation 2000;101:221–222.6. Ohnesorge B, Flohr T, Becker C, Kopp AF, Schoepf UJ, Baum K, Knez A,Klingenbeck-Regn K, Reiser MF. Cardiac imaging by means of electrocardio-graphically gated multisection spiral CT: initial experience. Radiology 2000;217:564–571.7. Becker CR, Ohnesorge B, Schoepf UJ, Reiser MF. Current development ofcardiac imaging with multidetector-row CT. Eur J Radiol 2000;36:97–103.8. Austen W, Edwards J, Frye R, Gensini G, Gott V, Griffith L, McGoon D,Murphy M, Roe B. A reporting system on patients evaluated for coronary arterydisease: Report of the Ad Hoc Committee for Grading of Coronary ArteryDisease, Council on Cardiovascular Surgery, American Heart Association.Circulation 1992;232:232–246.9. Budoff MJ, Oudiz RJ, Zalace CP, Baksheshi H, Goldberg SL, French WJ,Rami TG, Brundage BH. Intravenous three-dimensional coronary angiographyusing contrast enhanced electron beam computed tomography. Am J Cardiol1999;83:840–845.10. Schmermund A, Rensing BJ, Sheedy PF, Bell MR, Rumberger JA. Intrave-nous electron-beam computed tomographic coronary angiography for segmentalanalysis of coronary artery stenoses. J Am Coll Cardiol 1998;31:1547–1554.11. Achenbach S, Giesler T, Ropers D, Ulzheimer S, Derlien H, Schulte C,Wenkel E, Moshage W, Bautz W, Daniel WG, Kalender WA, Baum U. Detectionof coronary artery stenoses by contrast-enhanced, retrospectively electrocardio-graphically-gated, multislice spiral computed tomography. Circulation 2001;103:2535–2538.12. Niemann K, Oudkerk M, Rensing B, van Ooijen P, Munne A, van Geuns RJ,de Feyter PJ. Coronary angiography with multi-slice computed tomography.Circulation 2001;357:599–603.

Direct Angioplasty Eliminates Sex Differences inMortality Early After Acute Myocardial Infarction

Bernd Waldecker, MD, Erika Grempels, MD, Wolfgang Waas, MD,Werner Haberbosch, MD, Reinhard Voss, MD, and Harald Tillmanns, MD

Ahigher early mortality after acute myocardial infarc-tion (AMI) has been found in women than in

men.1–9 Differences in age, comorbidity, time to hospi-talization, and modes of treatment may partly explain thegenerally poorer prognosis of female patients with AMI.However, most studies exploring sex-based differencesafter AMI have analyzed cohorts of patients who havereceived either no specific revascularization therapy orwho have undergone noninvasive attempts to reopen theoccluded coronary artery. Therefore, we hypothesized

that immediate coronary angiography with the intentionto reopen the infarct vessel using percutaneous translu-minal coronary angioplasty (PTCA) (or emergency by-pass surgery) in women with AMI would result in asimilarly favorable survival compared with men. Therationale for this hypothesis is the observation that earlyand complete vessel patency is a powerful indicator forsurvival.10 Such attempts to reopen the infarct arteryappear to be underused in women in the US.7,11–15 DirectPTCA can reopen acute coronary occlusions and canobtain high patency rates.16–18 It can also be performedin most patients irrespective of significant comorbidity.We report here 30-day results of this approach in 178consecutive and unselected women. Results in womenwere compared with those of 513 consecutive and un-selected men with direct angiography/PTCA for AMI.

• • •In all, 178 women and 513 men presented with

From the Medizinische Klinik I, Justus-Liebig University of Giessen,Giessen, Germany. This report was supported by the Willy undMonika Pitzer-Stiftung e.V., Bad Nauheim, Germany. Dr. Waldeck-er’s address is: Medizinische Klinik I Kardiologie-Angiologie, Univer-sitat Giessen, Klinikstrasse 36, D-35392 Giessen, Germany. E-mail:bernd.waldecker@innere.med.uni-giessen.de. Manuscript receivedApril 24, 2001; revised manuscript received and accepted July 2,2001.

TABLE 3 Diagnostic Accuracy of MSCT Angiography in Detecting Stenosis �50% and Total Occlusions in Assessable Segments

AssessableSegments

SensitivityStenosis

(�50% to �100%)SensitivityOcclusion

OverallSensitivity Specificity

Left main 43/43 (100%) 2/2 (100%) 0 2/2 (100%) 41/41 (100%)Left anterior descending 123/129 (95%) 17/19 (89%) 5/7 (71%) 22/26 (85%) 93/97 (96%)Left circumflex 78/86 (91%) 4/7 (57%) 0/2 (0%) 4/9 (44%) 68/69 (98%)Right 114/129 (88%) 6/7 (86%) 5/6 (83%) 11/13 (85%) 99/101 (98%)Total 358/387 (94%) 29/35 (83%) 10/15 (67%) 39/30 (78%) 301/308 (98%)

1194 ©2001 by Excerpta Medica, Inc. All rights reserved. 0002-9149/01/$–see front matterThe American Journal of Cardiology Vol. 88 November 15, 2001 PII S0002-9149(01)02061-6