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    Anne Kaltoft

    We hypothesized that not only the location but also extent of myocardial ischemia (area at risk, AAR) during acute myocardial infarction could be estimated from the spatial distribution of ST-segment deviations in the ECG. Standard... more
    We hypothesized that not only the location but also extent of myocardial ischemia (area at risk, AAR) during acute myocardial infarction could be estimated from the spatial distribution of ST-segment deviations in the ECG. Standard 12-lead ECGs and SPECT images were obtained from 75 patients. Precordial ST-segment deviations were organized according to spatial orientation. An ST-profile was obtained: a semicircle of ST-deviations centered on the ST-injury vector. Spatial features of the profile were calculated, the R wave vector magnitude was obtained, and an automated method of patient separation into culprit artery groups was developed. A linear regression model between optimal features and AAR yielded: r = 0.64(p
    Research Interests:
    The impact of angiographically visible distal embolization (DE) and distal protection occurring during primary percutaneous coronary intervention (PCI) on long-term outcome has not been studied in a contemporary ST-segment elevation... more
    The impact of angiographically visible distal embolization (DE) and distal protection occurring during primary percutaneous coronary intervention (PCI) on long-term outcome has not been studied in a contemporary ST-segment elevation myocardial infarction (STEMI) cohort. To evaluate the association between DE and long-term outcome in STEMI patients treated with primary PCI with or without distal protection. In this post-hoc analysis of a randomized study, 591 STEMI patients were randomized to conventional primary PCI or primary PCI with distal protection and followed for 5 years. There was no statistically significant difference in MACE rate between patients treated with or wthout distal protection (19% versus 25%; p=0.10). There seemed to be interaction between distal protection and DE in major adverse cardiac events (MACE) (p=0.08), mortality (p=0.02) and reinfarction (p=0.06), but not admission for heart failure (p=0.40). DE was related to increased risk of admission for heart fai...
    Primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction results in TIMI 3 flow in most patients. However, despite TIMI 3 flow, some patients do not achieve adequate tissue perfusion and have large... more
    Primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction results in TIMI 3 flow in most patients. However, despite TIMI 3 flow, some patients do not achieve adequate tissue perfusion and have large infarctions. Techniques that, in the acute setting, could identify these patients at increased risk would potentially enable specific interventions to enhance perfusion. The object of the present study was to test whether corrected TIMI frame count (CTFC), myocardial blush grade (MBG), ST-segment resolution, and myocardial perfusion imaging (MPI) can identify those patients who, despite successful treatment with primary PCI for ST-elevation myocardial infarction, are at risk for large infarcts. In 61 patients with TIMI 3 flow after primary PCI, CTFC, MBG, ST-segment resolution, and quantitative MPI by technetium Tc 99m sestamibi single photon emission computed tomography were estimated immediately after primary PCI. Infarct size was assessed by peak lactate ...
    The use of drug-eluting stents (DESs) versus bare metal stents (BMSs) in primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction is a matter of debate. Therefore, we examined the risk of target... more
    The use of drug-eluting stents (DESs) versus bare metal stents (BMSs) in primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction is a matter of debate. Therefore, we examined the risk of target lesion revascularization (TLR), stent thrombosis, myocardial infarction, and death after the implantation of DES or BMS in primary PCI patients in Western Denmark. A total of 3756 consecutive patients with ST-segment elevation myocardial infarction treated with primary PCI and stent implantation, recorded in the Western Denmark Heart Registry from January 2002 through June 2005, were followed up for 2 years. We used Cox regression analysis to control for confounding. The 2-year incidence of definite stent thrombosis was 1.9% in the DES group and 1.1% in the BMS group (adjusted relative risk [RR]=1.53; 95% CI=0.84 to 2.78; P=0.17). Very late definite stent thrombosis (> or =12 months) was seen in 0.4% in the DES group and 0.06% in the BMS group (adjus...
    We compared 5-year clinical outcomes in diabetic and nondiabetic patients treated with Endeavor zotarolimus-eluting stents (ZESs; Endeavor Sprint, Medtronic, Santa Rosa, California) or Cypher sirolimus-eluting stents (SESs; Cordis,... more
    We compared 5-year clinical outcomes in diabetic and nondiabetic patients treated with Endeavor zotarolimus-eluting stents (ZESs; Endeavor Sprint, Medtronic, Santa Rosa, California) or Cypher sirolimus-eluting stents (SESs; Cordis, Johnson & Johnson, Warren, New Jersey) coronary implantation. We randomized 2,332 patients to either ZESs (n = 1,162, n = 169 diabetic patients) or SESs (n = 1,170, n = 168 diabetic patients) stratified according to presence or absence of diabetes mellitus. End points included major adverse cardiac event (MACE), a composite of cardiac death, myocardial infarction, target vessel revascularization (TVR), and definite stent thrombosis. Among diabetic patients, MACE occurred more frequently in patients treated with ZESs than SESs (48 [28.4%] vs 31 [18.5%]; odds ratio [OR] 1.75, 95% confidence interval [CI] 1.05 to 2.93, p = 0.032) because of a higher rate of TVR (32 [18.9%] vs 14 [8.3%]; OR 2.57, 95% CI 1.32 to 5.02, p = 0.006). Among nondiabetic patients, ZE...
    Fractional flow reserve (FFR) is the standard of reference for assessing the hemodynamic significance of coronary stenoses in patients with stable coronary artery disease. Noninvasive FFR derived from coronary CT angiography (FFRCT) is a... more
    Fractional flow reserve (FFR) is the standard of reference for assessing the hemodynamic significance of coronary stenoses in patients with stable coronary artery disease. Noninvasive FFR derived from coronary CT angiography (FFRCT) is a promising new noninvasive method for assessing the physiologic significance of epicardial stenoses. The reproducibility of FFRCT has not yet been established. The aim of this study was to evaluate the variation of repeated analyses of FFRCT per se and in the context of the reproducibility of repeated FFR measurements. Coronary CT angiography and invasive coronary angiography with repeated FFR measurements were performed in 28 patients (58 vessels) with suspected stable coronary artery disease. Based on the coronary CT angiography data set, FFRCT analyses were performed twice by 2 independent blinded analysts. In 12 of 58 (21%) vessels FFR was ≤ 0.80. The standard deviation for the difference between first and second FFRCT analyses was 0.034 vs 0.033 for FFR repeated measurements (P = .722). Limits of agreement were -0.06 to 0.08 for FFRCT and -0.07 to 0.06 for FFR. The coefficient of variation of FFRCT (CVFFRct) was 3.4% (95% confidence interval [CI], 1.4%-4.6%) vs 2.7% (95% CI, 1.8%-3.3%) for FFR. In vessels with mean FFR ranging between 0.70 and 0.90 (n = 25), the difference between the first and second FFRCT analyses was 0.035 and FFR repeated measurements was 0.043 (P = .357), whereas CVFFRct was 3.3% (95% CI, 1.5%-4.3%) and coefficient of variation for FFR was 3.6% (95% CI, 2.3%-4.6%). The reproducibility of both repeated FFRCT analyses and repeated FFR measurements is high.
    Intracoronary imaging provides accurate lesion delineation and precise measurements for sizing and positioning of coronary stents. During percutaneous coronary intervention (PCI), it may be challenging to identify corresponding segments... more
    Intracoronary imaging provides accurate lesion delineation and precise measurements for sizing and positioning of coronary stents. During percutaneous coronary intervention (PCI), it may be challenging to identify corresponding segments between intracoronary imaging and angiography. Computer based online co-registration may aid the target segment identification. The DOCTOR fusion study was a prospective, single arm, observational study including patients admitted for elective PCI. Optical coherence tomography (OCT) was acquired pre-stent implantation for sizing of stents. The operator subsequently indicated on the angiogram the target area as identified by OCT. Computer based co-registration was performed on-line immediately after pre-stent acquisition to assess feasibility. The cumulated numerical difference between operator based, and computer based co-registration was assessed as the "Operator Registration Error". The operator implanted the stent blind to the co-registr...
    The study sought to compare the risk of late outcome with a focus on very late definite stent thrombosis of the everolimus-eluting stent (EES) with that of the sirolimus-eluting stent (SES) at 3-year follow-up. In the SORT OUT IV (SORT... more
    The study sought to compare the risk of late outcome with a focus on very late definite stent thrombosis of the everolimus-eluting stent (EES) with that of the sirolimus-eluting stent (SES) at 3-year follow-up. In the SORT OUT IV (SORT OUT IV Trial), comparing the EES with the SES in patients with coronary artery disease, the EES was noninferior to the SES at 9 months. The SORT OUT IV trial provides long-term head-to-head randomized comparison of the EES with the SES. We prospectively randomized 2,774 patients in the SORT OUT IV trial. Follow-up through 3 years was complete in 2,771 patients (99.9%). The 3-year pre-specified endpoints were composites of safety and efficacy (major adverse cardiac events [MACE]: cardiac death, myocardial infarction, target vessel revascularization, and definite stent thrombosis). At 3 years, the composite endpoint MACE occurred in 9.8% of the EES group and in 11.1% of the SES group (hazard ratio [HR]: 0.89, 95% confidence interval [CI]: 0.70 to 1.12)....
    We sought to assess changes in the left ventricular systolic and diastolic function in patients with antecedent hypertension and an acute myocardial infarction. A group of 38 patients with antecedent hypertension and acute myocardial... more
    We sought to assess changes in the left ventricular systolic and diastolic function in patients with antecedent hypertension and an acute myocardial infarction. A group of 38 patients with antecedent hypertension and acute myocardial infarction were compared with an age-matched nonhypertensive control group. There was a 30-day follow-up. Outcome measures were left ventricular volumes and ejection fraction, systolic velocities, and strain. Diastolic function was assessed by mitral inflow combined with tissue velocities of the mitral ring. Patients with antecedent hypertension did not experience any regression in the E/E' ratio (16.5 +/- 7.5 vs 17.1 +/- 9.0, P = not significant) or increase in the E'/A' ratio (0.76 +/- 0.5 vs 0.84 +/- 0.6, P = not significant) compared with significant improvements in E/E' ratio (18.9 +/- 8.7 vs 12.8 +/- 7.4, P < .01) and E'/A' ratio (0.76 +/- 0.5 vs 1.1 +/- 0.7, P < .01) in the control group. This was found despite similar changes ejection fraction, volumes, and systolic strain. Patients with antecedent hypertension have incomplete improvement of the diastolic function compared with control subjects despite comparable left ventricular volumes and ejection fraction after an acute myocardial infarction.
    Patients scheduled for myocardial perfusion imaging are often taking several antianginal drugs. There is presently no consensus concerning a regimen of discontinuation before either rest or pharmacologic stress myocardial perfusion... more
    Patients scheduled for myocardial perfusion imaging are often taking several antianginal drugs. There is presently no consensus concerning a regimen of discontinuation before either rest or pharmacologic stress myocardial perfusion imaging. Whether antianginal treatment affects diagnostic sensitivity and specificity is not well documented. Methods and results The effect of the three most commonly used antianginal drugs (nitroglycerin, 400 microg [NTG]; metoprolol, 50 mg [MET]; and amlodipine, 5 mg [AML]) on myocardial perfusion was tested in 49 patients (age, 63 +/- 8 years; 43 men) allocated prospectively to one of the treatments (NTG, n = 25; MET, n = 14; and AML, n = 10). All patients had documented coronary artery disease and were scheduled for elective percutaneous coronary intervention. Patients were studied once on treatment and once off treatment with an interval of 1 to 3 weeks. For NTG, the measurements were performed on the same day with an interval of 1 hour. The MET and AML groups were also studied during dipyridamole-induced hyperemia (0.56 mg. kg(-1). min(-1) for 4 minutes). So that a quantitative value of myocardial perfusion in milliliters per gram per minute could be obtained, myocardial perfusion was quantified with nitrogen 13 ammonia positron emission tomography as an average of the midventricular perfusion in each of the 3 vascular territories. NTG treatment increased the overall resting perfusion (0.75 +/- 0.18 vs 0.86 +/- 0.22, P <.05), whereas resting perfusion was reduced after MET treatment (0.92 +/- 0.14 vs 0.82 +/- 0.17, P <.05). AML treatment did not alter resting perfusion (0.87 +/- 0.22 vs 0.87 +/- 0.23, P = NS). Dipyridamole-induced hyperemia was reduced after treatment with MET (2.02 +/- 0.66 vs l.57 +/- 0.52, P <.001), whereas the hyperemic response was unchanged after treatment with AML (1.54 +/- 0.49 vs 1.86 +/- 0.91, P = NS). Antianginal medication can alter both resting and hyperemic myocardial perfusion and might affect the ability to detect flow-limiting stenosis. NTG increases perfusion, MET reduces perfusion, and AML does not affect perfusion. Larger-scale trials are warranted to establish a consensus for optimal antianginal medication for patients undergoing perfusion imaging.
    Analysis of ST deviations from the 12-lead electrocardiogram allows for estimation of a spatial ST injury vector. The goal of the present study was to compare the location and extent of transmural myocardial ischemia evaluated by... more
    Analysis of ST deviations from the 12-lead electrocardiogram allows for estimation of a spatial ST injury vector. The goal of the present study was to compare the location and extent of transmural myocardial ischemia evaluated by myocardial perfusion imaging with the direction and magnitude of the ST injury vector. Twelve-lead electrocardiograms were recorded from 75 acute myocardial infarction patients with single-vessel disease and thrombolysis in myocardial infarction (TIMI) flow 0/1 (30 left anterior descending [LAD], 28 right coronary artery [RCA], 17 left circumflex artery [LCX]). ST deviations were measured in the J point in all leads and used to estimate ST injury vectors for each patient. Myocardial perfusion imaging was performed to evaluate the extent and location of myocardial ischemia at the time of coronary intervention. Ninety-two percent of the patients showed ST injury vectors within the expected directional range for the identified anatomic segment of ischemia by myocardial perfusion imaging. ST injury vector direction separated LAD, RCA, and LCX occlusion patients; 90% of the LAD patients showed anterior vectors, 82% of the RCA patients showed posteroinferoseptal vectors, and 59% of the LCX patients showed posteroinferolateral vectors. Eight patients did not fulfill the ST elevation criteria for ST elevation myocardial infarction but showed anterior ST depression and prominent ST injury vectors in the posterior torso direction. There was a moderate correlation between the extent of ischemia and ST injury vector magnitude for the ischemic patients, r = 0.29. We found strong agreement between the direction of the ST injury vector and the location of myocardial ischemia. The ST injury vector may be the key to higher diagnostic accuracy for inferobasal transmural ischemia and may help distinguishing between RCA and LCX occlusions in the acute phase.
    In STEMI, grade-3 ischemia (G3) on admission ECG predicts larger infarct size (IS) than grade-2 (G2). We evaluated whether pre-hospital G3 and its temporal behavior are associated with IS and salvage after pPCI. In 401 STEMI patients,... more
    In STEMI, grade-3 ischemia (G3) on admission ECG predicts larger infarct size (IS) than grade-2 (G2). We evaluated whether pre-hospital G3 and its temporal behavior are associated with IS and salvage after pPCI. In 401 STEMI patients, pre-hospital and pre-PCI ECGs were classified as G3 or G2. IS was assessed by single-photon emission computed tomography (SPECT) at 30days. In 245 patients, pre-PCI SPECT was available to determine myocardium at risk (MaR). G3 criteria were met by 88, and G2 by 313 patients. G3 was independently associated with IS (p=0.006). With ST resolution (STR) group as a reference, G2->G2, G2->G3 and G3->G3 were associated with larger IS (B=4.4, p=0.004; B=5.4, p=0.01; B=10.2, p<0.001, respectively), whereas G3->G2 was not. Salvage was similar between G3 and G2 on pre-hospital ECG if treated early, however lower for G3 when treated later (>2.5h); 48% (35-78) vs 62% (40-87); p=0.04. Development or persistence of G3 is associated with larger IS and less salvage, but decreasing grade G3->G2 was not.
    Implantation of drug-eluting stents (DES) limits the rate of coronary restenosis in most patients with coronary artery disease, but data are scarce with regard to their use in patients with ST-segment-elevation myocardial infarction and... more
    Implantation of drug-eluting stents (DES) limits the rate of coronary restenosis in most patients with coronary artery disease, but data are scarce with regard to their use in patients with ST-segment-elevation myocardial infarction and in connection with distal protection of the microvascular perfusion during primary percutaneous coronary intervention. We randomly assigned 626 patients referred within 12 hours from symptom onset of an ST-elevation myocardial infarction to have a DES or a bare metal stent implanted in the infarct-related lesion with or without distal protection during primary percutaneous coronary intervention. Quantitative coronary angiography was performed during the index treatment and 8 months later. The primary end point was loss of the lumen diameter in the infarct-related lesion induced by neointimal proliferation. Patients were comparable with regard to baseline demographic and angiographic characteristics. The mean late lumen loss was significantly lower in patients treated with a DES (0.06 mm; SD, 0.66 mm) than in patients who had a bare metal stent implanted (0.47 mm; SD, 0.69 mm; P<0.001). The rate of the composite end point of cardiac death, recurrent myocardial infarction, and target lesion revascularization was 8.6% in the DES group versus 14.4% in the bare metal stent group (P=0.03). Cardiac death occurred in 4.2% and 1.6% of the patients (P=0.09) and stent thrombosis occurred in 2.0% and 2.6% (P=0.72), respectively. Implantation of DES improves the angiographic outcome and need for repeat revascularization without increasing the short-term risk of stent thrombosis but has a tendency to increase cardiac death in patients with ST-segment-elevation myocardial infarction.