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Publications and source records attributed to P Thayssen.
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OBJECTIVE: To investigate in a prospective randomised study both long term clinical effects and cost effectiveness of percutaneous coronary interventions (PCI) with or without intravascular ultrasound (IVUS) guidance. METHODS: 108 male patients with stable angina referred for PCI of a significant coronary lesion were randomly assigned to IVUS guided PCI or conventional PCI. Individual accumulated costs of the entire follow up period were calculated and compared in the randomisation groups. Effectiveness of treatment was measured by freedom from major adverse cardiac events. RESULTS: Cost effectiveness of IVUS guided PCI that was noted at six months was maintained and even accentuated at long term follow up (median 2.5 years). The cumulated cost level was found to be lower for the IVUS guided group, with a cumulated cost of &163 672 in the IVUS guided group versus &313 706 in the coronary angiography group (p = 0.01). Throughout the study, mean cost per day was lower in the IVUS guided PCI group (&2.7 v & 5.2; p = 0.01). In the IVUS group, 78% were free from major adverse cardiac events versus 59% in the coronary angiography group (p = 0.04) with an odds ratio of 2.5 in favour of IVUS guidance. CONCLUSION: IVUS guidance results in continued improvement of long term clinical outcome and cost effectiveness. The results of this study suggest that IVUS guidance may be used more liberally in PCI.
Intensive lowering of serum cholesterol in patients with ischaemic heart disease may retard atherosclerotic progression, and may even cause a limited regression in some patients and partly restore endothelial function. Coronary angiography has been the standard method to evaluate coronary anatomy. However, coronary angiography delineates only the vessel lumen as a silhouette, a perspective that is incapable of reflecting the irregular nature of the atherosclerotic vessel wall changes. Three-dimensional intravascular ultrasound provides cross-sectional and longitudinal images of both the vessel lumen and wall and the plaque volume can be measured in entire arterial segments. Three-dimensional intravascular ultrasound is a reliable technique to measure progression and regression of atherosclerosis in coronary arteries.
INTRODUCTION: Myocardial perfusion imaging (MPI) demonstrates regional hypoperfusion, whereas coronary angiography shows anatomical stenoses in epicardial arteries. Both modalities are potentially relevant in patients with stable angina pectoris. MATERIALS AND METHODS: MPI was undertaken before angiography in 86 randomly selected patients with stable angina pectoris. RESULTS: Of 78 adequately stressed patients, MPI was normal in 28 (36%) and showed reversible and irreversible perfusion abnormalities in 30 (38%) and 20 patients (26%), respectively. Coronary angiograms were normal in 28 (36%) and revealed at least one > or = 50% stenosis in 50 patients (64%) (16 with single vessel and 34 with multivessel disease). With angiography as reference, the sensitivity and specificity of MPI in the detection of coronary artery disease were 88% and 93%, respectively. DISCUSSION: Patients with stable angina pectoris and a normal MPI have a very low risk of cardiac events and do not usually require invasive investigation and therapy. Reversible ischaemia and irreversible ischaemia with viable tissue call for coronary revascularisation.
The aim of this study was to evaluate the reproducibility of intravascular ultrasound (IVUS) and intracoronary (IC) Doppler flow velocity measurements. The use of IVUS and IC Doppler has been suggested as a means for percutaneous coronary intervention (PCI) guidance in a series of studies. This would require an acceptable level of accuracy and reproducibility of these two methods for lesion evaluation. In this study, the main focus was on the issue of reproducibility. One hundred and eight patients referred for PCI entered into the study. Inter- and intraobserver variability was measured. Catheter difference was assessed. On-line and off-line measurements were compared. MUSIC criteria were assessed off-line, twice. Calculated and measured diameters were compared. After having obtained initial IC Doppler measurements, the Doppler wire was immediately withdrawn and repositioned for reacquisition of Doppler measurements. IVUS measurements are reproducible and reliable off-line and, to a slightly lesser degree, on-line. Area measurements should be performed more than once and the mean used for vessel description. Lumen diameters should be calculated from the mean of the area measurements. A measuring technique consensus should be reached and adhered to. CFR measurements can be used to determine reduced vs. normal flow reserve. In this study, it was found that proximal to distal velocity ratio and diastolic to systolic velocity ratio variability made these parameters unsuitable for PCI guidance.
OBJECTIVE: Investigation of the cost-effectiveness of intravascular ultrasound (IVUS) guided percutaneous coronary intervention (PCI) compared to PCI guided by coronary angiography (CAG). METHODS: One hundred and eight men referred for PCI, were randomized to IVUS or CAG guided PCI. After 6 months, the patients were subjected to a study related clinical and invasive follow-up investigation by CAG, IVUS and intracoronary Doppler flow measurements. Incremental costs of IVUS guided procedures and costs of re-interventions were estimated using the Activity Based Costing (ABC) method. RESULTS: Patients randomized to IVUS guided PCI experienced an improved clinical outcome, with lower angina levels than patients in the CAG guided group. The initial cost of performing IVUS guidance was increased due to extra procedure time, IVUS catheters and slightly more balloons and stents, but fewer patients in the IVUS guided group needed re-intervention. Overall, these savings outweighed the initial cost increase. CONCLUSION: Our data suggest that when performing IVUS guided PCI, costs as well as benefits increase. The increased benefits measured as cost savings resulting from less restenosis outweigh the cost increase from performing the IVUS guided PCI as opposed to CAG guided PCI.
BACKGROUND: Observer variability of 99Tcm-sestamibi myocardial perfusion imaging (MPI) has rarely been investigated. The aim of our study was to evaluate the interpretive reproducibility with this technique. PATIENTS: We report on 108 consecutive male patients with stable angina pectoris, investigated before and after percutaneous transluminal angioplasty (PTCA). METHODS: A 2-day rest/stress 99Tcm-sestamibi gated single photon emission computed tomography (SPECT) protocol was used. MPI was interpreted by two independent observers without knowledge of clinical data, using a 20-segment scoring model. RESULTS: Intra- and interobserver agreement was found to be good to excellent (kappa = 0.71-0.85) with regard to the overall diagnosis as well as the individual vessel diagnosis (kappa = 0.60-0.87). However, agreement was higher for left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX) vascular territories than for the right coronary artery (RCA) territory. Moderate to good intraobserver agreement (kappa = 00.54-0.68) and slightly lower interobserver agreement (kappa = 0.52-0.56) was found for segmental score interpretation. When comparing the interpretive reproducibility before and after PTCA intra- and interobserver agreement was better after PTCA, probably reflecting the increase in normal scans after revascularization. CONCLUSIONS: In a group of consecutive male patients with stable angina pectoris interpretive reproducibility (overall and individual vessel diagnosis) was good to excellent. However, segmental scoring reproducibility was moderate to good.
OBJECTIVE: To assess the mechanism of restenosis after balloon angioplasty. DESIGN: Prospective study. PATIENTS: 13 patients treated with balloon angioplasty. INTERVENTIONS: 111 coronary subsegments (2 mm each) were analysed after balloon angioplasty and at a six month follow up using three dimensional intravascular ultrasound (IVUS). MAIN OUTCOME MEASURES: Qualitative and quantitative IVUS analysis. Total vessel (external elastic membrane), plaque, and lumen volume were measured in each 2 mm subsegment. Delta values were calculated (follow up - postprocedure). Remodelling was defined as any (positive or negative) change in total vessel volume. RESULTS: Positive remodelling was observed in 52 subsegments while negative remodelling occurred in 44. Remodelling, plaque type, and dissection were heterogeneously distributed along the coronary segments. Plaque composition was not associated with changes in IVUS indices, whereas dissected subsegments had a greater increase in total vessel volume than those without dissection (1.7 mm(3) v -0.33 mm(3), p = 0.04). Change in total vessel volume was correlated with changes in lumen (p < 0.05, r = 0.56) and plaque volumes (p < 0.05, r = 0.64). The site with maximum lumen loss was not the same site as the minimum lumen area at follow up in the majority (n = 10) of the vessels. In the multivariate model, residual plaque burden had an influence on negative remodelling (p = 0.001, 95% confidence interval (CI) -0.391 to -0.108), whereas dissection had an effect on total vessel increase (p = 0.002, 95% CI 1.168 to 4.969). CONCLUSIONS: The mechanism of lumen renarrowing after balloon angioplasty appears to be determined by unfavourable remodelling. However, different patterns of remodelling may occur in individual injured coronary segments, which highlights the complexity and influence of local factors in the restenotic process.
INTRODUCTION: The patho-physiological cause of angina pectoris is myocardial ischaemia, which can be objectified by myocardial perfusion imaging (MPI). METHODOLOGY: MPI was undertaken prior to coronary angiography (CAG) in 86 randomly selected patients with known or suspected stable angina pectoris. RESULTS: Among 78 adequately stressed patients, MPI was normal in 28 (36%) and showed reversible and irreversible perfusion abnormalities in 30 (38%) and 20 patients (26%), respectively. Coronary angiograms were normal in 28 (36%) and revealed at least one > or = 50% stenosis in 50 patients (64%) (16 with single and 34 with multi vessel disease). Using angiography as a reference, the sensitivity and specificity of MPI in detecting coronary artery disease was 88% and 93%, respectively. DISCUSSION: MPI demonstrates regional hypoperfusion whereas CAG depicts anatomical stenosis in epicardial arteries. Both modalities are potentially relevant in patients with stable angina pectoris. The functional significance of coronary artery lesions is, however, variable and MPI can demonstrate normal myocardial perfusion in the presence of moderate lesions. MPI exhibited a high sensitivity and specificity regarding significant lesions. More than one third of the subjects had a normal MPI and a normal CAG. Patients with stable angina pectoris and a normal MPI have a very low risk of cardiac events and do usually not require further invasive investigation or therapy. Reversible ischaemia and irreversible ischaemia with demonstration of viable tissue call for coronary revascularisation.
INTRODUCTION: To compare an invasive strategy employing percutaneous transluminal coronary angioplasty (PTCA) or coronary artery by-pass grafting (CABG) with a medical strategy in patients who had received thrombolytic treatment for first acute myocardial infarction (AMI), and with signs of inducible ischaemia. METHODS: In a prospective study 1008 patients were randomized, 503 to invasive treatment, of whom 266 (52.9%) had PTCA, and 147 (29.2%) CABG, 505 to conservative treatment, of whom eight (1.6%) were revascularized within two months. RESULTS: After a median follow-up of 2.4 years the mortality in the invasive group was 3.6% vs. 4.4% (p = 0.45) in the conservative group, re-infarction incidence was 5.6% vs. 10.5% (p = 0.0038) and percentage of admissions with unstable angina was 17.9% vs. 29.5% (p < 0.00001). DISCUSSION: We conclude that post-infarct patients with inducible ischaemia should be referred to coronary angiography and revascularised accordingly.
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Coronary complications caused by percutaneous transluminal coronary angioplasty (PTCA) may necessitate emergency coronary artery bypass grafting (CABG). In 1994-1998, 132 patients (1.5% of the patients registered in the Danish PTCA registry) underwent CABG within 24 h because of angioplasty complications. We reviewed the files of 86 patients who had emergency operations within 6 h and found that 35% suffered from 1-vessel disease. Fifty-eight percent were taken directly to the operating room from the cardiovascular laboratory, and 13% were given preoperative cardiovascular resuscitation. The vessels most frequently injured were the right coronary artery and the left anterior descending branch (LAD). The patients received a mean of 2.4 coronary bypasses each. Forty-three percent of the patients with lesions of the left main coronary artery and/or the LAD received a vein graft to the LAD. A perioperative Q-wave myocardial infarction developed in 51% of the patients. The in-hospital mortality rate was 12%. These results are inferior to those obtained after elective surgery. Local cardiothoracic backup is vital when PTCA is performed in an unselected patient group.
Dilatation of the left ventricle predicts morbidity and mortality after acute myocardial infarction. We compared serial echocardiographic examinations of the left atrium and ventricle with measurements of plasma atrial natriuretic peptide (ANP) and plasma N-terminal pro atrial natriuretic peptide (NT-proANP) in 22 patients during the first 6 months following a first myocardial infarction. ANP, but not NT-proANP, was found to be significantly correlated to the diastolic/systolic size of the left atrium (r = 0.58/0.60) and the systolic size of the left ventricle (r = 0.43) in the acute phase 2-4 days after infarction. At 10-12 days after the infarction, we found a significant correlation between all sizes of the left-sided chambers and ANP, whereas NT-proANP only correlated with the left atrial sizes. Three months after the infarction, all sizes of the left-sided chambers correlated with both ANP and NT-proANP, with the exception of a non-significant correlation between NT-proANP and the left atrial diastolic size. After 6 months only the area of the diastolic and systolic left atrium correlated with plasma ANP and only the systolic size of the left atrium correlated with NT-proANP. The percentage change in the size of the left atrium, but not the left ventricle, correlated significantly with the percentage change in both ANP (r = 0.57) and NT-proANP (r = 0.70). We conclude that the distension of the left atrium rather than the dilatation of the left ventricle is related to the concentration of ANP and NT-proANP after an acute myocardial infarction.
Intravascular ultrasound (IVUS) is a well-established diagnostic tool that supplements coronary angiography in the evaluation of angiographical intermediate lesions as well as guiding Percutaneous transluminal coronary angioplasty. In this case report we describe the benefit of IVUS in diagnosing pseudostenosis as opposed to angiographically suspected guidewire induced dissection, and suggest the use of IVUS in all cases where angiography is equivocal. We also report a case of preoperative IVUS where the IVUS finding resulted in further coronary artery bypass grafting and suggest IVUS as a feasible alternative to probing of coronary arteries suspected of stenosis during coronary artery bypass grafting.
Intracoronary doppler blood flow velocity measurements supply important information for clinical decision making during angioplasty, especially with regard to stenoses of ambiguous severity. In the presence of an intermediate stenosis of unknown physiological impact (40-60%), determination of normal flow parameters (coronary flow reserve: CFR, diastolic to systolic velocity ratio: DSVR and proximal to distal velocity ratio: P/D) will make deferment of treatment acceptable. Post-angioplasty success can be based on restoral of normal flowparameters. The inability to achieve normal CFR immediately after angioplasty does not indicate an unsuccessful procedure, it remains to be shown whether a lack of normalization of DSVR and/or P/D does so. Continuous post-lesional flow monitoring can show and quantify the existence of collateral flow.
BACKGROUND: The aim of the DANish trial in Acute Myocardial Infarction (DANAMI) study was to compare an invasive strategy of percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) with a conservative strategy in patients with inducible myocardial ischemia who received thrombolytic treatment for a first acute myocardial infarction (AMI). METHODS AND RESULTS: Of the 503 patients randomized to an invasive strategy, PTCA was performed in 266 (52.9%) and CABG in 147 (29.2%) from 2 to 10 weeks after the AMI. Of the 505 patients in the conservative treatment group, only 8 (1.6%) had been revascularized 2 months after the AMI. The patients were followed up from 1 to 4.5 years. The primary end points were mortality, reinfarction, and admission with unstable angina. At 2.4 years' follow-up (median), mortality was 3.6% in the invasive treatment group and 4.4% in the conservative treatment group (not significant). Invasive treatment was associated with a lower incidence of AMI (5.6% versus 10.5%; P=.0038) and a lower incidence of admission for unstable angina (17.9% versus 29.5%; P<.00001). The percentages of patients with a primary end point were 15.4% and 29.5% at 1 year, 23.5% and 36.6% at 2 years, and 31.7% versus 44.0% at 4 years (P=<.00001) in the invasive and conservative treatment groups, respectively. At 12 months, stable angina pectoris was present in 21% of patients in the invasive treatment group and 43% in the conservative treatment group. CONCLUSIONS: Invasive treatment in post-AMI patients with inducible ischemia results in a reduction in the incidence of reinfarction, fewer admissions due to unstable angina, and lower prevalence of stable angina. We conclude that patients with inducible ischemia before discharge who have received treatment with thrombolytic drugs for their first AMI should be referred to coronary arteriography and revascularized accordingly.
Angiopeptin, a somatostatin analogue, inhibits intimal hyperplasia after (percutaneous transluminal coronary angioplasty) (PTCA) in several animal models. This pilot study sought to determine the effect of subcutaneous infusion of angiopeptin on clinical events and restenosis in patients undergoing successful PTCA. One hundred and twelve patients were randomized to receive continuous subcutaneous angiopeptin (750 micrograms/day) or placebo infusion from the day before PTCA and for the following four days in a double-blind study. Eighty patients had a successful PTCA, and 75 of these patients with 94 lesions underwent angiography 6 +/- 2 months after PTCA. All 112 patients underwent clinical follow-up at 12 months. The 12-month event rate (death, myocardial infarction, coronary artery bypass grafting and re-PTCA) was reduced from 34% to 25% (p = 0.30) by angiopeptin by intention to treat analysis. Restenosis (> or = 50% diameter stenosis) was significantly reduced in lesions treated with angiopeptin (12% vs 40%; p = 0.003). Late lumen loss was also significantly reduced after angiopeptin treatment (0.12 +/- 0.46 mm vs 0.52 +/- 0.64 mm; p = 0.003). In conclusion, continuous subcutaneous angiopeptin infusion for five days tended to decrease clinical events and restenosis after PTCA.