Electron-beam computed tomography in the assessment of coronary artery disease after heart transplantation.

BACKGROUND: Our aim was to compare the electron-beam CT (EBCT) features of coronary arteries in heart transplant recipients with those of biplane coronary angiography and intracoronary ultrasound (ICUS). METHODS AND RESULTS: We examined 112 heart transplant recipients (25 female; age, 17 to 69 years; median, 52 years) 1 to 153 months (median, 46 months) after surgery by EBCT to detect coronary artery calcifications. Calcifications were quantified by the Agatston scoring system. EBCT scores were compared with coronary angiography in all patients and ICUS of the left anterior descending coronary artery (LAD) in 100 patients. Coronary artery calcifications were found in 84 patients (75%). Angiographically, 16 patients displayed >50% coronary artery stenoses, all of whom had some degree of coronary artery calcification and only 1 of whom had a score of <55 (P<0.0001). With this threshold, EBCT had a sensitivity of 94%, a specificity of 79%, a positive predictive value of 43%, and a negative predictive value of 99% for detecting stenosis. ICUS confirmed the presence of calcified plaques in all patients with an LAD score >9. EBCT total calcium score was associated with the degree of intimal proliferation in that patients without ICUS features of allograft vasculopathy had a median score of 0 (25th percentile, 0; 75th percentile, 0), whereas patients with Stanford class IV vasculopathy had a median score of 41 (9 to 98, P<0.0001). CONCLUSIONS: EBCT is a promising noninvasive test for the detection of coronary heart disease in cardiac transplant recipients.

Use of intravascular ultrasound to compare effects of different strategies of lipid-lowering therapy on plaque volume and composition in patients with coronary artery disease.

BACKGROUND: We studied whether lipid-lowering therapy with atorvastatin (target LDL cholesterol [LDL-C] <100 mg/dL) compared with a moderate treatment regimen that used other lipid-lowering drugs led to a lesser progression of atherosclerosis and to different changes in plaque echogenicity in patients with coronary artery disease. METHODS AND RESULTS: This study was a 12-month, open-label, randomized, multicenter trial, which used serial 3D intracoronary ultrasound to calculate plaque volume and plaque echogenicity. After transcatheter therapy, 131 patients were randomized (atorvastatin n=65, usual care n=66). The target plaque had to be a minor lesion (ie, a diameter stenosis of <50% on angiography). After 12 months, mean LDL-C was reduced from 155 to 86 mg/dL in the atorvastatin group and from 166 to 140 mg/dL in the usual care group. Mean absolute plaque volume showed a larger increase in the usual care group compared with the atorvastatin group (usual care 9.6+/-28.1 mm(3), atorvastatin 1.2+/-30.4 mm(3); P=0.191). The hyperechogenicity index of the plaque increased to a larger extent for the atorvastatin group than for the usual care group, with a significant treatment effect for the percent change (atorvastatin 42.2%, usual care 10.1%; P=0.021). CONCLUSIONS: One year of lipid-lowering therapy to <100 mg/dL LDL-C most likely led to a slowdown of plaque growth of minor lesions. The significantly larger increase in plaque hyperechogenicity is most likely due to a change in plaque composition.

Changes in surface expression of platelet membrane glycoproteins and progression of heart transplant vasculopathy.

BACKGROUND: Transplant vasculopathy is the main limiting factor of the long-term success of heart transplantation. We sought to establish the role of platelets in the development and progression of transplant vasculopathy. METHODS AND RESULTS: Platelet analysis and intracoronary ultrasound examination were performed in 78 heart transplant recipients. Quantitative intracoronary ultrasound was used to define the severity of disease at baseline (48.8+/-4.5 months after transplantation) and at 1-year follow-up. Platelet activation was assessed with the use of immunological surface markers of activation (ligand-induced binding site 1 [LIBS-1], P-selectin, GPIIb-IIIa) and flow cytometry. We found that LIBS-1 immunoreactivity was significantly increased in patients with diffuse disease when compared with focal transplant disease (median [quartile], 27[14, 64] versus 18[7.9, 47], P=0.04). In a logistic regression model, we found that LIBS-1 was an independent predictor for the presence and progression of diffuse transplant vasculopathy (P=0.04). Patients with enhanced LIBS-1 levels (>75% quartile) had a 3.3-fold increased relative risk (95% CI 1.8 and 18.9, P=0.002) for the presence of diffuse transplant vasculopathy. When a cutoff value of 16.5 for the level of LIBS-1 was used, patients had a 4.8-fold increased relative risk (95% CI 1.9 and 12.5, P<0.01) for the progression of transplant vasculopathy. CONCLUSIONS: Enhanced platelet activation is strongly associated with the development and progression of transplant vasculopathy. Understanding the underlying pathophysiological mechanisms might contribute to the development of treatment strategies to prevent transplant vasculopathy.

Prevalence of aspirin resistance in patients with type 2 diabetes.

Aspirin resistance has been recognised to occur in patients with cardiovascular disease and is associated with poor clinical prognosis. The purpose of the present study was to evaluate the prevalence of aspirin resistance in 172 patients with diabetes mellitus type 2 (DM-2). Platelet function of 172 consecutive patients with type 2 diabetes on chronic aspirin therapy was evaluated. The effect of aspirin was assessed using the platelet function analyser (PFA-100) system, reporting platelet-dependent thrombus formation as the time required to close a small aperture in a biologically active membrane. Resistance to aspirin was defined as a normal collagen/epinephrine-induced closure time (82-165 s). Aspirin responders were defined when closure time was > or =300 s. Thirty-seven (21.5%) of the type 2 diabetic patients were found to be resistant to chronic aspirin therapy, 29 (16.9%) were semi-responders and 106 (61.6%) were responders. Univariate analysis revealed that aspirin non-responders were significantly younger (p<0.05) compared to aspirin responders. A significant number of type 2 diabetic patients are resistant to aspirin therapy. Aspirin resistance can be evaluated by point-of-care testing and should be recognised in diabetic patients that are treated for primary or secondary prevention.

Safety of intracoronary ultrasound imaging in patients with acute myocardial infarction.

In 103 patients with acute myocardial infarction, intracoronary ultrasound imaging (ICUS) was performed before and after percutaneous transluminal coronary angioplasty (PTCA) with a pre-PTCA success rate of 79 of 103 patients (76.7%), post-PTCA rate of 88 of 103 patients (85.4%), and a reversible subacute occlusion rate after initial ICUS of 3.9%. Time consumption was 7 +/- 1 minute for pre-PTCA ICUS and 3 +/- 1 minute for post-PTCA ICUS.

Medium-term results of heart transplantation using older donor organs.

BACKGROUND: Donor heart shortage has necessitated the expansion of the donor pool by the use of older hearts. PATIENTS AND METHODS: In a 13-year period, 1,070 heart transplants were performed in 1,035 adults at the German Heart Institute Berlin. We divided the patients into 3 groups: Group I, donor age <35 years (n = 524); Group II, donor age 35 to 50 years (n = 379); Group III, donor age >50 years (n = 167). We analyzed post-operative mortality (up to 30 days), cumulative survival rates, cardiac dependent morbidity, and changes in the left/right ventricular ejection fraction as well as freedom from cytomegalovirus infection and freedom from acute rejection episodes grade >/= 2 (International Society for Heart and Lung Transplantation). We also calculated the rate of cardiac interventions per patient in the groups. RESULTS: Recipients in Group III were significantly older, compared with Groups I and II. The post-operative mortality was 16.8% in Group I, 29.8% in Group II, and 23.4% in Group III. The differences were significant (p = 0. 00001) between Group I and Group II. The long-term cumulative survival rates were significantly better in Group I when compared with Groups II and III (p < 0.00001, p = 0.014), but it did not differ between Groups II and III (p = 0.18). However, cardiac morbidity in Groups I and II was significantly lower when compared with Group III (p = 0.0009, p = 0.037). Mean left and right ventricular ejection fraction was >55% and did not significantly change in groups for up to 10 years. Freedom from cytomegalovirus infection was not significantly different between Groups II and III (p = 0.09). Significantly fewer percutaneous transluminal coronary angioplasties were performed in Group I, but comparable numbers were carried out in Groups II and III (p = 0.53). For retransplantation a similar situation occurred. CONCLUSION: We did not find significant differences in the mid-term follow-up between patients who received hearts from 35- to 50-year-old donors and from those who had received hearts from donors >50 years, despite increased cardiac morbidity in Group III. Close monitoring of the coronary situation after heart transplantation and expanded indications for revascularization in Group III makes heart transplantation with older hearts a suitable option to save the lives of patients in end-stage heart failure.

Does dobutamine stress echocardiography induce damage during viability diagnosis of patients with chronic regional dysfunction after myocardial infarction?

Experimental hibernating-model investigations of animals have shown that myocardial necrosis can be induced by longer-term intracoronary dobutamine infusion. This study was designed to determine whether myocardial infarction could be ascertained in patients with chronic regional wall motion abnormalities and greater than 75% stenosis in the supplying coronary artery through dobutamine stress echocardiography. Twenty patients with coronary artery disease and regional resting wall motion abnormalities were examined with a standard dobutamine protocol (5 to 50 microg/kg/min). Exclusion criteria were an acute coronary syndrome, severe heart failure, and severe hypertension. Creatine kinase (CK, CKMB), myoglobin, and troponine-I were measured before and at each of the first 7 hours after beginning of infusion. Fourteen of these 20 patients exhibited viable myocardium. The serum markers CK, CKMB, myoglobin, and troponin-I demonstrated no increase beyond the reference range, suggesting that with this protocol, no myocardial necrosis was induced.

Intravascular ultrasound assessment of direct percutaneous transluminal coronary angioplasty in patients with acute myocardial infarction.

BACKGROUND: Acute myocardial infarction is caused by sudden thrombotic occlusion of the coronary artery due to a previous rupture of atherosclerotic plaque. OBJECTIVE: To use intracoronary ultrasound measurements to evaluate lumen and plaque changes in patients with acute myocardial infarction. METHODS: Patients (n = 103) with acute myocardial infarction who had been scheduled to undergo primary percutaneous transluminal coronary angioplasty (PTCA) were selected. Both before and after successful coronary angioplasty, intracoronary 30 MHz ultrasound studies were performed using a 3.5F monorail catheter. The ultrasound catheter was successfully advanced into the occluded vessel segment without major complications prior to PTCA in 79 of 103 (76.7%) patients and after PTCA in 88 of 103 (85.3%) patients. RESULTS: The plaques were eccentric in 66 patients (83.5%). The plaque morphology was purely low echogenic in 14 (17.7%), highly echogenic in six (7.6%) and mixed in 59 (74.7%) patients. Partial (59 of 79, 74.7%) or ring-like calcification (3 of 79, 3.8%) was observed in 62 patients (78.5%). Plaque fissuring or dissection was detected prior to PTCA in 25 patients (31.7%). Coronary angioplasty successfully enlarged the inner luminal area from 2.1 +/- 0.7 to 7.4 +/- 1.9 mm2 (P < 0.01), whereas the plaque-thrombus area decreased significantly (13.8 +/- 1.7 mm2 before and 9.0 +/- 1.9 mm2 after PTCA; P < 0.01). The total vessel area remained virtually constant (15.9 +/- 1.9 mm2 before and 16.4 +/- 2.5 mm2 after PTCA, NS). PTCA-induced plaque rupture or dissection was observed in only 13 (16.5%) patients. CONCLUSION: Intracoronary ultrasound imaging can be performed safely and successfully prior and subsequent to PTCA in selected patients with acute myocardial infarction. Early reperfusion via PTCA seems to be attributable to a significant reduction in the amount of low-echogenic plaque and thrombus material, whereas factors like balloon-induced dissection and stretching of vessels play only a minor role.

Intravascular ultrasound imaging in patients with acute myocardial infarction: comparison with chronic stable angina pectoris.

BACKGROUND: Myocardial infarction is the result of acute thrombotic occlusion of a coronary artery, most likely secondary to rupture of an atherosclerotic plaque. Intracoronary ultrasonic (ICUS) examinations were performed in patients with acute myocardial infarction (AMI) in order to describe intraluminal ultrasonic findings at the site of acute coronary occlusion. METHODS: Coronary angiography and ICUS studies were performed consecutively within 6 h of the onset of chest pain in 30 patients with AMI prior to percutaneous transluminal coronary angioplasty (PTCA). The control group consisted of 30 patients with chronic stable angina pectoris (SAP). Following angiographic documentation of a proximal stenosis or occlusion, a 3.5 or 4.8 F mechanical ultrasound catheter (20 MHz) was advanced successfully through the lesion in 25 of 30 (83%) patients with AMI and in 15 of 30 (50%) patients with SAP (P < 0.01). RESULTS: Intracoronary ultrasound permitted differentiation between pulsatile, low-echogenic intraluminal material suggesting thrombus and mural highly echogenic atherosclerotic plaque in 22 of 25 (88%) patients with AMI. A negative imprint of the ICUS catheter was documented within the low-echogenic material in 17 of 25 (68%) patients with AMI. Low-echogenic intraluminal material was found in 18 of 25 (72%) segments proximal and in 12 of 25 (48%) segments distal to the highly echogenic plaque, indicating prestenotic and post-stenotic thrombus in AMI. The plaque appeared eccentric in 22 of 25 (88%) patients with AMI. In comparison, stenotic lesions in chronic SAP patients were less frequently eccentric (5/15, 33%, P < 0.01) and contained a higher proportion of pure highly echogenic material (12/15, 80%). Cross-sectional area stenosis due to highly echogenic plaque averaged 52 +/- 13% in AMI and 82 +/- 3% in SAP (P < 0.01). Calcification of plaque was evident in 21 of 25 patients with AMI (SAP 12/15, 80%, NS). The surface of the plaque was rough in 13 of 25 (52%) AMI patients (SAP 4/15, 27%, P < 0.05). Fissures were detected in only seven (28%) patients and dissection was observed in two (8%) cases. The low incidence might be a result of the limited resolution of the ICUS system. CONCLUSION: This study demonstrates that ICUS with 4.8 or 3.5 F catheters is feasible and safe in selected patients with AMI, and adds little to the overall duration of the angioplasty procedure. The identification and demarcation of atherosclerotic plaque provided by ICUS could prove valuable in guiding PTCA, in deciding on appropriate therapy, and in acute and long-term follow-up of AMI patients.

Reproducibility of serial intravascular ultrasound measurements in patients with angiographically silent coronary artery disease after heart transplantation.

BACKGROUND: Intracoronary ultrasound (ICUS) imaging is the most sensitive method for the early detection and serial evaluation of vasculopathy of transplants. Both lack of agreement between observers and lack of agreement between serial, independent pullback procedures (repeatability), which can result in a variable intraluminal catheter position may limit the reproducibility of ICUS measurements. OBJECTIVE: To evaluate the reproducibility of serial measurements of standard linear and area cross-sectional coronary dimensions in patients with non-obstructive transplant vasculopathy. METHODS: We performed ICUS imaging of patients without angiographic evidence of obstructive epicardial coronary artery disease after heart transplantation. A 30 MHz phased-array transducer was used. Two independent pullbacks of the left anterior descending coronary artery were performed and recorded on CD-ROM for off-line quantitative analysis of the most severely diseased site. Agreement of observers and repeatability of serial measurements were calculated by the use of linear regression analysis and Bland-Altman plots. RESULTS: Regarding agreement of observers, correlation coefficients for intra-observer agreement ranged from r = 0.98 to r = 0.99; those for interobserver agreement ranged from r = 0.87 to r = 0.98. Serial measurements of the identical coronary artery cross-section within independent catheter pullback procedures were possible for 104 of 112 target lesions (92.90/%). Correlation coefficients ranged from r = 0.91 to r = 0.97 (for lumen diameter r = 0.91, for lumen area r = 0.93, for vessel diameter r = 0.91, for vessel area r = 0.97, for thickness of plaque r = 0.96 and for area of plaque 0.94). The mean difference of measurements was around zero for all parameters with SD from 0.13 to 0.4 mm for linear parameters and from 1.53 to 1.82 mm2 for area parameters. CONCLUSION: Serial intravascular ultrasound measurements are highly reproducible without any evidence of systematic error and a SD of differences of measurements beyond the maximal spatial resolution of currently available intravascular ultrasound catheters.

Remodeling of myocardium and arteries by chronic angiotensin converting enzyme inhibition in hypertensive patients.

AIM: To investigate changes in left ventricular hypertrophy and diastolic function in hypertensive patients treated with an angiotensin converting enzyme (ACE) inhibitor. METHODS: Structural and functional changes in the heart and iliac artery were studied by echocardiography and intraluminal ultrasound in 15 hypertensive patients following 6 months of treatment with the ACE inhibitor quinapril at 10-40 mg/day. RESULTS: Systolic/diastolic blood pressure was reduced from 156/100 mmHg to 128/82 mmHg within 2 months and remained stable during the next 4 months of the study. The left ventricular mass index was significantly reduced from 174 +/- 86 to 161 +/- 75 g/m2 (-7.4%, P < 0.05). The reduction in left ventricular hypertrophy was associated with a trend towards an improvement in diastolic function, but left ventricular systolic function did not change. There was a 3.9% increase in iliac lumen area and a significant decrease of 10.7% (P < 0.05) in the ratio between the intimal-medial and lumen area, which represents a decrease in wall thickness. A key result was a statistically significant decrease in pulse-wave velocity, from 13.7 +/- 2.6 to 12.1 +/- 2.0 m/s, and in the modulus of elasticity, from 20.5 +/- 7.2 to 15.8 +/- 5.6 x 10(4) N/m2 (P < 0.05). CONCLUSION: The present study demonstrates that 6 months of treatment with an ACE inhibitor induced a significant regression in left ventricular hypertrophy and a reduction in wall thickness. In addition, the results indicate that chronic ACE inhibition can decrease the stiffness of large elastic arteries independently of a reduction in blood pressure.

["Cryptogenic" coronary embolism - Case 4/2011]. / "Kryptogene" Koronarembolie - Fall 4/2011.

HISTORY AND ADMISSION FINDINGS: We report on a 42-year-old patient who presented with acute chest pain which occurred during defaecation. History revealed no cardiovascular risk factors. INVESTIGATIONS: ECG and laboratory testing showed an non-ST-elevation myocardial infarction (NSTEMI). DIAGNOSIS, TREATMENT AND COURSE: Coronary angiography revealed an embolic occlusion of the ramus intermedius. As origin of the embolus a deep vein thrombosis and a persistent foramen ovale (PFO) was diagnosed. We occluded the PFO with an Amplatz occluder. Because of the traumatic deep vein thrombosis phenprocoumon and clopdiogrel were given for 6 months. CONCLUSIONS: Patients with no cardiovascular risk profile, who present with typical chest pain, an embolic cause is an important differential diagnosis. Especially history is very helpful for the correct diagnosis. Interventional occlusion of PFO is a simple and safe approach for patients with symptomatic PFO regarding no permanent antithrombotic medication.

[Stress echocardiography--an evaluation of current status]. / Stressechokardiographie--eine Standortbestimmung.

Exercise echocardiography, a versatile, noninvasive diagnostic test of left ventricular wall motion performed at rest and under induced stress, enables the cardiologist to detect and assess coronary artery disease. Stress-induced ischemia is thereby expressed as left ventricular regional wall motion abnormality. By using various physical (bicycle or treadmill exercise) and pharmacological (dipyridamole, dobutamine, adenosine) stress inducers, the test provides information about the localization and extent of coronary artery disease in addition to detecting stress-induced coronary insufficiency. As regards diagnostic accuracy in detecting coronary artery disease, stress echocardiography is superior to exercise electrocardiography and, according to the available data, it is comparable to perfusion scintigraphic testing. Studies have demonstrated the clinical value of stress echocardiography in detecting residual stenosis after angioplasty, for diagnosing bypass dysfunction after heart surgery, for preoperative risk assessment in noncardiac surgeries, and for obtaining prognostic information, e.g., after myocardial infarction. Preliminary studies have shown that pharmacological exercise echocardiography is able to identify viable myocardium in the early phases after acute myocardial infarction. Furthermore, it is able to predict the functional success of revascularization in chronic regional left ventricular dysfunction. In addition to the wide range of diagnostic possibilities in coronary artery disease, other notable applications include stress testing for assessment of global left ventricular pump function in patients with aortic regurgitation or cardiomyopathy.

[Stress echocardiography: evaluation of left ventricular function after administration of the transpulmonary echo contrast medium SHU 508 A]. / Stressechokardiographie: Beurteilung der linksventrikulären Funktion nach Gabe des lungengängigen Echokontrastmittels SHU 508 A.

Stress echocardiography has recently gained increased importance as a method for assessment of left ventricular function. However, suboptimal image quality in some patients may limit use of this technique. In the present study, 10 patients with moderate image quality in the resting echocardiograms (apical 4-chamberview) were reinvestigated after administration of the intravenous transpulmonary saccharide-based left heart contrast agent SHU 508 A. Duration of contrast enhancement in the left ventricle determined by visual assessment was 135 s (SEE +/- 39) at rest and 112 s (+/- 24) during maximum exercise. On a scale ranging from O (no contrast) to 4 (excessively strong contrast) enhancement averaged 2.5 at rest and during exercise. The left ventricle was divided into three segments (septum, apex, lateral wall) and delineation of the endocardial border was assessed. Detection of the border improved significantly after contrast administration, especially at the lateral wall. Despite better visual assessment of the endocardial border, there was no improvement in automatic or semi-automatic contour recognition. No clinically significant side-effects were observed. Three patients reported a sensation of warmth at the injection site. In conclusion, intravenous administration of SHU 508 A improves visual detection of the left ventricular endocardial border in patients with suboptimal image quality and helps to achieve acceptable diagnostic accuracy with stress echocardiography in these patients.