Stefan Pfleger

Role of vessel size as a predictor for the occurrence of in-stent restenosis in patients with diabetes mellitus

Intracoronary stents have been shown to reduce the rate of restenosis when compared with balloon angioplasty, but in-stent restenosis continues to be an important clinical problem. It was therefore the aim of this registry to identify procedural and angiographic predictors for the occurrence of in-stent restenosis. We analyzed 368 patients with 421 lesions who underwent coronary stent implantation between January 1998 and February 2000. Indications for the placement of a coronary stent were severe dissections (37%), suboptimal angiographic results (38%), restenotic lesions (20%), and graft lesions (4%). Angiographic follow-up was obtained in 270 patients (73%) with 293 lesions after 6 months. Clinical and angiographic variables were analyzed by univariate and multivariate models for the ability to predict the occurrence of in-stent restenosis, defined as a diameter stenosis >50%. In-stent restenosis was angiographically documented in 67 patients and 68 lesions (23%). Under all tested variables the reference luminal diameter before stent implantation (p = 0.006) and diabetes mellitus (p = 0.023) were identified as independent predictors for the occurrence of in-stent restenosis. The comparison of diabetic and nondiabetic patients according to vessel size revealed a 2 times higher rate of in-stent restenosis in small vessels (44% vs 23%, p = 0.002), whereas in vessels >3.0 mm the rate of in-stent restenosis was not significantly different between the 2 groups. In this registry, the clinical variable diabetes and the procedural variable reference vessel size were independent predictors for the occurrence of in-stent restenosis. In these patients, the rate of in-stent restenosis was as high as 45%.

Detection of a pseudonormal mitral inflow pattern: an echocardiographic and tissue Doppler study.

Objective: The aim of this study was to assess the ability of several echocardiographic and tissue Doppler imaging (TDI) derived parameters to improve the noninvasive diagnosis of a pseudonormal mitral inflow pattern. Methods: Ninety‐eight consecutive patients with age‐related normal transmitral Doppler profile underwent echocardiography including TDI and measurement of left ventricular end‐diastolic pressure (LVEDP) using fluid‐filled catheters. Peak transmitral velocities were determined at rest (E, A) and during the strain phase of a Valsalva maneuver. The difference in duration between the pulmonary venous retrograde velocity and the transmitral A‐velocity (PVR–A) was calculated from pulsed Doppler recordings. Propagation velocity of the early mitral inflow (VP) was determined by color M‐mode. Early diastolic peak mitral annulus velocities (E′) and the early diastolic transmyocardial velocity gradient of the posterior basal wall (MVG) were obtained by TDI. Results: Fifty‐two patients presented with normal diastolic function (group I: LVEDP 9.5 ± 3 mm Hg , E/A 1.1 ± 0.19 ), while pseudonormalization, defined as LVEDP 15 mm Hg and E/A > 0.9, was found in 46 patients (group II: LVEDP 23 ± 7 mm Hg , E/A 1.43 ± 0.83 ). The coefficient of linear correlation (r) and the area under ROC – curve (AUC) to predict LVEDP values 15 mm Hg were maximal for the index PVR–A ( AUC = 0.92, r = 0.77 ), followed by E/E′ (AUC = 0.80, r = 0.46), MVG (AUC = 0.65, r = 0.33) and E/VP (AUC = 0.69, r = 0.30), P < 0.01 , whereas the decrease in E/A ratio during Valsalva maneuver failed to reach significance. Similar results were observed when echocardiographic parameters were used to estimate the left ventricular diastolic pressure before atrial contraction. Conclusions: PVR–A enabled the most accurate estimation of LVEDP. TDI‐derived indices E/E′ and MVG are also reliable alternatives superior to the classical Valsalva maneuver to detect a pseudonormal transmitral Doppler profile. (ECHOCARDIOGRAPHY, Volume 20, May 2003)

BOLD-MRI in ten patients with coronary artery disease: evidence for imaging of capillary recruitment in myocardium supplied by the stenotic artery

Changes of myocardial oxygenation can be studied by measurements of the apparent transverse relaxation timeT2*, which is correlated with the oxygenation state of hemoglobin. In this study, ten patients with coronary artery disease (CAD) underwent blood oxygenation level dependent (BOLD)T2* measurements using a segmented gradient echo pulse sequence with ten echoes.T2* measurements were performed in a single short-axis slice of the heart at rest and under pharmacological stress with dipyridamole (DIP), which increases myocardial blood flow. For comparison, all patients underwent X-ray angiography and stress-echocardiography within 4 days after the MR exam. In one patient, MR examination was repeated 10 weeks after percutaneous transluminal coronary angioplasty (PTA). In the differentialT2* maps, expected ischemic areas of myocardium were identified in six patients. In these regions,T2* values (30±8 ms) were significantly reduced when compared to the remaining myocardium (48±9 ms,P<0.01). In four patients, the myocardial region of interest could not be assessed owing to severe susceptibility artifacts in the ischemic region. The success of the PTA treatment could be visualized from a more homogeneous DIP induced increase inT2* within the ischemic myocardium (from 26±1 to 29±1 ms before PTA versus 26±1 to 31±4 ms after PTA,P<0.001.

Correlation of degree of aortic valve stenosis by Doppler echocardiogram to quantity of calcium in the valve by electron beam tomography

The present study shows that in calcific AS, the quantification of valvular calcium by EBT is possible with a low intraobserver variability. The extent of valvular calcium is inversely correlated with aortic valve area. Correction for background scatter does not further improve this correlation. The present data suggest that the progression of calcific AS severity by echocardiography is closely linked to a progression in aortic valve calcium. Given these findings and the low interscan variability described by other groups, 3,4 EBT may be a useful imaging modality for noninvasive monitoring of the course of calcific AS by quantification of aortic valve calcium.

Continuous Measurement of Hemodynamic Alterations During Pharmacologic Cardiovascular Stress Using Automated Impedance Cardiography

The contribution of computerized impedance cardiography in monitoring and differentiating cardiovascular responses to pharmacologic stress after the administration of dipyridamole (group 1, n = 24) or dobutamine (group 2, n = 26) was investigated during stress echocardiography. Heart rate, stroke volume index, cardiac index and systemic vascular resistance index were evaluated continuously with an automated, computerized, signal‐averaged impedance cardiography system. Dipyridamole had little average effect on heart rate, stroke volume index, and cardiac index. The responses were similar in patients with positive (n = 9) or negative (n = 15) stress echocardiography test results (as characterized by echocardiographic wall‐motion abnormalities). Dobutamine induced a similar mean increase in heart rate in patients with negative (n = 13) or positive (n = 13) results on stress echocardiography. The mean increase in stroke volume index induced by dobutamine was greater in patients with negative stress echocardiography test results than in patients with stress‐induced wall‐motion abnormalities. This distinction was also seen in the cardiac index; the mean change in patients with negative stress echocardiography test results was larger than in patients with positive results. It is concluded that automated computerized impedance cardiography not only allows surveying and monitoring hemodynamic changes during pharmacologic stress echocardiography but also contributes to differentiation of pathologic stress responses.

Detection of patients with restenosis after PTCA by dipyridamole-atropine-stress-echocardiography

Stress-echocardiography (SE) has been proven to be a valuable method for the diagnosis of coronary artery disease. For patients who cannot exercise, pharmacological stress-echocardiography represents an alternative method for the induction of cardiovascular stress. Few studies exist concerning the value of dipyridamole-SE for the detection of restenosis in patients after primary successful PTCA. It has been demonstrated that the addition of atropine can significantly increase the diagnostic potential of dipyridamole-SE, especially in patients with 1- or 2-vessel disease. The purpose of our study was to investigate the diagnostic value of high-dose dipyridamole-SE plus atropine (DASE) for the detection of restenosis after primary successful PTCA. We investigated 65 patients 3–6 months after PTCA before a control angiography was performed. Restenosis was defined as > 70% lumen narrowing, determined by quantitative coronary angiography. In 20/27 patients with restenosis the DASE was pathologic (sensitivity 74%), in 34/38 patients without restenosis the DASE was normal or showed no induced WMA (specificity 89%). Patients with tight restenosis (> 90%) were always correctly detected by DASE. Concerning the different vessels, restenosis of the LAD was correctly predicted by DASE in 11/12 patients, restenosis of the LCX in 6/9 patients and restenosis of the RCA in 8/11 patients. Conclusions: From our results of our study we conclude that DASE is a reliable diagnostic method for the non-invasive evaluation of patients after PTCA. DASE can identify patients with relevant restenosis after PTCA and help to select those patients who will probably benefit from further coronary interventions.

Does competitive apnea diving have a long-term risk? Cardiopulmonary findings in breath-hold divers.

Study Purpose:The aim of this study was to investigate the cardiopulmonary status in a competitive apnea diving team. Design:This study was conducted with a cross-sectional study design in which subjects had to undergo a predefined series of cardiopulmonary examinations. Subjects:Eight competitive apnea divers (mean age, 26.9 ± 5.3 years) who were participating in international apnea diving contests. Methods:Electrocardiographic, 2-dimensional echocardiographic, Doppler-echocardiographic, and oxymetric examinations were performed in each subject during an apnea test. Results:Apnea diving experience was 2.5 ± 0.58 years, with a training frequency of 8.9 ± 6.0 dives per week. During an apnea test, mean apnea time was 4.5 ± 0.96 minutes. While 2-dimensional echocardiography showed normal morphologic findings of cardiac dimensions and function, electrocardiography, and Doppler echocardiography revealed indicators suggesting the beginning of right ventricular strain. Conclusions:We interpret the findings of our study as the onset of pulmonary hypertension resulting from repetitive pulmonary vasoconstriction together with severe hypoxia during apnea diving. We conclude that regular competitive apnea diving over a period of >2 to 3 years might carry a chronic cardiopulmonary risk that may lead from early functional changes to manifestation of pulmonary hypertension.

Automated impedance cardiography for detecting ischemic left ventricular dysfunction during exercise testing.

Automated impedance cardiography (ICG) is an attractive method for noninvasive hemodynamic evaluation. The objective of our study was to evaluate the feasibility and diagnostic value automated ICG in patients with suspected coronary artery disease (CAD). We measured stroke index (SI) and cardiac index (CI) in 65 patients with suspected CAD at rest and during bicycle exercise testing. All patients underwent subsequent cardiac catheterization including coronary angiography (CA). Depending on the results of CA, patients were divided into three groups, patients without significant CAD (group 0), single vessel disease (group 1) or multivessel disease (group 2–3). In a subset of 20 patients, automated ICG was compared to measurements of CI by the thermodilution (TD) method. Results: There were no significant differences in SI and CI at baseline between the three groups. At 75- and 100-watt exercise, patients in group 2–3 showed significantly lower mean values of SI and CI as compared to patients of group 0 and group 1 (all p < 0.05), indicating exercise-induced ischaemic left ventricular (LV) dysfunction. Three patients had to be excluded because of inappropriate quality of the ICG signals during exercise. Comparison of automated ICG with TD measurements of CI showed good correlations between both methods at rest (r = 0.73) and during exercise (r = 0.89–0.91). Conclusions: We conclude that hemodynamic monitoring by automated ICG is both feasible and practical during exercise testing. Automated ICG can provide reliable and valuable additional diagnostic information on LV function during exercise which is helpful for selecting those patients for angiography who are likely to benefit from coronary interventions.

Right Atrial Primary Cardiac Lymphoma Presenting With Stroke

An immunocompetent 79-year-old man presented with acute dysarthria and hemiparesis on the left side. The cranial CT revealed the typical findings of a middle cerebral artery territory infarction of embolic origin, likely from previously unknown nonvalvular atrial fibrillation. The results of the duplex ultrasound of the carotid arteries were normal. Transesophageal echocardiography, however, showed a right atrial tumor, which suggested either thrombus or myxoma (Figure 1A, Movie I). No evidence of a thrombus or spontaneous echo contrast was observed in …

Resolution of clinical and MR abnormalities in sudden onset massive hypertensive brain stem edema.

Sirs: In patients with hypertensive encephalopathy (HE), a disturbance of the blood-brain-barrier and development of brain oedema is a well-recognised feature now frequently diagnosed with MRI. In a small subset of patients the infratentorial brain parenchyma may also be involved. Exclusive infratentorial HE with disturbances of vigilance (somnolence-coma) and other brain stem symptoms or signs has rarely been reported [4, 15]. We describe a patient with subacute development of severe neurological deficits along with gross abnormalities of the brain stem and midbrain on MRI and subsequent complete resolution of clinical and MRI findings within three weeks from onset of symptoms. A 57 year old man was brought to the emergency room with a history of limb weakness, gait unsteadiness and increasing lethargy for 2 weeks. On admission the patient was somnolent but fully orientated and co-operative. He appeared slow with a compromised ability to focus. His speech was slightly dysarthric and there was a flapping tremor in both hands. Examination revealed a systemic blood pressure of 255/110 mm/Hg. Fundoscopy was consistent with long-standing retinal arterial hypertensive disease. The ECG showed signs of cardiac hypertrophy. The remainder of his medical and neurological examination was unremarkable. CT (not shown) demonstrated ill-defined infratentorial structures. MRI showed grossly enlarged pontine tissue with symmetric T2hyperintensity in the medulla and the entire pons extending into the midbrain involving fibres of the internal capsule in a symmetrical pattern (Fig. 1). T2-hyperintensity seemed to respect some nuclear structures (e. g. dentate nucleus, the red nucleus) that were strongly contrasted against the bright T2 abnormality in the white matter. Diffusion weighted MRI (DWI) showed no corresponding hyperintensity but slight hypointensity and the apparent diffusion coefficient (ADC) was increased both in keeping with vasogenic oedema. On contrast enhanced MRI no pathological enhancement was present. Routine laboratory data revealed raised renal retention indicators (urea nitrogen 14.14 mmol/L, creatinine 284.8 μmol/L) and a slight leukocytosis (12.4 10E9/l). Investigations showed no indication of metabolic and hepatic encephalopathy, or signs of infection or autoimmune disease. CSF protein was slightly elevated (1.01 g/L) with a normal cell count. There was no evidence for CNS-specific oligoclonal bands or intrathecal production of immunoglobulins. CSFscreening for infectious agents was negative. The clinical findings were compatible with the diagnosis of anuric renal failure on the basis of untreated arterial hypertension. Within 12 hours the patient developed acute anuric renal failure. He was admitted to an intensive care unit, but medical control of hypertension was difficult, and was finally achieved by using a combination therapy (clonidine, amlodipine, metoprolole). Parallel to the signs of renal failure, his clinical condition deteriorated and he was intubated and ventilated for 3 days. At that point he was comatose, corneal reflexes were still present, oculocephalic reflexes were preserved, pupils were equal but did not react to light. Focal neurological signs such as hemiparesis or cranial nerve palsy remained absent. EEG revealed general slowing, brain stem evoked potentials and somatosensory evoked potentials were unremarkable. Over the next 7 days, renal parameters as well as neurological symptoms normalised gradually after 3 courses of haemodialysis. He regained consciousness on day three after admission. No underlying cause of arterial hypertension was identified. He was discharged with a normal neurological examination and a combination therapy of 5 antihypertensive agents (clonidine, amlodipine, metoprolole, ramiprile, torasemide, alphacalcidole). Follow-up MRI 3 weeks after admission demonstrated completely normal signal of infratentorial brain parenchyma. The massive medullary, brainstem and midbrain oedema and swelling had completely resolved (Fig. 2). Chronic periventricular symmetric T2-weighted hyperintense signal change at the anterior and posterior horns of the lateral ventricles remained. On the follow-up examination after 8 months, the patient had remained well without new symptoms or neurological signs. The unusual feature in this patient was the extensive and predominant involvement of posterior fossa brain tissue. Reversible white matter abnormalities in patients with hypertension, renal insufficiency, or in those receiving imLETTER TO THE EDITORS