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Biomedical subjects

J Schofer

Publications and source records attributed to J Schofer.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Does rotablation of complex coronary artery stenosis lower the risk of subsequent PTCA?].

To answer the question of whether pretreatment of complex coronary artery lesions via rotablation reduces the risk of subsequent PTCA, we compared the results of PTCA of 250 patients with Typ B- and C-lesions treated between April 1 and November 11 1991 (Group A) with a group of 437 patients treated between January 1 and May 1 1992 (Group B), for whom not only PTCA but also rotablation was available. Rotablation was successful in 102 of 119 procedures (85.7%), the rate of major complications was 1.8%. The primary success rate for treatment of all complex lesions was higher in group B (87.3%) in which 22.2% of the lesions were treated with the rotablator than in group A (83.1%). Dissection rate was similar in both groups (18.5% in group A, 17.5% in group B). In group B patients, however, dissections could be controlled more frequently by the use of a reperfusion catheter (21% vs 8.3% in group A). Serious complications caused by a dissection were not so often observed. In group B patients the rate of major complications due to dissection was lower (2.5% vs 4.4% in group A). In summary, pretreatment of complex coronary artery lesions via rotablation seems to increase the success rate of the following PTCA and to reduce its risks.

Adult↗
PubMed1993

Time course of left ventricular function and coronary patency after saruplase vs streptokinase in acute myocardial infarction. The PRIMI Trial Study Group.

As part of a prospective randomized double-blind trial (PRIMI) to study the early patency rate of the infarct-related artery after saruplase (INN for recombinant unglycosylated full-length human single-chain urokinase-type plasminogen activator) vs streptokinase in a subgroup of patients, left ventricular function was compared between both treatment groups at 90 min and 24 h after thrombolysis and at discharge, and ventricular function was related to the coronary perfusion grade. Despite a higher patency rate in the saruplase group 60 min after initiating thrombolysis, neither global ejection fraction nor hypokinesia at the infarct site were significantly different between the treatment groups at any of the three time points when function was measured. Hypokinesia at the infarct site remained almost equally severe throughout the study in patients with perfusion grade O, I, and II, and was consistently significantly milder in patients with perfusion grade III. In contrast, in patients with perfusion grade II there was a significant drop in hyperkinesia at the opposite wall at 24 h after thrombolysis and before discharge despite unchanged wall motion at the infarct site. Although patients treated with saruplase had a higher patency rate in the infarct related vessel shortly after the start of thrombolysis, no difference was found in left ventricular function compared to patients treated with streptokinase. Complete reperfusion (TIMI grade III) seems to be a prerequisite for left ventricular function recovery after thrombolysis, whereas only an occluded vessel (TIMI grade O and I) seems to be related to a longer lasting hyperkinesia at the opposite wall.

Double-Blind Method↗
PubMed1993

[Early hemostasis after coronary therapeutic interventions by using a collagen plug].

Significant bleeding at the puncture site is one of the most important problems in the care of patients undergoing interventional coronary procedures like PTCA, rotablation, laser angioplasty or stent implantation. This is due to systemic application of heparin, acetylic salicic acid and, in stent patients, even additional coumadine. Furthermore, the interventional systems implement catheter systems with a large inner and outer lumen leading to increased vessel trauma. To decrease the risk of bleeding and to reduce the time of pressure dressing and bed rest, a bovine collagen plug (VasoSeal) was used in 600 consecutive patients undergoing one of the above-mentioned interventional procedures. In the majority of patients (pts.) (474/600 = 79%) either no (404 pts.) or minimal (70 pts.) bleeding occurred. Bed rest could be reduced from more than 24 h to 6-12 h. In 65/600 pts. (11%) significant bleeding developed which could be controlled by compression. Bed rest in these patients was 13-20 h. Larger bleedings or complications occurred in 61/600 pts. (10.2%) and could be controlled conservatively in all but eight patients. One patient (0.2%) had a narrowing of the artery at the puncture site after the procedure, probably due to intraarterial plug application. In another patient (0.2%) embolization of the plug into the popliteal artery occurred which could be treated by embolectomy using a Fogarty-catheter. Arteriovenous fistulae or aneurysms developed in 8/600 pts. (1.3%) but these are no specific complications of the hemostatic device. The plug could not be placed in 13/600 pts. (2%), mainly in the beginning of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Early detection of coronary artery patency after thrombolysis by determination of the MM creatine kinase isoforms in patients with acute myocardial infarction. PRIMI Study Group.

To evaluate the role of MM creatine kinase isoforms in detecting infarct vessel patency in 84 patients with acute myocardial infarction, total creatine kinase, MB creatine kinase, and MM isoforms were determined at the start of thrombolytic therapy and 30, 60, and 120 minutes later. Enzyme data were related to the reperfusion grade of the infarct artery, which was assessed by angiography 60 and 90 minutes after the start of thrombolysis. In 50 patients the infarct vessel was found patent at 60 and at 90 minutes after thrombolysis; in 19 patients it was occluded at both time points. In contrast to the patients with a persistently occluded infarct artery, in the patient group with a patent infarct vessel total creatine kinase and MB creatine kinase increased significantly at 60 minutes after the start of thrombolysis and MM3 creatine kinase activity and the ratio MM3:MM1 had already increased at 30 minutes after the start of thrombolytic therapy. The increases from baseline of creatine kinase and creatine kinase MB activity were significantly higher 120 minutes after the start of thrombolysis; increases of creatine kinase MM3 and the ratio of MM3:MM1, however, by 60 minutes after the start of thrombolysis were already increased compared with the increases in enzyme activity in patients with an occluded artery. Thus the rise in MM3 creatine kinase and the ratio of MM3:MM1 can be used for early detection of reperfusion after intravenous thrombolytic therapy in acute myocardial infarction.

Adult↗
PubMed1992

[Increase in creatine kinase and its MM isoforms after successful and uncomplicated coronary angioplasty].

During successful and uncomplicated angioplasty (PTCA), we studied the effect of a short lasting myocardial ischemia on plasma creatine kinase, creatine kinase MB-activity, and creatine kinase MM-isoforms (MM1, MM2, MM3) in 23 patients. Eleven patients, in whom diagnostic coronary angiography was performed, served as the control group. Blood was sampled after PTCA and every 2 h for the next 12 h, and after 24 h. CK- and CK-MB activities were determined enzymatically, the MM-isoforms by isoelectric focussing. After PTCA total CK and CK-MM3 increased significantly from 23 +/- 10 to 40 +/- 31 U/I (p less than 0.01) and from 18 +/- 5 to 32 +/- 10% (p less than 0.0005), respectively. The ratio MM3:MM1 also increased significantly from 0.4 +/- 0.1 to 1.2 +/- 0.7 (p less than 0.0005). Enzyme maxima for CK-MM3 and the ratio MM3:MM1 were reached 6 h after PTCA, for total CK 10 h after PTCA. This increase was independent of changes in the ECG, of symptoms during PTCA, as well as of the number and duration of balloon inflations. In the control group no changes in enzyme activity were found. Thus, after uncomplicated PTCA a significant increase of total CK and CK-MM-isoforms can be found, which may be due to the short-lasting myocardial ischemia following coronary occlusion.

Angioplasty, Balloon, Coronary↗
PubMed1991

[Results of emergency bypass operation following percutaneous transluminal coronary angioplasty].

Between 1980 and 1988, percutaneous transluminal coronary angioplasty (PTCA) was performed in 1,514 patients. Fifty-five patients (3.6%) underwent emergency coronary bypass surgery because of an acute occlusion of the vessel or a dissection with sustained angina and signs of ischemia on the electrocardiogram. Twenty-five of these 55 patients had a myocardial infarction and 5 patients died, 3 perioperatively, 2 after hospital discharge. The degree of stenosis of the dilated vessel significantly influenced the incidence of infarction, while left ventricular ejection fraction prior to PTCA significantly influenced mortality. Patients who underwent surgery with an occluded vessel experienced myocardial infarction significantly more often (87%) than patients with a patent vessel (24%). The incidence of infarction was 27% when reperfusion of the vessel occluded during PTCA was achieved with a reperfusion catheter, repeated PTCA or intracoronary lysis. The patients' age, presence of unstable angina, left ventricular ejection fraction prior to PTCA, the dilated vessel, the extent of coronary artery disease, collateralization of the dilated vessel, and the time between the onset of the event necessitating bypass surgery and the beginning of extracorporeal circulation were found to have no influence on the incidence of infarction. Patients who died had a significantly lower ejection fraction before PTCA than survivors and all patients who died had experienced a large perioperative myocardial infarction.

Adult↗
PubMed1990

Prehospital thrombolysis in acute myocardial infarction.

The benefit and risk of prehospital thrombolysis for acute myocardial infarction (AMI) were evaluated in a double-blind randomized trial. Patients presenting less than 4 hours after symptom onset received 2 million units of urokinase as an intravenous bolus either before (group A, n = 40) or after (group B, n = 38) hospital admission. The mean time interval from onset of symptoms to thrombolytic therapy was 85 +/- 51 minutes in group A and 137 +/- 50 minutes in group B (p less than 0.0005). In 91% of the patients, thrombolytic therapy was administered less than 3 hours after symptom onset. Complication rates during the pre- and in-hospital period were low and did not differ between groups. Three patients died (1 in group A, 2 in group B) from reinfarction 7 to 14 days after admission. Left-sided cardiac catheterization before discharge revealed a patency rate in the infarct-related artery of 61% in group A and 67% in group B (difference not significant). Global left ventricular function and regional wall motion at the infarct site did not differ significantly between group A and B (ejection fraction 51 +/- 10%, n = 28 vs 53 +/- 14%, n = 28; wall motion -2.3 +/- 1.3 vs -2.2 +/- 1.1 standard deviation, respectively). Also, peak creatine kinase did not differ significantly (838 +/- 634 U/liter in group A vs 924 +/- 595 U/liter in group B). Prehospital thrombolysis using a bolus injection of urokinase has a low risk when performed by a trained physician with a mobile care unit. The saving of 45 minutes in the early stage of an acute infarction through prehospital thrombolysis did not appear to be important for salvage of myocardial function.

Ambulances↗
PubMed1990

[The thrombolysis treatment of acute myocardial infarct at the site of the emergency. A randomized double-blind study].

Two million units of urokinase were administered intravenously as a bolus, either before (group I, n = 40) or after hospital admission (group II, n = 38), to 66 men and 12 women (mean age 55 +/- 8 years) with typical symptoms of acute myocardial infarction of less than 4 hours' duration. Time elapsed between onset of symptoms and urokinase administration averaged 85 +/- 51 min for group I and 137 +/- 50 min for group II (P less than 0.005). The complication rate was low, both during the pre-hospital and the hospital phases, without any significant differences between the two groups. The rate of open infarct vessels (by angiography before discharge from hospital) was 61% for group I and 67% for group II (no significant difference). Global left ventricular function, regional wall motion in the infarct area and maximal creatinekinase values did not significantly differ between the two groups (ejection fraction 51 +/- 10% and 53 +/- 14%, respectively; creatinekinase 838 +/- 634 U/l and 924 +/- 595 U/l, respectively). The data indicate that thrombolytic pre-hospital treatment carried a low risk. The gain of 45 min, however, seems to be of secondary importance in any significant diminution of the acute infarction size.

Coronary Angiography↗
PubMed1990

Acute and long-term haemodynamic and neurohumoral response to nisoldipine vs captopril in patients with heart failure: a randomized double-blind study.

To study the haemodynamic and neurohumoral effects of nisoldipine (2 X 10 mg) vs captopril (3 X 25 mg), 24 patients with heart failure (New York Heart Association class II and III) due to coronary artery disease were treated in a randomized double-blind trial over 3 months. Both drugs were well tolerated. Clinical status was similarly improved in both groups, nisoldipine exerted an additional antiischaemic effect. Nisoldipine lowered the mean arterial pressure and capillary wedge pressure acutely and also after long-term treatment. The increase in cardiac index and stroke volume index, however, which was pronounced after acute administration, was no longer present after 3 months of therapy at rest and was abolished during exercise. Norepinephrine plasma concentration increased after the first dose, plasma renin activity did not change, and aldosterone plasma concentration showed a small insignificant decrease. Urine concentrations of norepinephrine and vasopressin were slightly elevated after the 3-month therapy. After captopril, mean arterial pressure and pulmonary capillary wedge pressure decreased acutely and at follow up. Cardiac index and stroke volume index increased significantly only during exercise at follow-up. Plasma renin activity was significantly elevated and aldosterone plasma concentration only slightly lowered. In contrast to what was seen with nisoldipine, plasma norepinephrine concentration and urine catecholamine and vasopressin concentrations remained unchanged. In conclusion, the pronounced haemodynamic effects seen after the first dose of nisoldipine are mostly abolished after long-term treatment, probably due to neurohumoral counterregulation. The haemodynamic response to captopril is complete only after long-term treatment, without evidence of activation of the neurohumoral systems.

Adult↗
PubMed1990

[Morphologic findings in dilated cardiomyopathy and their relation to hemodynamics and catecholamine concentrations in the plasma and myocardium].

In 72 patients with dilated cardiomyopathy the degree of morphological alterations were studied by transvenous endomyocardial biopsy. These findings were correlated to the clinical status, left ventricular ejection fraction, and to the catecholamine concentrations in plasma and myocardium. Muscle fiber diameter was negatively correlated to ejection fraction (r = -0.3, p = 0.02) and to the volume fraction of mitochondria (r = -0.32, p = 0.001). Between plasma norepinephrine concentration and ejection fraction a significant negative correlation was found (r = -0.37, p = 0.001). In contrast, myocardial norepinephrine concentration was positively correlated to ejection fraction (r = 0.25, p = 0.04). Between myocardial norepinephrine concentration and muscle fiber diameter a negative correlation was found (r = -0.46, p = 0.004). Patients with an EF of less than 30% and an EF of greater than 45% could be differentiated with an accuracy of 79%, when muscle fiber diameter, plasma norepinephrine concentration, and the density of capillary vessels were entered into a multi-variant analysis. In conclusion, dilated cardiomyopathy is associated with morphological alterations and alterations in plasma and myocardial catecholamine concentrations. Patients with highly reduced ventricular function could be best identified by the combined assessment of plasma catecholamine concentration, muscle fiber diameter, and density of capillary vessels.

Adult↗
PubMed1989

Digital flashing tomosynthesis (DFTS)--a technique for three-dimensional coronary angiography.

Digital Flashing Tomosynthesis (DFTS) represents a technique for three-dimensional (3D) coronary angiography. Four ECG-gated simultaneously flashed X-ray tubes generate a multiperspective digital substraction image as DFTS multiangiogram for 3D reconstruction and visualization. Computerized morphologic and morphometric quantitative analysis can be performed including videodensitometry. Postmortem coronary angiography of 30 human hearts with suspected coronary artery disease was performed by 35-mm cine technique and by DFTS. The results of angiographic measurements in 50 stenotic arterial segments were compared with the histologic reference and show excellent regression results with correlation coefficients of more than 0.95 (p less than or equal to 0.0001). No significant differences in standard errors of estimates between the techniques were found. DFTS yields an accuracy in depiction of the coronary arteries and angiographic estimation of arterial lumen equivalent to 35-mm cineangiography. DFTS images can be directly used for visual interpretation and for computerized morphologic and morphometric quantitative analysis. DFTS technology reduces the amount of radiation exposure, the amount of contrast medium, and the time of the procedure. DFTS offers the possibility to obtain 3D images of the coronary artery tree.

Aged↗
PubMed1989

Bleeding after thrombolysis in acute myocardial infarction.

232 consecutive patients with acute myocardial infarction were treated either with 2 x 10(6) IU urokinase as an intravenous bolus injection, or 250,000 IU streptokinase intracoronary, or 60 mg recombinant tissue-type plasminogen activator (rt-PA) over 90 min. All patients enrolled had chest pain for more than 30 min and less than 3 h before admission and a typical electrocardiogram. Contra-indications to thrombolytic treatment were absent. All bleeding complications occurring within 24 h after admission were assumed to be due to thrombolytic therapy. Bleeding complications occurred in 14 patients (6.5%). Only seven patients received a blood transfusion (3%). No correlation was evident between previous hypertension, diabetes mellitus, smoking, sex, age, fibrinogen level before and 24 h after thrombolytic therapy and bleeding complications. The risk of bleeding was not significantly different between the different thrombolytic regimens despite marked differences in the fall of the fibrinogen level. The decrease of fibrinogen following thrombolytic therapy did not influence the patency rate of the infarct vessel. Thrombolytic therapy in acute myocardial infarction is a safe treatment even among patients advanced in years and with medically controlled hypertension and diabetes mellitus, irrespective of the kind of thrombolytic treatment.

Female↗
PubMed1989

Impact of compensatory enlargement of atherosclerotic coronary arteries on angiographic assessment of coronary artery disease.

To determine whether compensatory enlargement of atherosclerotic coronary arteries occurs and to what degree it affects the angiographic assessment of coronary artery disease, we performed postmortem coronary angiography of 30 human hearts with suspected coronary artery disease and studied 70 histologic cross sections of the proximal left anterior descending artery and proximal right coronary artery. Angiographic and morphometric analyses of 50 stenoses in proximal and middle sections of the left anterior descending artery, right coronary artery, and left circumflex artery were performed. The control group of 10 human hearts without suspected coronary artery disease was evaluated in the same way. For this purpose, coronary arteries were filled with a methylmethacrylic radiopaque resin at a pressure of 100 mm Hg and closely embedded in a methylmethacrylic resin by use of which shrinkage and mechanical artifacts could be avoided. The area circumscribed by the internal elastic lamina was taken as a measure of the area of the arterial lumen if no plaque had been present. The angiographic and corresponding morphometric degree of stenosis was assessed. A significant correlation (r = 0.85, p less than or equal to 0.0001) was found between the internal elastic lamina area and the area of the plaque (lesion area), suggesting that coronary arteries may enlarge as lesion area increases. With the morphometric degree of stenosis, the expected anatomic diminution of the coronary artery was abolished (r = 0.79, p less than or equal to 0.0001), indicating compensatory enlargement in atherosclerotic segments. Accordingly, the degree of stenosis assessed from in vitro angiograms was underestimated. Compensatory coronary enlargement of the stenotic segment was the main reason for angiographic underestimation. The underestimation factor of up to 3.50 for very mild stenoses decreased to 1.37 at an angiographic degree of 50% area stenosis and 30% diameter stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Catheter atherectomy: functional results in peripheral arterial disease.

In 10 patients with peripheral arterial disease (PAD) atherectomy was performed with the Simpson atherectomy catheter. PAD was diagnosed by clinical evaluation, oxzillography, Doppler ultrasound examination, treadmill walking, and angiography. Eight patients belonged to stage II and 2 to stage IV. Two stenoses were located in the iliac artery, and the others in the superficial femoral artery or popliteal artery or both. The treadmill walking distance before the intervention ranged from 24 to 67 m before and 105 to 115 m after the procedure (speed 2 mph; gradient 12.5%). After atherectomy, the walking distance improved by 35% to 126%. No patient in stage II perceived pain. In these patients treadmill exercise was terminated because of dyspnea. The ankle/arm ratio (Doppler ultrasound) ranged from 0.4 to 1.0 before atherectomy with a mean improvement of 0.15 afterward (stages II and IV). Control angiography within three to six months in 4 patients did not reveal any significant change at the site of the original stenosis.

Aged↗
PubMed1989

[Myocardial noradrenaline content: a factor not considered up to now for the prognosis of patients with dilated cardiomyopathy].

To evaluate the prognosis of patients with idiopathic dilated cardiomyopathy (EF less than 50%) in 55 patients the myocardial catecholamine concentration, plasma catecholamine concentration, and left ventricular ejection fraction were determined. The follow-up time ranged from 7 to 47 months. At the time of follow-up 10 of the 55 patients (group A) had died and three had undergone hearttransplantation. Group A patients had a significant lower EF (27 +/- 10 vs 36 +/- 9%, p less than 0.03), a lower myocardial norepinephrine (254 +/- 168 vs 579 +/- 416 pg/mg, p less than 0.007), higher plasma norepinephrine (640 +/- 333 vs 372 +/- 254 pg/ml, p less than 0.008) and plasma epinephrine (391 +/- 340 vs 116 +/- 81 pg/ml, p less than 0.006) in comparison to patients, who were still alive and not transplanted (group B). Survival was significantly lower in patients with an EF less than 30%, a plasma norepinephrine concentration greater than 350 pg/ml, a plasma epinephrine concentration greater than 125 pg/ml, and a myocardial norepinephrine content less than 400 pg/mg. Cox regression analysis revealed that the ratio of plasma vs myocardial norepinephrine was the best prognostic indicator for patients with an EF less than 30% and this ratio plus the plasma norepinephrine concentration were the best prognostic indicators for the whole group of patients. These data suggest that myocardial norepinephrine content is an important prognostic factor in patients with idiopathic dilated cardiomyopathy.

Adult↗
PubMed1988

[Lysis treatment of left ventricular thrombi. Acute and long-term results].

Intravenous thrombolysis with urokinase (60,000 U/h) was undertaken in 15 patients with large thrombi in the left ventricle (demonstrated by echocardiography) after myocardial infarction. Complete lysis was achieved in ten, partial in four. None had post-thrombolysis signs of arterial emboli, two patients developed haematuria and one had partial separation of the thrombus which required operative removal. Four patients who had a mean ejection fraction of 37 +/- 12% had died a sudden cardiac death within six months of the thrombolysis. Nine patients survived for up to four years without recurrence of thrombi: seven of them had been treated with aspirin (acetylsalicylic acid), two with coumarin derivatives. Two patients could not be followed-up. These preliminary results suggest that large left-ventricular thrombi can be successfully lysed by intravenous thrombolysis without significant complications, probably without recurrent thrombi.

Adult↗