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Biomedical subjects

H J Rupprecht

Publications and source records attributed to H J Rupprecht.

At least 19 recordsLinked to original sources
PubMed1999

[Nicorandil: acute hemodynamic effects of 2 different oral doses of a potassium channel opener in patients with coronary heart disease].

BACKGROUND: In medical treatment of angina pectoris the 3 major groups of antianginal agents are nitrates, beta blockers and calcium antagonists. Now a new class of drugs is introduced in the therapy: the potassium channel openers. One of the first potassium channel openers is nicorandil. We examined the acute hemodynamic effects of 2 different oral nicorandil doses in patients with coronary heart disease. PATIENTS AND METHODS: Twenty patients with angiographic proven coronary heart disease and stable angina pectoris were treated with a dose of 2 x 10 mg Nicorandil on day 1 and 2 x 20 mg Nicorandil on day 2, while being hemodynamically monitored on an intensive care unit with a pulmonary artery catheter. RESULTS: Through the hemodynamic monitoring a dose dependent, significant reduction of systolic blood pressure was found (6%/9%), while the heart rate increased dose dependently (6%/11%). The rate pressure product as a marker of myocardial oxygen demand did not increase significantly. CONCLUSION: The oral application of nicorandil causes an acute, dose dependent, significant decrease in systolic blood pressure and induces a reflextachycardia.

Administration, Oral↗
PubMed1998

Coronary-artery stenting compared with balloon angioplasty for restenosis after initial balloon angioplasty. Restenosis Stent Study Group.

BACKGROUND: Intracoronary stenting reduces the rate of restenosis after angioplasty in patients with new coronary lesions. We conducted a prospective, randomized, multicenter study to determine whether intracoronary stenting, as compared with standard balloon angioplasty, reduces the recurrence of luminal narrowing in restenotic lesions. METHODS: A total of 383 patients who had undergone at least one balloon angioplasty and who had clinical and angiographic evidence of restenosis after the procedure were randomly assigned to undergo standard balloon angioplasty (192 patients) or intracoronary stenting with a Palmaz-Schatz stent (191 patients). The primary end point was angiographic evidence of restenosis (defined as stenosis of more than 50 percent of the luminal diameter) at six months. The secondary end points were death, Q-wave myocardial infarction, bypass surgery, and revascularization of the target vessel. RESULTS: The rate of restenosis was significantly higher in the angioplasty group than in the stent group (32 percent as compared with 18 percent, P= 0.03). Revascularization of the target vessel at six months was required in 27 percent of the angioplasty group but in only 10 percent of the stent group (P=0.001). This difference resulted from a smaller mean (+/-SD) minimal luminal diameter in the angioplasty group (1.85+/-0.56 mm) than in the stent group (2.04+/-0.66 mm), with a mean difference of 0.19 mm (P=0.01) at follow-up. Subacute thrombosis occurred in 0.6 percent of the angioplasty group and in 3.9 percent of the stent group. The rate of event-free survival at 250 days was 72 percent in the angioplasty group and 84 percent in the stent group (P=0.04). CONCLUSIONS: Elective coronary stenting was effective in the treatment of restenosis after balloon angioplasty. Stenting resulted in a lower rate of recurrent stenosis despite a higher incidence of subacute thrombosis.

Aged↗
PubMed1998

Randomized evaluation of anticoagulation versus antiplatelet therapy after coronary stent implantation in high-risk patients: the multicenter aspirin and ticlopidine trial after intracoronary stenting (MATTIS).

BACKGROUND: Although the association of ticlopidine and aspirin has been shown to be superior to anti-vitamin K agents and aspirin after coronary stent implantation in low-risk patients, the latter combination has remained an unproven reference regimen for high-risk patients until recently. METHODS AND RESULTS: We randomized 350 high-risk patients within 6 hours after stent implantation to receive during 30 days either aspirin 250 mg and ticlopidine 500 mg/d (A+T group) or aspirin 250 mg/d and oral anticoagulation (A+OAC group) targeted at an international normalized ratio of 2.5 to 3. The primary composite end point was defined as the occurrence of cardiovascular death, myocardial infarction, or repeated revascularization at 30 days. Patients were eligible if (1) the stent(s) were implanted to treat abrupt closure after PTCA; (2) the angiographic result after implantation was suboptimal; (3) a long segment was stented (>45 mm and/or >/=3 stents); or (4) the largest balloon inflated in the stent had a nominal diameter of </=2.5 mm. The primary cardiac end point was reached for 10 patients (5.6%) in the A+T group and 19 (11%) in the A+OAC group (relative risk [RR], 1. 9; 95% CI, 0.9 to 4.1; P=0.07). Major vascular and bleeding complications were less frequent in the A+T group (3 patients, 1.7%) than in the A+OAC group (12 patients, 6.9%) (RR, 4.1; 95% CI, 1.2 to 14.3; P=0.02). CONCLUSIONS: High-risk patients should be treated with A+T rather than A+OAC after coronary stenting because the bleeding and vascular complications are significantly reduced and there is a marked trend suggesting a decrease in cardiac events.

Adult↗
PubMed1998

Comparison of antiplatelet effects of aspirin, ticlopidine, or their combination after stent implantation.

BACKGROUND: This study was performed to analyze the influence of either aspirin, ticlopidine, or their combination on platelet activation and aggregation parameters after stent implantation. METHODS AND RESULTS: Sixty-one patients with successful implantation of a single Palmaz-Schatz stent in a native coronary artery were randomly assigned to either group A (aspirin 300 mg/d+ticlopidine 2X250 mg/d), group B (ticlopidine 2X250 mg/d), or group C (aspirin 300 mg/d). Platelet activation was evaluated on days 1, 7, and 14 by flow cytometry measurement of expression of CD62p (p-selectin) and the binding of fibrinogen to the platelet surface glycoprotein IIb/IIIa receptor. Platelet aggregation was induced by addition of ADP or collagen. Differences between treatment groups were compared by ANOVA. Between days 1 and 14, we observed a significant decrease in collagen-induced platelet aggregation in group A (62.2+/-2.5% versus 36.9+/-3.1%), whereas an increase was seen in group B (58.3+/-2.5% versus 67.7+/-3.2%) and no change was seen in group C (P<.0001). The ADP-induced aggregation declined significantly in group A (74.7+/-1.4% versus 55.3+/-2.6%), whereas a delayed reduction was seen in group B (72.0+/-3.0% versus 52.6+/-4.2%) and no change was seen in group C (P=.0017). The CD62p expression declined significantly in groups A (68.2+/-2.7% versus 41.3+/-2.7%) and B (64.8+/-2.9% versus 39.3+/-3.5%) but not in group C (P<.0001). Moreover, the fibrinogen binding decreased significantly in group A (61.0+/-4.3% versus 36.3+/-4.2%) and with delay in group B (58.3+/-2.2% versus 39.4+/-3.0%), whereas no alterations were seen in group C (P=.012). CONCLUSIONS: Our results demonstrate synergistic and accelerated platelet inhibitory effects of ticlopidine plus aspirin in patients after stent implantation compared with a monotherapy with either ticlopidine or aspirin alone.

Angioplasty, Balloon, Coronary↗
PubMed1998

Impact of routine angiographic follow-up after angioplasty.

BACKGROUND: There is an ongoing controversy as to whether repeat coronary angiography should be routinely performed after successful percutaneous transluminal coronary angioplasty (PTCA). METHODS: We examined the 10-year outcome in 400 patients who had or had not undergone an angiographic control 6 months after successful PTCA and a subsequent event-free 6-month period. Our comparison was based on data gathered by questionnaire and telephone interview in 315 patients with (group A) and 85 patients without (group B) a routine 6-month angiographic control. Multivariate analysis (Cox model) was performed to identify predictors of adverse events. RESULTS: During the 10-year follow-up period, 22 (7%) of the 315 patients in group A died, compared with 16 (19%) patients in group B (P= .003). In groups A and B, respectively, acute myocardial infarction occurred in 28 (9%) and 10 (12%) patients (not significant [NS]); coronary artery bypass grafting (CABG) was performed in 42 (13%) and 14 (16%) patients (NS); repeat PTCA was performed in 89 (28%) and 11 (13%) patients (P= .012); and serious adverse events (death, myocardial infarction, CABG) occurred in 76 (24%) and 32 (38%) patients (P= .02). Absence of a 6-month angiographic follow-up was identified as an independent predictor of death associated with a 2.7 times higher mortality rate during the 10-year follow-up period. Previous myocardial infarction increased the risk of death 2.5 times. Any increase of residual diameter stenosis by 10% was combined with a 1.4 times higher mortality rate. The chance of bypass surgery was higher in patients with multivessel disease (2.9 times), in patients with unstable angina (2.1 times), and in case of an increase of residual diameter stenosis by 10% (1.3 times). No predictor for the risk of myocardial infarction was found. Angiographic follow-up increased the likelihood of PTCA 2.5 times. CONCLUSIONS: A routinely performed angiographic control 6 months after successful PTCA is associated with a significantly higher rate of repeat PTCA but, most important, is correlated with a significantly lower mortality rate during the 10-year follow-up period.

Adult↗
PubMed1998

Transesophageal ultrasonographic imaging in rat hearts: visualization of aortic valve vegetations in non-bacterial thrombotic endocarditis.

The aim of this study was to test the feasibility of transesophageal ultrasonography in rats by using an intravascular ultrasound system for visualization of vegetations at the aortic valve in the animal model of experimental endocarditis. After anesthesia and preparation of the right carotid artery, a polyethylene catheter was advanced across the aortic valve into the left ventricle in 91 rats. For transesophageal ultrasonography an intravascular ultrasound catheter (3.5 French; 30 MHz) linked to an imaging system was introduced into the esophagus. Sonographic investigations were performed every 24 hours until death. The presence, size, and echogenicity of vegetations were evaluated. Presence and size were compared to autopsy findings. No complications occurred as a result of the sonographic investigation. Left-sided valvular structures were imaged regularly. For detection of vegetations, sensitivity and specificity were 93% and 88%, respectively. Comparing the measurements of the vegetation size the following regression equation was obtained: y = 0.74x + 0.04 (r = 0.89; standard error of estimate = 0.02 cm). Inter- and intraobserver variabilities for sonographic measurements were 8.3% and 6.2%, respectively. Transesophageal ultrasonography permits reliable detection and repetitive accurate quantification of vegetations in the rat model of endocarditis. The technique enhances longitudinal studies of the dynamic process of the growth of vegetations under defined microbial conditions.

Animals↗
PubMed1998

In vitro examination of the coronary artery wall after balloon angioplasty using intracoronary ultrasound.

After autopsy 12 human coronary arteries were investigated by intracoronary ultrasound in order to measure the vessel wall dimensions and to detect damage on the vessel wall architecture after balloon angioplasty. Histology revealed artherosclerosis in 11/12 arteries. A total of 41 representative coronary segments were selected for further off-line ultrasound and histological analysis. Intracoronary ultrasound and histological measurements of the vessel wall thickness after balloon dilatation demonstrated a good correlation between the maximum thickness of the intima (histology 0.62 mm vs. intracoronary ultrasound 0.65 mm, r = 0.87) and the intima-media complex (0.80 mm vs. 0.83 mm, r = 0.87), in contrast to a weak one between the minimum thickness (r = 0.46 and r = 0.37). A total of 21 cases of damage occurred during angioplasty; intracoronary ultrasound detected 17. Further analysis showed that it imaged 10 of 11 cases of damage involving more than 30 degrees of the vessel circumference and 7 of 10 cases of damage involving less than 30 degrees of the vessel circumference. After balloon angioplasty of diseased coronary arteries, intracoronary ultrasound is therefore reliable in measuring the maximum wall thickness and in imaging damage involving more than 30 degrees of the vessel wall circumference.

Angioplasty, Balloon↗
PubMed1998

Impact of restenosis 10 years after coronary angioplasty.

AIMS: The aim of the study was to compare the 10-year follow-up results of patients with or without restenosis following single-vessel percutaneous transluminal coronary angioplasty (PTCA). METHODS AND RESULTS: A total of 313 patients with successful PTCA (> or = 20% reduction in luminal diameter narrowing without acute complications) and a control angiography 6 months after PTCA were included in the study. Events during the follow-up period were defined as death, myocardial infarction, bypass surgery, or repeat PTCA. Statistical evaluation was performed by the Fisher test, logistic regression, and life-table analysis. Restenosis (loss of > 50% of the initial gain and diameter stenosis of 50%) was found in 87 (28%) patients. During follow-up, 11 patients (5%) without restenosis (group A) and 11 (13%) patients with restenosis (group B) died (P < 0.05). In group A, 17 (8%) patients and in group B, 11 (13%) patients suffered myocardial infarction (ns); 17 group A (8%) patients and 25 (29%) group B patients had bypass surgery (P < 0.0001), and 34 (15%) group A patients and 55 (63%) group B patients underwent repeat PTCA (P < 0.0001). Logistic regression analysis identified restenosis as an independent risk factor that increases the risk of death 2.8-fold (P = 0.02), bypass surgery 5.6-fold (P < 0.0001), and repeat PTCA 10-fold (P < 0.0001). CONCLUSION: We conclude that patients with restenosis had a poorer long-term outcome than patients without restenosis. Although most patients with restenosis underwent repeat PTCA, the survival rate without any serious adverse events was only 59%, compared with 83% in patients without restenosis (P < 0.0001).

Adult↗
PubMed1997

Intracoronary application of C1 esterase inhibitor improves cardiac function and reduces myocardial necrosis in an experimental model of ischemia and reperfusion.

BACKGROUND: Myocardial injury from ischemia can be aggravated by reperfusion of the jeopardized area. The precise underlying mechanisms have not been clearly defined, but proinflammatory events, including complement activation, leukocyte adhesion, and infiltration and release of diverse mediators, probably play important roles. The present study addresses the possibility of reducing reperfusion damage by the application of C1 esterase inhibitor (C1-INH). METHODS AND RESULTS: Cardioprotection by C1-INH 20 IU/kg IC was examined in a pig model with 60 minutes of coronary occlusion, followed by 120 minutes of reperfusion. C1-INH was administered during the first 5 minutes of coronary reperfusion Compared with the NaCl controls, C1-INH reduced myocardial injury (48.8 +/- 7.8% versus 73.4 +/- 4.0% necrosis of area at risk, P < or = .018). C1-INH treatment significantly reduced circulating C3a and slightly attenuated C5a plasma concentrations. Myocardial protection was accompanied by reduced plasma concentration of creatine kinase and troponin-T. C1-INH had no effect on global hemodynamic parameters, but local myocardial contractility was markedly improved in the ischemic zone. In the short-axis view, 137 degrees of the anteroseptal region showed significantly improved wall motion at early and 29 degrees at late reperfusion with C1-INH treatment. CONCLUSIONS: C1-INH significantly protects ischemic tissue from reperfusion damage, reduces myocardial necrosis, and improves local cardiac function.

Anaphylatoxins↗
PubMed1997

[Effect of qualitative stenosis characteristics on the quality of measurements of various QCA systems].

Reproducibility and accuracy of in vitro measurements are very high using recently developed QCA systems. We analyzed the impact of lesion characteristics ad the image quality on the quality of measurements under clinical conditions. For the study we selected 57 coronary artery lesions which had a clinically relevant distribution for stenosis severity, lesion characteristics, and image quality. Every effort was made to eliminate procedural sources of error. Three investigators measured each lesion five times with each of three QCA systems (AWOS, Cardio and CMS). Only the measurements of the minimal stenosis diameter were analyzed. The precision of all the measurements was high with the AWOS (0.04 mm), the Cardio (0.05 mm), and the CMS systems (0.06 mm). Variability of measurements increased for the following criteria: Ambrose-III morphology (CMS 0.082 mm), surface irregularities (Cardio 0.069 mm, CMS 0.073 mm), TIMI I (Cardio 0.084 mm, CMS 0.0121 mm), and moderate image quality (CMS 0.07 mm). There were no differences in the precision of the measurements in the other groups of lesion characteristics. There were no relevant differences in any of the measurements between the systems (AWOS-Cardio -0.07 mm, AWOS-CMS-0.11 mm, Cardio-CMS-0.04 mm). Smaller diameters were measured with the AWOS system than with the CMS and the Cardio systems when the lesion was calcified (AWOS-Cardio-0.109 mm, AWOS-CMS-0.161 mm). This was only a trend, however, and did not reach statistical significance, which was also true for the other differences found between the systems according to various lesion characteristics. In summary, we found that the measurement quality of the QCA systems used in this study is not altered by the underlying lesion characteristics or the image quality.

Coronary Angiography↗
PubMed1997

[Clinical value of Doppler ultrasound controlled puncture of the inguinal vessels with the "Smart Needle" within the scope of heart catheter examination].

Due to the increasing number of diagnostic heart catheterizations, especially in elderly patients, as well as the increase of percutaneous transluminal coronary angioplasties, we are confronted with a rise in peripheral complications evolving from difficulties in the procedure of the puncture of the femoral artery or vene. The development of greater hematomas in the area of the puncture, the formation of arterio-venous fistulas and aneurysma spuria are the foremost complications. It was the aim of the study to investigate in as far an improved puncture technique could reduce the rate of peripheral complications. In this comparative study the vessel punctures were carried out by the conventional Judkins puncture technique and a new method using a special puncture needle. (Smart Needle" R), with an integrated ultrasonic sound device. In this study 114 patients--age 23 to 82 years--undergoing heart catheterization (91 diagnostics, 23 PTCAs) were examined. In all cases a puncture of the arterial and venous femoral vessel was done. 50 patients received a puncture via "Smart Needle" and the remaining 64 patients were punctured conventionally. In contrast to the group of patients receiving conventional puncture of the femoral artery, where in 72% more than one try was needed, in all patients of the "Smart Needle" group the first puncture was successive. Concerning the puncture of the venous vessels no significant difference between the two groups was observed. This difference between arterial and venous puncture outcome results from the difference between arterial and venous flow signals detected by the ultrasonic sound device. As to the bleeding complications hematomas following to "Smart Needle" puncture occurred less frequently-in 25%--and were significantly smaller than in the conventional group where hematomas were seen in 46%. The number of patients with hematomas with diameters of more than 5 cm was twice as high in the conventionaly punctured group (28%) than in the "Smart Needle" group (14%). However, patients suffering from arterial hypertension or hemostatic disorders showed an increased risk of vascular complications. In regard to the cost-benefit relation an indication for the use of the new technique is to be seen especially in overweight patients and patients suffering to aortic stenosis or cardiogenic shock.

Adult↗
PubMed1997

[Quantitative effect of a standardized pressure bandage on arterial and venous circulation in the lower extremities after heart catheter examination].

AIM: The aim of the study was to evaluate the effect of a conventional pressure dressing on arterial and venous blood flow of the legs after cardiac catheterization. METHODS: Duplexsonographic measurements were performed of both legs in 100 consecutive patients before catheterization and with a pressure dressing after the procedure. The pressure dressing was applied by means of a pressure pad on the punctured leg, so that the ankle-arm-index (blood pressure at the leg/blood pressure at the arm) was not influenced. Arterial and venous blood flow of the superficial femoral artery and vein were registered. We evaluated both legs by means of duplex sonography to detect arterial or venous complications after cardiac catheterization. Statistical evaluation was performed using the 1-sample Wilcoxon test. RESULTS: There was a significant reduction of venous blood flow in the punctured leg from a mean of 119 ml/min before puncture to 84 ml/min during pressure dressing (29% flow reduction, p < 0.01), and a reduction of arterial blood flow from a mean of 132 ml/min before puncture to 84 ml/min during pressure dressing (36% flow reduction, p < 0.01). In the contralateral leg, venous blood flow was reduced from about 118 ml/min to 96 ml/min during pressure dressing (19% flow reduction, p < 0.01), and arterial blood flow was reduced from about 129 ml/min to 93 ml/min during pressure dressing (28% flow reduction, p < 0.01). There were no venous complications, 5 patients suffered false aneurysm (5%), and one patient had an arteriovenous fistula (1%). CONCLUSION: A conventional pressure dressing caused a significant reduction of arterial as well as venous blood flow of both the punctured leg and the contralateral leg. This is of clinical relevance especially in patients with known peripheral arterial disease or patients at risk for deep venous thrombosis.

Adult↗
PubMed1997

Transthoracic three-dimensional echocardiographic volumetry of distorted left ventricles using rotational scanning.

The purpose of this study was to evaluate the relation of transthoracic three- and two-dimensional echocardiographic left ventricular volumetry to cineventriculographic volumetry. Twenty-five patients with distorted left ventricles were included in the study. To demonstrate the impact of acquiring data by rotational scanning, we performed three- and two-dimensional echocardiography in 36 latex ventricles with data acquisition in different areas of the ultrasound sectors. Interobserver and intraobserver variability were calculated to test for reproducibility. The three-dimensional imaging system consisted of a rotation motor device, a transthoracic 2.5 MHz transducer, a conventional ultrasound unit, and a work-station (TomTec) which provides data acquisition, post-processing, and two- or three-dimensional visualization of digitized data. The transducer moved automatically at 2-degree increments with data acquisition at each tomographic level. The mean investigation time for three-dimensional echocardiography was 21 +/- 6 minutes. In the central near field of the transducer, differences from true volumes in latex ventricles were remarkably smaller for three-dimensional compared with two-dimensional echocardiography (root mean square percent error: three-dimensional echocardiography = 5.3% versus two-dimensional echocardiography = 14.6%). In three-dimensional echocardiography, there was considerable overestimation of volumes in the lateral far field (root mean square percent error = 13.2%) of the ultrasound sector. Differences between two-dimensional echocardiographic human left ventricular volumes and cineventriculography increased with larger volumes. In three-dimensional echocardiography the differences remained constant. Interobserver and intraobserver variability is reduced nearly twofold by three-dimensional echocardiography. Three-dimensional echocardiographic volumetry provides fewer discrepancies to cineventriculography and lesser variability than two-dimensional echocardiography. With the use of rotational scanning, the ventricle has to be positioned in the central near field of the transducer.

Adult↗
PubMed1997

Comparison of QCA systems.

AIMS: Excellent agreement between different 'second generation' systems for quantitative coronary arteriography (QCA) has been found in in vitro measurements. To verify the quality and stability of QCA when used in clinical practice, three QCA systems (AWOS, Cardio, and CMS) were used in a representative set of coronary artery lesions. METHODS AND RESULTS: This set consisted of angiographic stenosis images of 57 patients which varied in stenosis severity and morphology. The process of image acquisition, calibration, and measurement was strictly standardized to eliminate procedural sources of error. Three observers performed QCA five times in each lesion with each QCA system. Interobserver variability was low (Dnorm 0.01-0.05 mm, Dmin 0.01-0.02 mm, %stenosis 0.3-0.7%). Values of system precision were excellent (Dnorm 0.11-0.13 mm, Dmin 0.04-0.06 mm, %stenosis 2.1-2.6%). Comparison of measurements between three QCA systems revealed good agreement (range of mean differences for Dnorm 0.03-0.12 mm, Dmin 0.04-0.11 mm, and %stenosis 0.5-3.6%) and high correlation (corr 0.902-0.977). There was a tendency to measure smaller values for Dmin and consequently to identify more severe stenoses with the AWOS system than with the Cardio and CMS systems. All QCA results were compared to measurements done with the Brown Dodge method to reveal failure of the QCA measurements. These results showed excellent agreement without any systematic deviation (mean differences for Dnorm 0.01-0.08 mm, Dmin 0.02-0.06 mm, and %stenosis 1.3-1.8%). None of the differences were statistically significant. CONCLUSION: We therefore conclude that using the defined version of the AWOS, Cardio, and CMS systems, there is no difference in precision or accuracy when used for QCA of coronary artery lesions.

Algorithms↗
PubMed1997

Tissue Doppler echocardiography: a new method of evaluating perfusion-dependent myocardial function during PTCA.

The increasing demand for insight into the relationship between coronary perfusion and myocardial function stimulated the development of tissue Doppler echocardiography. This new technique was applied simultaneously with PTCA of a subtotal LAD lesion (single vessel disease, no collaterals) in a 68-year-old patient suffering from unstable angina pectoris. Prior to the conventional signs of ischaemia a decrease in myocardial tissue velocities and a loss of color-coded heart cycle intervals was observed. A myocardial velocity gradient calculated from the higher subendocardial and lower subepicardial velocity decreased from 3.3 to 1.3. This decrease was prevented by an active autohaemoperfusion device which supplied blood distally to an insufflated balloon (60 ml/min). Thus, contractility and viability might be maintained by preserving myocardial velocity gradients.

Aged↗