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Biomedical subjects

H W Höpp

Publications and source records attributed to H W Höpp.

At least 19 recordsLinked to original sources
PubMed2001

[Angiographically unexplained myocardial ischemia in high grade coronary stenosis with main stem involvement in intravascular ultrasound].

HISTORY AND ADMISSION FINDINGS: For seven weeks a 57-year-old man had been complaining of recurrent non-radiating retrosternal pain and pressure on slightest exertion. Admission physical examination was unremarkable except for evidence of peripheral vascular disease. Cardiovascular risk factors were hypertension, hyperlipoproteinaemia and obesity. INVESTIGATIONS: The resting ECG was unremarkable. Objective signs of myocardial ischaemia were produced in the exercise ECG (angina at 100 Watt, negative T waves in V2 to V6 and borderline S-T depression in V4). Myocardial scintigraphy showed reversible reduced perfusion of the anterior wall near the apex and also of the apex and septum. Left ventricular (LV) angiography demonstrated a normally contracting LV, while selective coronary angiogram revealed a 20% reduction in caliber of the proximal branch of the anterior interventricular branch (AIVB), with otherwise normal coronary arteries. Subsequent intravascular ultrasound (IVUS) showed a circular echo-poor 80% stenosis at the origin of the AIVB with extension to the main stem. TREATMENT AND COURSE: A bypass from the internal mammary artery to the AIVB and an aortocoronary venous bypass to the intermediate branch were performed. The patient was free of symptoms postoperatively. CONCLUSION: If cases where there is a discrepancy between clinical and coronary angiographic findings--the latter being unclear or inconsistent, especially in the area of the left main stem, bifurcations or vessel origin--IVUS may contribute decisively to demonstrating coronary anatomy or pathology, and to indicating the type of revascularizing measures.

Coronary Angiography↗
PubMed2001

Vascular remodeling in atherosclerotic coronary arteries is affected by plaque composition.

BACKGROUND: Narrowing of lumen in atherosclerotic lesions is determined not solely by accumulation of plaque but also by constrictive or expansive vascular remodeling. Underlying mechanisms and determinants of these bidirectional processes are not known. OBJECTIVES: To elucidate the response of vascular remodeling to progressive atherosclerosis by analyzing its potential association with composition of plaque. METHODS: Seventy patients with 77 de-novo coronary artery lesions underwent intravascular ultrasound imaging before coronary intervention. Target lesions were defined as soft, fibrous/mixed, and calcified plaques. Quantitative measurements of area of lumen (A(L)), total area of vessel (A(TV)) and area of plaque (A(P) = A(TV)-A(L)) were performed at the lesion site and at the proximal and distal reference sites. Remodeling was determined by using a remodeling index [I(R) = (stenosis of A(TV)/mean reference A(TV)) x 100]. RESULTS: Overall vascular remodeling was balanced with a mean remodeling index of 100.2+/-19.3% and a high interlesion range (60.2-152.4%). The remodeling index for soft lesions was significantly higher than those for fibrous/mixed and calcified lesions (110+/-18.8 versus 96.2+/-14.4 and 85.9+/-15.1%, P < 0.01). Calcified lesions exhibited lower remodeling indexes than did uncalcified lesions (85.9+/-15.1 versus 104.6+/-18.4%, P < 0.01). CONCLUSIONS: Processes involved in vascular remodeling are affected by composition of plaque insofar as there is a higher prevalence of constrictive remodeling among calcified plaques and a higher prevalence of expansive remodeling among soft lesions. These findings indicate that constrictive remodeling is a late manifestation in atherogenesis. Future studies are warranted in order to enhance the understanding of progression of atherosclerosis, and of mechanisms of vascular remodeling and their impacts on interventional therapy.

Coronary Artery Disease↗
PubMed2000

A synergistic approach to optimal stenting: directional coronary atherectomy prior to coronary artery stent implantation--the AtheroLink Registry. AtheroLink Study Group.

OBJECTIVES: The AtheroLink registry sought to observe the effect of plaque burden reduction by directional coronary atherectomy (DCA) prior to stenting on acute lesion success rate, on the clinical success rate and on the incidence of in-stent restenosis six months after intervention. BACKGROUND: Although coronary stenting has reduced restenosis, its effect has been less favorable in complex lesions with a high plaque burden that results from suboptimal stent expansion. Therefore, plaque removal by DCA may improve the results of coronary stenting. METHODS: A total of 167 patients with >60% stenosis in a native coronary artery of 2.8 to 4.0 mm in diameter were enrolled in 10 study centers on an intention-to-treat basis. All patients underwent DCA aimed at an optimal result (residual diameter stenosis <20%) followed by stenting. Angiographic follow-up was performed in 120 (71.8%) patients at 5.3+/-2.8 months. RESULTS: Lesion success was achieved in 164/167 (98.2%) patients, and the clinical success rate was 95.2% (159/167 patients). The overall restenosis rate in the 120 patients with angiographic follow-up was 10.8% (13/120). Incidence of restenosis was lower (8.4%) in patients with optimal stent deployment following DCA compared to patients with a persisting caliber reduction >15% (restenosis rate 15.3.%) and restenosis occurred with a significantly higher frequency (p<0.04) in distal lesions (37.5%) compared to proximal stenoses (9.0%). CONCLUSIONS: This observational multicenter registry points to a potential reduction in restenosis by a synergistic approach of DCA and stenting performed under routinely accessible angiographic guidance. Therefore, multicenter-based randomized clinical trials are clearly warranted to finally clarify the validity of this complex approach versus conventional angioplasty plus stenting.

Aged↗
PubMed2000

In vivo uptake of azithromycin in human coronary plaques.

Ten patients with symptomatic coronary artery disease received oral azithromycin for 3 days and underwent directional atherectomy on the third day. Azithromycin was found in all plaque samples with a median concentration of 284 ng/ml (95% confidence interval 163 to 517 ng/ml).

Anti-Bacterial Agents↗
PubMed2000

[Stent implantation as initial coronary interventional therapy? A theoretical model on clinical and economical consequences of in-stent restenosis].

The reduction of acute complications and late restenosis compared to conventional PTCA has led to a rapid increase in stent implantation as initial treatment for coronary stenosis. As a result, in-stent restenosis has become an important clinical and economical problem, especially the diffuse form, which is much more likely to reappear. In order to compare the consequences of initial stenting and initial angioplasty, we developed an analytic model, considering the differences between diffuse and focal in-stent restenosis. The simulation based on the optimized therapeutic proceeding following an elective 1-vessel revascularization of a 60-year-old patient, dealing with probabilities for acute complications and late restenosis taken from the literature and in-hospital costs obtained from 200 elective interventions. In the stent group 71.0% of patients were free of any target lesion-related event, compared to 60.2% in the PTCA group. Catheter reintervention was necessary for 32.1% of the patients initially treated with angioplasty and for 17.6% of the initially stented patients, whereas 7.7% of the stent patients had to undergo elective bypass surgery as final treatment compared to 2.8% in the PTCA arm. Long-term medical costs for initial stenting (6,237 Euros) were 14% higher than for conventional PTCA (5,345 Euros). Taking also into consideration the indirect costs (loss of productivity) for a collective with an employment rate of 50%, the difference between stent implantation (9,067 Euros) and angioplasty (8,581 Euros) is smaller. Initial treatment of coronary stenosis by stent implantation decreases the rate of repeat revascularization compared to initial PTCA, but there is a greater likelihood that elective bypass surgery will become necessary. This difference in following treatment is related to the occurrence of diffuse in-stent restenosis. When calculating the long-term costs stenting still appeared to be more expensive than PTCAA because the savings in following costs can not compensate for the higher primary in-hospital costs. An empirical study which collects cost data in different hospitals as well as in the outpatient setting over 1 year is necessary to confirm this preliminary result.

Angioplasty, Balloon, Coronary↗
PubMed1999

Thrombus formation after transcatheter closure of atrial septal defect.

Thrombotic layers and/or atrial thrombi were detected by transesophageal echocardiography as a usual finding after transcatheter closure of atrial septal defects with the ASDOS device. The size of the thrombotic structures regularly decreased within 6 months without any clinical signs of embolization.

Adult↗
PubMed1999

[Percutaneous transvenous mitral valvuloplasty in a pregnant patient. Successful treatment of severe mitral stenosis].

HISTORY AND CLINICAL FINDINGS: A 31-year-old woman presented in the 25th week of pregnancy with ankle and pretibial oedema and increasing dyspnoea, ultimately in class IV (New York Heart Association classification). There were fine rales on auscultation and dullness on palpation over both lung bases. The heart rate was regular at 110/min. The first heart sound was very loud, and there was a mitral opening snap and a loud diastolic murmur maximal, over the cardiac apex. INVESTIGATIONS: The ECG showed sinus rhythm at a rate of 110/min, left axis deviation, incomplete right bundle branch block and P biatriale, but no other abnormalities. Echocardiography revealed biatrial enlargement and an enlarged right ventricle as well as pulmonary systolic hypertension of 100 mm Hg. Doppler sonography demonstrated severe mitral stenosis with a calculated mitral opening area of 0.9 cm2. DIAGNOSIS, TREATMENT AND COURSE: The symptoms improved only slightly under conservative drug treatment. The mitral valve changes, as noted sonographically, met the criteria for percutaneous transluminal balloon mitral valvoplasty (PTBMV), which was successfully performed. Afterwards the mitral opening area was 2.6 cm2 and pulmonary artery pressure gradually became normal. She was delivered without complication of a healthy child in the 39th week of pregnancy. CONCLUSION: PTBLMV is a relatively low-risk treatment in pregnant women with symptomatic mitral stenosis.

Adult↗
PubMed1999

[Type and extent of vascular remodeling in significant coronary lesions: An intravascular ultrasound study].

The purpose of this study was to assess the dimension of regional vascular remodeling and its influence on lumen narrowing in vivo. Sixty-three patients with 68 coronary lesions were imaged by intravascular ultrasound before transcatheter therapy. Quantitative measurements of lumen area, vessel area, and plaque area were performed at the lesion site and at the proximal and distal reference site. Area stenosis was calculated as plaque area/vessel area. 100. The extent of remodeling was quantified by a remodeling index (RI = stenosis vessel area - mean reference vessel area/mean reference vessel area. 100). Additionally, three different groups of vascular remodeling were defined: 1) positive remodeling = stenosis vessel area > maximal reference vessel area; 2) intermediate remodeling = maximal reference vessel area >/= stenosis vessel area >/= minimal reference vessel area; 3) negative remodeling = stenosis vessel area < minimal reference vessel area. In 57% of lesions stenosis vessel area was not in between the proximal and distal reference area: 29% of lesions (20/68) had positive, 28% (19/68) negative, and 43% (29/68) intermediate remodeling. Overall remodeling index averaged -0.8+/-19.7%. In the negative remodeling group, reduction of vessel area contributed to 40+/-21% of lumen narrowing, in the positive remodeling group, stenosis vessel area was 21+/-12% enlarged (p<0.001). Lesions with negative remodeling exhibit a lesser plaque area, lesions with positive remodeling a larger than other vessels (8.2+/-2.4 mm(2), 13.8+/-3.7 mm(2), 10. 8+/-3.7 mm(2); p <0.001). Distinct vascular remodeling occurred in the majority of atherosclerotic lesions and is a bidirectional process. Overall, the extent and the frequency of positive and negative remodeling was almost balanced. In lesions with negative remodeling the plaque area was significantly lesser than in other lesions.

Adult↗
PubMed1999

A prognostic computer model to individually predict post-procedural complications in interventional cardiology: the INTERVENT Project.

AIMS: The purpose of this part of the INTERVENT project was (1) to redefine and individually predict post-procedural complications associated with coronary interventions, including alternative/adjunctive techniques to PTCA and (2) to employ the prognostic INTERVENT computer model to clarify the structural relationship between (pre)-procedural risk factors and post-procedural outcome. METHODS AND RESULTS: In a multicentre study, 2500 data items of 455 consecutive patients (mean age: 61.1+/-8.3 years: 33-84 years) undergoing coronary interventions at three university centres were analysed. 80.4% of the patients were male, 16.7% had unstable angina, and 5.1%/10.1% acute/subacute myocardial infarction. There were multiple or multivessel stenoses in 16.0%, vessel bending >90 degrees in 14.5%, irregular vessel contours in 65.0%, moderate calcifications in 20.9%, moderate/severe vessel tortuosity in 53.2% and a diameter stenosis of 90%-99% in 44.4% of cases. The in-lab (out-of-lab) complications were: 0.4% (0.9%) death, 1.8% (0.2%) abrupt vessel closure with myocardial infarction and 5.5% (4.0) haemodynamic disorders. CONCLUSION: Computer algorithms derived from artificial intelligence were able to predict the individual risk of these post-procedural complications with an accuracy of >95% and to explain the structural relationship between risk factors and post-procedural complications. The most important prognostic factors were: heart failure (NYHA class), use of adjunctive/alternative techniques (rotablation, atherectomy, laser), acute coronary ischaemia, pre-existent cardiac medication, stenosis length, stenosis morphology (calcification), gender, age, amount of contrast agent and smoker status. Pre-medication with aspirin or other cardiac medication had a beneficial effect. Techniques, such as laser angioplasty or atherectomy were predictors for post-procedural complications. Single predictors alone were not able to describe the individual outcome completely.

Adult↗
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

Transcatheter closure of atrial septal defect and patent foramen ovale with ASDOS device (a multi-institutional European trial).

A clinical trial was conducted to assess the feasibility, safety, and efficacy of the atrial septal defect (ASD) occlusion system for transcatheter closure of secundum ASD and patent foramen ovale (PFO) after episodes of cerebral embolism. Occlusion was attempted in 200 patients aged 1 to 74 years (mean 32). The procedure failed in 26 patients (13%); the device was retrieved through a catheter in 20 and through surgery in 6 patients. Procedure-related complications necessitating surgical removal of the device included device embolization in 2, device entrapment within the Chiari network in 1, frame fracture in 1, and perforation of atrial wall in 2. All 6 patients experienced an uneventful postoperative course. An additional 11 patients (6%) underwent surgical removal of the device during follow-up. There were 163 patients (81%) with an implanted ASD occlusion system at follow-up of from 6 to 36 months (mean 17). Thrombus formation around the device was detected by transesophageal echocardiography in 9 patients 1 to 4 weeks after implantation. One of these patients (who had a coagulation factor XII deficiency) suffered a cerebral thromboembolism. Late atrial wall perforation (5, 6, and 8 months after implantation) occurred in 3 adult patients. Infectious endocarditis developed in 2 adult patients (1%). No late device embolization and no atrioventricular valve injury occurred. An asymptomatic device frame fracture was found in 14% and frame deformity in 4% of all patients during the follow-up period of >230 patient-years. Immediately after closure, a moderate/large residual shunt remained in 8% and a small shunt in 29% of patients. After 1 year, a moderate/large shunt was present in 2% and a small one in 26% of patients. During a total follow-up of 49 patient-years, only 1 of 46 patients with PFO had a transient neurologic event after the closure. The study indicates that patients with centrally situated secundum ASD and those with PFO after cerebral embolism can be treated with this system with a high success rate and an acceptable morbidity.

Adolescent↗
PubMed1997

[Intracoronary ultrasound changes the therapeutic approach in ambivalent angiography findings].

Despite careful evaluation of multiple projections, coronary angiography may give ambiguous results of lesion severity. The purpose of this study was to analyze the impact of ultrasound imaging on revascularization treatment strategy in angiographically ambiguous findings. We reviewed our experience with such equivocal angiographic findings before intervention in 31 patients (34 lesions) who had additional intravascular ultrasound (IVUS) to clarify coronary anatomy. Intervention was felt to be indicated if area stenosis by IVUS exceeded 50% in the left main or 75% in other major coronary arteries. To evaluate the clinical efficacy of IVUS based management strategies, all patients had clinical follow-up after 1 year. Seven of nine ostial lesions were overestimated by angiography, but two of three left main lesions were found to be significant. Seven lesions in one of the proximal coronary arteries whose significance was difficult to judge by angiography were found not to be significant by IVUS, whereas in the other four severe obstruction was confirmed. Membranes by angiography corresponded to remnants of ruptured plaques by IVUS in all five patients. However, significant narrowing was found in only two patients. Side branch ostial lesions were ruled out by IVUS in all four instances. Two patients with unstable angina but normal angiograms showed complex atherosclerotic plaques in the left coronary artery. IVUS led to a change of therapy in 21 patients (revascularization instead of conservative treatment in two and cancellation of initially intended intervention in 19). At follow-up examination, 17 of these 21 patients were free of cardiac symptoms. Interventions at the site thought not severely diseased by IVUS had to be performed in two patients with persistent angina who were afterwards free of symptoms. One patient with persistent chest pain had a second coronary angiogram during the follow-up period, but conservative therapy was continued. Evaluation was impossible in one patient because of bypass surgery due to another coronary lesion. In conclusion, IVUS was clinically useful in patients with angiographically ambiguous findings and resulted in a change of therapy in 21/31 patients obviating interventions in 19 patients with excellent clinical results.

Adult↗
PubMed1997

A prognostic computer model to predict individual outcome in interventional cardiology. The INTERVENT Project.

It is not yet possible to predict an individual's outcome from percutaneous transluminal coronary angioplasty or alternative/adjunctive coronary interventional techniques. The purpose of the INTERVENT project is to redefine complications associated with coronary interventions, to set up a prognostic computer model to predict individual outcome and to compare the results to those of conventional statistical techniques. 2500 data items were analysed in 455 consecutive patients (mean age: 61.1 +/- 8.3 years; range 33-84 years; 80.4% male, 16.7% unstable angina, 5.1%/10.1% acute/subacute myocardial infarction) undergoing coronary interventions at three university centres. In-lab/out-of-lab complication rates were 0.4%/0.9% (death), 1.8%/0.2% (abrupt vessel closure with myocardial infarction) and 5.5%/4.0% (haemodynamic complications). Computer algorithms derived by applying techniques from artificial intelligence were able (1) to reduce the set of possible relevant risk factors from 2500 to about 40, (2) to predict individual risk with an accuracy of > 95% and (3) to explain the structural relationship between outcome and risk factors. Patient data from two centres were used to construct and test the algorithm. Data from a third centre were used to evaluate the algorithm. The most important predictors-were acute myocardial infarction, heart failure (NYHA class > II), unstable angina, complex lesions, high low density lipoprotein cholesterol and duration of coronary heart disease. Neither age nor gender impaired the percutaneous transluminal coronary angioplasty results in acute ischaemic syndromes; however, for stable angina, procedural risk increased with age. There was little risk from primary percutaneous transluminal coronary angioplasty in acute myocardial infarction in patients with NYHA heart failure classes I-II; however, the risk was high for patients in NYHA classes > II, either with or without additional thrombolysis. Alternative/adjunctive intervention techniques were no predictors for in-lab-, but were predictors for post-procedural complications.

Adult↗
PubMed1997

Dipyridamole scintigraphy and intravascular ultrasound after successful coronary intervention.

UNLABELLED: Despite angiographically successful interventions, perfusion defects are not uncommonly observed in postinterventional perfusion scintigrams. The aim of this study was to test the hypothesis that perfusion defects after coronary intervention are associated with a significant residual stenosis in the treated vessel segment detectable by intravascular ultrasound but not by angiography. METHODS: Forty consecutive patients with angiographically successful coronary interventions were prospectively studied by intravascular ultrasound immediately after the intervention. Within 48 hr after the intervention all patients had myocardial scintigraphy using 99mTc-methoxyisobutyl-isonitrile SPECT after dipyridamole stress. Myocardial perfusion defects in the scintigram were assigned to a segmental left ventricular model and compared to the perfusion territory of the treated vessel estimated from the coronary angiogram. RESULTS: Twenty of 40 patients had reversible myocardial perfusion defects. Mean ultrasound area stenosis was 50% in these patients and 33% in patients without perfusion defects (p < 0.002); ultrasound percent plaque area was 75% versus 63% (p < 0.0001), respectively. The best concordance between residual area stenosis and perfusion defects was found for an ultrasound area stenosis > or = 40%. CONCLUSION: Patients with stress-induced myocardial perfusion defects immediately after successful coronary intervention show high-grade residual stenoses that are more pronounced in patients with perfusion defects than in patients with normal postinterventional scintigrams. In addition, vessels serving myocardial regions with perfusion defects showed a significantly higher plaque burden indicating diffuse atherosclerotic changes in the vessel. The evaluation of the postprocedural result by intravascular ultrasound contributes to a better understanding of the discrepancy between the angiographic finding of a widely patent vessel but scintigraphic evidence of impaired perfusion.

Adult↗