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Biomedical subjects

Dieter Horstkotte

Publications and source records attributed to Dieter Horstkotte.

At least 19 recordsLinked to original sources
PubMed2006

Percutaneous septal ablation for symptomatic hypertrophic obstructive cardiomyopathy: managing the risk of procedure-related AV conduction disturbances.

AIM: To provide tools for predicting the course of AV conduction disturbances after ethanol-induced septal ablation (PTSMA) for hypertrophic obstructive cardiomyopathy (HOCM). METHODS AND RESULTS: Based on a scoring system developed 1996-1998 and including parameters from baseline ECG, heart rate profile, severity of outflow obstruction (LVOTO), peri-interventional enzyme kinetics, and peri-interventional conduction problems, the risk of permanent AV block following PTSMA was assessed in 155 consecutive HOCM patients (pts.; mean age: 53+/-13 years) between 1999 and 2004. During PTSMA with 2.1+/-0.5 ml of ethanol, transient complete AV block occurred in 71 pts. (46%). Pts. were grouped into a low, intermediate, and high risk group for permanent conduction damage, and treated accordingly (early discharge from monitoring, prolonged monitoring, early DDD-PM implantation). Permanent pacing was necessary in 11 cases (7%), 0/116 of these (0%) in the low, 4/31 (13%) in the intermediate, and 7/8 (87%) in the high-risk group. While a new right bundle branch block was the most frequent ECG finding after PTSMA, a left bundle branch block at baseline was associated with 4 of the 11 DDD-PM implantations (p<0.0001). In-hospital mortality was 0%, short-term (3-months) follow up was complete. During follow-up, AV conduction recovered in 4 pts. (46%) with a DDD-PM. New onset AV blocks did not occur. Significant improvement of symptoms was reported by 141 pts. (91%). CONCLUSIONS: Catheter-based septal ablation is an effective non-surgical technique for reducing symptoms and outflow gradients in HOCM. The proposed scoring system appears to reliably discriminate pts. with a high risk for permanent PM dependency from those with stable AV conduction after PTSMA. Pts. with left bundle branch block at baseline should undergo DDD-PM implantation prior to ablation.

Analysis of Variance↗
PubMed2006

Sleep-disordered breathing in patients with symptomatic heart failure: a contemporary study of prevalence in and characteristics of 700 patients.

AIM: Evaluation of the prevalence and nature of sleep-disordered breathing (SDB) in patients with symptomatic chronic heart failure (CHF) receiving therapy according to current guidelines. METHODS AND RESULTS: We prospectively screened 700 patients with CHF (NYHA class> or =II, LV-EF< or =40%) for SDB using cardiorespiratory polygraphy (Embletta). Furthermore, echocardiography, cardiopulmonary exercise and 6-min walk testing were performed. Medication included ACE-inhibitors and/or AT1-receptor blockers in at least 94%, diuretics in 87%, beta-blockers in 85%, digitalis in 61% and spironolactone in 62% of patients. SDB was present in 76% of patients (40% central (CSA), 36% obstructive sleep apnoea (OSA)). CSA patients were more symptomatic (NYHA class 2.9+/-0.5 vs. no SDB 2.57+/-0.5 or OSA 2.57+/-0.5; p<0.05) and had a lower LV-EF (27.4+/-6.6% vs. 29.3+/-2.6%, p<0.05) than OSA patients. Oxygen uptake (VO(2)) was lowest in CSA patients: predicted peak VO(2) 57+/-16% vs. 64+/-18% in OSA and 63+/-17% in no SDB, p<0.05. 6-min walking distances were 331+/-111 m in CSA, 373+/-108 m in OSA and 377+/-118 m in no SDB (p<0.05). CONCLUSIONS: This study confirms the high prevalence of SDB, particularly CSA in CHF patients. CSA seems to be a marker of heart failure severity.

Aged↗
PubMed2006

Myocardial sympathetic innervation in patients with chronic coronary artery disease: is reduction in coronary flow reserve correlated with sympathetic denervation?

PURPOSE: Higher sensitivity of sympathetic nerves to ischaemia in comparison with myocytes has been observed and has been claimed to contribute to poor prognosis in patients with coronary artery disease (CAD). The aim of this study was to evaluate the dependency of myocardial sympathetic innervation on restrictions in coronary flow reserve (CFR). METHODS: We analysed 27 non-diabetic patients with advanced CAD. We determined quantitative myocardial blood flow using (13)N-ammonia PET, myocardial viability with (18)F-FDG PET and cardiac innervation with (11)C-HED PET. Scarred segments were excluded from analysis. We investigated the relationship between regional HED retention, blood flow and CFR. RESULTS: There was no correlation between rest perfusion and HED retention within a flow range from approximately 30 to 120 ml/(100 ml x min). A slight correlation was observed between stress perfusion values and HED retention (p<0.001), and between CFR and HED retention (p<0.001). CONCLUSION: In non-diabetic CAD patients, HED retention in vital myocardium does not correlate with myocardial rest perfusion over a large flow range. The observed relation between HED retention and CFR indicates that sympathetic innervation can be preserved even when there is major impairment of myocardial blood supply. Most probably the occurrence of denervation depends not only on reductions in CFR, but also on the duration and severity of resulting ischaemic episodes.

Chronic Disease↗
PubMed2006

The paclitaxel-eluting Coroflex Please stent pilot study (PECOPS I): acute and 6-month clinical and angiographic follow-up.

BACKGROUND AND OBJECTIVES: Various active stent coatings significantly reduce restenosis rates and target lesion revascularization compared to bare metal stents. Therefore, the procedural and 6-month performance of the new paclitaxel-eluting Coroflex. Please stent was investigated. METHODS: Ninety-seven patients (66 +/- 7.6 years, 34/97(35.1%) diabetics, 11/97(11.3%) unstable angina) were enrolled per protocol for elective single stent deployment into native coronary de-novo or post-PTCA restenotic lesions (stenosis: >or= 70%, < 100%; reference diameter >or= 2.25 mm and <3.3 mm; lesion length <or= 16 mm) with 13/97(13.4%) lesion type A, 64/97(66%) type B1, 20/97(20.6%) type B2). The mean reference diameter was 2.88 +/- 0.42 mm, the lesion length 10.03 +/- 2.93 mm, and the minimal lumen diameter 0.64 +/- 0.22 mm. RESULTS: The success rates of procedure and study stent deployment were 100% and 94.8%, respectively. In 5/97(5.2%) two stents were implanted. Follow-up was performed clinically in 86/87(98.9%) and angiographically in 77/87(88.5%) patients after 6.1 +/- 0.7 months. Major adverse cardiac events occurred in 7/87(8%) 1/87(1.2%) subacute thrombosis 10.3hrs post procedure, 1/87(1.2%) myocardial infarction, 5/87(5.7%) target lesion revascularizations. The in-segment stenosis declined from 78 +/- 7.2% to 9.4 +/- 6.2% after stenting increasing to 31.9 +/- 18.6% at follow-up. The in-segment late loss and the late loss index were 0.47 +/- 0.6 mm and 0.23 +/- 0.29 resulting in 6/77(7.8%) in-segment restenoses three each of which were located either within or beyond the stent structure. The outcome was neither influenced by the prevalence of diabetes ( p = 0.4), hypercholesterolemia ( p = 1), hypertension ( p = 1), overweight ( p = 1), nor by the family history of coronary artery disease ( p = 0.7). CONCLUSION: The data of the paclitaxel-eluting Coroflex. Please stent tested in PECOPS I are within the range other available paclitaxel-eluting stent.

Aged↗
PubMed2006

Reoperation of the aortic valve in octogenarians.

BACKGROUND: Because of increasing life expectancy of patients with heart valve replacement and a limited durability of heart valve bioprostheses, cardiac reoperation becomes necessary in a significant percentage of patients. Reliable data on mortality and risk factors in octogenarians after replacement of aortic valve prostheses are scanty, however. METHODS: We retrospectively analyzed 71 patients aged 80 years and older who underwent cardiac reoperation of the aortic valve (69 bioprostheses, 2 mechanical prostheses) between 1991 and 2004 at our heart center. Survival rate of the study cohort was compared with a control group of octogenarians matched for age, sex, and year of aortic valve replacement. To assess predictors of 30-day survival and 3-year survival, we performed univariate and multivariate analyses. RESULTS: Survival rates at 30 days, 1 year, 3 years and 5 years were 83.6%, 76.1%, 70.8%, and 51.3%, respectively. Results did not differ significantly between the study cohort and the controls. Patients with reoperation had an estimated median survival of 5.6 years. Postoperative complications such as low cardiac output syndrome and intestinal failure were the only independent predictors of 30-day survival (p = 0.020 and p = 0.015, respectively). Low cardiac output, intestinal failure, and diabetes mellitus were independent predictors of 3-year survival (p = 0.001 to 0.033). CONCLUSIONS: Our data demonstrate that it is possible to achieve an acceptable outcome in octogenarians who have reoperation of the aortic valve prosthesis. Early and mid-term survival is predominantly influenced by unexpected postoperative complications and not by preoperative risk factors, with the exception of diabetes mellitus.

Age Factors↗
PubMed2006

Improved coronary vasodilatatory capacity by H.E.L.P. apheresis: comparing initial and chronic treatment.

Hypercholesterolemia impairs endothelial function and subsequently decreases coronary vasodilatatory capacity. We examined the quantitative effects of one single LDL apheresis on vasodilatatory capacity. Using N-13 ammonia as a tracer for dynamic quantitative positron emission tomography (PET), mean myocardial perfusion measurements were carried out before and 20 h later after LDL apheresis, both under resting conditions and after pharmacological vasodilatation with dipyridamole. LDL apheresis was carried out using the heparin induced extracorporeal LDL precipitation (H.E.L.P.) procedure. We examined 47 patients (12 women and 35 men), with angiographically-proven coronary artery disease. All of them suffered from hypercholesterolemia. Of the patients, 35 received a chronic weekly H.E.L.P. procedure (group A), while H.E.L.P. procedure treatment was started for the first time in 12 patients, who were subsequently enrolled in a chronic apheresis program (group B). H.E.L.P. apheresis was combined with cholesterol lowering drugs in all patients. Both groups underwent positron emission tomography twice (prior to LDL apheresis and 20 h later). In group A, LDL cholesterol levels decreased from 175 +/- 50 mg/dL to 60 +/- 21 mg/dL immediately after H.E.L.P. (77 +/- 25 mg/dL before the second PET). Corresponding values for fibrinogen levels were 287 +/- 75 mg/dL to 102 +/- 29 mg/dL (155 +/- 52 mg/dL), minimal coronary resistance dropped from 0.56 +/- 0.20 to 0.44 +/- 0.17 mm Hg x 100 g x min/mL (P < 0.0001). Plasma viscosity decreased by 7.8%. In group B, LDL cholesterol decreased from 187 +/- 45 mg/dL to 75 +/- 27 mg/dL (85 +/- 29 mg/dL) and fibrinogen from 348 +/- 65 mg/dL to 126 +/- 38 mg/dL (168 +/- 45 mg/dL). Minimal coronary resistance was reduced from 0.61 +/- 0.23 to 0.53 +/- 0.19 mm Hg x 100 g x min/mL (P < 0.01). Plasma viscosity was observed to decrease by 7.6%. The strong LDL drop in patients under chronic H.E.L.P. treatment has a significant impact on coronary vasodilatatory capacity within 20 h leading to an improved overall cardiac perfusion. Nearly the same effect can be seen in patients after their first H.E.L.P. treatment.

Blood Component Removal↗
PubMed2006

Cardiac efficiency and oxygen consumption measured with 11C-acetate PET after long-term cardiac resynchronization therapy.

UNLABELLED: Cardiac resynchronization therapy (CRT) is a treatment option in patients with severe heart failure and left bundle-branch block (LBBB). This study evaluated the effects of 4 and 13 mo of CRT on myocardial oxygen consumption (MVO2) and cardiac efficiency as compared with mild heart failure patients without LBBB. METHODS: Sixteen patients with severe heart failure and LBBB due to idiopathic cardiomyopathy were studied at baseline and after 4 and after 13 mo of therapy. Thirteen patients with mild heart failure without LBBB served as a comparison group. The clearance rate (k2) of 11C-acetate was measured with PET to assess MVO2. Stroke volume was derived from the dynamic PET data according to the Stewart-Hamilton principle and, furthermore, cardiac efficiency using the work metabolic index. RESULTS: After 4 mo of CRT, stroke volume index (SVI) increased by 50% (P = 0.012) and cardiac efficiency increased by 41% (P < 0.001). Global k2 remained unchanged but regional k2 demonstrated a more homogeneous distribution pattern. The parameters showed no significant changes during therapy. Under CRT, cardiac efficiency, SVI, and the distribution pattern of regional k2 did not differ from mild heart failure patients without LBBB. CONCLUSION: CRT improves cardiac efficiency for at least 13 mo, as demonstrated by a higher SVI, whereas MVO2 remains unchanged. Cardiac efficiency, SVI, and the MVO2 distribution pattern reach the level of patients with mild heart failure without LBBB. The unfavorable hemodynamic performance in heart failure with LBBB is effectively restored by long-term CRT to the level of an earlier disease state.

Acetates↗
PubMed2005

Beneficial effects of atorvastatin on myocardial regions with initially low vasodilatory capacity at various stages of coronary artery disease.

PURPOSE: The aim of this study was to analyse non-invasively the regional effect of therapy with an HMG-CoA reductase inhibitor on myocardial blood flow in patients with coronary artery disease (CAD) with special reference to segments with initially substantially impaired vasodilation. METHODS: The study included 26 patients with untreated hypercholesterolaemia. Coronary angiography revealed CAD in nine patients with stenosis >50% and wall irregularities or minimal stenosis <30% in 17 patients. Before and 4.6+/-1.8 months after atorvastatin therapy, ( 13)N-ammonia positron emission tomography (PET) studies were performed at rest and under pharmacological stress. Minimum coronary vascular resistance (MCR) and coronary flow reserve (CFR) were determined. Segments were divided into those with normal or near-normal (MBF during adenosine > or =2.0 ml/min/g) and those with abnormal (MBF<2.0 ml/min/g) vasodilator flow response. In CAD patients, 156 segments were analysed, 85 of which had abnormal MBF; in the non-obstructive group, 59 of 297 segments had abnormal MBF. RESULTS: LDL cholesterol decreased after atorvastatin therapy from 186+/-43 mg/dl to 101+/-26 mg/dl (p<0.001). In normal segments no significant changes in MBF, CFR and MCR were found. However, initially abnormal segments showed significant improvements in MCR (15%, p<0.0001) and MBF during adenosine (30%, p<0.0001) after therapy. CONCLUSION: The improvement in regional coronary vasodilator function after atorvastatin in patients with coronary atherosclerosis may be caused, at least in part, by increased flow-mediated (endothelium-dependent) dilation of the total arteriolar and arterial vascular system. These data further support the concept of non-invasive management of stable CAD by statin therapy and life-style modification guided by PET.

Aged↗
PubMed2005

Global and regional myocardial oxygen consumption and blood flow in severe cardiomyopathy with left bundle branch block.

OBJECTIVE: In patients with dilated cardiomyopathy (DCM), left bundle branch block (LBBB) is a common finding. The characteristic feature is an asynchronous septal wall motion and most frequently a delay of the lateral and/or posterior wall segments. With the onset of cardiac resynchronization therapy, there is a focus on the specific pathophysiology of a LBBB. However, quantitative data on regional myocardial oxygen consumption (MVO(2)) and blood flow (MBF) are missing. METHODS: We studied 31 patients with severe DCM and LBBB (ejection fraction 22.1+/-7.1%) and 14 patients with mild to moderate DCM without LBBB (ejection fraction 46.7+/-7.9%). Global and regional MVO(2) as well as MBF were determined from a dynamic (11)C-acetate positron emission tomography (PET) study. RESULTS: Global MVO(2) and MBF were lower in the DCM group with LBBB than in the control group (P<0.05). Regionally, the LBBB group revealed a higher (P<0.05) MVO(2) and MBF in the lateral wall than in the other walls. The control group did not show significant differences between the myocardial walls and demonstrated a smaller variability of the parameters. CONCLUSION: DCM patients with LBBB exhibit a more heterogeneous distribution of MVO(2) and MBF among the myocardial walls than DCM patients without LBBB. Due to the LBBB associated electromechanical alterations, the highest regional values of MVO(2) and MBF are found in the lateral wall.

Adult↗
PubMed2005

Drug insight: an overview of current anticoagulation therapy after heart valve replacement.

Vitamin K antagonists, such as warfarin, are the gold standard approach for the long-term anticoagulant therapy of patients with mechanical heart valves. Management decisions are, however, based predominantly on expert consensus and on data from nonrandomized, follow-up studies, which have inherent limitations in their methods. Low-intensity anticoagulation therapy provides protection against thromboembolic complications in patients with most types of modern prosthetic heart valve. The addition of low-dose aspirin is safe if international normalized ratio values below 3.5 are maintained. A combined regimen should be considered in high-risk patients and those with coexistent coronary artery or cerebrovascular disease, and in patients who have suffered a thromboembolic event despite a therapeutic international normalized ratio. Thromboprophylaxis with unfractionated or low-molecular-weight heparins is restricted to specific situations, such as when a patient is intolerant to vitamin K antagonists, when surgical procedures require discontinuation of oral anticoagulation, or when the patient is pregnant. A lack of uniformity across practice guidelines make it difficult to reach treatment decisions. Each patient's preference, expressed after counseling about the risks and benefits of each treatment strategy, and an individual assessment of the patient's risk factors, should guide treatment decisions. At present, new anticoagulant agents such as factor Xa inhibitors do not represent a treatment option for heart valve recipients.

Anticoagulants↗