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Biomedical subjects

H W M Plokker

Publications and source records attributed to H W M Plokker.

At least 19 recordsLinked to original sources
PubMed2007

Patent foramen ovale and migraine.

Migraine is a common neurological disorder with a great impact on the quality of life and social activities. The patent foramen ovale (PFO) is an intra-atrial right-to-left shunt with a prevalence of 25% in the general population. An increased prevalence is found in patients with migraine, especially in migraine with aura. Percutaneous PFO closure might decrease the prevalence of migraine. However, most of these observational studies were retrospective without a randomized design and the results need to be interpreted with caution. In this review we describe the association between PFO and migraine and the different pathophysiological hypotheses, which have been proposed to explain this relationship.

Cardiac Catheterization↗
PubMed2006

Determinants of increased angiotensin II levels in severe chronic heart failure patients despite ACE inhibition.

INTRODUCTION: The beneficial effects of ACE inhibitors are generally ascribed to blockade of neurohormonal activation. However, especially in chronic heart failure (CHF) patients plasma angiotensin II and aldosterone levels can be elevated despite ACE inhibition, the so-called ACE escape. In the present study, we aimed to identify the frequency and determinants of ACE escape in CHF patients. METHODS: We studied 99 stable chronic heart failure patients (NYHA class III and IV, 66% ischemic etiology) receiving long-term therapy with ACE inhibitors. In all patients, cardiac, renal, and neurohormonal parameters were measured. ACE escape was defined as plasma angiotensin level > or = 16 pmol/L. RESULTS: Mean (+/- SD) left ventricular ejection fraction of our 99 patients (79 men and 20 women, age 69 +/- 12 years) was 28 +/- 10%. In addition to an ACE inhibitor, 93% of patients received diuretics, 71% a beta-blocker, and 49% spironolactone. None of the patients used an angiotensin receptor blocker. In our population, 45% of the patients had an angiotensin II plasma concentration higher than 16 pmol/L (median concentration was 14.1 pmol/L). Spironolactone use was an independent predictor of elevated plasma angiotensin II levels. Furthermore, spironolactone users had significantly higher plasma active renin protein and aldosterone levels. Plasma angiotensin II concentration was positively correlated to active renin, plasma angiotensin I and plasma aldosterone. No correlation was found between plasma angiotensin II levels and serum ACE activity, dose of ACE inhibitor, or duration of use. CONCLUSION: In a group of severe chronic heart failure patients, 45% had elevated plasma angiotensin II levels independent of serum ACE activity despite long-term ACE inhibitor use. Although a causal link could not be proven, an association was found between spironolactone use and active renin protein, angiotensin II and aldosterone levels, suggesting that escape from ACE is mainly caused by a feedback mechanism.

Aged↗
PubMed2006

Embolization of pulmonary arteriovenous malformations and decrease in prevalence of migraine.

OBJECTIVE: To determine if embolization of pulmonary arteriovenous malformations (PAVMs) decreases the occurrence of migraine. METHODS: All 105 patients with hereditary hemorrhagic telangiectasia (HHT), minimum age 16 years, who underwent an embolization of PAVM in our hospital between June 1995 and April 2004, were included in this study. A structured headache questionnaire was sent to all patients and focused on two periods: 1 year before and at least 6 months after embolization. Two independent neurologists diagnosed migraine according to the International Headache Society criteria. RESULTS: Eighty-four patients (80%) sent back the questionnaire (mean age 47.8 +/- 15.1 years, 51 female). Median follow-up time was 48 months (first quartile: 23 months; third quartile: 66 months). The overall prevalence of migraine decreased from 45.2% before to 34.5% after embolization (p = 0.01). The prevalence of migraine with aura decreased from 33.3% before to 19.0% after embolization (p = 0.002). The severity of headache attacks decreased in patients who still had migraine (p = 0.15) or migraine with aura after embolization (p = 0.11). CONCLUSION: Embolization of pulmonary arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia seems to be related to a decrease in prevalence of migraine, suggesting that the presence of a right-to-left shunt rather than the localization of this shunt plays a causative role in the pathogenesis of migraine.

Adult↗
PubMed2005

Effects of rosuvastatin on postprandial leukocytes in mildly hyperlipidemic patients with premature coronary sclerosis.

We investigated whether pro-inflammatory aspects of the postprandial phase can be modulated by rosuvastatin in premature coronary artery disease (CAD) patients. Herefore standardized 8 h oral fat loading tests were performed off-treatment and after rosuvastatin 40 mg/d in 20 male CAD patients (50 +/- 4 years). The expression of leukocyte activation markers CD11a, CD11b, CD62L and CD66b was studied using flowcytometry. Migration of isolated neutrophils towards chemoattractants was determined in a fluorescence-based assay. Rosuvastatin did not affect baseline leukocyte counts nor the postprandial neutrophil increment (maximum mean increase +10% pre- and +14% post-treatment, P < 0.01 for each). Rosuvastatin reduced baseline platelets (from 266 +/- 78 to 225 +/- 74 x 10(9) cells/L, P < 0.001) and blunted the postprandial platelet count change (maximum mean increase +6%, P = 0.01, and 0%, respectively). The baseline expression of CD11a, CD11b and CD62L increased on most types of leukocytes by rosuvastatin, whereas the postprandial responses were unaffected. Pretreatment, postprandial neutrophil migration increased dose-dependently, but there were no postprandial changes after rosuvastatin. The latter effect was unrelated to changes in lipoprotein concentrations. In conclusion, in CAD patients postprandial pro-inflammatory and pro-coagulant changes can be modified by rosuvastatin. These apparently lipid-lowering independent effects may render protection against atherosclerosis.

Adult↗
PubMed2005

Pre-procedural ACE-activity does not predict symptomatic in-stent restenosis.

BACKGROUND: Several studies indicate that ACE-activity is related to atherosclerosis. We investigated the correlation between ACE-activity, in plasma as well as in the atherosclerotic plaque, and in-stent restenosis. METHODS AND RESULTS: ACE-activity was measured in blood samples from 178 patients who underwent a percutaneous coronary intervention with stent placement. During 8 months follow-up, 51 of these patients had an adverse clinical event. ACE-activity did not differ between patients with or without adverse events (21.5 vs. 23.1 nM/ml/min; P=0.36). Tissue samples were obtained with an atherectomy catheter before elective stent placement in another group of 13 patients with de novo stenosis. In this tissue, we determined the ACE-content immunohistologically. These patients were scheduled for follow-up quantitative coronary angiography after 12 months. In this group, the quantity of ACE was not correlated to the late luminal loss (0.31 vs. 0.38 mm; P=0.76). CONCLUSION: In this study, pre-procedural ACE-activity, in plasma as well as in the atherosclerotic plaque, does not predict the occurrence of in-stent restenosis.

Angioplasty, Balloon, Coronary↗
PubMed2005

Effects of increasing doses of simvastatin on fasting lipoprotein subfractions, and the effect of high-dose simvastatin on postprandial chylomicron remnant clearance in normotriglyceridemic patients with premature coronary sclerosis.

Postprandial hyperlipidemia has been linked to premature coronary artery disease (CAD) in fasting normotriglyceridemic patients. We investigated the effects of increasing doses of simvastatin up to 80 mg/day on fasting and postprandial lipoprotein metabolism in 18 normotriglyceridemic patients with premature CAD. Fasting lipoprotein subfractions and cholesteryl ester transfer protein (CETP) activity were determined after each 5-week dose titration (0, 20, 40 and 80 mg/day). At baseline and after treatment with simvastatin 80 mg/day, standardised Vitamin A oral fat loading tests (50 g/m2; 10 h) were carried out. Ten normolipidemic healthy control subjects matched for gender, age and BMI underwent tests without medication. Treatment with simvastatin resulted in dose-dependent reductions of fasting LDL-cholesterol, without changing cholesterol levels in the VLDL-1, VLDL-2 and IDL fractions. In addition, simvastatin decreased CETP activity dose-dependently, although HDL-cholesterol remained unchanged. Simvastatin 80 mg/day decreased fasting plasma triglycerides (TG) by 26% (P < 0.05), but did not decrease significantly TG levels in any of the subfractions. The TG/cholesterol ratio increased in all subfractions. The plasma TG response to the oral fat loading test, estimated as area under the curve (TG-AUC), improved by 30% (from 21.5 +/- 2.5 to 15.1 +/- 1.9 mmol h/L; P < 0.01). Treatment with simvastatin 80 mg/day improved chylomicron remnant clearance (RE-AUC) by 36% from 30.0 +/- 2.6 to 19.2 +/- 3.3 mg h/L (P < 0.01). After therapy, remnant clearance in patients was similar to controls (19.2 +/- 3.3 and 20.3 +/- 2.7 mg h/L, respectively), suggesting a normalization of this potentially atherogenic process. In conclusion, high-dose simvastatin has beneficial effects in normotriglyceridemic patients with premature CAD, due to improved chylomicron remnant clearance, besides effective lowering of LDL-cholesterol. In addition, the lipoprotein subfractions became more cholesterol-poor, as reflected by the increased TG/cholesterol ratio, which potentially makes them less atherogenic.

Apolipoproteins↗
PubMed2004

[Dyspnoea in pregnant female immigrants due to unexpected mitral valve stenosis].

Three female patients, a 22-year-old Moroccan woman, a 25-year-old Turkish woman and a 35-year-old Iraqi woman, became increasingly dyspnoeic during their pregnancy; this was a symptom of congestive heart failure due to mitral valve stenosis. Since all patients were refractory to medical treatment, they underwent invasive therapy by percutaneous transvenous mitral balloon valvotomy (PTMV). In two patients this therapy was successful, but in one patient a closed mitral valvotomy was needed. All three women delivered healthy infants, two immediately following the PTMV; at follow-up 2-4 years later, the women and infants were all doing well. The prevalence of mitral valve stenosis in the western world is increasing because of changing immigration patterns. When pregnant patients start complaining about dyspnoea, especially if they are immigrants, one should be aware of the possibility of mitral valve stenosis. PTMV is a safe and successful treatment for these patients and is preferred above surgical therapy because of its low morbidity and mortality for both mother and foetus. PTMV must be performed in a thoracic surgery centre by an experienced team and the X-ray exposure should be minimised.

Adult↗
PubMed2004

New pharmacological strategies in chronic heart failure.

Diuretics, ACE inhibitors and betablockers form the cornerstone of pharmacological treatment of chronic heart failure (CHF), while angiotensin receptor blockers are gaining ground. However, despite optimal treatment CHF remains a syndrome with poor prognosis. For this reason, a large number of new agents have been developed as add-on treatment over the last few years. Vasopeptidase inhibitors, moxonidine, endothelin antagonists, vasopressin antagonists, and selective aldosterone antagonists, are some of the new agents that were designed to interfere with different neurohormonal pathways. Immunomodulating agents, growth hormone, caspase inhibitors, adrenomedullin, and erythropoietin have different modes of action, which in general are less understood. Although most of the agents exhibited efficacy in preclinical trials, the clinical results have not always been similarly positive. The results of trials involving vasopeptidase inhibitors, endothelin antagonists, immunomodulating agents, and growth hormone have been disappointing. Other compounds like caspase inhibitors, adrenomedullin, and vasopressin antagonists are still at the early stages of development. Currently, the two most promising agents seem to be erythropoietin and the selective aldosterone receptor blocker eplerenone. In the present article an overview of new pharmacological developments for CHF is given, and the clinical value of these developments is discussed.

Cardiovascular Agents↗
PubMed2004

Activation of leukocytes by postprandial lipemia in healthy volunteers.

Activation of leukocytes is obligatory for inflammation and atherogenesis by adhering to the endothelium via specific ligands. Although in vitro studies have shown that triglycerides (TG) can activate leukocytes, it is unknown whether this occurs in vivo. Using flowcytometry, we studied the expression of leukocyte activation markers CD11A, CD11B, CD62L (all involved in endothelium adhesion) and CD66B (a neutrophil degranulation marker) during a 6 h fat challenge (50 g/m2) and a water test in 10 healthy males (52 +/- 3 years). After fat, neutrophil counts were increased between t=1 and t =6 h, with a maximum at t=3 h (+32% versus t=0, P <0.05), while they remained unchanged after water. Both tests showed gradual lymphocyte count increments. The expression of activation markers on lymphocytes was low and showed comparable responses after both tests. After fat, a significant increase up to a maximum at t=6 h was seen for CD11B on monocytes and on neutrophils for CD11B, CD62L and CD66B. Postprandial activation of monocytes and neutrophils was higher after fat than after water. The maximal postprandial TG increment was significantly related to the increase of CD11B on monocytes (Pearson's R=0.64, P <0.05). In conclusion, postprandially there is a TG-specific increase of neutrophil counts and increased activation of monocytes and neutrophils. These results are suggestive of a pro-inflammatory situation that may correspond with increased adhesive capacity of these cells contributing to the inflammatory component of atherosclerosis.

Adult↗
PubMed2003

Gender differences in postprandial ketone bodies in normolipidemic subjects and in untreated patients with familial combined hyperlipidemia.

OBJECTIVE: An increased hepatic flow of free fatty acids (FFAs) is associated with impaired peripheral FFA trapping by malfunctioning of the complement component 3 (C3)/acylation-stimulating protein system and overproduction of VLDL in familial combined hyperlipidemia (FCHL). Postprandial ketone bodies reflect FFA oxidation in the liver, but the postprandial changes in male and female patients separately have not been determined yet. Gender differences in postprandial ketone bodies and C3 changes were investigated in normolipidemic patients and patients with untreated FCHL. METHODS AND RESULTS: Thirty-two normolipidemic patients (16 female and 16 male) and 19 patients with untreated normolipidemia (9 female and 10 male) underwent an oral fat-loading test. Total and incremental areas under the curves (AUC and dAUC, respectively) after the oral fat load were calculated. Triglyceride AUC was similar between genders in each group. Normolipidemic female subjects showed a higher levels of dAUC-hydroxybutyric acid than male subjects (1.37+/-0.49 and 0.98+/-0.43 mmol x h/L). In FCHL, a similar trend was observed in female (1.92+/-0.38) compared with male (1.55+/-0.87) subjects. In contrast to normolipidemia, FCHL did not show a postprandial increase in C3, although C3 was higher in FCHL. CONCLUSIONS: Women have higher postprandial ketone bodies than men, probably reflecting enhanced postprandial hepatic FFA oxidation. In FCHL, both genders have higher postprandial ketone bodies and therefore higher hepatic FFA delivery. The higher fasting and postprandial C3 levels in FCHL may reflect resistance of the C3/acylation-stimulating protein system to promote peripheral fatty acid trapping.

3-Hydroxybutyric Acid↗
PubMed2003

Normalization of daytime triglyceridemia by simvastatin in fasting normotriglyceridemic patients with premature coronary sclerosis.

Postprandial hyperlipidemia is associated with premature coronary sclerosis in fasting normolipidemic subjects. Self-determined daytime capillary triglyceride (cTG) profiles were compared between 26 fasting normotriglyceridemic patients with premature coronary artery disease (CAD) and 26 controls matched for gender, age and BMI. Daytime triglyceridemia was calculated as total area under the cTG-curve (cTG-AUC). Total and LDL cholesterol were not different between CAD patients (5.4+/-0.8 mmol/l and 3.6+/-0.7 mmol/l, respectively) and controls (5.0+/-0.9 mmol/l and 3.3+/-0.8 mmol/l, respectively). Patients with CAD were characterized by a 44% higher cTG-AUC than matched controls (P<0.01). Using logistic regression analysis, cTG-AUC was the strongest predictor of the presence of CAD (P<0.001). Adding apo AI to the model improved the predictive power from 71 to 77%. Sixteen patients were studied after increasing doses of simvastatin up to 80 mg/day. Although the target for LDL cholesterol was reached by simvastatin 20mg/day, significant effects on cTG-AUC were found only by higher doses of simvastatin. Simvastatin 40 mg/day decreased cTG-AUC by 28% (P<0.05 versus baseline), reaching comparable values as in controls, without further improvement with simvastatin 80 mg/day (26% reduction versus baseline; P<0.05). Daytime triglyceridemia is linked to premature coronary sclerosis in fasting normotriglyceridemic patients. A higher dose of simvastatin was needed to normalize daytime triglyceridemia than was required to "normalize" LDL cholesterol.

Adult↗
PubMed2003

Venous coronary artery bypass surgery: a more than 20-year follow-up study.

AIMS: Atherosclerosis in venous coronary artery bypass grafts begins early and accelerates from the fifth post-operative year. We studied the influence of 18 variables existing at the time of operation, and of 'classical' risk factors present at 1 and 5 years after operation on the long-term outcome of this type of surgery. METHODS AND RESULTS: Four hundred twenty-eight consecutive patients who underwent isolated venous coronary bypass surgery between April 1, 1976 and April 1, 1977 were followed prospectively. Follow-up was 99.3% complete with a mean duration of 22.8 years for the survivors. Multivariate analysis was performed using the Cox regression model. Actuarial survival after 5, 10, 15 and 20 years is 95, 83, 63 and 47%, respectively. The cumulative probability of event-free survival for cardiac death, acute myocardial infarction and re-intervention at 5, 10, 15 and 20 years, respectively, are 98, 90, 74, 60%; 99, 91, 83, 77%; and 97, 86, 67, 57%. Age and left ventricular functions are continuous incremental risk factors for mortality. Left ventricular function and completeness of revascularization, and age and vessel disease are independent predictors of cardiac death and re-intervention, respectively. Hypertension, diabetes mellitus, hypertriglyceridemia, obesity and smoking, present after operation have an independent influence on the occurrence of cardiac events. CONCLUSIONS: Risk factors (still) existing 1 and 5 years after operation have a negative influence on the long-term results. This emphasizes the need of treatment of these 'classical' risk factors still present after operation.

Adult↗
PubMed2003

Four cardiac myxomas diagnosed three times in one patient.

A left atrial myxoma was surgically removed in a 58-year-old man following several embolic events. Five months later, a new myxoma was found in the right ventricular outflow tract and surgically removed. In this patient, we visualized two more recurrences 14 years later, one in the left atrium and the other in the left ventricle. A short review of the literature concerning recurrent cardiac myxomas is given.

Echocardiography↗
PubMed2003

Long-term follow-up of cardiac rhythm after percutaneous mitral balloon valvotomy. Does atrial fibrillation persist?

AIMS: Little information is available about short-term and none about long-term follow-up of cardiac rhythm after percutaneous mitral balloon valvotomy (PTMV). METHODS AND RESULTS: We studied the long-term course of the supraventricular rhythm in 137 consecutive patients with severe mitral stenosis, who underwent PTMV. The rhythm before PTMV was sinus rhythm (SR) in 55% and chronic AF in 45% of patients. The mean follow-up time was 3.7+/-2.5 years (n=126). In patients with SR before PTMV, SR persisted in 91% of patients at the end of follow-up. In patients with chronic AF before PTMV, 84% of these patients were still in chronic AF at the end of follow-up, spontaneous conversion to SR did not occur. In 12 of 14 patients (85%), selected for cardioversion, SR was achieved, by DC cardioversion (n=11) or by drugs alone (n=1). After 2 years this outcome persisted, but after 4 years only 38% remained in SR. CONCLUSION: Pre-procedural SR will persist following PTMV. However in patients with chronic AF PTMV is not associated with reversion to SR, suggesting that measures should be undertaken to restore sinus rhythm.

Atrial Fibrillation↗
PubMed2003

Long term follow up after elective percutaneous coronary intervention for unprotected non-bifurcational left main stenosis: is it time to change the guidelines?

BACKGROUND: According to the American College of Cardiology/American Heart Association guidelines, percutaneous coronary intervention (PCI) for left main coronary artery (LMCA) stenosis is contraindicated and coronary artery bypass graft surgery (CABG) is preferred. However, PCI of the LMCA is performed under exceptional circumstances. OBJECTIVE: To analyse the data of patients who underwent PCI of the unprotected LMCA in St Antonius Hospital, Nieuwegein, Netherlands. RESULTS: In a database of 17 683 PCI procedures, 71 patients (0.4%) were found with non-bifurcational LMCA stenosis who underwent an elective PCI between 1991 and 2001. Ages ranged from 26.7-86.5 years. Severe concomitant disease was the most frequent argument in favour of PCI instead of CABG. PCI consisted of only balloon angioplasty in 23 cases (32.4%). A stent was used in 46 cases (64.4%). Average follow up was 43 months (range 0-121 months). One patient died one day after the procedure. The total one year survival rate was 98.6% (70/71). Seven patients died during the follow up period, mostly because of non-cardiac reasons. The annual mortality rate was 2.5%. Recurrent elective percutaneous transluminal coronary angioplasty for restenosis of the LMCA was performed in one patient (1.4%) six weeks after the initial procedure. CABG was required in 13 patients (18.3%) throughout the follow up period. CONCLUSION: These results suggest that at highly experienced centres, elective PCI of the non-bifurcational LMCA can be performed safely where the anatomy is suitable.

Adult↗
PubMed2003

Optimisation of the antibiotic guidelines in The Netherlands. VII. SWAB guidelines for antimicrobial therapy in adult patients with infectious endocarditis.

The Working Party on Antibiotic Policy (Dutch acronym is SWAB) is a Dutch organisation that develops guidelines for in-hospital antimicrobial therapy of bacterial infectious diseases. This present guideline describes the antimicrobial treatment for adult patients with infective endocarditis. The choice and duration of antimicrobial therapy is determined by the infecting micro-organism, sensitivity of this micro-organism for antimicrobial therapy, location of the endocarditis, left-sided or right-sided, and presence of intracardial prosthetic material. In this guideline, the empirical therapy for endocarditis is discussed as well as the therapy for the most frequent causative organisms: streptococci, enterococci, staphylococci and HACEK micro-organisms.

Adult↗