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Piet W Boonstra

Publications and source records attributed to Piet W Boonstra.

15 recordsLinked to original sources
PubMed2006

Favorable long-term outcome of Maze surgery in patients with lone atrial fibrillation.

BACKGROUND: Rhythm control is indicated for patients suffering from symptomatic atrial fibrillation (AF), but remains difficult to establish. We investigated the long-term outcome of Cox maze III surgery in patients with symptomatic lone AF refractory to antiarrhythmic drug therapy. METHODS: Patients with a history of symptomatic paroxysmal or persistent AF refractory for at least two class I or III antiarrhythmic drugs and without structural heart disease or bradyarrhythmias were included. All patients underwent Cox maze III surgery. Complete success was defined as the absence of AF without antiarrhythmic drugs beyond 3 months after the procedure, and partial success as the absence of AF with antiarrhythmic drug use. RESULTS: A total of 29 patients were included (27 male), with a mean age of 48 +/- 6 years. At the time of surgery, 11 patients (38%) had persistent AF. After a mean follow-up of 4.8 +/- 2.4 years, 79% of patients had complete success, and 2 patients (7%) were free of AF with antiarrhythmic drugs. At the end of follow-up, left ventricular fractional shortening was significantly improved (from 31% +/- 10% to 39% +/- 8%, p = 0.002), left atrial size was unchanged, exercise capacity was within normal ranges, and quality of life was comparable with that of healthy controls. Severe complications included reoperations for postoperative bleeding (n = 3), pericardial effusion (n = 1), and mediastinitis (n = 1). In 2 patients, a pacemaker was implanted postoperatively because of sinus node dysfunction. CONCLUSIONS: Cox maze III surgery is a highly effective therapy for drug-refractory lone AF, and therefore remains an alternative to transvenous pulmonary vein ablation.

Adult↗
PubMed2005

Effect of intensive versus moderate lipid lowering on endothelial function and vascular responsiveness to angiotensin II in stable coronary artery disease.

Recent evidence has demonstrated that intensive lipid-lowering therapy with a high-dose statin provides significant clinical benefit beyond moderate lipid-lowering therapy. However, dose-dependent effects of short-term statin therapy on vascular function have not been demonstrated. We studied endothelial function and vascular responsiveness to angiotensin II in patients who had coronary artery diseased and were randomized to receive low- or high-dose atorvastatin (10 or 80 mg, respectively) or placebo. Internal thoracic artery segments were obtained during coronary bypass surgery and studied in vitro. Endothelium-dependent vasodilation was increased with atorvastatin therapy (p = 0.035) but was significantly increased further in patients who received 80 mg compared with those who received 10 mg of atorvastatin (p = 0.05). Endothelium improvement was accompanied by decreased vascular response to angiotensin II (p = 0.039). These findings suggest a mechanism for the clinical benefit of intensive lipid-lowering treatment in coronary heart disease.

Aged↗
PubMed2004

Comparison of late (four years) functional health status between percutaneous transluminal angioplasty intervention and off-pump left internal mammary artery bypass grafting for isolated high-grade narrowing of the proximal left anterior descending coronary artery.

In a 4-year follow-up study, we compared functional health status (FHS) in patients randomized to surgery (n = 51) or angioplasty (n = 51) for an isolated narrowing of the proximal left anterior descending coronary artery. FHS was assessed with the Short Form-36 and the Minnesota Living with Heart Failure questionnaires. Although the occurrence of angina (p = 0.036) and major adverse cardiac and cerebrovascular events (p = 0.02) was significantly higher 4 years after angioplasty, FHS did not differ between treatments and was comparable to a healthy reference population.

Angina Pectoris↗
PubMed2004

Sertraline causes strong coronary vasodilation: possible relevance for cardioprotection by selective serotonin reuptake inhibitors.

OBJECTIVE: Although Selective Serotonin Reuptake Inhibitors (SSRIs) are important antidepressant drugs, knowledge of their vaso active effects is limited. Vaso active effects of the SSRI sertraline were studied in rings of rat aorta, human Internal Mammary Arteries (IMAs) and in Langendorff perfused rat hearts. METHODS: The effects of sertraline (0.1 to 300 micromol x L(-1)) on precontracted rat aortic and IMA rings were evaluated in organ bath chambers. Precontraction was elicited by serotonin (5-HT; 10 micromol x L(-1)), phenylephrine (PE; 10 micromol x L(-1)) and potassium chloride (KCl; 50 mmol x L(-1)). In addition, the effects of sertraline on PE induced contraction curves were established by subjecting vascular rings to increasing doses of PE (1 nmol x L(-1) to 10 (micro)mol x L(-1)) in the presence of sertraline or vehicle. Finally, the effects of sertraline on ex vivo coronary flow in rat hearts were examined using a retrograde Langendorff perfusion model. RESULTS: Sertraline elicited dose-dependent relaxation, independent of the substance used for precontraction (p < 0.025). Sertraline showed a rightward shift of dose-response curves to PE (p < 0.01). Vasodilatory effects of SSRIs were endothelium independent. In perfused rat hearts, sertraline (0.3 to 10 micromol x L(-1)), showed a concentration-dependent increase in coronary flow that returned to baseline levels after wash-out of the antidepressant (p = 0.005). CONCLUSIONS: One of the SSRIs, sertraline, showed marked vasodilatory effects in rat aorta and human IMAs. Sertraline elicited vasodilatation in coronary arteries during perfusion of rat hearts. These hemodynamic effects may explain

Animals↗
PubMed2004

Isolated high-grade lesion of the proximal LAD: a stent or off-pump LIMA?

OBJECTIVES: The objective of this study was to compare the long-term outcome of patients with an isolated high-grade stenosis of the left anterior descending (LAD) coronary artery randomized to percutaneous transluminal coronary angioplasty with stenting (PCI, stenting) or to off-pump coronary artery bypass grafting (surgery). METHODS: Patients with an isolated high-grade stenosis (American College of Cardiology/American Heart Association classification type B2/C) of the proximal LAD were randomly assigned to stenting (n=51) or to surgery (n=51) and were followed for 3-5 years (mean 4 years). Primary composite endpoint was freedom from major adverse cardiac and cerebrovascular events (MACCEs), including cardiac death, myocardial infarction, stroke and repeat target vessel revascularization. Secondary endpoints were angina pectoris status and need for anti-anginal medication at follow-up. Analysis was by intention to treat. RESULTS: MACCEs occurred in 27.5% after stenting and 9.8% after surgery (P=0.02; absolute risk reduction 17.7%). Freedom from angina pectoris was 67% after stenting and 85% after surgery (P=0.036). Need for anti-anginal medication was significantly lower after surgery compared to stenting (P=0.002). CONCLUSION: Patients with an isolated high-grade lesion of the proximal LAD have a significantly better 4-year clinical outcome after off-pump coronary bypass grafting than after PCI.

Angioplasty, Balloon, Coronary↗
PubMed2002

A prospective randomized trial comparing stenting with off-pump coronary surgery for high-grade stenosis in the proximal left anterior descending coronary artery: three-year follow-up.

OBJECTIVES: This study was done to identify the best treatment for an isolated high-grade stenosis of the proximal left anterior descending coronary artery (LAD). BACKGROUND: Percutaneous transluminal coronary angioplasty with stenting (PCI) and off-pump coronary artery bypass grafting (surgery) are used to treat single-vessel disease of a high-grade stenosis of the proximal LAD. Midterm results of both treatments are compared in this prospective randomized study. METHODS: In a single-center prospective trial, we randomly assigned 102 patients with a high-grade stenosis of the proximal LAD (American College of Cardiology/American Heart Association classification type B2 or C) to PCI (n = 51) or surgery (n = 51). Primary composite end point was freedom from Major Adverse Cardiac and Cerebrovascular Events (MACCE) at follow-up, including death, myocardial infarction, cerebrovascular accident, and repeat target vessel revascularization (TVR). Secondary end points were angina pectoris class and need for antianginal medication at follow-up. Analysis was by intention-to-treat (ITT) and received treatment (RT). RESULTS: Mean follow-up time was three years (90% midrange, two to four years). Incidence of MACCE was 23.5% after PCI and 9.8% after surgery; p = 0.07 ITT (24.1% vs. 8.3%; p = 0.04 RT). After surgery a significantly lower angina pectoris class (p = 0.02) and need for antianginal medication (p = 0.01) was found compared to PCI. Target vessel revascularization was 15.7% after PCI and 4.1% after surgery (p = 0.09). CONCLUSIONS: At three-year follow-up (range, two to four years), a trend in favor of surgery is observed in regard to MACCE-free survival with a significantly lower angina pectoris status and significantly lower need for antianginal medication.

Angioplasty, Balloon, Coronary↗
PubMed2002

Functional antagonism of different angiotensin II type I receptor blockers in human arteries.

OBJECTIVES: To evaluate and compare the functional type and the degree of antagonism of the selective angiotensin II type 1 receptor blockers (ARB) losartan, EXP 3174 (the active metabolite of losartan), valsartan and candesartan in human internal mammary arteries. METHODS: Human internal mammary arteries were obtained as excess graft material during coronary bypass surgery. Vessels were prepared as rings and mounted in an organ bath in which vasoconstriction and -dilation can be measured. Concentration-response curves of angiotensin II-mediated vasoconstriction were measured in absence or presence of different concentrations of one of the ARBs. RESULTS: Losartan showed a rightward shift of the angiotensin II-mediated vasoconstriction, whereas addition of its metabolite EXP 3174 caused a decrease of the maximal effect of angiotensin II. Incubation with valsartan and candesartan also resulted in a decrease of the maximal effect. The inhibiting effects on the angiotensin II-mediated vasoconstriction by the highest concentration of EXP 3174, valsartan and candesartan did not differ significantly. CONCLUSION: In human internal mammary arteries, losartan acts as a surmountable antagonist. On the other hand, EXP 3174, valsartan and candesartan demonstrate an insurmountable type of antagonism. Furthermore, the inhibiting effects of EXP 3174, valsartan and candesartan in our study are equal in the highest concentrations.

Angiotensin II↗
PubMed2002

Minimally invasive coronary artery bypass grafting versus percutaneous transluminal coronary angioplasty with stenting in isolated high-grade stenosis of the proximal left anterior descending coronary artery: six months' angiographic and clinical follow-up of a prospective randomized study.

OBJECTIVE: We sought to compare minimally invasive coronary artery bypass grafting (surgical intervention) with percutaneous transluminal coronary angioplasty with primary stenting (stenting) in patients having an isolated high-grade stenosis (American College of Cardiology/American Heart Association classification type B2 or C) of the proximal left anterior descending coronary artery. At 6 months, both procedures were compared on the basis of quantitative angiography and clinical outcome. METHODS: Both treatments were compared in a single-center, prospective, randomized study. The primary end point of this study was quantitative angiographic outcome at 6 months. The secondary end point was 6-month clinical outcome. Statistical analysis was performed in accordance with the intention-to-treat principle. RESULTS: From March 1997 to September 1999, patients with angina pectoris caused by an isolated high-grade stenosis of the proximal left anterior descending coronary artery were randomly assigned to surgical intervention (n = 51) or stenting (n = 51). At 6 months, quantitative coronary angiography showed an anastomotic stenosis rate of 4% after surgical intervention and a restenosis rate of 29% after stenting (P <.001). Periprocedural events did not significantly differ between surgical intervention and stenting. After surgical intervention, 2 patients died; no patients died after stenting. After 6 months, no significant difference was found for major adverse cardiac or cerebral events and need for repeat target vessel revascularization. After 6 months, return of angina pectoris, physical work capacity, and use of antianginal drugs did not significantly differ between treatments. CONCLUSIONS: After 6 months, surgical intervention had a significantly better angiographic outcome than stenting in patients with an isolated high-grade stenosis of the proximal left anterior descending coronary artery. Clinical outcome did not significantly differ between treatments.

Angina Pectoris↗
PubMedDate not supplied

Acute isovolemic hemodilution triggers proinflammatory and procoagulatory endothelial activation in vital organs: role of erythrocyte aggregation.

OBJECTIVES: The essential role of erythrocytes as oxygen carriers is historically well established, but their function to aggregate and the consequences on the microcirculation is under debate. The pathogenic potential of low erythrocyte aggregation could be important for patients undergoing on-pump cardipopulmonary bypass. These patients are severely hemodiluted due to preoperative isovolemic hemodilution (IHD), circuit priming, and large fluid infusions perioperatively. Considering the vascular endothelium sensitivity to variations in blood rheology, the authors hypothesize that low erythrocyte aggregation will be responsible for activation of vascular endothelium during acute IHD. METHODS: Acute IHD (30 mL/kg exchange transfusion with colloid solutions) was induced in an "aggregating species"(pigs, n = 15). The hypoxic oxidative stress (plasma malondialdehyde, ex vivo oxygen radicals production in heart, lung, kidney, liver, and ileum tissue biopsies), erythrocyte aggregation (LORCA), and endothelial activation (real-time quantitative RT-PCR on von Willebrand factor (vWF), E- and P-selectins, endothelial nitric oxide synthase gene-expression in tissue biopsies) were investigated. RESULTS: The production of superoxide and hydroxyl radicals, measured as H2O2 generation, was similar at all times in sham-operated and hemodiluted animals, proving a maintained oxygen delivery to tissues. Acute IHD was followed by a dramatic drop in erythrocyte aggregation and immediate prothrombotic (significant vWF mRNA upregulation in heart, lungs, kidney, liver, ileum) and proinflammatory (significant E- and P-selectins mRNA upregulation in lungs and ileum) endothelial activation. Low erythrocyte aggregation was significantly correlated with increased mRNA-expression of vWF (heart, liver, ileum) and P-selectin (lungs, ileum, and heart). CONCLUSIONS: These results suggest that low erythrocyte aggregation might trigger endothelium-dependent thrombogenic and proinflammatory response during acute isovolemic hemodilution.

Animals↗