Left atrium (LA) dilation is associated with adverse cardiovascular (CV) outcomes. Blood stasis, ... more Left atrium (LA) dilation is associated with adverse cardiovascular (CV) outcomes. Blood stasis, thrombus formation and atrial fibrillation may occur, especially in heart failure (HF) patients. It is not known whether preventive antithrombotic treatment may decrease the incidence of CV events in HF patients with LA enlargement. We investigated the relationship between LA enlargement and CV outcomes in HF patients and the effect of different antithrombotic treatments. Two-dimensional echocardiography with LA volume index (LAVi) measurement was performed in 1148 patients with systolic HF from the Warfarin versus Aspirin in Reduced Ejection Fraction (WARCEF) trial. Patients were randomized to warfarin or aspirin and followed for 3.4 ± 1.7 years. While the primary aim of the trial was a composite of ischaemic stroke, death, and intracerebral haemorrhage, the present report focuses on the individual CV events, whose incidence was compared across different LAVi and treatment subgroups. Af...
Previous studies in patients with atrial fibrillation showed that a history of heart failure (HF)... more Previous studies in patients with atrial fibrillation showed that a history of heart failure (HF) could negatively impact anticoagulation quality, as measured by the average time in therapeutic range (TTR). Whether additional markers of HF severity are associated with TTR has not been investigated thoroughly. We aimed to examine the potential role of HF severity in the quality of warfarin control in patients with HF with reduced ejection fraction. Data from the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction Trial were used to investigate the association between TTR and HF severity. Multivariable logistic regression models were used to examine the association of markers of HF severity, including New York Heart Association (NYHA) class, Minnesota Living with HF (MLWHF) score, and frequency of HF hospitalization, with TTR ≥70% (high TTR). We included 1,067 participants (high TTR, N = 413; low TTR, N = 654) in the analysis. In unadjusted analysis, patients with a high TTR ...
Patients with peripheral artery disease have an increased risk of cardiovascular morbidity and mo... more Patients with peripheral artery disease have an increased risk of cardiovascular morbidity and mortality. Antiplatelet agents are widely used to reduce these complications. This was a multicentre, double-blind, randomised placebo-controlled trial for which patients were recruited at 602 hospitals, clinics, or community practices from 33 countries across six continents. Eligible patients had a history of peripheral artery disease of the lower extremities (previous peripheral bypass surgery or angioplasty, limb or foot amputation, intermittent claudication with objective evidence of peripheral artery disease), of the carotid arteries (previous carotid artery revascularisation or asymptomatic carotid artery stenosis of at least 50%), or coronary artery disease with an ankle-brachial index of less than 0·90. After a 30-day run-in period, patients were randomly assigned (1:1:1) to receive oral rivaroxaban (2·5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban twice a day (5 m...
The aim of this study was to determine whether aspirin increases heart failure (HF) hospitalizati... more The aim of this study was to determine whether aspirin increases heart failure (HF) hospitalization or death in patients with HF with reduced ejection fraction receiving an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). Because of its cyclooxygenase inhibiting properties, aspirin has been postulated to increase HF events in patients treated with ACE inhibitors or ARBs. However, no large randomized trial has addressed the clinical relevance of this issue. We compared aspirin and warfarin for HF events (hospitalization, death, or both) in the 2,305 patients enrolled in the WARCEF (Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction) trial (98.6% on ACE inhibitor or ARB treatment), using conventional Cox models for time to first event (489 events). In addition, to examine multiple HF hospitalizations, we used 2 extended Cox models, a conditional model and a total time marginal model, in time to recurrent event analyses (1,078 events). After adjustment for baseline covariates, aspirin- and warfarin-treated patients did not differ in time to first HF event (adjusted hazard ratio: 0.87; 95% confidence interval: 0.72 to 1.04; p = 0.117) or first hospitalization alone (adjusted hazard ratio: 0.88; 95% confidence interval: 0.73 to 1.06; p = 0.168). The extended Cox models also found no significant differences in all HF events or in HF hospitalizations alone after adjustment for covariates. Among patients with HF with reduced ejection fraction in the WARCEF trial, there was no significant difference in risk of HF events between the aspirin and warfarin-treated patients. (Warfarin Versus Aspirin in Reduced Cardiac Ejection Fraction trial [WARCEF]; NCT00041938).
To compare long-term outcome of an early to a delayed invasive strategy in high-risk patients wit... more To compare long-term outcome of an early to a delayed invasive strategy in high-risk patients with non-ST elevation acute coronary syndrome (NSTE-ACS). This prospective, multicentre trial included patients with NSTE-ACS and at least two out of three of the following high-risk criteria: (1) evidence of extensive myocardial ischaemia on ECG, (2) elevated biomarkers for myocardial necrosis and (3) age above 65 years. Patients were randomised to either an early (angiography and revascularisation if appropriate <12 hours) or a delayed invasive strategy (>48 hours after randomisation). Endpoint for this prespecified long-term follow-up was the composite incidence of death or reinfarction after 2 years. Data collection was performed by telephone contact with the patients, their relatives or general practitioner and by review of hospital records. Endpoint status after 2-year follow-up was collected in 521 of 542 initially enrolled patients. Incidence of death or reinfarction was 11.8%...
The hemodynamic effects of two low osmolar contrast media, iohexol and ioxaglate, were compared i... more The hemodynamic effects of two low osmolar contrast media, iohexol and ioxaglate, were compared in 24 patients undergoing selective coronary angiography because of suspected significant coronary heart disease. Neither medium had a significant effect on left ventricular function when injected into the left or right coronary artery. The image quality and radiological value of the media were similar. Mild side effects were suffered by 14 patients but no statistical difference was shown between the media as to the number of adverse reactions.
... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterH... more ... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterHJM Dunselman, for ... Nijmegen, ILD Nauta; Groot Ziekengasthuis 's Her-togenbosch, RJJ Claessens; Rijnstate Hospital Arnhem, L van Kempen; Deventer Hospital, DJA ...
... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterH... more ... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterHJM Dunselman, for ... Nijmegen, ILD Nauta; Groot Ziekengasthuis 's Her-togenbosch, RJJ Claessens; Rijnstate Hospital Arnhem, L van Kempen; Deventer Hospital, DJA ...
Netherlands heart journal : monthly journal of the Netherlands Society of Cardiology and the Netherlands Heart Foundation, 2009
Background. Patients with coronary artery disease are at high risk of coronary events and death, ... more Background. Patients with coronary artery disease are at high risk of coronary events and death, but effective secondary prevention can reduce this risk. There is a gap between guidelines on secondary prevention and the implementation of these measures, which could potentially be reduced by nurse led prevention clinics (NLPC).Objectives. The aim of the current study is to quantify the impact of NLPC on the risk of cardiovascular events in patients with established coronary artery disease.Methods. A randomised, multicentre clinical trial of NLPC in addition to usual care or usual care alone in post-acute coronary syndrome patients. (Neth Heart J 2009;17:322-8.).
... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterH... more ... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterHJM Dunselman, for ... Nijmegen, ILD Nauta; Groot Ziekengasthuis 's Her-togenbosch, RJJ Claessens; Rijnstate Hospital Arnhem, L van Kempen; Deventer Hospital, DJA ...
Journal of The American College of Cardiology, 1999
OBJECTIVESThe purpose of this study was to compare recombinant hirudin and heparin as adjuncts to... more OBJECTIVESThe purpose of this study was to compare recombinant hirudin and heparin as adjuncts to streptokinase thrombolysis in patients with acute myocardial infarction (AMI).BACKGROUNDExperimental studies and previous small clinical trials suggest that specific thrombin inhibition improves early patency rates and clinical outcome in patients treated with streptokinase.METHODSIn a randomized double-blind, multicenter trial, 1,208 patients with AMI ≤6 h were treated
The ratio of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol (LDL-C/... more The ratio of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol (LDL-C/HDL-C) is a reliable predictor of cardiovascular risk. Low HDL-C levels in patients with coronary artery disease are associated with a high risk for cardiovascular events. This study compared the effects of rosuvastatin and atorvastatin on the LDL-C/HDL-C. Patients aged 40-80 years with established cardiovascular disease and HDL-C &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 1.0 mmol/L (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 40 mg/dL) entered as a 6-week dietary run-in period, before randomisation to open-label treatment with rosuvastatin 10 mg (n = 230) or atorvastatin 20 mg (n = 231) for 6 weeks. Doses were increased after 6 weeks to rosuvastatin 20 mg or atorvastatin 40 mg, and after 12 weeks to rosuvastatin 40 mg or atorvastatin 80 mg. Serum lipid parameters were measured at baseline and 6, 12 and 18 weeks. After 6 weeks of treatment, mean percentage change from baseline in LDL-C/HDL-C ratio was -47.0% in the rosuvastatin group and -41.9% in the atorvastatin group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05 for between-group comparison). After 12 and 18 weeks of treatment, change from baseline was -53.0% and -57.3%, respectively, for rosucastatin, compared with -47.9% and -49.6%, respectively, for atorvastatin (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01 and p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001, respectively, for between-group comparison). Rosuvastatin also reduced LDL-C, total cholesterol/HDL-C significantly more than atorvastatin at all three time points, and significantly improved total cholesterol/HDL-C and apolipoprotein B/A-I ratios. Rosuvastatin 10, 20 and 40 mg is significantly more effective than atorvastatin 20, 40 and 80 mg, respectively, in improving the LDL-C/HDL-C ratio in patients with cardiovascular disease and low HDL-C. Further studies are required to clarify the benefits of rosuvastatin for reduction of cardiovascular risk.
Background. Patients with coronary artery disease are at high risk of coronary events and death, ... more Background. Patients with coronary artery disease are at high risk of coronary events and death, but effective secondary prevention can reduce this risk. There is a gap between guidelines on secondary prevention and the implementation of these measures, ...
... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterH... more ... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterHJM Dunselman, for ... Nijmegen, ILD Nauta; Groot Ziekengasthuis 's Her-togenbosch, RJJ Claessens; Rijnstate Hospital Arnhem, L van Kempen; Deventer Hospital, DJA ...
Left atrium (LA) dilation is associated with adverse cardiovascular (CV) outcomes. Blood stasis, ... more Left atrium (LA) dilation is associated with adverse cardiovascular (CV) outcomes. Blood stasis, thrombus formation and atrial fibrillation may occur, especially in heart failure (HF) patients. It is not known whether preventive antithrombotic treatment may decrease the incidence of CV events in HF patients with LA enlargement. We investigated the relationship between LA enlargement and CV outcomes in HF patients and the effect of different antithrombotic treatments. Two-dimensional echocardiography with LA volume index (LAVi) measurement was performed in 1148 patients with systolic HF from the Warfarin versus Aspirin in Reduced Ejection Fraction (WARCEF) trial. Patients were randomized to warfarin or aspirin and followed for 3.4 ± 1.7 years. While the primary aim of the trial was a composite of ischaemic stroke, death, and intracerebral haemorrhage, the present report focuses on the individual CV events, whose incidence was compared across different LAVi and treatment subgroups. Af...
Previous studies in patients with atrial fibrillation showed that a history of heart failure (HF)... more Previous studies in patients with atrial fibrillation showed that a history of heart failure (HF) could negatively impact anticoagulation quality, as measured by the average time in therapeutic range (TTR). Whether additional markers of HF severity are associated with TTR has not been investigated thoroughly. We aimed to examine the potential role of HF severity in the quality of warfarin control in patients with HF with reduced ejection fraction. Data from the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction Trial were used to investigate the association between TTR and HF severity. Multivariable logistic regression models were used to examine the association of markers of HF severity, including New York Heart Association (NYHA) class, Minnesota Living with HF (MLWHF) score, and frequency of HF hospitalization, with TTR ≥70% (high TTR). We included 1,067 participants (high TTR, N = 413; low TTR, N = 654) in the analysis. In unadjusted analysis, patients with a high TTR ...
Patients with peripheral artery disease have an increased risk of cardiovascular morbidity and mo... more Patients with peripheral artery disease have an increased risk of cardiovascular morbidity and mortality. Antiplatelet agents are widely used to reduce these complications. This was a multicentre, double-blind, randomised placebo-controlled trial for which patients were recruited at 602 hospitals, clinics, or community practices from 33 countries across six continents. Eligible patients had a history of peripheral artery disease of the lower extremities (previous peripheral bypass surgery or angioplasty, limb or foot amputation, intermittent claudication with objective evidence of peripheral artery disease), of the carotid arteries (previous carotid artery revascularisation or asymptomatic carotid artery stenosis of at least 50%), or coronary artery disease with an ankle-brachial index of less than 0·90. After a 30-day run-in period, patients were randomly assigned (1:1:1) to receive oral rivaroxaban (2·5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban twice a day (5 m...
The aim of this study was to determine whether aspirin increases heart failure (HF) hospitalizati... more The aim of this study was to determine whether aspirin increases heart failure (HF) hospitalization or death in patients with HF with reduced ejection fraction receiving an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). Because of its cyclooxygenase inhibiting properties, aspirin has been postulated to increase HF events in patients treated with ACE inhibitors or ARBs. However, no large randomized trial has addressed the clinical relevance of this issue. We compared aspirin and warfarin for HF events (hospitalization, death, or both) in the 2,305 patients enrolled in the WARCEF (Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction) trial (98.6% on ACE inhibitor or ARB treatment), using conventional Cox models for time to first event (489 events). In addition, to examine multiple HF hospitalizations, we used 2 extended Cox models, a conditional model and a total time marginal model, in time to recurrent event analyses (1,078 events). After adjustment for baseline covariates, aspirin- and warfarin-treated patients did not differ in time to first HF event (adjusted hazard ratio: 0.87; 95% confidence interval: 0.72 to 1.04; p = 0.117) or first hospitalization alone (adjusted hazard ratio: 0.88; 95% confidence interval: 0.73 to 1.06; p = 0.168). The extended Cox models also found no significant differences in all HF events or in HF hospitalizations alone after adjustment for covariates. Among patients with HF with reduced ejection fraction in the WARCEF trial, there was no significant difference in risk of HF events between the aspirin and warfarin-treated patients. (Warfarin Versus Aspirin in Reduced Cardiac Ejection Fraction trial [WARCEF]; NCT00041938).
To compare long-term outcome of an early to a delayed invasive strategy in high-risk patients wit... more To compare long-term outcome of an early to a delayed invasive strategy in high-risk patients with non-ST elevation acute coronary syndrome (NSTE-ACS). This prospective, multicentre trial included patients with NSTE-ACS and at least two out of three of the following high-risk criteria: (1) evidence of extensive myocardial ischaemia on ECG, (2) elevated biomarkers for myocardial necrosis and (3) age above 65 years. Patients were randomised to either an early (angiography and revascularisation if appropriate <12 hours) or a delayed invasive strategy (>48 hours after randomisation). Endpoint for this prespecified long-term follow-up was the composite incidence of death or reinfarction after 2 years. Data collection was performed by telephone contact with the patients, their relatives or general practitioner and by review of hospital records. Endpoint status after 2-year follow-up was collected in 521 of 542 initially enrolled patients. Incidence of death or reinfarction was 11.8%...
The hemodynamic effects of two low osmolar contrast media, iohexol and ioxaglate, were compared i... more The hemodynamic effects of two low osmolar contrast media, iohexol and ioxaglate, were compared in 24 patients undergoing selective coronary angiography because of suspected significant coronary heart disease. Neither medium had a significant effect on left ventricular function when injected into the left or right coronary artery. The image quality and radiological value of the media were similar. Mild side effects were suffered by 14 patients but no statistical difference was shown between the media as to the number of adverse reactions.
... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterH... more ... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterHJM Dunselman, for ... Nijmegen, ILD Nauta; Groot Ziekengasthuis 's Her-togenbosch, RJJ Claessens; Rijnstate Hospital Arnhem, L van Kempen; Deventer Hospital, DJA ...
... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterH... more ... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterHJM Dunselman, for ... Nijmegen, ILD Nauta; Groot Ziekengasthuis 's Her-togenbosch, RJJ Claessens; Rijnstate Hospital Arnhem, L van Kempen; Deventer Hospital, DJA ...
Netherlands heart journal : monthly journal of the Netherlands Society of Cardiology and the Netherlands Heart Foundation, 2009
Background. Patients with coronary artery disease are at high risk of coronary events and death, ... more Background. Patients with coronary artery disease are at high risk of coronary events and death, but effective secondary prevention can reduce this risk. There is a gap between guidelines on secondary prevention and the implementation of these measures, which could potentially be reduced by nurse led prevention clinics (NLPC).Objectives. The aim of the current study is to quantify the impact of NLPC on the risk of cardiovascular events in patients with established coronary artery disease.Methods. A randomised, multicentre clinical trial of NLPC in addition to usual care or usual care alone in post-acute coronary syndrome patients. (Neth Heart J 2009;17:322-8.).
... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterH... more ... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterHJM Dunselman, for ... Nijmegen, ILD Nauta; Groot Ziekengasthuis 's Her-togenbosch, RJJ Claessens; Rijnstate Hospital Arnhem, L van Kempen; Deventer Hospital, DJA ...
Journal of The American College of Cardiology, 1999
OBJECTIVESThe purpose of this study was to compare recombinant hirudin and heparin as adjuncts to... more OBJECTIVESThe purpose of this study was to compare recombinant hirudin and heparin as adjuncts to streptokinase thrombolysis in patients with acute myocardial infarction (AMI).BACKGROUNDExperimental studies and previous small clinical trials suggest that specific thrombin inhibition improves early patency rates and clinical outcome in patients treated with streptokinase.METHODSIn a randomized double-blind, multicenter trial, 1,208 patients with AMI ≤6 h were treated
The ratio of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol (LDL-C/... more The ratio of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol (LDL-C/HDL-C) is a reliable predictor of cardiovascular risk. Low HDL-C levels in patients with coronary artery disease are associated with a high risk for cardiovascular events. This study compared the effects of rosuvastatin and atorvastatin on the LDL-C/HDL-C. Patients aged 40-80 years with established cardiovascular disease and HDL-C &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 1.0 mmol/L (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 40 mg/dL) entered as a 6-week dietary run-in period, before randomisation to open-label treatment with rosuvastatin 10 mg (n = 230) or atorvastatin 20 mg (n = 231) for 6 weeks. Doses were increased after 6 weeks to rosuvastatin 20 mg or atorvastatin 40 mg, and after 12 weeks to rosuvastatin 40 mg or atorvastatin 80 mg. Serum lipid parameters were measured at baseline and 6, 12 and 18 weeks. After 6 weeks of treatment, mean percentage change from baseline in LDL-C/HDL-C ratio was -47.0% in the rosuvastatin group and -41.9% in the atorvastatin group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05 for between-group comparison). After 12 and 18 weeks of treatment, change from baseline was -53.0% and -57.3%, respectively, for rosucastatin, compared with -47.9% and -49.6%, respectively, for atorvastatin (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01 and p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001, respectively, for between-group comparison). Rosuvastatin also reduced LDL-C, total cholesterol/HDL-C significantly more than atorvastatin at all three time points, and significantly improved total cholesterol/HDL-C and apolipoprotein B/A-I ratios. Rosuvastatin 10, 20 and 40 mg is significantly more effective than atorvastatin 20, 40 and 80 mg, respectively, in improving the LDL-C/HDL-C ratio in patients with cardiovascular disease and low HDL-C. Further studies are required to clarify the benefits of rosuvastatin for reduction of cardiovascular risk.
Background. Patients with coronary artery disease are at high risk of coronary events and death, ... more Background. Patients with coronary artery disease are at high risk of coronary events and death, but effective secondary prevention can reduce this risk. There is a gap between guidelines on secondary prevention and the implementation of these measures, ...
... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterH... more ... Dirk JA Lok, Rich JJ Claessens, Peter JLM Bemink, W. Hans Pasteuning, J. Herre Kingma, PeterHJM Dunselman, for ... Nijmegen, ILD Nauta; Groot Ziekengasthuis 's Her-togenbosch, RJJ Claessens; Rijnstate Hospital Arnhem, L van Kempen; Deventer Hospital, DJA ...
Uploads
Papers by Dirk Lok