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Biomedical subjects

Luc A Piérard

Publications and source records attributed to Luc A Piérard.

17 recordsLinked to original sources
PubMed2006

Exercise ventilation inefficiency in heart failure: pathophysiological and clinical significance.

Heart failure (HF) is a complex syndrome characterized by myocardial dysfunction and a poor prognosis. Among multiple markers of severity, an exercise ventilation inefficiency has important clinical and prognostic value. The pathophysiology determining exercise ventilatory inefficiency is complex and not definitively clarified. Three different mechanisms have been identified: (i) increased dead space, (ii) early occurrence of lactic acidosis, and (iii) abnormal chemoreflex and/or metaboreflex activity. Besides its prognostic value, abnormal ventilation can be influenced by pharmacological and non-pharmacological therapies such as beta-blockers, selective cyclic 3'-5' guanosine monosphosphate phosphodiesterase inhibitors, physical training, and nocturnal continuous positive airway pressure. There is an increasing interest for the exercise periodic breathing, which is frequently associated with HF syndrome and has prognostic importance. The precise mechanisms sustaining exercise periodic breathing are not fully defined but ventilatory and metabo-haemodynamic hypotheses have been proposed.

Adrenergic beta-Antagonists↗
PubMed2006

Quantitative analysis of semi-supine exercise echocardiography--influence of age on myocardial Doppler imaging indices.

OBJECTIVES: This study was performed to evaluate the feasibility of quantitative analysis of exercise echocardiography using pulsed wave Doppler myocardial imaging (DMI) and to examine the relation between age and DMI parameters at rest and during graded exercise in normal subjects. METHODS AND RESULTS: Seventy-two healthy volunteers were divided into three age groups (group I, age < or = 40 years, group II, age 41 - 59 years and group III, age > or = 60 years), and underwent a semi-supine exercise echocardiogram. Peak systolic velocity (SV), time to peak SV (TPV), systolic velocity time integral (VTI) and peak diastolic velocities (VE and VA) were measured off-line. There was a heterogeneity in DMI parameters between different myocardial walls and a gradient was found between basal and mid segments. Both persisted during exercise. Group I had significantly higher TPV than groups II and III. Increase in workload was accompanied by an increase in velocities, while TPV decreased. Differences between groups persisted throughout exercise. CONCLUSIONS: Off-line measurements of DMI parameters are feasible during exercise. SV and E decline as age increases while A increases. SV already increases at low charge exercise and may serve as a quantitative marker for the detection of myocardial viability. Change of the absolute DMI velocity values during exercise may provide a better indicator of ischaemia or viability than the absolute values themselves.

Adult↗
PubMed2005

Acute neutrophil activation in direct stenting: comparison of stable and unstable angina patients.

BACKGROUND: Polymorphonuclear neutrophils have been implicated in the pathophysiology of atherosclerosis. A substantial body of evidence has emerged to implicate the role of specific leucocyte derived enzyme myeloperoxidase in atherogenesis, since its initiation through progression until destabilization. The aim of the study was to determine the presence of polymorphonuclear neutrophils activation after coronary stenting, to compare this activation between stable and unstable setting and to evaluate the kinetic relation of this activation with inflammatory response following atherosclerotic plaque rupture. METHODS: Myeloperoxidase, lactoferrin, elastase, C-reactive protein and cytokine plasma levels were assessed in 15 patients undergoing direct coronary stenting for unstable angina (Group A) and compared to 11 patients undergoing this procedure for stable angina (Group B). Serial sampling starting before arteriography and continued for 24 h was carried out in all patients. RESULTS: A significant elevation in myeloperoxidase and lactoferrin levels was observed after stenting in both group A (p<0.0001) and group B (p<0.0001), but was higher in group A. Interleukin-8, interleukin-12 and interleukin-6 levels increased temporarily after stenting in the 2 groups. Baseline values of C-reactive protein were similar in the 2 groups and a progressive increase was observed after the intervention. CONCLUSIONS: Direct coronary artery stenting is associated with an early polymorphonuclear neutrophils activation followed by release of inflammatory cytokines (interleukin-6, interleukin-8, interleukin-12) and C-reactive protein elevation in both stable and unstable patients. We conclude that stenting by itself is associated with myeloperoxidase liberation with a significantly enhanced response in unstable patients.

Adult↗
PubMed2005

Long-term outcome of patients with heart failure and dynamic functional mitral regurgitation.

AIMS: In patients with heart failure and chronic ischaemic mitral regurgitation (MR), the mortality risk is related to the quantified severity of MR at rest and its dynamic changes during exercise. The impact of dynamic MR on long-term mortality, hospital admission for heart failure, and major adverse cardiac events has never been investigated. METHODS AND RESULTS: We prospectively studied 161 patients with chronic ischaemic left ventricular (LV) dysfunction and at least mild MR who underwent quantitative measurement of the effective regurgitant orifice (ERO) of MR at rest and during semi-supine exercise test and who were followed up for 35+/-11 months. The 20 patients who underwent surgery were censored at the time of operation. Of the 141 patients who were treated medically, 23 died, 22 required hospitalization for heart failure, 4 had nonfatal myocardial infarction, and 11 developed unstable angina. By multivariate analysis, an exercise-induced increase in ERO by > or =13 mm(2) and a greater increase in transtricuspid pressure gradient during exercise emerged as predictors of mortality and of hospital admission for heart failure. MR severity under basal conditions (ERO> or =20 mm(2)) was an independent predictor of only cardiac death. Greater LV volumes at rest and lack of contractile reserve during exercise were additional independent markers of poor outcome. CONCLUSION: In patients with ischaemic heart disease and LV dysfunction, large exercise-induced increases in MR identify patients at high risk of morbidity and of death.

Aged↗
PubMed2005

Early release of neutrophil markers of activation after direct stenting in patients with unstable angina.

OBJECTIVE: To assess polymorphonuclear neutrophils activation after stenting in acute coronary syndromes studied by myeloperoxydase, lactoferrin and elastase release in this clinical setting. METHODS: Myeloperoxydase, lactoferrin, elastase, C-reactive protein and cytokines serum levels were assessed in 20 patients undergoing catheterization for unstable angina. Serial sampling starting before arteriography and continued up to 24 h was carried out in 15 patients undergoing direct stenting (group A) and in five patients assessed by coronary angiography only (group B). RESULTS: Myeloperoxydase, lactoferrin and elastase levels remained unchanged following catheterization, whereas a significant increase in myeloperoxydase (P = 0.0009) and lactoferrin (P = 0.004) was observed after stenting. No change in levels of tumour necrosis factor alpha, interleukin (IL)-8 and IL-11 was found in group B after catheterization at the different sampling times, although IL-8 and IL-11 levels increased transiently following stenting. IL-6 values increased in both groups. Baseline values of C-reactive protein were similar in each group. A progressive increase in C-reactive protein was noted in both groups and appeared to be larger following stenting (group A: P = 0.0002; group B: P = 0.01). CONCLUSIONS: In patients with unstable angina, stenting is associated by immediate neutrophil activation followed by release of inflammatory cytokines (IL-6, IL-8, IL-11) and C-reactive protein elevation. This study points out a potential role of myeloperoxydase as a trigger for inflammatory reaction in patients with unstable coronary syndromes undergoing percutaneous coronary intervention.

Adult↗
PubMed2004

The role of ischemic mitral regurgitation in the pathogenesis of acute pulmonary edema.

BACKGROUND: Acute mitral regurgitation may cause pulmonary edema, but the pathogenetic role of chronic ischemic mitral regurgitation, a dynamic condition, has not yet been characterized. METHODS: We prospectively studied 28 patients (mean [+/-SD] age, 65+/-11 years) with acute pulmonary edema and left ventricular systolic dysfunction and 46 patients without a history of acute pulmonary edema. The two groups were matched for all baseline characteristics. Patients underwent quantitative Doppler echocardiography during exercise. Exercise-induced changes in the left ventricular volume, the ejection fraction, the mitral regurgitant volume, the effective regurgitant orifice area, and the transtricuspid pressure gradient were compared in patients with and without acute pulmonary edema. RESULTS: The two groups had similar clinical and baseline echocardiographic characteristics. They also had similar exercise-induced changes in heart rate, systolic blood pressure, and left ventricular volumes. In the univariate analysis, patients with recent pulmonary edema had a much higher increase than did the patients without pulmonary edema in mitral regurgitant volume (26+/-14 ml vs. 5+/-14 ml, P<0.001), the effective regurgitant orifice area (16+/-10 mm2 vs. 2+/-9 mm2, P<0.001), and the transtricuspid pressure gradient (29+/-10 mm Hg vs. 13+/-11 mm Hg, P<0.001). In the multivariate analysis, exercise-induced changes in the effective regurgitant orifice area (P<0.001), in the transtricuspid pressure gradient (P=0.001), and in the left ventricular ejection fraction (P=0.02) were independently associated with a history of recent pulmonary edema. CONCLUSIONS: In patients with left ventricular systolic dysfunction, acute pulmonary edema is associated with the dynamic changes in ischemic mitral regurgitation and the resulting increase in pulmonary vascular pressure.

Acute Disease↗
PubMed2004

Predictors of rapid QRS widening in patients with coronary artery disease and left ventricular dysfunction.

To assess the predictors of rapid QRS widening in patients with chronic ischemic left ventricular dysfunction, 82 patients who underwent > or =2 electrocardiograms and exercise Doppler echocardiography were studied. In a multivariate analysis, left ventricular end-diastolic volume, a large increase in mitral regurgitant volume during exercise, and diabetes emerged as independent predictors of QRS widening.

Aged↗
PubMed2003

Determinants of exercise-induced changes in mitral regurgitation in patients with coronary artery disease and left ventricular dysfunction.

OBJECTIVES: We sought to examine the determinants of exercise-induced changes in ischemic mitral regurgitation (MR) in patients with left ventricular (LV) dysfunction. BACKGROUND: In the post-myocardial infarction (MI) phase, ischemic MR contributes to worsening of symptoms and of LV dysfunction. METHODS: In this study, 70 patients in the chronic, post-MI phase, with LV ejection fraction <45% and at least mild MR, underwent semi-supine exercise Doppler echocardiography. The effective regurgitant orifice (ERO) of MR was quantified at rest and during exercise. Exercise-induced changes in ERO were compared with changes in mitral deformation and in local and global LV remodeling. RESULTS: The wide range of exercise-induced ERO changes that were observed was unrelated to the degree of MR at rest (r = 0.20). Effective regurgitant orifice changes correlated best with changes in mitral deformation (i.e., differences in systolic mitral tenting area, systolic annular area, and coaptation height) (p < 0.0001). Posterior displacement of the papillary muscles was associated with larger changes in the ERO in both infarct groups. In patients with inferior MI, a decrease in the ERO was related to improvement in wall motion (r = 0.68). The independent predictors of ERO changes during exercise were changes in systolic annular area for all infarct categories, in tenting area and wall motion score in the global population and those with inferior infarction, and in apical displacement of mitral leaflets for patients with anterior MI. CONCLUSIONS: The degree of MR at rest is unrelated to exercise-induced changes in EROs, which are related to those in local LV remodeling and in mitral deformation but not those in global LV function.

Echocardiography, Doppler↗
PubMed2003

Detection and clinical usefulness of a biphasic response during exercise echocardiography early after myocardial infarction.

OBJECTIVE: The aim of this study was to determine the accuracy of exercise echocardiography (EE) for detecting infarct-related artery (IRA) stenosis and predicting functional recovery early after acute myocardial infarction (AMI). BACKGROUND: Dobutamine stress echocardiography is widely used for identifying jeopardized myocardium. The clinical usefulness of a biphasic response detected during EE has never been investigated. METHODS: A total of 114 consecutive patients with a first AMI and > or = 2 dyssynergic segments in the infarct-related territory underwent semi-supine continuous EE 6 +/- 2 days after AMI. Quantitative coronary angiography was performed in all patients after EE. A follow-up echocardiogram was obtained one month later. RESULTS: Ninety-seven patients had significant (> or = 50%) IRA stenosis, and 26 had multivessel disease. Residual ischemia was identified in 77 patients (biphasic response in 62 and worsening response in 15). The sensitivity and specificity of ischemia during EE for predicting IRA stenosis were 75% and 76%, respectively. The sensitivity of a biphasic response was higher than the sensitivity of a worsening response (61% vs. 14%, p < 0.0001). Wall motion abnormalities induced in other vascular territories were specific (97%) and moderately sensitive (62%) for the detection of multivessel disease. Functional recovery was observed in 75 patients. Two independent variables predicted contractile recovery: contractile reserve during EE (p < 0.0001) and elective angioplasty of the IRA (p = 0.002). A biphasic response, but not sustained improvement, predicted reversible dysfunction (73% vs. 9%, p < 0.0001). CONCLUSIONS: A biphasic response can be detected during exercise. Exercise echocardiography is an accurate tool for detecting IRA stenosis and predicting functional improvement early after AMI.

Cardiotonic Agents↗
PubMed2002

Persistent negative T waves in the infarct-related leads as an independent predictor of poor long-term prognosis after acute myocardial infarction.

This study sought to determine the long-term prognostic significance of persistent or transient negative T waves in infarct-related leads. After acute myocardial infarction (AMI), QRS and T wave alterations may resolve. No clinical study has investigated the prognostic importance of persistent versus transient negative T waves. We studied 147 consecutive patients with first AMI and >/=2 negative T waves in the infarct-related leads on the electrocardiogram. One hundred twenty patients developed Q waves. Patients were followed clinically for 60 +/- 21 months. T-wave normalization was observed early (before hospital discharge) in 34 patients and late (at 4 +/- 1 months) in 65. Thirty patients had Q-wave regression. Adverse outcome occurred in 57 patients. There were 23 hard events (cardiac death in 12 patients and nonfatal AMI in 11). Patients with early or late T-wave normalization had similar event-free survival curves that diverged rapidly from that of patients with persistent negative T waves, who had a worse outcome (p <0.0001). Patients with or without Q-wave regression had similar survival curves. Using multivariate Cox regression analysis, higher end-systolic volume (hazard ratio [HR] 1.01, p = 0.007), the presence of multivessel disease (HR 3.33, p = 0.009), and persistent negative T waves (HR 2.92, p = 0.024) predicted hard events. Persistent negative T waves 4 months after first AMI were independently associated with a worse outcome, whereas Q-wave regression has no long-term prognostic importance.

Adult↗