Comparison between initial and chronic response to clopidogrel therapy after coronary stenting for acute coronary syndrome and influence on clinical outcomes.

BACKGROUND: Studies have addressed the benefit of tailored therapy based on initial response to clopidogrel loading dose. However, the appropriate timing for platelet testing remains uncertain. METHODS: The present study was performed to compare initial clopidogrel response after 600 mg loading dose and 1-month platelet response and their relationship with ischemic and bleedings events. A total of 475 patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention have been included in the present study. All patients were treated with 600 mg clopidogrel followed by 150 mg daily. Clopidogrel low response was defined by high on-treatment platelet reactivity (HPR) with vasoactive stimulated phosphoprotein >50%, and "hyperresponse," as platelet reactivity index vasoactive stimulated phosphoprotein (PRI VASP) <95th percentile after 600 mg. RESULTS: After 600 mg, 210 patients were identified with HPR (44%), and 23 patients (5%), with hyperresponse (PRI VASP <8%). At 1 month on 150 mg clopidogrel daily, 184 patients (39%) had HPR (39%), 14 patients (3 %) had hyperresponse, and mean PRI VASP was significantly lower (43% ± 19% vs 46% ± 21%, P = .04). At 1 month, among the 210 patients with HPR after 600 mg, 127 (60%) remained, whereas among the 265 patients responders after 600 mg, only 57 (22%) remained with HPR (60% vs 22%, P < .0001). Initial response was significantly associated with risk of stent thrombosis and bleeding complications, whereas 1-month assessment was only linked with bleeding events. CONCLUSION: In conclusion, the present study showed that initial clopidogrel response in patients with acute coronary syndrome is not a reliable predictor of response to maintenance therapy and their values for prediction of clinical outcome are likely to be different.

Characteristics of the paralysed diaphragm studied by M-mode ultrasonography.

BACKGROUND: M-mode ultrasonography might be useful for detecting hemidiaphragm paralysis. The objective of the present study was to describe the motion recorded by M-mode ultrasonography of both diaphragmatic leaves in patients with a pre-established diagnosis of hemidiaphragm paralysis. METHODS: A study was conducted in 26 patients (18 men, 8 women) with unilateral diaphragmatic paralysis. They were referred to two different rehabilitation centres after thoracic surgery in 23 cases and cardiac interventional procedures in three cases. The pulmonary function tests and the study of the diaphragmatic motion using M-mode ultrasonography were recorded. RESULTS: The pulmonary function tests showed a restrictive pattern. The M-mode ultrasonography reported either the absence of motion or a weak paradoxical (cranial) displacement (less than 0·5 cm) of the paralysed hemidiaphragm during quiet breathing. A paradoxical motion was recorded in all patients during voluntary sniffing, reaching around -1 cm. During deep breathing, a paradoxical motion at the beginning of the inspiration was observed. Thereafter, a re-establishment of the motion in the craniocaudal direction was recorded. The excursions measured on the healthy side, during quiet breathing and voluntary sniffing, were increased in patients suffering from contralateral hemidiaphragm paralysis, when compared with 170 healthy volunteers. CONCLUSIONS: To detect diaphragmatic dysfunction in patients at risk, it would be useful to study diaphragmatic motion by M-mode ultrasonography during quiet breathing, voluntary sniffing and deep breathing.

[Cardiac disease at risk in the young athlete]. / Pathologies cardiaques à risque chez le jeune sportif.

Physical training significantly reduces all cause mortality in the general population. Eligibility for competitive sport participation in athletes with cardiovascular diseases is based on recommendations. Incidence of sudden cardiac death in young athletes is low (0.5 to 2/100,000 athletes/year). The most common cardiac diseases at risk are hypertrophic cardiomyopathies, congenital coronary arteries abnormalities, arrhythmogenic right ventricular cardiomyopathy and acute myocarditis. Pre-participation screening is based on the cardiovascular evaluation, including ECG (repeated every 3years since the age of 12 and every 5years since the age of 20 to the age of 35). Some events are unpredictable (idiopathic ventricular fibrillation, sudden death related to congenital coronary arteries abnormalities or commotio cordis). A better access to public defibrillation is needed.

Role of endogenous adenosine as a predictive marker of vasoplegia during cardiopulmonary bypass and postoperative severe systemic inflammatory response.

OBJECTIVE: Systemic inflammatory response (SIRS) and severe SIRS (SIRS with organ dysfunction) occurring after cardiopulmonary bypass (CPB) are common causes of morbidity and mortality among cardiac surgical patients. These syndromes are often preceded by a profound vasodilation, characterized by vasoplegia occurring during surgery. Many substances have been implicated in their pathophysiology. Adenosine is a strong endogenous vasodilating agent released by endothelial cells and myocytes under metabolic stress and may be involved in blood pressure failure during CPB induced by severe SIRS. DESIGN: A prospective comparative observational study. SETTING: The operating room and intensive care unit of a tertiary care university hospital. PATIENTS: Adenosine plasma levels (mean+/-sd; APLs) were measured before (baseline), during, and immediately after surgery in 35 patients who underwent aortic valve replacement involving CPB. APLs were correlated to operative and postoperative clinical courses. MEASUREMENTS AND MAIN RESULTS: APLs were significantly higher in seven patients with vasoplegia and postoperative severe SIRS (1.6 micromol.L [0.2-2.6] vs. 0.4 micromol.L [0.1-1.0]) at baseline and during surgery. The duration of mechanical ventilation and stay in the intensive care unit were significantly longer for patients with higher APLs. Mean arterial pressure was inversely correlated with mean arterial APLs (Pearson's correlation coefficient: R=-0.66; p<.001). CONCLUSIONS: High APLs were found in patients with operative vasoplegia and postoperative severe SIRS occurring after cardiopulmonary bypass. This suggests that adenosine release is involved in vasoplegia that occurs during the systemic inflammatory response to cardiac surgery. Further studies are needed to clarify the association between cytokine production and adenosine release in severe SIRS following cardiac surgery.