Effect of caffeine on platelet inhibition by clopidogrel in healthy subjects and patients with coronary artery disease.

Background: Clopidogrel inhibits the platelet P2Y12 receptor, leading to increased intracellular cyclic AMP (cAMP) levels. Caffeine also causes a rise in platelet cAMP. We aimed to test the effect of acute caffeine administration on platelet inhibition by clopidogrel, in healthy volunteers and patients with coronary artery disease.

Effect of ranitidine on the antiplatelet effects of aspirin in healthy human subjects.

Aspirin is often taken with H2-receptor antagonists. In vitro data suggest that certain antagonists, such as ranitidine, have inhibitory effects on platelet function. There are no reports on the combined effect of aspirin and H2-receptor antagonists on platelet function in humans.

Platelet reactivity in patients with subacute stent thrombosis compared with non-stent-related acute myocardial infarction.

Background: Recent case control studies suggest that patients with subacute stent thrombosis (SAT) have increased platelet reactivity. However, SAT often presents as acute myocardial infarction (AMI), which is also associated with augmented platelet activation. We therefore compared platelet reactivity in patients with SAT and patients with AMI unrelated to stenting.

Potential role of activated platelets in homing of human endothelial progenitor cells to subendothelial matrix.

Endothelial progenitor cells (EPCs) mobilize from the bone marrow in response to tissue injury and participate in vascular repair. However, there is limited data about the homing mechanisms of EPCs to vascular injury sites. Recently animal experiments indicated that platelets play a role in recruitment of EPCs to injury sites.

Color tissue Doppler myocardial velocities consistently underestimate spectral tissue Doppler velocities: impact on calculation peak transmitral pulsed Doppler velocity/early diastolic tissue Doppler velocity (E/Ea).

Background: Color tissue Doppler (TD) measures mean myocardial velocities, whereas spectral TD measures peak velocities. Given that most data on left ventricular (LV) diastolic function used spectral TD, we investigated whether the differences in myocardial velocities between these modalities resulted in discrepancies in calculated E/Ea.

Methods: Patients were imaged using an ultrasound machine.

Matrix metalloproteinases in ascending aortic aneurysms: bicuspid versus trileaflet aortic valves.

Background: Abnormal matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) expression contributes to the development of abdominal aortic aneurysms. Recent data suggest that MMP-2 and MMP-9 may also play a role in thoracic aortic disease. We sought to determine (1) whether ascending aortic aneurysms are associated with increased MMP expression and (2) whether aortic inflammation and MMP expression differ between patients with congenital bicuspid aortic valves (BAVs) and those with trileaflet aortic valves (TAVs).

Deployment of balloon expandable stents during open repair of thoracoabdominal aortic aneurysms: a new strategy for managing renal and mesenteric artery lesions.

Objective: Patients undergoing graft repair of thoracoabdominal aortic aneurysms (TAAAs) often require concomitant correction of ostial stenoses or dissection involving visceral branches. The purpose of this report is to describe our initial experience with a new strategy for addressing these lesions during open TAAA repair-direct deployment of balloon expandable stents into the renal and mesenteric arteries.

Methods: Over a two-year period, 367 patients have undergone TAAA surgery.

Achieving greater reductions in cardiovascular risk: lessons from statin therapy on risk measures and risk reduction.

Reductions in low-density lipoprotein (LDL) cholesterol with statins have been shown to significantly reduce risk of coronary heart disease (CHD) in the primary- and secondary-prevention settings. Benefit has been observed even in high-risk patients whose baseline LDL cholesterol levels were below the drug initiation levels recommended by current treatment guidelines. Levels of non-high-density lipoprotein cholesterol or total apolipoprotein B more accurately reflect circulating levels of atherogenic particles than does LDL cholesterol concentration, and may provide a surrogate marker that correlates better to CHD event reduction after statin therapy than LDL cholesterol level.

Left heart bypass during descending thoracic aortic aneurysm repair does not reduce the incidence of paraplegia.

Background: The preferred technique for spinal cord protection during surgical repair of descending thoracic aortic aneurysms (DTAAs) remains controversial. The purpose of this retrospective analysis was to determine if the use of left heart bypass (LHB) reduced the incidence of paraplegia in patients who underwent DTAA repair.

Methods: Over a 15-year period 387 consecutive patients underwent surgical repair of DTAAs using either the "clamp-and-sew" technique (341 patients, 88.

Platelet-monocyte complex formation: effect of blocking PSGL-1 alone, and in combination with alphaIIbbeta3 and alphaMbeta2, in coronary stenting.

Background: Binding of platelet P-selectin to P-selectin glycoprotein ligand 1 (PSGL-1) is an initial event in the interactions between platelets and monocytes. Platelet-monocyte complexes (PMCs) have been implicated in several vascular disease processes, including acute coronary syndromes (ACS) and complications after percutaneous coronary intervention (PCI). We investigated the effect of ex vivo blockade of PSGL-1, alone and in combination with blockade of the alphaMbeta(2) (Mac-1) and alpha(IIb)beta(3) (GP IIb/IIIa) integrins, on PMC formation.

Evolving revascularization approaches for myocardial ischemia.

Stable angina pectoris secondary to ischemic heart disease is a common and disabling condition. Medical therapy aims to relieve symptoms, improve exercise capacity, and decrease cardiac events by reducing myocardial oxygen demand or improving coronary blood supply to the ischemic myocardium. If medical treatment is inadequate, invasive revascularization procedures to improve coronary perfusion are considered.

Identification of hibernating myocardium with quantitative intravenous myocardial contrast echocardiography: comparison with dobutamine echocardiography and thallium-201 scintigraphy.

Background: There are currently no data on the accuracy of intravenous myocardial contrast echocardiography (MCE) in detecting myocardial hibernation in man and its comparative accuracy to dobutamine echocardiography (DE) or thallium 201 (Tl(201)) scintigraphy.

Methods And Results: Twenty patients with coronary artery disease and ventricular dysfunction underwent MCE 1 to 5 days before bypass surgery and repeat echocardiography at 3 to 4 months. Patients also underwent DE (n=18) and rest-redistribution Tl(201) tomography (n=16) before revascularization.

Is glycoprotein IIb/IIIa antagonism as effective in women as in men following percutaneous coronary intervention?. Lessons from the ESPRIT study.

Objective: The study was done to determine whether eptifibatide, a platelet glycoprotein (GP) IIb/IIIa antagonist, prevents ischemic complications following percutaneous coronary interventions (PCIs) in women as well as in men.

Background: Eptifibatide reduces ischemic complications after nonurgent coronary stent interventions.

Methods: We compared outcomes in women (n = 562) and men (n = 1,502) enrolled in the Enhanced Suppression of the Platelet GP IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial of double-bolus eptifibatide during PCI.

Prospective analysis of creatine kinase muscle-brain fraction and comparison with troponin T to predict cardiac risk and benefit of an invasive strategy in patients with non-ST-elevation acute coronary syndromes.

Objective: We sought to determine whether elevation of plasma creatine kinase muscle-brain fraction (CK-MB) would be useful to triage patients with acute coronary syndromes (ACS) to early angiography/revascularization.

Background: It is unknown whether the measurement of CK-MB is effective for triage to an aggressive management strategy.

Method: Patients in the Treat Angina With Aggrastat and Determine Cost of Therapy With an Invasive or Conservative Strategy (TACTICS-TIMI) 18 study received aspirin, heparin, and tirofiban for treatment of ACS, were randomized to an invasive or a conservative strategy (angiography/revascularization between 4 and 48 h), and were followed up for a composite end point of death, myocardial infarction, or rehospitalization for ACS.

Morbidity and mortality after extent II thoracoabdominal aortic aneurysm repair.

Background: Surgical repair of Crawford extent II thoracoabdominal aortic aneurysms (TAAAs) carries substantial risk for morbidity and mortality. The purpose of this study was to analyze the results of a large consecutive series of extent II TAAA repairs and identify factors that influence morbidity and survival.

Methods: Of 1,415 consecutive patients who underwent TAAA operations over a 13-year period, 442 (31.