Donald Palisaitis

• Université de Montréal

Objective: Although brachial cuff SBP is universally used to guide hypertension management, it can differ significantly from intraarterial SBP. We examine the potential impacts of cuff-to-intraarterial brachial SBP (bSBP) mismatch on hypertension treatment and accuracy towards central SBP. Methods: In 303 individuals, cuff bSBP (CUFF-bSBP) and c...

Objective Cuff-based brachial blood pressure (BP) is universally used as a guide to treat hypertension, although it can differ from the intraarterial BP. In this study, we examine the potential impact of cuff-to-intraarterial brachial systolic BP (bSBP) mismatch phenotypes on BP treatment and its impact on determination of central BP. Design and m...

Objectives: The objective was to assess the effect of ultrasound (US)-guidance compared to the anatomical landmark (AL) approach in patients requiring femoral artery (FA) access for coronary angiography/percutaneous coronary interventions (PCI). Background: US-guidance has been proposed as a strategy to optimize FA access, potentially leading to...

Transesophageal echocardiography. Two-dimensional midesophageal view of the aortic valve at 120° confirmed a large burden of hypoechogenic material consistent with thrombus diffusely apposed to the ventricular side of the leaflets.

Transesophageal echocardiography. Three-dimensional midesophageal short-axis view of the prosthetic aortic valve showed severely reduced opening.

Transthoracic echocardiography. Apical five-chamber view showing a mass in the left ventricular outflow tract.

Transthoracic echocardiography at 3-month follow-up. Zoomed apical five-chamber view showing resolution of the mass in left ventricular outflow tract.

Highlights • A case of very severe transcatheter heart valve thrombosis is described. • The patient was treated with warfarin with success. • The first line of treatment of transcatheter heart valve thrombosis is anticoagulation. • A trial of 2-3 months of warfarin should be tried before considering alternatives.

Abstract Epidemiological studies have linked clopidogrel discontinuation with an increased incidence of ischemic events. This has led to the hypothesis that clopidogrel discontinuation may result in a pharmacological rebound. We evaluated the impact of clopidogrel discontinuation on platelet function. Platelet aggregation was measured by light tran...

Background Following the approval of transcatheter aortic valve replacement (TAVR) for high-risk and inoperable patients with severe aortic stenosis (AS), many low- and moderate-volume TAVR programs have been initiated. Contemporary outcomes from these newly-initiated centers remain unknown. Methods In March 2013, our institution was authorized by...

Aspirin remains the most widely used drug in patients with cardiovascular disease to prevent acute ischemic events. Its daily administration reduces the risk of stroke, myocardial infarction and death by approximately 25%. However, inhibition of platelet aggregation by aspirin is variable, the cause of this phenomenon being most likely multifactori...

Interventional cardiology is a subspecialty of adult cardiology dedicated to the use and application of imaging-based diagnostic techniques and minimally invasive modalities for the treatment of cardiovascular disease. Currently, interventional cardiologists must demonstrate expert knowledge of cardiac imaging, along with cardiovascular anatomy and...

Platelets, long believed to be incapable of de novo protein synthesis, may retain their ability to form the cyclooxygenase (COX) enzyme once it has been inactivated by aspirin. This may explain the inefficacy of the drug to induce sustained platelet inhibition in certain patients. We evaluated the stability of platelet inhibition following once-dai...

Objective: Clopidogrel discontinuation is associated with increased incidence of ischemic events, which may signal a pharmacological rebound. We evaluated the impact of clopidogrel discontinuation on platelet function in CAD patients. Methods: Platelet aggregation was measured by VerifyNow ® P2Y 12 and by light transmission aggregometry (LTA) in re...

This study sought to assess whether inadequate platelet responses to aspirin and clopidogrel are distinct phenomena caused by different mechanisms or different facets of the same phenomenon (i.e., general platelet hyperactivity). A total of 85 patients with stable coronary artery disease who were taking aspirin and clopidogrel daily for > or =3 mon...

Adequate platelet inhibition before percutaneous coronary intervention (PCI) reduces periprocedural and long-term ischemic complications. Reduced response to clopidogrel has been associated with subsequent major adverse cardiovascular events. Strategies to optimize platelet inhibition pre-PCI are under investigation. This study evaluated the effect...

When studying the efficacy of clopidogrel to inhibit platelet aggregation by light transmission aggregometry, technical decisions must be taken prior to assessment or during analysis, including, but not limited to, concentration of agonist to use and timing of the evaluation of the response on the aggregation curve obtained (peak ADP-stimulated pla...

Several patient characteristics have been shown to increase the risk of inadequate platelet inhibition by aspirin, yet underlying mechanisms remain mostly unknown. We explored whether oxidative stress, via isoprostane formation, was associated with inadequate platelet response to aspirin. Additionally, we sought to investigate whether individual pr...

Hyporesponsiveness to antiplatelet agents has been linked to an increased risk of major adverse cardiovascular events. However, light transmission aggregometry (LTA), the gold standard methodology for assessing platelet function, requires expertise and is labour-intensive, which render its use in clinical settings impractical. We assessed whether p...

We investigated the comparability of platelet function tests in quantifying platelet inhibition achieved by clopidogrel. This pre-specified substudy of a randomized, double-blind trial included 116 patients with stable coronary artery disease requiring diagnostic angiography. Patients received clopidogrel for 1 (300 or 600 mg) or 7 days (300 + 75 o...

Previous studies have shown that the diagnosis and localization of previous non-Q wave myocardial infarction (NQMI) is possible by body surface potential mapping (BSPM), but the criteria for the discrimination between anteroseptal and inferoseptal middle regions remain to be determined. BSPM using 63 unipolar leads was recorded in 119 patients with...

We sought to compare the results obtained from six major platelet function tests in the assessment of the prevalence of aspirin resistance in patients with stable coronary artery disease. 201 patients with stable coronary artery disease receiving daily aspirin therapy (> or =80 mg) were recruited. Platelet aggregation was measured by: (i) light tra...

Acetylsalicylic acid, or aspirin (ASA), is widely used in patients with cardiovascular disease to prevent acute ischemic events. However, platelet response to ASA is not equal in all individuals, and a high variability in the prevalence of ASA resistance is reported in the literature (0.4-83%). Actually, ASA resistance is poorly understood; this st...

Prospective follow-up at 2 years was obtained for 98.7% of the pooled 1,510 patients enrolled in SIRIUS, E-SIRIUS and C-SIRIUS, 3 randomized controlled trials that compared sirolimus-eluting stents (SESs) with bare metal stents (BMSs) to treat long stenoses in small coronary arteries. By 720 days, clinically driven target lesion revascularizations...

Body surface potential mapping has been shown to be a useful tool in the diagnosis and localization of remote non-Q wave and Q wave myocardial infarction, but human expertise is required to interpret the maps. To identify quantitative body surface potential mapping parameters that could enable a computer-based diagnosis. Body surface isopotential m...

To evaluate the effect of tirofiban (a glycoprotein IIb-IIIa inhibitor) in preventing streptokinase-induced, antibody-mediated platelet aggregation after administration of streptokinase or development of a streptococcal infection. Prospective analysis. Research center of a Canadian hospital. Forty-five healthy volunteers, 45 patients who had receiv...

We investigated whether higher doses of ticlopidine combined with acetylsalicylic acid would allow a faster inhibition of platelet activation and aggregation in patients with acute coronary syndromes potentially undergoing percutaneous coronary intervention with stent placement. Seventeen patients presenting with acute coronary syndromes and candid...

Streptokinase use, in acute myocardial infarction, is hindered by failure to reperfuse (60%) and early reocclusion (16%). This phenomenon may, among other causes, be due to systemic inactivation of streptokinase, as well as streptokinase-induced platelet aggregation and clot propagation from antibodies to streptokinase produced after streptokinase...

A 46-year-old woman developed an anaphylactic reaction during percutaneous coronary intervention after she was pretreated with prednisone and diphenhydramine for a known allergy to iodine. She developed pruritus, edema, and nausea, which were followed by bradycardia and shock, minutes after administration of a bolus and standard-dose infusion of ab...

We undertook an angiographic, dose-finding study of staphylokinase (SAK42D variant) to evaluate its efficacy and safety in patients with acute ST-segment myocardial infarction. Patients were studied within 6 hours of symptom onset and received SAK42D as a 30-minute infusion with 20% of the total dose given as a bolus. Eighty-two patients with a med...

Potential losses caused by stable non-Q-wave myocardial infarction (MI) are too small to diagnose with the use of standard ECG. The aim of the present study was to obtain accurate diagnostic criteria for this prognostically important disease with the help of body surface mapping. Body surface potentials were recorded with the use of 63 unipolar lea...

In order to characterize ST-segment shifts during transient coronary artery occlusion, 24 patients with single-vessel disease were continuously monitored during percutaneous transluminal coronary angioplasty by use of a computerized orthogonal lead system. Changes of ST-segment (J + 60 ms) in leads X, Y, and Z and of the ST vector magnitude were an...

A 49-year-old obese female was admitted for acute onset pleuritic chest pain. Previous history was significant for surgical correction of a lower esophageal ring. Echocardiography revealed a pericardial effusion, which resolved with steroids. One week later, the patient complained of similar symptoms. Physical examination was consistent with tampon...

Body surface QRS potentials were recorded with 63 chest leads in 20 patients with proximal single-vessel disease located on either the left anterior descending coronary artery (n = 10), the right coronary artery (n = 6), or the left circumflex coronary artery (n = 4) before, during, and after percutaneous transluminal coronary angioplasty. In each...