Cerebrovascular steal phenomenon in a patient undergoing dipyridamole nuclear perfusion cardiac imaging.

Transient ischemic neurological deficits following intravenous dipyridamole administration during pharmacological cardiac stress test are seldom reported, but there can be serious vascular complications. We report a case of a 58-year-old Caucasian male who developed expressive aphasia after dipyridamole infusion during an elective dipyridamole-technetium cardiac stress test performed for chest pain. Computed tomography angiogram of the neck revealed a known total occlusion of the right internal carotid artery and 50% stenosis of the left internal carotid artery. The patient's aphasia spontaneously resolved within 24 h. In this paper, we report a unique case in which the administration of intravenous dipyridamole precipitated transient ischemic attack in a patient with stable asymptomatic bilateral carotid artery disease and prior carotid endarterectomy. We also discuss the intracerebral vascular steal phenomenon as a possible pathophysiological mechanism in this patient.

Comprehensive meta-analysis on drug-eluting stents versus bare-metal stents during extended follow-up.

BACKGROUND: Several observational reports have documented both increased and decreased cardiac mortality or Q-wave myocardial infarction with drug-eluting stents compared with bare-metal stents. METHODS: We sought to evaluate the safety and efficacy of drug-eluting stents compared with bare-metal stents early after intervention (<1 year) and late (>1 year) among a broad population of patients, using a meta-analysis of randomized clinical trials. RESULTS: We identified 28 trials with a total of 10,727 patients and a mean follow-up of 29.6 months. For early outcomes (<1 year), all-cause mortality for drug-eluting stents versus bare-metal stents was 2.1% versus 2.4% (risk ratio [RR] 0.91, [95% confidence interval (CI), 0.70-1.18]; P=.47), non-Q-wave myocardial infarction was 3.3% versus 4.4% (RR 0.78 [95% CI, 0.61-1.00]; P=.055), target lesion revascularization was 5.8% versus 18.4% (RR 0.28 [95% CI, 0.21-0.38]; P <.001), and stent thrombosis was 1.1% versus 1.3% (RR 0.87 [95% CI, 0.60-1.26]; P=.47). For late outcomes (>1 year), all-cause mortality for drug-eluting stents versus bare-metal stents was 5.9% versus 5.7% (RR 1.03 [95% CI, 0.83-1.28]; P=.79), target lesion revascularization was 4.0% versus 3.3% (RR 1.22 [95% CI, 0.92-1.60]; P=.16), non-Q-wave myocardial infarction was 1.6% versus 1.2% (RR 1.36 [95% CI, 0.74-2.53]; P=.32) and stent thrombosis was 0.7% versus 0.1% (RR 4.57 [95% CI, 1.54-13.57]; P=.006). CONCLUSIONS: There was no excess mortality with drug-eluting stents. Within 1 year, drug-eluting stents appear to be safe and efficacious with possibly decreased non-Q-wave myocardial infarction compared with bare-metal stents. After 1 year, drug-eluting stents still have similar mortality, despite increased stent thrombosis. The reduction in target lesion revascularization with drug-eluting stents mainly happens within 1 year, but is sustained thereafter.

Clopidogrel and coronary stents: risks and benefits.

Clopidogrel has become increasingly important in the management of patients with coronary stents. Clopidogrel is an oral agent that acts on the adeno-sine diphosphate receptor to irreversibly inhibit platelet aggregation. Along with aspirin, clopidogrel has a significant role in the treatment of atherothrombotic diseases. Recent concerns about late stent thrombosis highlight the need for long-term therapy with clopidogrel in addition to aspirin in these populations. This article reviews the role of clopidogrel in the treatment of atherothrombotic diseases and after coronary intervention, as well as the current approach in the prevention of stent thrombosis. It also discusses experimental and upcoming drugs that may be superior to clopidogrel.

Clopidogrel and risk for acute coronary events.

Clopidogrel bisulfate is a potent adenosine diphosphate receptor blocker that irreversibly inhibits platelet aggregation by preventing the activation of the glycoprotein IIb/IIIa pathway. This helps to prevent thrombus formation and resultant ischemic or thrombotic complications. Clopidogrel was proven to be superior to aspirin in the treatment of atherothrombotic diseases. Clopidogrel plus aspirin, known as dual antiplatelet therapy, is highly effective in patients with acute coronary syndromes or undergoing percutaneous coronary intervention. There is no apparent benefit of dual antiplatelet therapy in primary prevention. In this article, we review the benefits of clopidogrel as an antiplatelet agent and its role in the management of acute coronary syndromes and following percutaneous coronary intervention.

Meta-analysis of the role of statin therapy in reducing myocardial infarction following elective percutaneous coronary intervention.

Statin medications initiated during percutaneous coronary intervention have been evaluated in clinical trials mainly to assess if this therapy reduces subsequent restenosis. The benefit of statin therapy on individual cardiovascular outcomes other than restenosis is largely unknown. Hence, a meta-analysis of the available randomized trials was conducted to evaluate individual cardiovascular outcomes with statin therapy compared with placebo after elective percutaneous coronary intervention. In all, there were 6 studies available for analysis (Prevention of Restenosis by Elisor After Transluminal Coronary Angioplasty [PREDICT], Fluvastatin Angioplasty Restenosis [FLARE], the Lescol Intervention Prevention Study [LIPS], German Atorvastatin Intravascular Ultrasound [GAIN], Atorvastatin for Reduction of Myocardial Damage During Angioplasty [ARMYDA], and a study by Briguori et al) that randomized 3,941 patients (1,967 to statins and 1,974 to placebos). Clinical follow-up ranged from 1 day to 45 months. The incidence of myocardial infarction was 3.0% in the statin group and 5.2% in the placebo group (odds ratio [OR] 0.57, 95% confidence interval [CI] 0.42 to 0.78, p<0.0001). The incidence of all-cause mortality was 2.3% versus 3.0% (OR 0.74, 95% CI 0.50 to 1.1, p=0.14), that of cardiovascular mortality was 0.71% versus 1.2% (OR 0.58, 95% CI 0.30 to 1.11, p=0.10), and that of repeat surgical or percutaneous revascularization was 19.6% versus 21.9% (OR 0.89, 95% CI 0.78 to 1.02, p=0.098) in the statin arm versus the placebo arm, respectively. The incidence of stroke was 0.4% in the statin arm and 0.08% in the placebo arm (OR 3.00, 95% CI 0.60 to 14.77, p=0.18). In conclusion, statin therapy initiated at the time of elective percutaneous coronary intervention significantly reduces myocardial infarction.

Long-term benefit of statin therapy initiated during hospitalization for an acute coronary syndrome: a systematic review of randomized trials.

OBJECTIVE: This study sought to determine if the initiation of statin (HMG-CoA reductase inhibitor) therapy during acute coronary syndromes reduces long-term mortality and other adverse cardiac outcomes. BACKGROUND: Initiation of statin therapy during acute coronary syndromes has not been shown to reduce mortality, myocardial infarction or stroke within 4 months of follow-up. METHODS: Clinical trials that randomized patients with acute coronary syndromes to early statin therapy compared with less intensive lipid reduction (placebo/lower-dose statin/usual care), and reported long-term outcomes were included for analysis. RESULTS: In all, there were seven studies (L-CAD, PTT, FLORIDA, Colivicchi et al., PROVE-IT, ESTABLISH, and A-to-Z) with 9553 patients who started statin therapy within 12 days of hospital presentation. The incidence of all-cause mortality was 3.4% in the statin group versus 4.6% in the less intensive lipid reduction group over a weighted mean follow-up of 22.9 months (relative risk [RR] 0.74; 95% CI 0.61, 0.90; p = 0.003). The number of patients needed to treat to prevent one death was 84 patients. Similarly, the incidence of cardiovascular mortality in the statin versus the less intensive lipid reduction group was 2.4% versus 3.3% (RR 0.74; 95% CI 0.58, 0.93; p = 0.010), unstable angina 4.1% versus 5.0% (RR 0.81; 95% CI 0.68, 0.98; p = 0.027), revascularization 11.2% versus 12.9% (RR 0.86; 95% CI 0.78, 0.96; p = 0.006), stroke 1.1% versus 1.2% (RR 0.90; 95% CI 0.62, 1.30; p = 0.56), and myocardial infarction 6.6% versus 7.0% (RR 0.94; 95% CI 0.81, 1.09; p = 0.41). CONCLUSIONS: The benefit of early initiation of statin therapy during acute coronary syndromes slowly accrues over time so that a survival advantage is seen around 24 months. Relatively few patients need to be treated to prevent one death over this time period. Furthermore, this approach significantly reduces unstable angina and the need for revascularization.

Preventing venous thromboembolism in cardiology and cardiac surgery.

Venous thromboembolism (VTE) has proven to be one of the major causes for increasing morbidity among general medical and surgical patients. VTE may have a major role after cardiac surgery by increasing morbidity related to hospital stay, economic burden, discharge planning, complications associated with anticoagulation therapy, and mortality when it ends as a fatal pulmonary embolism (PE). However, patients who undergo cardiac procedures or surgeries pose unique challenges in prevention and treatment of VTE. Clinical diagnosis is always difficult in these patients due to non-specific symptoms or because the patient is asymptomatic. Among the cardiology and cardiac surgery population, thrombosis risk appears to be inherent as a result of multiple co-morbidities as well as direct trauma to the vasculature. Prevention of VTE by prophylactic measures remains the most economical and effective method in current clinical practice. However, many modalities used for VTE prophylaxis have been restricted to the general surgical orthopedic population and can be difficult to apply, especially in patients following cardiac surgery.

Late thrombosis of drug-eluting stents: a meta-analysis of randomized clinical trials.

PURPOSE: Drug-eluting stents are commonly used for percutaneous coronary intervention. Despite excellent clinical efficacy, the association between drug-eluting stents and the risk for late thrombosis remains imprecisely defined. METHODS: We performed a meta-analysis on 14 contemporary clinical trials that randomized 6675 patients to drug-eluting stents (paclitaxel or sirolimus) compared with bare metal stents. Eight of these trials have reported more than a year of clinical follow-up. RESULTS: The incidence of very late thrombosis (>1 year after the index procedure) was 5.0 events per 1000 drug-eluting stent patients, with no events in bare metal stent patients (risk ratio [RR]=5.02, 95% confidence interval [CI], 1.29 to 19.52, P=.02). Among sirolimus trials, the incidence of very late thrombosis was 3.6 events per 1000 sirolimus stent patients, with no events in bare metal stent patients (RR=3.99, 95% CI, .45 to 35.62, P=.22). The median time of late sirolimus stent thrombosis was 15.5 months, whereas with bare metal stents it was 4 months. Among paclitaxel trials, the incidence of very late thrombosis was 5.9 events per 1000 paclitaxel stent patients, with no events in bare metal stent patients (RR=5.72, 95% CI, 1.08 to 32.45, P=.049). The median time of late paclitaxel stent thrombosis was 18 months, whereas it was 3.5 months in bare metal stent patients. CONCLUSIONS: Although the incidence of very late stent thrombosis more than 1 year after coronary revascularization is low, drug-eluting stents appear to increase the risk for late thrombosis. Although more of this risk was seen with paclitaxel stents, it remains possible that sirolimus stents similarly increase the risk for late thrombosis compared with bare metal stents.

Chylous pericardial effusion after minimally invasive mitral valve repair.

We would like to report the first case of chylous pericardial effusion after thymus gland injury in a middle-aged patient who underwent minimally invasive mitral valve surgery, and outline the surgical approach to manage this condition.