Fractional flow reserve (FFR), an index of coronary stenosis severity, can be calculated from the ratio of hyperemic distal to proximal coronary pressure. An FFR value of 0.75 can distinguish patients with normal and abnormal noninvasive stress testing in case of normal left ventricular function. The present study aimed at investigating the value of FFR in patients with a prior myocardial infarction. Methods and Results-- In 57 patients who had sustained a myocardial infarction >/=6 days earlier, myocardial perfusion single photon emission scintigraphy (SPECT) imaging and FFR were obtained before and after angioplasty. The sensitivity and specificity of the 0.75 value of FFR to detect flow maldistribution at SPECT imaging were 82% and 87%. The concordance between the FFR and SPECT imaging was 85% (P<0.001). When only truly positive and truly negative SPECT imaging were considered, the corresponding values were 87%, 100%, and 94% (P<0.001). Patients with positive SPECT imaging before angioplasty had a significantly lower FFR than patients with negative SPECT imaging (0.52+/-0.18 versus 0.67+/-0.16, P=0.0079) but a significantly higher left ventricular ejection fraction (63+/-10% versus 52+/-10%, P=0.0009) despite a similar degree of diameter stenosis (67+/-13% versus 68+/-16%, P=NS). A significant inverse correlation was found between LVEF and FFR (R=0.29, P=0.049).

Epidemiological studies suggest that tea consumption decreases cardiovascular risk, but the mechanisms of benefit remain undefined. Endothelial dysfunction has been associated with coronary artery disease and increased oxidative stress. Some antioxidants have been shown to reverse endothelial dysfunction, and tea contains antioxidant flavonoids. Methods and Results-- To test the hypothesis that tea consumption will reverse endothelial dysfunction, we randomized 66 patients with proven coronary artery disease to consume black tea and water in a crossover design. Short-term effects were examined 2 hours after consumption of 450 mL tea or water. Long-term effects were examined after consumption of 900 mL tea or water daily for 4 weeks. Vasomotor function of the brachial artery was examined at baseline and after each intervention with vascular ultrasound. Fifty patients completed the protocol and had technically suitable ultrasound measurements. Both short- and long-term tea consumption improved endothelium- dependent flow-mediated dilation of the brachial artery, whereas consumption of water had no effect (P<0.001 by repeated-measures ANOVA). Tea consumption had no effect on endothelium-independent nitroglycerin-induced dilation. An equivalent oral dose of caffeine (200 mg) had no short-term effect on flow-mediated dilation. Plasma flavonoids increased after short- and long-term tea consumption.

Left ventricular hypertrophy (LVH), the clinical hallmark of familial hypertrophic cardiomyopathy (FHCM), is absent in a significant number of subjects with causal mutations. In transgenic rabbits that fully recapitulate the FHCM phenotype, reduced myocardial tissue Doppler (TD) velocities accurately identified the mutant rabbits, even in the absence of LVH. We tested whether humans with FHCM also consistently showed reduced myocardial TD velocities, irrespective of LVH.

With the best prophylactics now available, venous thromboembolism after total knee replacement remains substantial (25% to 27%). Recombinant nematode anticoagulant protein c2 (rNAPc2) is a potent inhibitor of factor VIIa/tissue factor complex that has the potential to reduce this risk. The present study was performed to determine an efficacious and safe dose of rNAPc2 for prevention of venous thromboembolism after elective, unilateral total knee replacement.

We tested prospectively the hypothesis that stroke development can be predicted by echolucency of carotid atherosclerotic plaques in previously symptomatic and asymptomatic patients.

An elevated plasma concentration of high-sensitivity C-reactive protein (hs-CRP) is a strong predictor of cardiovascular events. However, there have been no longitudinal studies of the relations between development of atherosclerotic lesions and hs-CRP concentrations. Furthermore, it remains unknown whether increased hs-CRP concentrations result in the development of atherosclerosis.

Radiofrequency (RF) cardiac catheter ablation procedures may require extended fluoroscopic exposure resulting in elevated radiation risk. The aim of the present study was to accurately establish RF ablation radiation risk levels and to provide means for accurate patient risk estimation from studies performed in any electrophysiology laboratory.

This clinical investigation was performed to compare the effects of permanent dual-chamber cardiac pacing with pharmacological therapy in patients with recurrent vasovagal syncope.

Establishing a diagnosis in patients with unexplained syncope is complicated by infrequent and unpredictable events. Prolonged monitoring may be an alternative strategy to conventional testing with short-term monitoring and provocative tilt and electrophysiological testing.

Previous studies have shown disappointing results for immunosuppressive treatment in patients with dilated cardiomyopathy. Therefore, we studied the effectiveness of such therapy in patients with HLA upregulation on biopsy.

Distal embolization of debris during percutaneous carotid artery stenting may result in neurological deficit. Filter devices for cerebral protection potentially reduce the risk of embolization.

Patients with a non-ST-elevation acute coronary syndrome and prior CABG are at high risk of a recurrent ischemic event despite aspirin therapy. This trial investigated the potential benefit of secondary prevention with warfarin.

Common carotid artery intima-media thickness (IMT) progression was compared between 4 years of treatment with nifedipine and diuretic.

This study evaluates the role of RR interval distribution pattern as an outcome predictor of radiofrequency (RF) modification of atrioventricular (AV) node in chronic atrial fibrillation (AF) and attempts to elucidate the likely mechanism of rate control.

Experimental studies suggest that the cardioprotective effects of the late phase of ischemic preconditioning (PC) can be mimicked pharmacologically. However, to date, no drug has been tested with respect to its ability to elicit a late PC effect in humans. As a consequence, clinical exploitation of the powerful anti-stunning and anti-infarct actions of late PC has been elusive thus far.

PTCA of a coronary stenosis without documented ischemia at noninvasive stress testing is often performed, but its benefit is unproven. Coronary pressure-derived fractional flow reserve (FFR) is an invasive index of stenosis severity that is a reliable substitute for noninvasive stress testing. A value of 0.75 identifies stenoses with hemodynamic significance.

Prospective data relating previous exposure to cytomegalovirus (CMV) to the risk of cardiac mortality are controversial. We investigated the effect of previous exposure to CMV infection on the risk of future cardiac disease-related death in relation to an underlying inflammatory response.

Menopausal estrogen loss has been associated with increased cardiovascular disease in postmenopausal women. However, the link between estrogen and cardiovascular disease remains unclear. Some data suggest estrogen mediates its effect through changes in arterial pressure and its regulation. However, the data available in older women are equivocal regarding estrogen's ability to reduce resting arterial pressure or to improve its regulation.

Menopause heralds a dramatic increase in incident hypertension, suggesting a protective effect of estrogen on blood pressure (BP). In female rats, estrogen has been shown to decrease sympathetic nerve discharge (SND) and BP. SND, however, has not been recorded during estrogen replacement therapy (ERT) in humans. Methods and Results-In 12 normotensive postmenopausal women, we conducted a randomized crossover placebo-controlled study to test whether chronic ERT caused a sustained decrease in SND and BP. Twenty-four-hour ambulatory BP, SND, and arterial baroreflex sensitivity were measured before and after 8 weeks of transdermal estradiol (200 microgram/d), oral conjugated estrogens (0.625 mg/d), or placebo. To test the acute effects of estrogen on SND, additional studies were performed in the same women receiving intravenous conjugated estrogens or sublingual estradiol. After 8 weeks of transdermal ERT, the basal rate of SND decreased by 30% (from 40+/-4 to 27+/-4 bursts per minute, P=0.0001) and ambulatory diastolic BP fell by 5+/-2 mm Hg (P=0.0003). In contrast, SND and BP were unaffected either by 8 weeks of oral ERT or by acute estrogen administration. Neither transdermal nor oral ERT had any effects on baroreflex sensitivity.

Arterial recanalization precedes clinical improvement or may lead to hemorrhage or reperfusion injury. Speed of clot lysis was not previously measured in human stroke.