Detection of Early Ischemic Changes with Virtual Noncontrast Dual-Energy CT in Acute Ischemic Stroke: A Noninferiority Analysis.

BACKGROUND AND PURPOSE: Dual-energy virtual NCCT has the potential to replace conventional NCCT to detect early ischemic changes in acute ischemic stroke. In this study, we evaluated whether virtual NCCT is noninferior compared with standard linearly blended NCCT, a surrogate of conventional NCCT, regarding the detection of early ischemic changes with ASPECTS. MATERIALS AND METHODS: Adult patients who presented with suspected acute ischemic stroke and who underwent dual-energy NCCT and CTA and brain MR imaging within 48 hours were included. Standard linearly blended images were reconstructed to match a conventional NCCT. Virtual NCCT images were reconstructed from CTA. ASPECTS was evaluated on conventional NCCT, virtual NCCT, and DWI, which served as the reference standard. Agreement between CT assessments and the reference standard was evaluated with the Lin concordance correlation coefficient. Noninferiority was assessed with bootstrapped estimates of the differences in ASPECTS between conventional and virtual NCCT with 95% CIs. RESULTS: Of the 193 included patients, 100 patients (52%) had ischemia on DWI. Compared with the reference standard, the ASPECTS concordance correlation coefficient for conventional and virtual NCCT was 0.23 (95% CI, 0.15-0.32) and 0.44 (95% CI, 0.33-0.53), respectively. The difference in the concordance correlation coefficient between virtual and conventional NCCT was 0.20 (95% CI, 0.01-0.39) and did not cross the prespecified noninferiority margin of -0.10. CONCLUSIONS: Dual-energy virtual NCCT is noninferior compared with conventional NCCT for the detection of early ischemic changes with ASPECTS.

Celiprolol and propranolol for unstable angina pectoris.

BACKGROUND: Celiprolol, a novel beta-blocker, may be more effective than propranolol in unstable angina pectoris because of both its beta 1-receptor selectivity and its vasodilatory property. METHODS: Fifty-three patients with angiographic coronary artery disease but uncompromised left ventricular function and with recurrent angina pectoris in spite of bed rest, aspirin, and repeated sublingual administration of nitroglycerin were randomized for 1 week of treatment with equipotent doses of either the nonselective beta-blocker propranolol (80 mg/day) or celiprolol (200 mg/day). RESULTS: Angina frequency was higher in the propranolol group (p < 0.01), whereas myocardial oxygen demand as estimated by the double product (systolic blood pressure x heart rate) was equally reduced by the two beta-blockers. Forearm blood flow was higher in the celiprolol group (p < 0.001). A stepwise logistic regression analysis showed that the beneficial effects of the beta-blockers were largely dependent on their effect on peripheral flow, in addition to reduction of the double product. CONCLUSIONS: Both celiprolol and propranolol largely reduce angina pectoris frequency in unstable angina pectoris. Celiprolol contributes to nearly complete relief in three times as many patients as propranolol; after adjustment for double product, it did so in eight times as many patients. The similar effects of the two compounds on the double product, and the essentially different effects on peripheral flow, support the theory that celiprolol exerts its beneficial effect to a large extent through its vasodilatory property.

Low molecular weight heparins better than unfractionated heparin in unstable coronary artery disease? Unstable angina pectoris/non-Q wave infarction a partly outpatient clinic condition?

Important theoretical advantages of low molecular weight heparins compared to standard heparin include better inactivation of the coagulation mechanism as well as better bioavailability and pharmacokinetic properties. In patients with unstable angina pectoris/non-Q wave infarction these advantages may translate into a reduced combined risk of death, myocardial infarction, and recurrent angina as well as a reduced risk of bleeding, although data so far are limited. Data on quality of life, cost analysis, and patient compliance are missing. The initial benefit of both heparin and low molecular weight heparins are partly lost after withdrawal of therapy. The simple dosage regimen of low molecular weight heparins would, however, enable to continue therapy for longer periods of time. Long-term trials are in progress to further elucidate this important issue. The simple dosage regimen also would enable earlier discharge from hospital which would unburden crowded clinical departments and might contribute to patients' quality of life.

Pressor responses from noncardioselective beta-blockers.

This study reviews more than fifty papers dealing with pressor responses from noncardioselective beta-blockers. It is concluded that the responses are usually mild. They occur mainly in situations of increased sympathetic activity. Therefore some patients seem to be at risk, eg, patients with unstable diabetes type 1, sportsmen performing isometric exercise, and heavy smokers. In orthostatic hypotension, noncardioselective beta-blockers may be beneficial. Cardiac output tends, however, to decrease, and patients with orthostatic hypotension will probably not benefit from this effect.

Effects of beta adrenergic receptor agonists and antagonists in diabetics with symptoms of postural hypotension: a double-blind, placebo-controlled study.

Eleven patients with hyperadrenergic diabetic postural hypotension and vagal neuropathy were treated in a double-blind, placebo-controlled study with different beta-agonists and antagonists. A single dose of the beta 2-agonist terbutaline (5 mg) and the beta 1 + 2-agonist orciprenaline (10 mg) did not reduce the fall in systolic pressure on standing up, despite a significant increase in both supine and standing heart rates. The beta 1-antagonist with intrinsic sympathicomimetic activity (ISA) acebutolol (200 mg) and the beta 1-antagonist metoprolol (50 mg) did not influence the fall in systolic pressure either, despite a significant decrease in supine and standing heart rates and disappearance of increase in heart rate on standing up. Only the beta 1 + 2-antagonist propranolol and the beta 1 + 2-antagonist with ISA pindolol (5 mg) could significantly reduce or practically abolish the fall in systolic and diastolic pressure on standing up. This was accompanied by a slight decrease of heart rates and disappearance of difference between supine and standing heart rates, as seen with the other beta-antagonists. Thus, only beta 2-blockade reduced or abolished the fall in systolic pressure on standing up in our patients. These data were confirmed by a three-week crossover trial in 10 of these patients.

Celiprolol vs propranolol in unstable angina pectoris: a double-blind, randomized, parallel-group study.

Celiprolol, a novel beta blocker, may be more effective than propranolol in unstable angina pectoris because of both its beta-1-receptor selectivity and its vasodilator property. In the present report 53 patients with angiographic coronary artery disease but uncompromised left ventricular function and with electrocardiographically documented recurrent angina pectoris in spite of bed rest, aspirin, and repeated sublingual administration of nitroglycerin were studied. They were randomized for treatment with equipotent doses of either the nonselective beta blocker propranolol (80 mg/day) or the selective beta blocker with beta-2-agonistic property, celiprolol (200 mg/day) during one week. Angina frequency was higher in the propranolol group (P < 0.01), whereas myocardial oxygen demand as estimated by the double product (DP = SBP x HR, systolic blood pressure x heart rate) was equally reduced by the two beta blockers. Forearm blood flow was essentially higher in the celiprolol group (P < 0.001). A stepwise logistic regression analysis showed that the beneficial effects of the beta blockers were largely dependent on their effect on peripheral flow, in addition to reduction of the double product. The authors conclude that (1) Both celiprolol and propranolol largely reduce angina pectoris frequency in unstable angina pectoris. (2) Celiprolol contributes to nearly complete relief in three times as many patients as propranolol; after adjustment for double product or for systolic blood pressure plus heart rate it performs even eight times better. (3) The similar effects of the two compounds on the double product and the essentially different effects on peripheral flow support the conclusion that celiprolol exerts its beneficial effect to a large extent through its vasodilator property.

Randomized study of ceftazidime versus gentamicin plus cefotaxime for infections in severe granulocytopenic patients.

A randomized study of gentamicin plus cefotaxime versus ceftazidime alone was performed in 87 patients, with a neutrophil count of less than 1000/mm3 at the start of the treatment. The overall cure rate for the ceftazidime group was 71% and for the gentamicin plus cefotaxime 47%. This difference was shown to be statistically significant at a level of P less than 0.05. The cure rates for the microbiologically proven infections were 90 and 63% respectively. Serious adverse effects, causing preliminary withdrawal of therapy, have not been observed.