ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundChest pain frequently occurs without any signs of ischemia within the first 24 hours after coronary interventions. To test the hypothesis that this pain may be due to local vessel injury ("stretch pain"), we performed a prospective study enrolling patients after PTCA, stent implantation, or diagnostic coronary angiography alone.Methods and Results-A total of 145 patients after coronary angiography were evaluated by a validated questionnaire for quantifying postinterventional chest pain within 24 hours. To detect myocardial ischemia, all patients were evaluated with a 12-lead ECG and cardiac isoenzymes immediately after the procedure and the morning after. After stent implantation, 21 of the 51 patients (41.2%) developed chest pain, compared with 4 of the 33 patients (12.1%) undergoing PTCA and 6 of the 61 patients (9.8%) with a diagnostic angiography (P<0.001). Of these 31 patients who developed chest pain, only 3 (9.7%) felt that the pain was similar to previously experienced angina pectoris. The minimal lumen diameter after intervention was significantly larger in the stent group than in the PTCA group (3.14 +/- 0.75 versus 1.95 +/- 0.67 mm; P<0.001). No patient had changes in the ECG compared with before intervention, but 3 patients after stent implantation had a rise in cardiac isoenzymes. No other major adverse cardiac events occurred until discharge.ConclusionsNonischemic chest pain develops in almost half of all patients undergoing stent implantation and seems to be related to vessel overexpansion caused by the stent in the diseased vessel segment. (Circulation. 1998;98:2656-2658.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundWe conducted a 10-year follow-up of the 11 712 patients with acute myocardial infarction randomized in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto-1 study, the first large trial assessing thrombolytic therapy.Methods and Results-Information on survival at 10 years was obtained for the 93% of all randomized patients through the census offices of their towns of residence. The difference in survival produced by streptokinase and sustained up to 1 year was still significant at 10 years (log-rank test, P=0.02), with the absolute benefit of 19 (95% CI 1 to 37) lives saved per 1000 patients treated. The time dependence of the extent of the benefit was confirmed, as the higher mortality rate reductions found in patients treated earlier were still present at 10 years. In the overall population, most of the benefit was obtained before hospital discharge (RR 0.81, 95% CI 0.72 to 0.90), since no difference in survival between thrombolyzed and control patients discharged alive was found at 10 years (RR 0.98, 95% CI 0.90 to 1.06). However, a slight albeit nonsignificant divergence of the survival curves of patients randomized within the first hour was observed [90 (95% CI 34 to 146) lives saved per 1000 at 10 years versus 72 (95% CI 37 to 107) lives saved at hospital discharge].ConclusionsThe benefits of a single intravenous infusion of 1.5 million units of streptokinase in prolonging survival of patients with acute myocardial infarction is sustained up to 10 years, with a still-evident trend in favor of the patients admitted earlier. (Circulation. 1998;98:2659-2665.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundCurrent imaging modalities, such as contrast angiography, accurately determine the degree of luminal narrowing but provide no direct information on plaque size. Magnetic resonance imaging (MRI), however, has potential for noninvasively determining arterial wall area (WA). This study was conducted to determine the accuracy of in vivo MRI for measuring the cross-sectional maximum wall area (MaxWA) of atherosclerotic carotid arteries in a group of patients undergoing carotid endarterectomy.Methods and Results-Fourteen patients scheduled for carotid endarterectomy underwent preoperative carotid MRI using a custom-made phased-array coil. The plaques were excised en bloc and scanned using similar imaging parameters. MaxWA measurements from the ex vivo MRI were used as the reference standard and compared with MaxWA measurements from the corresponding in vivo MR study. Agreement between the in vivo and ex vivo measurement was analyzed using the Bland-Altman method. The paired in vivo and ex vivo MaxWA measurements strongly agreed: the mean difference (in vivo minus ex vivo) in MaxWA was 13.1 +/- 6.5 mm2for T1-weighted (T1W) imaging (mean MaxWA in vivo=94.7 mm2, ex vivo=81.6 mm2) and 14.1 +/- 11.7 mm2for proton density-weighted (PDW) imaging (mean MaxWA in vivo=93.4 mm2, ex vivo=79.3 mm2). Intraobserver and interobserver variability was small, with intraclass correlation coefficients ranging from 0.90 to 0.98.ConclusionsMRI is highly accurate for in vivo measurement of artery WA in atherosclerotic carotid lesions. This imaging technique has potential application monitoring lesion size in studies examining plaque progression and/or regression. (Circulation. 1998;98:2666-2671.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundTransplant coronary artery disease is a combination of atherosclerosis transmitted from the donor and new lesions of allograft vasculopathy. We sought to determine the morphological characteristics of allograft vasculopathy and differentiate it from donor-transmitted atherosclerosis with serial intravascular ultrasound.or=to0.5 mm) present at baseline examination were defined as donor lesions. On follow-up, lesions that developed at previously normal sites were defined as de novo lesions. The distribution and severity of donor and de novo lesions were similar in proximal, mid, and distal segments. The de novo lesions were less focal (43% vs 74%) and more circumferential (69% vs 45%) compared with the donor lesions, but there was significant morphological heterogeneity. Similar numbers of patients with and those without donor lesions developed de novo lesions. Moreover, progression of donor lesions was not associated with the presence or absence of de novo lesions.ConclusionsDifferentiation between early allograft vasculopathy from conventional atherosclerosis by distribution and morphology of lesions alone is difficult. Serial intravascular ultrasound imaging with early baseline examination is necessary to make this distinction. This distinction is important because the progression of donor lesions and the development of de novo lesions are independent of each other. (Circulation. 1998;98:2672-2678.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe accuracy of exercise echocardiography and201Tl single photon emission computed tomography (SPECT) is similar in the diagnosis of coronary artery disease (CAD). However, comparative data on long-term prognosis are lacking.Methods and Results-Clinical variables and exercise, echocardiographic, and (201) Tl tomographic parameters were studied in 248 patients (age, 56 +/- 12 years [mean +/- SD]; 189 men) who underwent simultaneous treadmill exercise201Tl SPECT and echocardiography. Follow-up was obtained in 225 patients (91%) at a mean of 3.7 +/- 2.0 years. A total of 64 cardiac events occurred. With the use of stepwise logistic regression, 4 models simulating clinical stress testing scenarios were evaluated in the prediction of all cardiac events, ischemic events, and/or cardiac death. The best clinical models were exercise echocardiography with exercise ECG and exercise (201) Tl SPECT with exercise ECG. Both models were comparable in the prediction of cardiac events. For the exercise echocardiography model, exercise wall motion score index and induction of ischemia were the strongest predictors of events with ORs of 2.63 per unit increment (95% CI, 1.34 to 5.17; P=0.005) and 4.1 (95% CI, 1.32 to 12.79; P=0.015), respectively. For the model with exercise201Tl SPECT, the strongest predictor was ischemic perfusion defect (OR, 4.93; 95% CI, 1.72 to 14.08; P=0.003). The absence of ST changes during exercise decreased the risk of events. For the prediction of ischemic events and/or cardiac death, echocardiographic and (201) Tl parameters were the only predictive variables.ConclusionsIn patients evaluated for CAD, exercise echocardiography and201Tl combined with ECG variables provide comparable prognostic information and can be used interchangeably for risk stratification. (Circulation. 1998;98:2679-2686.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe utility of contrast MRI for assessing myocardial viability in stable coronary artery disease (CAD) with left ventricular dysfunction is uncertain. We therefore performed cine and contrast MRI in 24 stable patients with CAD and regional contractile abnormalities and compared MRI findings with rest-redistribution201Tl imaging and dobutamine echocardiography.Methods and Results-Delayed MRI contrast enhancement patterns were examined from 3 to 15 minutes after injection of 0.1 mmol/kg IV gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). Comparable MRI and201Tl basal and midventricular short-axis images were subdivided into 6 segments. Segments judged nonviable by quantitative and qualitative assessment of201Tl scans showed persistent, systematically greater MRI contrast signal intensity than segments judged viable (P<or=to0.002). Delayed contrast hyperenhancement also occurred in segments judged nonviable by dobutamine echocardiography (P<or=to0.03). The presence or absence of hyperenhancement correlated most closely with nonviability and viability, respectively, in segments that were akinetic or dyskinetic under resting conditions (83% concordance with201Tl in both cases). In segments with resting hypokinesis, 58% of segments showing hyperenhancement were judged viable by201Tl and may have represented an admixture of scar tissue and viable myocardium.ConclusionsDelayed (by 3 to 15 minutes) hyperenhancement of Gd-DTPA contrast-enhanced MRI images occurs frequently in dysfunctional areas of the left ventricle in patients with stable CAD. Hyperenhancement is associated with nonviability by rest-redistribution (201) Tl scintigraphy and dobutamine echocardiography, particularly in regions exhibiting resting akinesis/dyskinesis. The absence of hyperenhancement correlates with radionuclide and echocardiographic determinations of viability, regardless of resting contractile function. (Circulation. 1998;98:2687-2694.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundApart from its established effects on vessel patency after percutaneous coronary revascularization, glycoprotein IIb/IIIa receptor blockade by abciximab may improve myocardial perfusion by inhibition of the interaction of platelets and platelet aggregates with the microvasculature. We investigated the effect of abciximab with stent placement in acute myocardial infarction.Methods and Results-In a prospective randomized trial, patients undergoing stenting in acute myocardial infarction within 48 hours after onset of symptoms were randomly assigned to receive either standard-dose heparin or abciximab plus low-dose heparin. Immediately after the procedure and at 14-day angiographic follow-up, we assessed flow velocity in the recanalized vessel with the Doppler wire and regional wall motion by the centerline method. End points were changes in papaverine-induced peak flow velocities and in wall motion indices. We assigned 98 patients to standard heparin and 102 to abciximab. We obtained 152 paired flow measurements and 151 paired left ventricular function studies. Residual stenoses of the treated lesions did not differ between the 2 groups. Improvement of peak flow velocity (mean [95% CI]: 18.1 cm/s [13.6 to 22.6 cm/s], n=80, versus 10.4 cm/s [5.4 to 15.4 cm/s], n=72, P=0.024) and wall motion index (0.44 SD/chord [0.29 to 0.59 SD/chord], n=79 versus 0.15 SD/chord [0.00 to 0.30 SD/chord], n=72, P=0.007) was significantly greater in patients assigned to abciximab than in those on heparin alone. At follow-up, the abciximab group had a higher global left ventricular ejection fraction than the heparin group (62% [59% to 65%] versus 56% [53% to 59%], P=0.003).ConclusionsAbciximab had important effects beyond the maintenance of large-vessel patency. It improved the recovery of microvascular perfusion and concomitantly enhanced the recovery of contractile function in the area at risk. (Circulation. 1998;98:2695-2701.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe intestine is an increasingly well-recognized site of first-pass drug metabolism. In this study, we determined the influence of dietary salt on the steady-state disposition of verapamil, a drug that undergoes extensive first-pass metabolism.Methods and Results-Eight normal volunteers received 120 mg of racemic verapamil orally twice a day for 21 days. The disposition kinetics of verapamil enantiomers were determined after coadministration of intravenous deuterated verapamil with the morning oral dose on days 7, 14, and 21. Each study day was preceded by 7 days on a fixed-salt diet: in 5 subjects, the initial study was conducted during a low-salt (10 mEq/d) diet, the second study during a high-salt (400 mEq/d) diet, and the third during a low-salt diet, whereas in the other 3 subjects, the sequence of diets was reversed. Plasma concentrations of both unlabeled enantiomers (ie, from oral therapy) were significantly (P<0.05) lower during the high-salt phase (eg, mean area under the time-concentration curve [0 to 12 hours] for S-verapamil: 7765 +/- 2591 ng [middle dot] min [middle dot] mL-1[high salt] versus 12 514 +/- 3527 ng [middle dot] min [middle dot] mL-1[low salt], P<0.05). Peak plasma concentrations were significantly lower and the extent of PR interval prolongation significantly blunted with the high-salt diet. In contrast, data with labeled drug (ie, reflecting the intravenous route) were nearly identical for the 2 diets.ConclusionsThese data indicate that a clinically important component of presystemic drug disposition occurs at the prehepatic (presumably intestinal) level and is sensitive to dietary salt. (Circulation. 1998;98:2702-2708.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID