Short-term effects of early intravenous treatment with a beta-adrenergic blocking agent or a specific bradycardiac agent in patients with acute myocardial infarction receiving thrombolytic therapy.

OBJECTIVES: This study was conducted to explore mechanisms that could explain the possible clinical benefit of early administration of a beta 1-selective adrenoreceptor blocking agent or a bradycardiac drug as adjunct to thrombolysis in acute myocardial infarction. BACKGROUND: The effects of beta-blockers given concomitantly with thrombolytic therapy in patients with acute myocardial infarction have not been fully examined. The potential role of specific bradycardiac agents lacking negative inotropism as an alternative to beta-blockers in this setting has never been studied in humans. METHODS: In a double-blind study, we examined the effects of early intravenous and continued oral administration of a beta-blocker (atenolol), a specific bradycardiac agent (alinidine) or placebo on left ventricular function, late coronary artery patency, infarct size, exercise capacity and incidence of arrhythmias. RESULTS: A total of 292 patients with acute myocardial infarction of < or = 5 h duration and without contraindications to thrombolytic or beta-blocker therapy were studied. Of these, 100 were allocated to treatment with atenolol (5 to 10 mg intravenously followed by 25 to 50 mg orally every 12 h), 98 to alinidine (20 to 40 mg intravenously followed by 20 to 40 mg orally every 8 h) and 94 to placebo. All patients received 100 mg of alteplase over 3 h and full intravenous heparinization. No significant differences in coronary artery patency, global ejection fraction or regional wall motion were observed at 10 to 14 days among the three groups. Likewise, enzymatic and scintigraphic infarct size were also very similar. Neither atenolol nor alinidine was associated with a significant reduction in the incidence of arrhythmias during the 1st 24 h. No significant differences in clinical events were observed, with the exception of a greater incidence of nonfatal pulmonary edema in the atenolol group (6% vs. 1% in the alinidine group and 0% in the placebo group, p = 0.021). CONCLUSIONS: In the absence of contraindications, the administration of a beta-blocker or a specific bradycardiac agent together with thrombolytic therapy was safe. In this limited number of patients, these agents did not appear to enhance myocardial salvage or preservation of left ventricular function or to reduce the incidence of major arrhythmias in the early phase of infarction.

Determinants of early and late results of combined valve operations and coronary artery bypass grafting.

BACKGROUND: Factors determining the outcome of operative correction of valvular abnormalities combined with coronary artery bypass grafting are still incompletely defined. METHODS: Determinants of early and late (more than 90 days) deaths and event-free survival were studied for combined valve operations and coronary artery bypass grafting in 741 patients using multivariate analysis. RESULTS: Ninety-day survival probability was 89% (95% confidence interval, 87% to 92%). Preoperative risk factors for early death were age, female sex, renal failure, New York Heart Association class IV or V, and mitral insufficiency. The operative risk factor was the duration of aortic cross-clamping. Five- and 10-year survival probabilities were 74% (95% confidence interval, 71% to 78%) and 43% (95% confidence interval, 36% to 50%), respectively. Preoperative risk factors for late death were age, preoperative renal failure, New York Heart Association class IV or V, vessel disease, and nonsinus rhythm. Five- and 10-year event-free survival probabilities were 57% (95% confidence interval, 53% to 61%) and 23% (95% confidence interval, 17% to 28%), respectively. Preoperative risk factors for non-event-free survival were age, female sex, reduced left ventricular function, mitral regurgitation, and pacemaker rhythm. CONCLUSION: The demographic factors of age and female sex; the comorbid condition of renal failure; the cardiac conditions of advanced New York Heart Association class, left ventricular function, mitral regurgitation, vessel disease, and cardiac rhythm; and the operative condition of ischemia time are the most important predictors of clinical outcome after combined valve operations and coronary artery bypass grafting.

Mitral valve surgery combined with coronary bypass grafting: multivariate analysis of factors predicting early and late results.

Total of 123 patients (mean age: 63.8 +/- 7.3 years, (male/female 65/35 percent) underwent mitral valve surgery combined with coronary artery bypass grafting during a seven year period. Preoperatively 12% of them belonged to NYHA functional class II, 54% to class III, 29% to class IV and 3% was operated under emergency conditions. The mitral valve lesion was most frequently either ischaemic (45%) or rheumatic (33%) in origin. Left ventricle function was moderately decreased in 18% and severely damaged in 3% of the patients as documented by preoperative ventriculography. Coronary surgery was performed in all cases with an average number of distal anastomosis of 2.2 +/- 1.1 per patient. The hospital mortality was 13%. Risk factors for early and late mortality were determined by univariate and multivariate analysis. Advanced preoperative functional class and decreased left ventricular function or ischaemic etiology were identified as significant risk factors for early mortality. The patients were followed for an average of 33 +/- 25 months. The majority of them experienced significant functional improvement postoperatively with 69% belonging to NYHA class I or II. The late survival for the 107 hospital survivors was 94.7% at one year, and 84.7% at five years, respectively. Late survival was independently determined by preoperative functional class or previous myocardial infarction. Freedom from ischemic and valve related complications at five years was 95% and 71.2% respectively. 58.2% of the hospital survivors were in functional class I or II and free of any valve related or ischemic complications at the end of the fifth follow up year.(ABSTRACT TRUNCATED AT 250 WORDS)

The Monostrut versus Medtronic Hall prosthesis: a prospective randomized study.

A prospective randomized study, comparing the clinical results between two groups of patients undergoing valve replacement with the Monostrut (MS) and Medtronic-Hall (MH) heart valve prosthesis was carried out between January 1985 and December 1988. A MS valve was implanted in 205, the MH in 198 patients selected randomly. Statistical analysis showed a perfect match between the two groups regarding preoperative and operative variables, including implantation site. All patients were given life-long anticoagulant therapy after operation. Follow up was 5.06 years (median) with a total of 1971.1 patient-years (pty) and 96.6% complete. The two groups showed no significant difference in the incidence of the following postoperative events: 30-day mortality, late mortality, reoperation, anticoagulant related bleeding, paravalvular leak, prosthetic valve endocarditis and thromboembolism (TE). Multivariate analysis indicated a borderline increased hazard of TE (2.1 +/- 0.4%/pty versus 0.7 +/- 0.2%/pty) (p = 0.0087, Bonferoni corrected significance) in the MS group. It is concluded that long term outcome is excellent with these two tilting disc valves. The marginally lower incidence of thromboembolism, however, favors the Medtronic Hall prosthesis.

Combined valve and coronary artery bypass surgery: early and late results.

Determinants of early, late and event-free survival of combined valve and coronary artery bypass graft (CABG) surgery were studied in 420 patients using multivariate analysis. It was found that the risk of hospital death increases 5 times when the preoperative NYHA class was > or = IV, 3 times when left ventricular (LV) function is significantly impaired and is double when mitral regurgitation is present. The survival probability of hospital survivors was 91% (87.3-94.5%) at 5 years. Late mortality was determined by advanced preoperative NYHA class ( > or = IV) and the presence of mitral regurgitation. The event-free survival probability of hospital survivors, i.e. total events including death, valve-related complications, ischemic complications and recurrent NYHA class > or = IV, was 73.0% (66.7-79.5%) at 5 years. Postoperative events were determined by the presence of preoperative NYHA class > or = IV, impaired ventricular function, mitral regurgitation and non-sinus rhythm. It is concluded that these parameters can be considered as the most important predictors of clinical outcome after combined valve and CABG surgery.

Early and late effects of rt-PA vs placebo on left ventricular function measured by nuclear ventriculography.

The aim of the study was the functional re-evaluation of 296 patients 12 to 18 months after a double-blind trial evaluating the effect of tissue plasminogen activator (rt-PA) versus placebo given within 5 h of onset of symptoms caused by an acute myocardial infarction. All patients underwent rest-stress radionuclide angiography (Egna). For each exercise level the global left ventricular ejection fraction (LVEF) was calculated together with an estimate of regional wall motion abnormalities (RWMA). A clear difference of the total workload and the peak workload was found between both therapeutic groups. Discriminant analysis evaluating four parameters (LVEF at peak exercise and at the endpoint and the workload at those levels) revealed a beneficial therapeutic effect. The RWM at rest showed only a difference in the apico-inferior region. There were less wall motion abnormalities in the treated group. Radionuclide analysis demonstrated a larger functional capacity and a better coordination of myocardial contractility during stress RNA one year after thrombolytic therapy. At rest, no major differences were found between the hospital stage and the follow-up in both therapeutic groups one year later.

Determinants of left ventricular function two weeks and one year after an acute myocardial infarction.

This study examines possible covariates of left ventricular function two weeks and sixteen months after an acute infarction. It was performed in a group of 312 patients randomized double blindly to recombinant tissue plasminogen activator (rt-PA) (n = 156) or placebo treatment and followed thereafter for at least one year. Two weeks after the infarction, enzymatic infarct size, infarct-related vessel, and number of diseased coronary arteries were significant determinants of the infarct-related regional wall motion (centerline method) (R2 = 0.25 to 0.60, P = 0.0001). Enzymatic infarct size, regional wall motion of both infarct-related and remote areas, reinfarction, and treatment allocation were significant independent correlates of ejection fraction (R2 = 0.76), end-diastolic volume (R2 = 0.20), and end-systolic volume (R2 = 0.69, P < 0.0001). Infarct-related coronary artery and predischarge end-systolic volume were significant independent covariates of ejection fraction at rest (R2 = 0.47) after sixteen months. Age, enzymatic infarct size, and predischarge end-diastolic volume were independent determinants of the maximal (R2 = 0.49, P < 0.0001) and peak exercise ejection fraction (R2 = 0.49, P < 0.0001).

Prediction of event-free survival after hospital discharge in acute myocardial infarction treated with tissue-plasminogen activator.

The incidence of recurrent ischemia, congestive heart failure and death during the first year after discharge were analysed prospectively in a group of 312 patients randomized double blindly to rt-PA (n = 156) or placebo within 5 hours after the onset of acute myocardial infarction. The in-hospital mortality was 4.4% in the rt-PA and 6.4% in the placebo group; the total-mortality after a follow-up of 16 months was respectively 7.6 and 9.6%. During 16 months follow-up reinfarction occurred in 5.4% of the rt-PA treated patients versus 0.0% in controls (p = 0.004). Revascularization was required in 17% of the population (24% in rt-PA versus 16% in controls, N.S.), angina at rest and congestive heart failure, demanding hospitalization developed in 5.1% of the patients (5.3% in rt-PA versus 4.7% in controls, N.S.) and 3.4% of the patients in each group died after discharge. A logistic model constructed to predict event-free survival showed that enzymatic infarct size, exercise capacity and the hemodynamic response at a predischarge bicycle exercise test and end-systolic volume at 2 weeks were predictors of new events. Considerable overlapping between patients with and without a new event was observed.

Calculation of power and sample size with bounded outcome scores.

The two-sample Wilcoxon rank sum test is the most popular non-parametric test for the comparison of two samples when the underlying distributions are not normal. Although the underlying distributions need not be known in detail to calculate the null distribution of the test statistic, parametric assumptions are often made to determine the power of the test or the sample size. We encountered difficulties with this approach in the planning of a recent clinical trial in stroke patients. It is shown that, for power and sample size estimation, it can be dangerous to apply the classical formulae routinely, especially with outcome scores having a U-shaped or a J-shaped distribution. As an example we have taken the Barthel index, a quality-of-life outcome measure in stroke patients. Further, we have investigated alternative methods by means of Monte Carlo simulation. The distributional characteristics of the estimated powers were compared. Our findings suggest more appropriate computer software is necessary for the calculation of power and sample size when efficacy is measured by a non-parametric method.

The influence of a desk-top analyser on the number of laboratory tests used in daily general practice. A randomized controlled trial.

This study evaluated the influence of a desk-top analyser, used in general practice, on the mean number of blood tests per contact, prescribed or analysed by general practitioners. A randomized controlled trial was used. The mean number of blood tests per contact requested by two groups of GPs, before and after the introduction of a Reflotron in the intervention group was compared. Practitioners were assigned to the control group or to the intervention group by stratified randomization. Flemish GPs, known by the Flemish Institute of General Practice as interested in research were enrolled into the study. There were two registration periods of 8 weeks each. The weekly number of doctor-patient contacts and all requested or performed blood tests for each patient were registered. During the second period the members of the intervention group were asked to use the Reflotron, following their own judgement, and to register the total number of tests per contact, performed with it, on a special form. In the Reflotron group there was a slight increase in the median of the relative differences between the intervention and the base-line period (3%). In the control group the median of the relative differences decreased (-7%). The difference between both groups was not statistically significant (P = 0.17). In both groups the size and direction of the relative differences of the individual practices were very different. No statistically significant differences were found in any of the subgroups.

At equipotent doses, isradipine is better tolerated than amlodipine in patients with mild-to-moderate hypertension: a double-blind, randomized, parallel-group study.

1. The objective of this double-blind parallel-group study was to compare the tolerability of isradipine and amlodipine, specifically, the side-effects known to be related to the use of dihydropyridine calcium antagonists. 2. A total of 205 patients with mild-to-moderate essential hypertension were randomized to receive either the sustained-release (SRO) formulation of isradipine (n = 103) or amlodipine (n = 102), both at dosages of 5 mg once daily. Blood pressure measurements were taken at the end of the dosing interval to assess the antihypertensive efficacy of the two drugs. 3. Adverse reactions were assessed in two ways: a) spontaneously reported adverse events were recorded and investigated in depth for severity, duration, relation to the study drug, and outcome; b) a questionnaire was used to elicit specific adverse reactions known to be related to the use of dihydropyridine calcium antagonists which were evaluated for severity, duration, relation to the study drug, and outcome. 4. After 6 weeks of active treatment, both isradipine and amlodipine reduced mean sitting systolic/diastolic blood pressure: from 165.1/100.1 to 145.2/89.7 mm Hg with isradipine; and from 164.1/100.6 to 145.7/90.5 mm Hg with amlodipine. There was no difference in antihypertensive effect between isradipine and amlodipine (95% CI: -3.73 to 4.73 and -1.89 to 3.49 for differences in systolic and diastolic blood pressure, respectively). 5. The number of patients spontaneously reporting adverse events was significantly higher (P = 0.02; 95% CI: 3.1 to 26.7%) with amlodipine (33.3%) than with isradipine (18.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of gonadotropin secretion in the hospitalized postmenopausal female as an effect of acute critical illness.

Plasma gonadotropins were measured in 126 postmenopausal women (age range 69-90 years) admitted to a geriatric ward. After clinical examination, patients were classified as 'acutely or severely ill' or as 'not ill'. Plasma gonadotropins were compared between both groups. Logistic regression was used to select clinical and/or biochemical parameters which differentiated patients with abnormal, low gonadotropins from patients with high gonadotropin concentrations. Plasma gonadotropins were significantly lower in the 'acutely or severely ill' than in the 'healthy' patient group. By logistic regression, blood sedimentation rate, total protein concentration, and serum thyrotropin concentration were significantly correlated with low gonadotropins. Linear regression analysis showed a significant linear relationship between plasma gonadotropins and age (at least for ages over 80 years), blood sedimentation rate (at values more than 65 mm) and total protein concentration. Marked suppression of plasma gonadotropins was frequently found to occur in acutely ill postmenopausal women, in relation to biochemical parameters of acute illness such as blood sedimentation rate, total protein concentration, and serum thyrotropin. In addition, ageing per se seems characterized by a progressive attenuation of the high postmenopausal gonadotropin levels.

Surgical strategies in esophageal carcinoma with emphasis on radical lymphadenectomy.

From 1975 through 1988, 257 patients with carcinoma of the thoracic esophagus have been treated in our department. Operability was 90% (232/257); overall resectability, 77% (198/257), and for the operated group, 85% (198/232). Hospital mortality rate was 9.6% but decreased to 3% over the period 1986 to 1988. There were 65% squamous cell epitheliomas and 35% adenocarcinomas. Tumor, nodes, and metastases (pTNM) staging was as follows: stage I, 11.6%; stage II, 23.2%; stage III, 37.9%; stage IV, 27.3%. Overall survival rate was 62.5% at 1 year, 42.4% at 2 years, and 30% at 5 years. According to the pTNM staging, 5-year survival was 90% for stage I, 56% for stage II, 15.3% for stage III, and 0 for stage IV. There were no statistically significant differences according to tumor localization, pathologic type, sex, or age. Introducing extensive resection and extended lymphadenectomy seems to improve significantly survival in patients in whom an operation with curative intention was performed, the 1 year survival rate being 90.8% versus 72%; 2-year survival, 81% versus 46%; and 5-year survival, 48.5% versus 41% for radical and nonradical resections, respectively. Based on multivariate Cox regression analysis, only TNM stage and presence or absence of lymph nodes are important factors in predicting survival: stage 1 tumors have lower risk, and involvement of lymph nodes creates higher risk. Using this analysis, there was only for the patients with involved lymph nodes (N1) a significantly better prognosis when a radical lymph node dissection was performed (p = 0.0055). Barrett adenocarcinomas have no worse prognosis than other esophageal carcinomas, with a 5-year survival rate of 91.5% if lymph nodes are negative, and a 54% overall 5-year survival rate. Functional results after restoration of continuity with gastric tubulation were judged excellent to very good in 86.5% at 1 year, but infra-aortic anastomoses have a much higher incidence of peptic esophagitis: 53% versus 8% for cervical anastomoses. From this study it can be concluded that in experienced hands surgery today offers the best chances for optimal staging, potential cure, and prolonged high-quality palliation.

Twelve weeks of continuous oral therapy for toenail onychomycosis caused by dermatophytes: a double-blind comparative trial of terbinafine 250 mg/day versus itraconazole 200 mg/day.

BACKGROUND: Dermatophyte infections of the toenail have been difficult to treat, requiring long courses of therapy and having high recurrence rates. New oral antifungal agents with better outcomes and minimal adverse events are needed. OBJECTIVE: The purpose of this study was to compare two newer antifungal compounds, terbinafine and itraconazole, for efficacy and safety in toenail onychomycosis caused by dermatophytes. METHODS: The study was randomized and double-blind. It compared 12 weeks of continuous oral treatment with terbinafine 250 mg/day or itraconazole 200 mg/day for confirmed toenail dermatophyte onychomycosis. Clinical symptoms and mycologic outcome were assessed at weeks 4, 8, 12, 24, 36, and 48. A total of 372 patients (186 in each group) with dermatophyte infection confirmed by microscopy and culture were included in the intent-to-treat analysis. RESULTS: At week 48, a statistically significantly greater percentage of the terbinafine group than itraconazole group showed negative mycology (73% [119 of 163] vs 45.8% [77 of 168]; p < 0.0001) (difference = 27.2%; 95% CI = [17.0%, 37.3%]). The difference was also confirmed clinically (p = 0.001) in the patients who were clinically cured or had only minimal symptoms at the end of the study (76.2% [125 of 164] vs 58.1% [100 of 172]) (difference = 18.1%; 95% CI = [8.24%, 27.9%]). The geometric mean length of healthy nail of the big toe was significantly greater in the terbinafine than itraconazole group (8.1 vs 6.4 mm; p = 0.026). Tolerability was good to very good in almost 90% of patients in both groups, and all reported adverse events were known for these compounds. CONCLUSION: Terbinafine produced higher rates of clinical and mycologic cure at follow-up than did itraconazole.

Variceal pressure is a factor predicting the risk of a first variceal bleeding: a prospective cohort study in cirrhotic patients.

Predictive criteria for a first variceal hemorrhage lack substantial accuracy. Cross-sectional studies suggest a close relationship between variceal pressure (VP) and the occurrence of variceal bleeding. In the present prospective cohort study, the significance of VP measurement for prediction of a first variceal bleed was assessed. Eighty-seven patients with cirrhosis and large esophageal varices who had never developed variceal bleeding were followed for 12 months. The endpoint of the study was the presentation or not of a variceal hemorrhage. Thirty-four patients (39%) were in Child's class A, 37 in class B (43%), and 16 in class C (18%). The median interval between endoscopic diagnosis of varices and the beginning of the study was 15 months. Twenty-eight patients (32%) developed a variceal hemorrhage with a bleeding-related mortality of 18% (n=5). The 1-year mortality overall was 16% (n=14). Variables predictive of a first bleed identified by Cox proportional hazards regression model were: the level of VP, the North Italian Endoscopic Club (NIEC) score, and the interval between the diagnosis of varices and the start of the study. By adding VP to NIEC, a significant gain in prognostic accuracy was obtained (P = .003). In conclusion, the present study provides evidence that the level of VP is a major predictive factor for variceal hemorrhage, and that it provides further prognostic information in addition to the NIEC index.

Early and late exercise capacity after acute myocardial infarction treated with recombinant tissue-plasminogen activator.

Thrombolytic therapy salvages jeopardized myocardium and preserves left ventricular function. Therefore, a beneficial effect on exercise tolerance and haemodynamic adaptation to exercise can be anticipated. In the present study the results of bicycle exercise tests, performed at 10 to 14 days and at more than 1 year after infarction, were compared between patients randomized double blindly to recombinant tissue plasminogen activator (rt-PA) or placebo. At 2 weeks, the maximal heart rate (140 vs 130 beats.min-1 P = 0.017), systolic blood pressure (169 vs 161 mmHg, P = 0.018) and pressure-rate product (22907 vs 20865 beats.min-1.mmHg, P = 0.0025) were higher in rt-PA treated patients (n = 145) than in controls (n = 142). At a mean follow-up of 16 months, rt-PA patients (n = 126) performed a higher total and peak work load (733 vs 600 Watts.min, P = 0.027 and 133 vs 100 Watts, P = -0.036, respectively) than control patients (n = 122). During both exercise tests the incidence of clinical or electrocardiographic signs of ischaemia was similar. Multiple regression analysis indicated that age and end-systolic volume were predictors of peak pressure-rate product at 2 weeks (R2 = 0.11, P = 0.0001). Age, sex and left ventricular ejection fraction at discharge were independent predictors of peak work load at 2 weeks (R2 = 0.32, P = 0.0001) and the square root of peak work load at 16 months (R2 = 0.39, P = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Only hibernating myocardium invariably shows early recovery after coronary revascularization.

BACKGROUND: The aims of this study were to identify hibernating myocardium (hypocontractile, hypoperfused viable myocardium that regains contractility after revascularization) in the clinical setting and to predict functional outcome in patients with coronary artery disease after coronary revascularization. METHODS AND RESULTS: Preoperative data related to the anterior free wall of the left ventricle were collected in 50 coronary bypass surgery candidates (positron emission tomography [PET], [13N]NH3 for flow, and [18F]FDG for metabolism [MET]; equilibrium-gated nuclear angiography [EGNA] for regional ejection fraction [REF]; and histological data from myocardial biopsies for percentage fibrosis and viable myocytes). Three months after surgery, the patients had follow-up PET and EGNA investigations. A principal-components analysis identified four patient clusters. Cluster 1 (n = 9) had normal viable myocardium. Cluster 2 (n = 18) had viable hypocontractile myocardium (REF, 39 +/- 12%) showing a PET mismatch pattern. Cluster 3 (n = 16) had viable hypocontractile myocardium associated with morphological myocyte injury showing a matched moderate decrease in flow (66 +/- 11%) and MET (70 +/- 11%). Cluster 4 (n = 7) had hypocontractile myocardium with mainly scar tissue (fibrosis, 74 +/- 12%). After surgery, only cluster 2, with hibernating myocardium, showed significant improvement in REF (from 39 +/- 12% to 50 +/- 13%, P < .05). Cluster 3, with sites of morphological myocyte injury, showed no recovery. The stepwise logistic regression showed a combination of low preoperative REF and high MET to be the best predictor of functional recovery (P < .008). CONCLUSIONS: Multivariate analysis identifies hibernating myocardium showing early postrevascularization recovery, as opposed to viable but myolytic myocardium with no early recovery. Postrevascularization recovery can be predicted (combination of low REF and high MET) by noninvasive techniques.

A new quantitative method for the analysis of cardiac perfusion tomography (SPET): validation in post-infarct patients treated with thrombolytic therapy.

In this study a new method for assessment of perfusion defects (PDs) derived from myocardial perfusion tomograms was evaluated in patients treated with thrombolytic therapy. Using global constraints and dynamic programming, a model-based delineation algorithm defined myocardial borders, the basal plane and absolute and relative PD size in 49 thallium-201 chloride (201TL CL) and 60 technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) tomograms. Tomographic (single-photon emission tomography: SPET) and planar quantification of PDs was compared to enzymatic infarct size as well as to global (LVEF) and regional ventricular function (RWM) obtained by contrast angiography. The algorithm delineated the myocardium and the valve plane in most cases, even when large PDs were present. Manual correction of the automatic delineation of the basal plane was necessary in less than 20% of the studies. Using 201Tl Cl, LVEF correlated better with tomographic PD (r = -0.67) than with planar PD (r = -0.54). Comparing planar to tomographic imaging using 99mTc-MIBI, a higher correlation with enzymatic infarct size (r = 0.73 vs 0.57) and with global ventricular function (r = 0.64 vs -0.52) was found when tomographic techniques were used. No close correlation between PD and RWM was found. The beneficial effect of thrombolysis was shown by a significant difference of PD in patients with open versus occluded infarct-related vessels. It can be concluded that this new automated algorithm for quantification of SPET perfusion defect size provides a useful tool in evaluating thrombolytic therapy.

Tomographic and planar quantitation of perfusion defects on technetium 99m-labeled sestamibi scans: evaluation in patients treated with thrombolytic therapy for acute myocardial infarction.

BACKGROUND: Our segmentation algorithm for single-photon emission computed tomographic perfusion studies was tested in 244 patients treated by thrombolysis within 5 hours after onset of symptoms. This algorithm uses radial slices to approximate true three-dimensional gradients, determines the apex and basal plane, and creates a perfusion and volume polar map. METHODS AND RESULTS: Perfusion defect size was compared with enzymatic infarct size and global and regional function. All patients underwent rest planar and tomographic 99mTc-labeled sestamibi scanning, contrast coronary angiography, and ventriculography 10 to 14 days after the start of treatment. Manual correction had to be performed in only 10% of the cases and presented no problems. The correlation coefficients (r) between planar and relative tomographic perfusion defects versus enzymatic infarct size were 0.71 and 0.73. A negative correlation was found with left ventricular ejection fraction: r = -0.65 and r = -0.60. A comparable correlation was also found between regional wall motion and perfusion defect size. Most correlations were higher in the case of anterior infarction. An excellent correlation was found between planar and tomographic defect size (r = 0.83). CONCLUSIONS: In most cases, our segmentation algorithm delineates myocardial edges and basal plane automatically. A good correlation was found between perfusion defect size, enzymatic infarct size, and global and regional ventricular function.