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The accuracy of dobutamine echocardiography (DE) early after reperfused acute myocardial infarction (AMI) without residual stenosis of the infarct-related artery is unknown. The objective of this study was to assess whether in reperfused AMI DE can predict early as well as late regional and global spontaneous functional recovery.DE was performed in 157 patients (61 +/- 11 years; 33 women) 3 days after AMI treated with successful direct percutaneous transluminal coronary angioplasty (Thrombolysis in Myocardial Infarction flow grade 3, residual stenosis30%). All patients underwent 2-dimensional echocardiography and coronary angiography at 1 month and 145 (92%) at 6 months.Patency and restenosis rate were similar between those who did and did not respond to DE. DE showed a high accuracy in predicting both early and late regional functional recovery (86% and 81%, respectively). DE accuracy in predicting early and late reversible dysfunction was also high on a patient-by-patient analysis (89% and 87%). In DE responders left ventricular ejection fraction increased from 44% +/- 9% at baseline to 57% +/- 9% at 6 months (P.00005), whereas only a slight, although significant improvement was found in nonresponders (from 40% +/- 10% to 44% +/- 12%; P =.03). A significant correlation was found between the number of dobutamine-responder segments and the magnitude of their functional improvement at peak dobutamine and changes in ejection fraction (r =.72; P.000001; r =.68, P.000001, respectively).These data indicate that in patients with AMI in whom anterograde flow is fully restored without residual stenosis, DE can predict the recovery of regional function and whether a relevant change in ejection fraction will occur at early and late follow-up.

Background —The relation between remodeling and left ventricular (LV) diastolic function has not yet been fully investigated. The aim of this study was to determine whether early assessment of Doppler-derived mitral deceleration time (DT), a measure of LV compliance and filling, may predict progressive LV dilation after acute myocardial infarction (AMI). Methods and Results —Fifty-one patients (aged 61±11 years; 6 women) with anterior AMI successfully treated with direct coronary angioplasty underwent 2-dimensional and Doppler echocardiographic examinations within 24 hours of admission, at days 3, 7, and 30 and 6 months after the index infarction. Mitral flow velocities were obtained from the apical 4-chamber view with pulsed Doppler. End-diastolic volume index (EDVI) and end-systolic volume index (ESVI) were calculated with the Simpson’s rule algorithm. Patients were divided according to the DT duration assessed at day 3 in 2 groups: group 1 (n=33) with DT >130 ms and group 2 (n=18) with DT ≤130 ms. Patency and restenosis rate at 6 months were similar between the 2 groups (94% group 1 vs 89% group 2; P =0.52; 27% group 1 vs 33% group 2; P =0.64, respectively). LV volume indexes were similar in both groups at baseline (EDVI: 71±3 group 1 vs 70±3 mL/m 2 group 2, P =0.42; ESVI: 43±3 group 1 vs 48±3 mL/m 2 group 2, P =0.13, respectively). From day 3 on, LV volume indexes progressively increased in group 2 and were significantly larger than those of group 1 at 6 months (LVEDVI 61±3 group 1 vs 104±6 mL/m 2 group 2, P =0.00001; LVESVI 31±3 group 1 vs 73±6 mL/m 2 group 2, P =0.00001, respectively). A significant inverse correlation was found between DT and changes in EDVI at 6 months ( r =−0.68; P P =0.02). Conclusions —These data suggest that early estimation (day 3) of Doppler-derived mitral DT provides a simple and accurate mean to predict late LV dilation after reperfused AMI.

Objectives. This prospective observational study was conducted to examine the apparent impact of a systematic direct percutaneous transluminal coronary angioplasty (PTCA) strategy on mortality in a series of 66 consecutive patients with acute myocardial infarction (AMI) complicated by cardiogenic shock, and to analyze the predictors of outcome after successful direct PTCA. Background. Previous studies have reported encouraging results with PTCA in patients with AMI complicated by cardiogenic shock, but a biased case selection for PTCA may have heavily influenced the observed outcomes. Methods. All patients admitted with AMI were considered eligible for direct PTCA, including those with the most profound shock, and no upper age limit was used. The treatment protocol also included stenting of the infarct-related artery for a poor or suboptimal angiographic result after conventional PTCA. Results. Between January 1995 and March 1997, 364 consecutive patients underwent direct PTCA, and in 66 patients AMI was complicated by cardiogenic shock. In patients with cardiogenic shock, direct PTCA had a success rate of 94%; an optimal angiographic result was achieved in 85%; primary stenting of the infarct-related artery was accomplished in 47%; and the in-hospital mortality rate was 26%. Univariate analysis showed that patient age, chronic coronary occlusion and completeness of revascularization were significantly related to in-hospital mortality. The mean follow-up period was 16 ± 8 months. Survival rate at 6 months was 71%. Comparison of event-free survival in patients with a stented or nonstented infarct-related artery suggests an initial and long-term benefit of primary stenting. Conclusions. Systematic direct PTCA, including stent-supported PTCA, can establish a Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in the great majority of patients presenting with AMI and early cardiogenic shock. High performance criteria, including new devices such as coronary stents, should be considered in randomized trials where mechanical revascularization therapy is being tested.

The aim of this study was to evaluate whether assessment of ST-segment changes in the 12-lead electrocardiogram from admission to 30 minutes after successful direct coronary angioplasty can predict myocardial damage and functional outcome in patients with acute myocardial infarction (AMI). Of 158 consecutive patients, 117 (92 men, aged 61 +/- 11 years) were prospectively classified into 2 groups: group 1,50% reduction in ST-segment elevation in a single selected lead (42 patients); group 2,or =50% reduction in ST-segment elevation (75 patients). Baseline characteristics were similar except for anterior wall AMI and Killip class2, which were more prevalent in group 1. Peak creatine kinase was significantly higher in group 1 (3,690 +/- 2,809 vs 2,592 +/- 1,960 U/L; p = 0.018). One-month echocardiograms were obtained in 102 patients (87%). Infarct zone wall motion score index decreased in both groups, but this reduction was higher in group 2 (p0.001). Functional recovery (0.22 decrease in infarct zone wall motion score index) was observed in 34% of group 1 and in 78% of group 2 patients (p0.001). One-month left ventricular ejection fraction was higher in group 2 (p0.001). At multivariate analysis, reduction of ST-segment elevation was the only independent predictor of functional recovery (p0.001). In conclusion, ST-segment analysis provides rapid and inexpensive information allowing identification of patients who are likely to benefit the most from myocardial reperfusion as early as 30 minutes after the last balloon inflation.

ObjectivesWe sought to compare myocardial contrast echocardiography with low dose dobutamine echocardiography for predicting 1-month recovery of ventricular function in acute myocardial infarction treated with primary coronary angioplasty.BackgroundThe relation between myocardial perfusion and contractile reserve in patients with acute myocardial infarction, in whom anterograde flow is fully restored without significant residual stenosis, is still unclear.MethodsThirty patients with acute myocardial infarction treated successfully with primary coronary angioplasty underwent intracoronary contrast echocardiography before and after angioplasty and dobutamine echocardiography 3 days after the index infarction. One month later, two-dimensional echocardiography and coronary angiography were repeated in all patients and contrast echocardiography in 18 patients.ResultsAfter coronary recanalization, 26 patients showed myocardial reperfusion within the risk area, although 4 did not. At 1-month follow-up, all patients had a patent infarct-related artery without significant restenosis. Both left ventricular ejection fraction and wall motion score index within the risk area significantly improved in the patients with reperfusion ([mean ± SD] 38 ± 8% vs. 48 ± 12%, p < 0.005; and 2.35 ± 0.5 vs. 2 ± 0.6, p < 0.001, respectively), but not in those with no reflow. Of the 72 nonperfused segments before angioplasty, 27 showed functional improvement at follow-up. Myocardial contrast echocardiography had a sensitivity and a negative predictive value similar to dobutamine echocardiography in predicting late functional recovery (96% vs. 89% and 89% vs. 93%, respectively), but a lower specificity (18% vs. 91%, p < 0.001), positive predictive value (41% vs. 86%, p < 0.001) and overall accuracy (47% vs. 90%, p < 0.001).ConclusionsMicrovascular integrity is a prerequisite for myocardial viability after acute myocardial infarction. However, contrast enhancement shortly after recanalization does not necessarily imply a late functional improvement. Thus, contractile reserve elicited by low dose dobutamine is a more accurate predictor of regional functional recovery after reperfused acute myocardial infarction than microvascular integrity.

The purpose of this study was to evaluate feasibility, safety, and efficacy of bailout Palmaz-Schatz stenting in a series of 39 patients with coronary dissection associated with acute or unequivocal threatened closure complicating conventional angioplasty. No anatomical characteristics other than reference vessel diameter3 mm were considered as contraindications for bailout coronary stenting. Stringent criteria were adopted in defining optimal results (10% residual stenosis, no angiographic evidence of residual dissection), suboptimal results (10% residual stenosis or angiographic evidence of residual dissection), deployment failure (failure to deploy the stent because of poor trackability or persistent occlusion despite stent deployment). A total of 49 stents and 7 half-stents were implanted in 36 patients (range 1-5; mean 1.45 +/- 0.84). Successful stenting without in-hospital death, urgent or semielective coronary surgery, stent thrombosis, or Q-wave myocardial infarction was achieved in 33/39 patients (85%). A suboptimal result was associated with an increased risk of in-hospital recurrence of ischemia and other related major adverse events (2/5 patients with suboptimal results vs. 1/31 patients with complete deployment success; P0.05). Multiple stents implantation did not carry a significant risk of major cardiac adverse events. The results of this study suggest that bailout Palmaz-Schatz stenting may be considered a stand-alone treatment of coronary dissection if an optimal acute angiographic result is achieved.

Objectives. This study investigated the role of nitrite technetium-99m sestamibi imaging in predicting the postrevascularization outcome of chronically hypoperfused asynergic territories. Background. Rest technetium-99m sestamibi myocardial scintigraphy underestimates the presence of viable myocardium in asynergic territories. Stimulation that improves coronary blood flow could increase tracer uptake in hibernating territories. Methods. Nineteen patients with a previous myocardial infarction and left ventricular dysfunction scheduled for revascularization underwent quantitative technetium-99m sestamibi tomography under baseline conditions and during isosorbide dinitrate infusion. Global and regional function were assessed, respectively, before and after revascularization by radionuclide angiocardiography and two-dimensional echocardiography. Results. Seven patients (group A) showed postrevascularization regional function recovery, and 12 (group B) showed no significant changes. In group A, nitrate infusion induced a decrease in the extent of the global uptake defect ([mean ± SD] −37.4 ± 21.6% of baseline value); in group B, ne change or a slight increase was observed (+5.8 ± 8.4%, p < 0.0005 vs. group A). The nitrate-induced changes in the extent of uptake defect correlated with postrevascularization changes in ejection fraction (r = −0.94, SEE 7.6). After revascularization, 11 asynergic vascular territories showed improvement (hibernating), and 34 remained unchanged (fibrotic). With administration of nitrates, 10 hibernating territories had a decrease in the extent of uptake defect, whereas only 4 of 34 of the fibrotic territories showed a nitrate-induced uptake improvement. Conclusions. Short-term administration of isosorbide dinitrate immediately before injection of technetium-99m sestamibi increases tracer uptake in some chronically hypoperfused asynergic territories. This finding correlates with the observation of postrevascularization functional recovery. Nitrate technetium-99m sestamibi myocardial scintigraphy could be a promising method for the noninvasive detection of viable hibernating myocardium.

To evaluate the prevalence of type I silent myocardial ischemia and silent myocardial infarction, 4,842 men aged 40 to 59 years, identified in occupational samples in Florence and Rome, and free from major heart disease, severe illnesses and chest pain, underwent a 3-stage diagnostic procedure. The first stage included resting electrocardiogram, hyperventilation test, exercise electrocardiogram and 24-hour Holter electrocardiogram. The subjects who were suspected of having type 1 silent myocardial ischemia or previous silent infarction at the first stage (n = 439; 9.1%) were entered into the second stage, which included echocardiogram, thallium 201 scintigraphy in conjunction with exercise testing or dipyridamole test, exercise radionuclide ventriculography and ergonovine test. Three hundred eighty-seven men participated in the second stage; after the diagnostic procedures were performed, 104 men (2.1%) were still suspected of having type 1 silent myocardial ischemia or infarction on the basis of predefined criteria. Sixty-two men continued on into the third diagnostic workup including coronary angiography. The final diagnosis of type 1 silent myocardial ischemia or infarction was reached in 25 patients (prevalence 0.52%; adjusted estimate 0.89%). Of these 25, 19 had coronary atherosclerotic disease, 1 had Kawasaki disease, 1 had coronary anomaly, 1 had induced focal coronary spasm, and 2 had normal coronary arteriograms despite the presence of unquestionable old myocardial infarction. Altogether, 6 patients with silent myocardial infarction were identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Background Notwithstanding the negative result of the International Study of Infarct Survival-4 (ISIS-4), the controversy about the role of magnesium in acute myocardial infarction is still open because, according to experimental data, magnesium could decrease myocardial damage and mortality only if infusion is started before reperfusion. This randomized placebo-controlled trial was designed to evaluate the effect of intravenous magnesium, delivered before, during, and after direct coronary angioplasty, in patients with acute myocardial infarction. Methods One-hundred fifty patients were randomized to intravenous magnesium sulfate or placebo. The primary end point was an infarct zone wall motion score index at 30 days, as a measure of infarct size. The secondary end points included creatine kinase peak, ventricular fibrillation/tachycardia within the first 24 hours, death and congestive heart failure within the 30-day follow-up, and 30-day left ventricular ejection fraction. Analysis was by intention to treat. Results There were no significant differences between the magnesium and placebo groups in the 30-day infarct zone wall motion score index (1.93 ± 0.61 vs 1.85 ± 0.51, P =.39), ventricular arrhythmias (24% vs 15%, P =.15), death (0 vs 1%, P =.32), heart failure (8% vs 7%, P =.75), and 30-day left ventricular ejection fraction (49% ± 11% vs 50% ± 9%, P = 0.55). There was a trend toward a higher creatine kinase peak in the magnesium group (3059 ± 2359 vs 2404 ± 1673, P =.052). Conclusions Intravenous magnesium delivered before, during, and after reperfusion did not decrease myocardial damage and did not improve the short-term clinical outcome in patients with acute myocardial infarction treated with direct angioplasty. (Am Heart J 2000;140:891-7.)

Background There are conflicting data about the efficacy of aggressive treatment and early intervention among high-risk patients with acute myocardial infarction (AMI), such as elderly patients. This study sought to determine the short- and long-term outcome of octogenarian and older patients after primary percutaneous transluminal coronary angioplasty (PTCA). Methods In our tertiary referral center a program of primary PTCA was begun in 1995, and the systematic care for AMI included primary PTCA in all patients with AMI, with no age restriction. Over a period of 3 years, 55 octogenarian or older patients underwent primary PTCA. Results Between January 1995 and July 1998, 719 patients with AMI underwent primary PTCA. Of these, 55 patients were octogenarians or older (mean age, 84 ± 3 years). Primary PTCA failure occurred in 3 (5%) patients. An optimal acute angiographic result was achieved in 51 (93%) patients. Stenting of the infarct vessel was accomplished in 33 (60%) patients. The 30-day mortality rate was 16%. The mortality rate was 4% in patients without cardiogenic shock on presentation and 70% in patients with cardiogenic shock. The recurrent ischemia rate was 13% and resulted in nonfatal reinfarction in 2 patients and repeat PTCA in 5 patients. As determined by multivariate analysis, an optimal acute angiographic result and cardiogenic shock were significantly related to mortality. The 1-year survival rate was 77%. Conclusions The results of this study suggest that the benefits of primary PTCA apply to the very elderly and support an early aggressive strategy for this high-risk patient subset. (Am Heart J 1999;138:670-4.)

Completed and ongoing randomized trials have provided results that favor primary infarct-related artery (IRA) stenting as opposed to primary percutaneous transluminal coronary angioplasty, but the applicability of the trial results to all patients with acute myocardial infarction (AMI) has not yet been investigated. This study sought to determine the applicability of an unconditional IRA stenting strategy in nonselected patients with AMI. After successful mechanical recanalization of the IRA, all patients with AMI and a reference diameter > or =2.5 mm were considered eligible for primary IRA stenting without any restriction regarding age or clinical status on presentation. The primary end point of the study was a composite end point defined as death, reinfarction, or repeat target lesion revascularization. Primary IRA stenting was successfully performed in 161 of 190 consecutive patients with AMI (85%), and of 162 (99%) considered suitable for stenting. Patients with nonstented IRA had a reference IRA diameter smaller than patients with a stent (2.71+/-0.48 vs 3.20+/-0.41 mm, p

The aim of this study was to evaluate the relation between myocardial perfusion and ST-segment changes in patients with acute myocardial infarction treated with successful direct angioplasty. Thirty-seven patients, successfully treated with direct angioplasty, underwent myocardial contrast echocardiography before and after angioplasty. The sum of ST-segment elevation divided by the number of the leads involved (ST-segment elevation index) was calculated at 1, 5, 10, 20, and 30 minutes after restoration of a Thrombolysis In Myocardial Infarction trial grade 3 flow. After recanalization, myocardial reperfusion within the risk area was observed in 26 patients, whereas a no-reflow phenomenon occurred in 11. In patients with myocardial reperfusion, the ST-segment elevation index progressively declined, whereas in patients with no reflow, no significant change was observed. Reduction of > or = 50% in the ST-segment elevation index occurred in 20 of the 26 patients with reflow and in 1 of the 11 with no reflow (p = 0.0002). An additional increase of > or = 30% in the ST-segment elevation index occurred in 3 patients with reflow and in 7 with no reflow (p = 0.003). Sensitivity, specificity, positive and negative predictive values, and accuracy of the reduction in the ST-segment elevation index for predicting microvascular reflow were 77%, 91%, 95%, 62%, and 81%, respectively. The corresponding values of the increase in ST-segment elevation index for predicting no reflow were 64%, 88%, 70%, 85%, and 81%, respectively. In conclusion, after successful angioplasty, different patterns of myocardial perfusion are associated with different ST-segment changes. Analysis of ST-segment changes predicts the degree of myocardial reperfusion.

Background Randomized trials have demonstrated that planned coronary stenting may lower restenosis rate in patients with de novo short lesions. In a prospective study we sought to determine the frequency of restenosis, reocclusion, and adverse cardiovascular events after coronary stenting in a series of 258 consecutive nonselected patients, including those with complex lesions not fulfilling past and ongoing randomized trial criteria for stent implantation. Methods Criteria for stenting were as follows: (1) dissection associated with occlusion or threatened closure, (2) a residual percentage stenosis ≤30% or nonocclusive dissection, (3) restenotic lesion or chronic total occlusion. Results In most cases (89%) the target lesion had two or more unfavorable morphologic characteristics, whereas only 11% of target lesions could be classified as type A or B1 lesions. Overall, the 6-month restenosis rate was 23%. By use of subgroup analysis restenosis rate was found to range widely, from 11% to 46%. With multivariate analysis, only four variables were found to be independently related to restenosis: age >63 years (odds ratio [OR] = 2.651, p = 0.011), female sex (OR = 3.807, p = 0.002), lesion length >12 mm (OR 3.185, p = 0.002), and type C lesion (OR 2.527, p = 0.014). Conclusions Results from randomized trials on coronary stenting cannot be extrapolated to current clinical practice because most of the treated lesions do not fulfill the criteria adopted in these studies for stent implantation. The restenosis rate is nearly four times greater for long and complex lesions treated by multiple stent implantation as compared with simple lesions, and additional studies need to be performed to evaluate the efficacy of stenting on these lesions. (Am Heart J 1998;135:510-8.)

This report describes our preliminary experience with coronary stent-supported angioplasty in long narrowings using a long stent with an innovative design. Twenty-seven consecutive patients with target lesions >20 mm in length had a stenting procedure using the Freedom Force long coronary stent (Global Therapeutics, Inc., Broomfield, CO). Target lesion length ranged from 20.7–57.5 mm (mean, 27.66 ± 9.41 mm). A total of 35 stents was implanted with a mean stented length of 36.26 ± 12.36 mm. The stenting procedure was successful in all patients. Single long stent implantation was performed in 19 patients, while 8 patients had double stent implantation. No major cardiac adverse events occurred during hospital stay. The restenosis rate at the 6-mo angiographic follow-up was 38% (follow-up rate, 96%). During follow-up, no major cardiac events such as death, myocardial infarction, or coronary artery surgery occurred, while 3 patients (11%), all with recurrent angina and angiographic restenosis, underwent repeat coronary angioplasty. Potential advantages of this innovative stent in long narrowings relate to its high flexibility in passing through long tortuous diseased segments, and in treating long lesions using only 1 or 2 stents. Cathet. Cardiovasc. Diagn. 43:163–167, 1998. © 1998 Wiley-Liss, Inc.

Background The relation between residual myocardial viability after acute myocardial infarction (AMI) and ventricular remodeling has yet to be fully elucidated. We hypothesized that the presence of residual viability would favorably influence left ventricular remodeling after AMI and that serial changes in left ventricular dimensions might be related to the extent of myocardial viability in the infarct zone. Methods and Results Ninety-three patients with a first AMI successfully treated with primary coronary angioplasty underwent two-dimensional echocardiography within 24 hours of admission and low-dose dobutamine echocardiography at a mean of 3 days after AMI. Two-dimensional echocardiography and coronary angiography were obtained in all patients 1 and 6 months after coronary angioplasty. On the basis of dobutamine echocardiography responses, patients were divided in two subsets: those with (n=48; group I) and those without (n=45; group II) infarct-zone viability. There was no difference in minimal lesion diameter and infarct-related artery patency at 1 and 6 months between the two groups. Group II patients had significantly greater end-diastolic (76±18 versus 53±14 mL/m 2 ; P 2 ; P r =−.66; P Conclusions After reperfused AMI, the degree of left ventricular dilation, when it occurs, is inversely related to the extent of residual myocardial viability in the infarct zone. Thus, the absence of residual infarct-zone viability discriminates patients who develop progressive left ventricular dilation after reperfused AMI from those who maintain normal left ventricular geometry.

This study provides the incidence of in-hospital and 1-month recurrent ischemia in 118 patients with acute myocardial infarction when an aggressive direct angioplasty strategy was performed, including stenting of the infarct artery. Coronary stenting in acute myocardial infarction is feasible, and acute and 1-month angiographic results after stenting seem superior to those after standard angioplasty alone.

The accuracy of sequential testing in the noninvasive diagnosis of coronary artery disease has been established in the symptomatic clinical populations, while little is known about its value when applied to low prevalence groups, such as totally asymptomatic men. To evaluate the accuracy of noninvasive sequential testing in the diagnosis of silent myocardial ischemia, data were collected from exercise electrocardiogram, 201Tl perfusion scintigraphy and radionuclide angiography for 62 totally asymptomatic middle-aged men who underwent coronary arteriography because they were positive for two or more markers of myocardial ischemia as determined by a diagnostic screening of a nonbiased population consisting of 4,842 presumably healthy men aged 40-59 years (the ECCIS Project). The predictive value of serial testing procedures for significant coronary artery obstruction was 35%. Predictive values of an abnormal electrocardiogram associated with either an abnormal 201Tl scintigram, an abnormal isotopic ventriculography, or both were 33, 38 and 31%, respectively. In asymptomatic middle-aged men, there is at least a 50% likelihood that an abnormal radionuclide test is a false-positive result, and the positive predictive value is not enhanced by the concordance of an abnormal 201Tl scintigraphy with an abnormal isotopic ventriculography. Thus, the application of noninvasive sequential testing in screening for asymptomatic coronary artery disease is limited by its low predictive value in accordance with the Bayesian probability theory.

This study aimed to verify whether the assessment of defect severity and the infusion of nitrates during tracer injection improve the capability of data-based 99mTc-labeled sestamibi single-photon emission computed tomography (SPECT) to recognize hibernating myocardium. Of 66 asynergic coronary territories in 40 patients with left ventricular dysfunction, 28 had postrevascularization functional recovery (hibernating) and 38 had unchanged dysfunction (fibrotic). Defect severity was lower in the hibernating than in the fibrotic territories on both baseline (p

An epidemiological study was conducted on 5163 men aged 40–59 years, made by occupational samples, from Florence and Rome to identify, by a three-stage procedure, subjects with asymptomatic silent ischemic heart disease (SIHD). This report describes some coronary risk factors. Men who are free from heart disease were compared with: (1) those having a low probability of SIHD (ECG signs only; n = 439); (2) those having a high probability of SIHD (ECG signs plus echographic signs, or positive markers of deficient perfusion, or altered radionuclide ventriculography; n = 104); (3) those having a definite SIHD (signs of the first two groups plus evidence from coronary angiography; n = 25). A clearcut increasing trend in the levels of major coronary risk factors, and in the multivariate estimated coronary risk for major events was found. The difference was not significant between highly probabile and definite cases of SIHD, due to the small numbers involved. Three multiple logistic models, with the three probability levels of silent ischemia as end-points, showed that four of 10 tested factors were associated with the presence of SIHD: age, systolic blood pressure, cigarette smoking and non-HDL serum cholesterol.

Pre- and post-treatment myocardial scintigraphy with technetium-99m hexakis 2-methoxy-isobutyl-isonitrile (Tc-99m sestamibi) was performed in patients who underwent thrombolytic therapy for acute myocardial infarction comparing planar imaging and single-photon emission computed tomography (SPECT). Twenty-one patients were injected with Tc-99m sestamibi before thrombolytic treatment. SPECT and planar imaging were acquired after completion of the treatment. The scintigraphy was repeated 5 days later in 20 subjects. Planar and SPECT studies were evaluated using an uptake score. Patients were divided according to the status of the infarct-related vessel (patent in 13 patients, group 1, and occluded in seven, group 2) and to the presence of functional recovery in serial echocardiographic controls (present in 10 patients, group A, and absent in 10, group B). The scintigraphic defect extent in the 5-day images correlated with the enzymatic infarct size: SPECT: r = 0.75, p less than 0.0002; planar: r = 0.68, p less than 0.002. The decrease of the uptake defects correlated with the reduction of the left ventricular wall asynergy (admission versus 1 month echocardiogram): SPECT: r = 0.92, p less than 0.000001; planar: r = 0.82, p less than 0.00001. The percent decrease of the uptake defects was significantly higher in patients in group 1 and group A compared with group 2 and, respectively, group B--SPECT: group 1: 51.4 +/- 27.7 versus group 2: 13.1 +/- 8.6, p less than 0.02; group A: 64.2 +/- 15.3 versus group B: 11.9 +/- 8.1, p less than 0.0002; planar group 1: 41 +/- 30.4 versus group 2: 7.7 +/- 6.2, p less than 0.05; group A: 52.5 +/- 24.3 versus group B: 6.1 +/- 6, p less than 0.0002. This study confirms the reliability of pre- and post-treatment myocardial scintigraphy with Tc-99m sestamibi for evaluating the outcome of thrombolytic treatment in myocardial infarction. The results seems slightly more accurate using SPECT, but a simple three-view planar study also gives useful data.

Single photon emission computed tomography (SPECT) with technetium-99m hexakis 2-methoxyisobutyl isonitrile was investigated as a method to evaluate the results of intravenous thrombolytic treatment in 14 patients (11 men and 3 women) with acute myocardial infarction admitted to the coronary care unit within 4 h of the onset of symptoms. All patients received an injection of 740 MBq of the tracer before starting the thrombolytic therapy, and isonitrile tomography was performed 3 to 4 h later. The tomographic study was repeated 5 days after the acute event. The results of thrombolytic treatment were independently evaluated taking into account the clinical, electrocardiographic (ECG) and enzymatic data and the findings of left ventricular and coronary angiography. Furthermore, all patients were studied with two-dimensional echocardiography on admission, 5 days later and 1 month later. The site and extent of the perfusion defects on admission scintigraphy were consonant with the ECG and echocardiographic findings. A good correlation could be established between the 5 day scintigraphic estimate of infarct dimension and the enzymatic infarct size (r = 0.907, p less than 0.00002). The comparison between pre- and postthrombolytic treatment images enabled the identification of successful and unsuccessful reperfusion even in patients whose other noninvasive findings were inconclusive. Finally, the reduction in defect size predicted late functional improvement that was demonstrated by echocardiography performed 1 month later (r = 0.89, p less than 0.00005). The results of the study suggest the feasibility and the possible usefulness of isonitrile tomography in demonstrating the presence and size of myocardial damage and in assessing the extent of myocardial salvage after thrombolytic therapy in acute myocardial infarction.