Prognostic value of divergent pattern detection by 99mTc-sestamibi gated SPECT in patients with anterior acute myocardial infarction.

PURPOSE: In gated myocardial perfusion SPECT, apical remodeling may be identified by the presence of a divergent pattern (DP) of the left ventricle (LV). METHODS AND RESULTS: We examined 150 anterior ST-elevation myocardial infarction (STEMI) patients, all successfully treated with primary percutaneous coronary interventions (PCI). Perfusion gated-SPECT to measure infarct size, LV end-diastolic (ED) and end-systolic (ES) volumes and ejection fraction (EF) was acquired before hospital discharge and repeated at 6-month follow-up. DP was observed in 26 patients, who had larger infarct size (28 ± 19% vs. 15.7 ± 17%, P < 0.02), and lower EF (33 ± 7% vs. 41 ± 10%, P < 0.001) than patients without DP. At follow-up, DP patients had significantly larger EDV (156 ± 54 vs. 107 ± 44 mL, P < 0.0001), ESV (104 ± 47 vs. 59 ± 36 mL, P < 0.0001) and lower EF (35 ± 12% vs. 48 ± 13%, P < 0.0001). 54% of DP patients developed remodeling at follow-up vs. 12% of those without DP (P < 0.001). During follow up, 7 events in the DP group (27%) and 11 events in patients without DP (9%; P < 0.02) occurred. Kaplan-Meier survival curves showed a worse prognosis for DP patients. CONCLUSION: In patients with anterior AMI, early DP detection is related to subsequent LV dysfunction, larger infarct size, and worse severity. It is helpful for predicting LV remodeling at short-term follow-up and has prognostic implications.

Time course of serum collagen types I and III metabolism products after reperfused acute myocardial infarction in patients with and without systemic hypertension.

We examined 55 consecutive patients successfully treated with primary percutaneous coronary intervention (PCI) for a first acute myocardial infarction with left ventricular (LV) systolic dysfunction. In all patients we performed echocardiographic examination, dosage of plasma brain natriuretic peptide, serum carboxy-terminal propeptide and telopeptide of procollagen type I and amino-terminal propeptide of procollagen type III at days 1 and 3, and at 1 and 6 months after index infarction. The hypertensive patients (group 1; n=30) differed for higher baseline blood pressure (133+/-4 mm Hg vs 118+/-4 mm Hg; P=0.03), greater LV mass index (108+/-5 vs 94+/-4 g m(-2), P=0.03) and lower mitral E/A wave peak (0.8+/-0.06 vs 1.1+/-0.12, P=0.02) with respect to non-hypertensive patients (group 2; n=25). From day 1 to month 6 carboxy-terminal propeptide of procollagen type I and amino-terminal propeptide of procollagen type III increased (P<0.005 and P<0.05, respectively) in both groups, whereas carboxy-terminal telopeptide of procollagen type I increased from day 1 to day 3 (P<0.01 in both groups, respectively) and then decreased from day 3 to month 6 (P<0.01 and P<0.05 in both groups, respectively). From day 1, brain natriuretic peptide decreased in both groups (P<0.005). There was no significant difference between the two groups in values of procollagens and natriuretic peptide. Finally, LV diastolic volume and function at 6 months were similar in the two groups. Thus, in patients with reperfused acute myocardial infarction and LV dysfunction, antecedent hypertension was not associated with a different pattern of serum procollagen release and ventricular remodelling at 6 months of follow-up.

Clinical, biochemical and therapeutical aspects of amiodarone-induced hypothyroidism (AIH) in geriatric patients with cardiac arrhythmias.

The clinical features and the laboratory aspects of the amiodarone-induced hypothyroidism (AIH) in the elderly as well as the effects of amiodarone treatment in aged AIH people have not yet been well clarified. In the present paper, we evaluated 18 subjects of both sexes (7 females, 11 males), aged 65-83 years, affected by AIH, recruited in Central Tuscany, Italy. The patients were divided in two subsets on the basis of thyroid stimulating hormone (TSH) values: mild (TSH < 20 mU/l; Group A, n=11) and severe (TSH > 20 mU/l; Group B, n=7) hypothyroid patients. On the basis of clinical features, hypothyroidism was diagnosed only in two patients (out of Group B). Concerning the hormonal pattern, we found that free tetraiodothyronine (fT4) levels were significantly lower than the normal range only in Group B subjects; TSH and thyroglobulin were higher than normal in both groups; free triiodothyronine (fT3) were always in the normal range. Thyroid autoantibodies were found positive only in one patient out of Group A and in two patients out of Group B. In 5/18 patients T4 substitutive therapy was rapidly assigned, because of severe degree of hypothyroidism. In the remaining 13/18 patients, we evaluated the clinical behavior of AIH. After additional cardiac evaluation, amiodarone was withdrawn in 5/13 patients: during follow-up period (4-10 months) four patients became quickly euthyroid while one worsened. In 8/13 patients, amiodarone treatment had to be carried on; during follow-up (2-48 months), four patients remained mildly hypothyroid, while other four patients became severely hypothyroid. In conclusion, in amiodarone treated elderly people, diagnosis of hypothyroidism is reliable only on the basis of high values of TSH; clinical features and fT3 serum levels never enable diagnosis.

Clinical and angiographic outcomes following elective implantation of the Carbostent in patients at high risk of restenosis and target vessel failure.

The Carbostent is a new balloon-expandable, stainless steel, tubular stent with innovative multicellular design and unique turbostratic carbon coating. The aim of this study was to assess clinical and angiographic outcomes after Carbostent implantation in 112 patients poorly suitable for an effective treatment with stenting because of the high risk of thrombosis, late restenosis, and clinical target vessel failure. The inclusion criteria were age > 75 years, diabetes mellitus, a lesion length > 10 mm, a reference vessel diameter < 3.0 mm, an ostial location of the target lesion, and chronic total occlusion. Overall, a total of 175 stents ranging from 9 to 25 mm in length were placed in 147 lesions. There were no stenting attempt failures. The acute gain after stent implantation was 2.46 +/- 0.51 mm, and the residual stenosis 0 +/- 4%. No stent thrombosis occurred, nor myocardial infarction. The 6-month event-free survival rate was 74% +/- 5%. The 6-month angiographic follow-up showed a late loss of 0.81 +/- 0.88 mm and a binary (> or = 50%) restenosis rate of 25%. The results of this study suggest that the Carbostent may be highly effective in patients at high risk of restenosis and target vessel failure.

Prognostic implications of restrictive left ventricular filling in reperfused anterior acute myocardial infarction.

OBJECTIVES: We sought to assess the relative prognostic role of a restrictive left ventricular (LV) filling pattern after a first anterior acute myocardial infarction (AMI) in patients treated with primary percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND: In thrombolized patients, a short Doppler-derived mitral deceleration time (DT) of early filling is a powerful independent predictor of heart failure and death. However, it is still unknown whether the outcome of patients with AMI with a short DT may be improved by a more aggressive treatment. METHODS: In 104 patients, two-dimensional and Doppler echocardiograms were obtained three days after the index AMI. Coronary angiography was performed in all patients one and six months after PTCA. The patients were classified into two groups according to the DT duration: group 1 (n = 34) with DT < or = 130 ms and group 2 (n = 70) with DT >130 ms. All patients were followed-up for a mean (+/- SD) period of 32 +/- 10 months. RESULTS: During the follow-up period, 14 patients (13%) were admitted to the hospital for congestive heart failure, and 9 patients (9%) died. All cardiac deaths (n = 7) occurred in group 1. The survival rate at mean follow-up was 79% in group 1 and 97.2% in group 2 (p = 0.003). Multivariate Cox analysis showed that only age and restrictive filling were independent predictors of event-free survival. Furthermore, when survival with no cardiovascular events was analyzed, a short DT still emerged as the most powerful independent predictor. CONCLUSIONS: Patients with a restrictive LV filling pattern early after anterior AMI have a poor clinical outcome, even if treated with primary PTCA.

Direct infarct artery stenting without predilation and no-reflow in patients with acute myocardial infarction.

BACKGROUND: In patients with acute myocardial infarction (AMI), the rate of microvascular embolization and no-reflow promoted by coronary stenting with the use of conventional techniques (CS) appears to be greater than the one that occurs with balloon angioplasty. The minor invasiveness of direct stenting (DS) of the infarct artery without predilation could be expected to reduce embolization in the coronary microvasculature and no-reflow in patients with AMI. METHODS: In a cohort of 423 consecutive patients with AMI who underwent infarct-artery stenting, we compared CS and DS in terms of angiographic no-reflow rate and 1-month clinical outcome. RESULTS: At baseline patients who underwent DS (n = 110) had a better risk profile compared with the use of CS (n = 313). The incidence of angiographic no-reflow was 12% in the CS group and 5.5% in the DS group (P =.040). The 1-month mortality rate was 8% in the CS group and 1% in the DS group (P =.008). The mortality rate was 11% in patients with no-reflow and 5.6% in patients with a normal flow. Multivariate analysis showed that age, preprocedure patent infarct artery, and lesion length were related to the risk of no-reflow. In the subset of patients with a target lesion length

Echo-Doppler evaluation of left ventricular diastolic dysfunction during acute myocardial infarction: methodological, clinical and prognostic implications.

Left ventricular (LV) diastolic dysfunction has been reported in the subacute and late phase after myocardial infarction and it is becoming increasingly clear that abnormalities of diastolic function during acute myocardial infarction (AMI) have a major role in affecting the prognosis. However, until recent years the study of patients with diastolic dysfunction has suffered from the substantial difficulties inherent in diagnosing, measuring, quantitating and in following it over time. Moreover, the complexity of events encompassed by diastole, which are often difficult to control in the clinical arena, and the lack of data available to guide therapy, have hampered the widespread application of diastology in the clinical setting of AMI. The advent of Doppler echocardiography and its complementary techniques have provided a bedside tool which yields reliable and useful measures of diastolic performance during AMI, placing such an assessment well within the grasp of every clinical echocardiographic laboratory. Determination of the pattern of LV filling by Doppler echocardiography provides important information about LV diastolic function in AMI patients. Clinical data gathered so far demonstrate that Doppler-derived LV filling, specifically the restrictive filling pattern, is a powerful independent predictor of late LV dilation and, most importantly, of cardiac death in patients with AMI and clearly indicate the need for evaluating and monitoring LV diastolic function in these patients. Large scale studies, utilizing simple and easy to measure Doppler indexes of LV filling are needed to assess the efficacy of medical therapy in patients with acute LV diastolic dysfunction during AMI.

Early dobutamine echocardiography predicts improvement in regional and global left ventricular function after reperfused acute myocardial infarction without residual stenosis of the infarct-related artery.

BACKGROUND: 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. METHODS: 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 stenosis <30%). All patients underwent 2-dimensional echocardiography and coronary angiography at 1 month and 145 (92%) at 6 months. RESULTS: 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). CONCLUSIONS: 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.

Early predictors of left ventricular remodeling after acute myocardial infarction.

Ventricular remodeling after acute myocardial infarction is characterized by alteration in left ventricular (LV) size, shape, and wall thickness and involves both the infarcted and the noninfarcted regions of the ventricle. These structural changes are the result of several distinct pathologic processes that contribute to progressive LV dilation: rearrangement of wall structure, myocyte hypertrophy, and increasing muscle mass without an increase in wall thickness (eccentric hypertrophy). The pathogenesis of LV remodeling is multifactorial. Multiple factors may in fact contribute at different stages from the time of coronary occlusion until the development of ventricular dilation: These include the magnitude of the loss of contractile elements, the abrupt alteration in systolic and diastolic loading conditions, the activation of circulating neurohormones and local autocrine trophic factors, and the patency of the infarct-related artery. Although remodeling occurring early after infarction may be an appropriate compensatory response to preserve ventricular function, recent observations have suggested that this long process has a deleterious effect on LV function and prognosis. Thus attempts to inhibit these structural changes have been the focus of recent experimental and clinical studies. This review focuses on interactive factors that influence postinfarction LV remodeling, emphasizing the role of some new emerging determinants such as the extent of surviving myocardium within the infarcted and noninfarcted zones.

Detecting myocardial salvage after primary PTCA: early myocardial contrast echocardiography versus delayed sestamibi perfusion imaging.

UNLABELLED: The extent of myocardial salvage after primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI) is variable and cannot be predicted on the basis of either vessel patency or early regional wall motion assessment. The aim of this study was to evaluate the reliability of microvascular integrity, as shown by myocardial contrast echocardiography (MCE), as an indicator of tissue salvage and a predictor of late functional recovery, and to compare MCE with the quantification of tracer activity in sestamibi perfusion imaging. METHODS: Twenty-six patients with AMI who received successful treatment with primary PTCA were examined with MCE during cardiac catheterization immediately before and after vessel recanalization. Myocardial contrast effect was scored as 0 (absent), 0.5 (partial) or 1 (normal). Wall motion was assessed by two-dimensional echocardiography on admission and 1 mo later with a 16-segment model and 4-point score. Resting sestamibi SPECT was collected within 1 wk after AMI. The risk area was defined by MCE as the sum of the segments with no perfusion (score 0) before PTCA. Myocardial viability was defined by MCE as an increase in contrast score in the same segments after PTCA and by sestamibi SPECT as a preserved tracer activity (>60% of peak activity). The functional recovery after 1 mo detected by two-dimensional echocardiography was the reference standard for viability. RESULTS: A total of 50 segments showed perfusion defects before PTCA (risk area). Immediately after PTCA, the MCE score increased in 44 of 50 segments, whereas sestamibi SPECT showed preserved activity in 22 of 50 segments. After 1 mo, the wall motion score decreased in 22 of 50 segments (viable segments) and was unchanged in the remaining 28 segments. Thus, MCE showed a sensitivity of 91% and a specificity of 14% in detecting viable myocardium, whereas sestamibi SPECT showed a lower sensitivity (68%) but a significantly higher specificity (75%; P < 0.00001). The positive predictive values were 45% and 68% for MCE and SPECT (P < 0.005), respectively, and the negative predictive values were 67% and 71%, respectively. On a patient basis, SPECT was more specific (79% versus 21%; P < 0.01) and showed a higher overall predictive accuracy (88% versus 50%; P < 0.01) than MCE. CONCLUSION: The demonstration of microvascular integrity by MCE performed immediately after primary PTCA has a limited diagnostic value in predicting salvaged myocardium. Conversely, tracer activity quantification in resting sestamibi SPECT performed in a later stage is confirmed to be a reliable approach for recognizing myocardial stunning and predicting functional recovery.

Doppler-derived mitral deceleration time: an early strong predictor of left ventricular remodeling after reperfused anterior acute myocardial infarction.

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

[Systematic treatment of acute myocardial infarction with primary angioplasty. Early clinical and angiographic results and after 6 months]. / Trattamento sistematico dell'infarto miocardico acuto con angioplastica primaria. Risultati clinici ed angiografici precoci e a sei mesi.

UNLABELLED: Starting in 1995, at our institution all patients with acute myocardial infarction (AMI) who gave informed consent were treated by primary percutaneous transluminal coronary angioplasty (PTCA) without limitations in entry criteria. This report presents early and six-month clinical and angiographic results of the 720 patients (77% male, median age 64 years) treated by direct PTCA between January 1, 1995 and July 31, 1998. On admission, 33% of patients were in Killip class > 1, and 101 patients (14%) were in early cardiogenic shock. Optimal acute angiographic success (TIMI grade 3 flow with residual stenosis < 30%) was achieved in 683 patients (95%). Primary or unplanned stenting of infarct related artery (IRA) for a suboptimal or poor angiographic result after primary PTCA was performed in 454 patients (63%). The mean time from hospital arrival to recanalization was 62 +/- 28 min. At 30 days, the mortality rate was 4.9% (1.8% in Killip class < 4 patients and 24% in patients with cardiogenic shock). The reinfarction rate was 1.2%. At 30 days, coronary angiography showed restenosis or reocclusion of the IRA in 55 patients (8.9%). During the six-month follow-up (30-180 days), there were 11 deaths (1.5%) and 2 non-fatal reinfarctions (0.3%). At six months, the IRA patency rate was 95%, while the mean ejection fraction improvement in 422 patients with paired ventriculograms was 7%. Recurrent ischemia occurred in 144 patients (20%) and resulted in 7 deaths, 11 non-fatal reinfarctions and 126 repeat targeted vessel revascularization. CONCLUSIONS: The major finding of our experience is that direct coronary angioplasty may result in excellent early and late outcome in a population without limitations in entry criteria. The low mortality and the few recurrent myocardial ischemic events are connected with the high patency rate at 6 months. The extensive use of stents improves the angiographic results and the clinical outcome.

Relation between ST-segment changes and myocardial perfusion evaluated by myocardial contrast echocardiography in patients with acute myocardial infarction treated with direct angioplasty.

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.

[Rapid resolution of ST-segment elevation predicts functional recovery in acute myocardial infarction treated with primary percutaneous transluminal coronary angioplasty]. / La rapida riduzione del sovraslivellamento del tratto ST è predittiva del recupero della funzione nell'infarto miocardico acuto trattato con angioplastica coronarcia primaria.

OBJECTIVES: This study was designed to prospectively assess the ability of the 12-lead electrocardiogram (ECG) and optimal ECG criteria to predict late functional recovery in patients with acute myocardial infarction (AMI) treated with primary coronary angioplasty (PTCA) BACKGROUND: A simple clinical method to predict clinical outcome in patients with reperfused AMI is highly desirable from a clinical point of view. METHODS: Seventy-five patients with AMI treated with successful PTCA (TIMI flow grade 3 and residual stenosis < 30%) underwent serial 12-lead ECG before PTCA and every hour for the first 6 hours and then at 9, 12, and 18 hours after PTCA. All patients underwent two-dimensional echocardiography before PTCA and 1 and 6 months later for the evaluation of regional wall motion. The ST segment level in the lead exhibiting the maximal ST elevation (ST increase max) and the sum of the ST segment elevation (sigma ST increases) were calculated on initial ECG and a cut-off values of > or = 50% reduction of ST increases max sigma ST increases elevation and sampling intervals were correlated with late functional recovery. A wall motion score index (WMSI: 1 = normal to 4 = dyskinesia) and 16-segment model were used. Reversible dysfunction was defined as a decrease of > or = 0.22 in WMSI. RESULTS: At univariate analysis a > or = 50% reduction of both ST increases max and sigma ST increases was related to late functional recovery. Multiple logistic regression analysis revealed that reduction of sigma ST increases was the most powerful predictor of late functional recovery (p = 0.008). A > or = 50% reduction of sigma ST increase within 4 hours of PTCA provided the optimal criterion for predicting late functional recovery. CONCLUSIONS: Rapid reduction of sigma ST increases elevation is an accurate predictor of left ventricular functional recovery in patients with AMI treated with primary PTCA. Optimal criteria include a reduction in sigma ST increases elevation > or = 50% within 4 hours of PTCA.

Restenosis after coronary stenting in current clinical practice.

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.

Influence of infarct-zone viability on left ventricular remodeling after acute myocardial infarction.

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/m2; P<.0003) and end-systolic (42+/-17 versus 22+/-11 mL/m2; P<.0003) volumes at 6 months than did patients in group 1. The extent of infarct-zone viability was significantly inversely correlated with percent changes in end-diastolic volumes at 6 months (r=-.66; P<.000001) and was the most powerful independent predictor of late left ventricular dilation. 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.

Effects of transdermal nitroglycerin on left ventricular function after acute myocardial infarction.

Progressive left ventricular dysfunction in acute myocardial infarction patients is associated with a poor prognosis. It has been shown that some therapeutic measures which have the potential for limiting the infarct size and preserving ventricular function, are also able to reduce the incidence of congestive heart and improve survival. The aim of this protocol was to assess the effects of transdermal nitroglycerin administered within 72 hours after the onset of acute myocardial infarction and for the following 6 months, on left ventricular function. A total of 98 consecutive acute myocardial infarction patients were randomly allocated, within 72 hours of onset of symptoms, to a double-blind 6-month-therapy with either 10 mg/24 hour transdermal nitroglycerin or placebo. Patients underwent two-dimensional echocardiography at entry, after 2 weeks, 3 months and 6 months. In the nitroglycerin group, end-diastolic volume increased during the follow-up (+6.7%, p < 0.05) while end-systolic volume remained nearly unchanged; ejection fraction and stroke volume increased progressively (+6.3%, p < 0.05, +14.2%, p < 0.05, respectively) and a important reduction of percent of dyssynergic segments was present (-19.2%, p < 0.005). In the placebo group end-diastolic volume and end-systolic volume slightly increased during the follow-up (+2% and +4.9% respectively); ejection fraction and stroke volume remained nearly unchanged during the study; percent of dyssynergic segments showed an important decrease after 2 weeks and 6 months (-21.3%, p < 0.005). A clinically relevant increase (> 20%) in ejection fraction was present more frequently in the nitroglycerin than in the placebo group (p < 0.001). In conclusion, the early (within 72 hours) and prolonged (6 months) administration of transdermal nitroglycerin in acute myocardial infarction improves ejection fraction and stroke volume but does not modify ventricular remodeling.

Myocardial contrast echocardiography versus dobutamine echocardiography for predicting functional recovery after acute myocardial infarction treated with primary coronary angioplasty.

OBJECTIVES: We 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. BACKGROUND: The 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. METHODS: Thirty 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. RESULTS: After coronary recanalization, 26 patients showed myocardial reperfusion within the risk area, although 4 did not. At 1-month follow-up, all patients had a patient 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). CONCLUSIONS: Microvascular 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.

[Comparison of outcome of primary PTCA for acute myocardial infarction in patients younger and older than 70 years of age]. / Confronto dei risultati della PTCA primaria nell'infarto miocardico acuto nei soggetti di età inferiore e superiore a 70 anni.

BACKGROUND: The Primary Angioplasty in Myocardial infarction Study Group reported that the benefit of primary PTCA was observed mainly among patients who were classified as "not low risk" including those over age 70, with anterior infarction and heart rate > 100 bpm. The present study compares procedural success rate and in-hospital and one-month clinical outcome of primary PTCA in acute myocardial infarction patients < 70 and > or = 70 years of age. METHODS AND RESULTS: During 1995 121 patients with acute myocardial infarction underwent primary PTCA within 6 hours of symptoms onset or within 24 hours in case of evidence of ongoing ischemia. Eighty-two patients (Group I) were < 70 (mean age 56 +/- 9) and 39 patients (Group II) were > or = 70 (mean age 75 +/- 3). In group II there was a trend, although not significant, toward a higher prevalence of prior angina and infarction. Multivessel disease was more frequent in group II than in group I (69% vs 48%; p = 0.041). Ejection fraction was markedly depressed in both groups (38 +/- 10% in group I vs 34 +/- 11% in group II). Ejection fraction < or = 30% and shock on admission were more frequent in group II (39% vs 15% and 36% vs 21%, respectively). Optimal angiographic success (< or = 30% stenosis associated with TIMI grade 3 flow) was achieved in 77% of group II and in 98% of group I (p = 0.00059). The in-hospital mortality rate was 26% in group II and 1.2% in group I (p = 0.000042). Shock on admission and PTCA failure predicted high mortality rates. There was no difference between the two groups as regards to non-fatal reinfarction, recurrent ischemia, life-threatening arrhythmias, severe heart failure, revascularization procedures. There were no strokes. At one-month follow-up, recurrence of ischemia or positive response to stress test were more frequent in group II (24% vs 8%; p = 0.039). CONCLUSIONS: In patients with acute myocardial infarction < 70 years of age primary coronary angioplasty is associated with low rates of mortality and cardiac events. Mortality rate remains high in patients over age 70, especially when shock is present on admission or PTCA falls.

[Myocardial scintigraphy with Tc-99m-teboroxime: its feasibility and the evaluation of its diagnostic reliability. A comparison with thallium-201 and coronary angiography]. / Scintigrafia miocardica con Tc-99m-teboroxime: fattibilità e valutazione dell'affidabilità diagnostica. Confronto con il tallio-201 e l'angiografia coronarica.

BACKGROUND: Tc-99m-teboroxime is a new tracer for myocardial perfusion scintigraphy. Its more remarkable features are the high myocardial extraction fraction, which is well correlated with the coronary blood flow, and the extremely rapid myocardial washout. This makes it necessary to complete the image collection shortly after the injection; on the other hand, repeated scans can be easily performed by renewed Tc-99m-teboroxime administrations. The aim of the present study was to test the feasibility of Tc-99m-teboroxime imaging and to evaluate its accuracy by comparing it with thallium-201 (TI-201) scintigraphy and coronary angiography. METHODS: The patient population included 16 male patients (mean age 57.8 +/- 6.3 years) affected by suspect effort angina and/or with signs of exercise-induced ischemia; 12 of them had history of previous myocardial infarction. They underwent effort TI-201 and Tc-99m-teboroxime myocardial scintigraphy within 48 hours; left heart catheterization and coronary angiography were performed within 5 days. Scintigraphic images were collected in 3 planar views; each projection was divided in 3 segments, with the apical one shared by all views, for a total of 7 segments/study. Tracer uptake was qualitatively assessed and graduated according to a scoring scheme (from 0 = normal through 4 = absent uptake). RESULTS: Tc-99m-teboroxime scans could be accomplished without major problems in all subjects. The image quality was comparable to TI-201 in 8 patients and poorer in the remaining 8. Coronary angiography showed 50% obstructions in 15 patients; of them 1 subject had a normal scintigraphic pattern with both TI-201 and Tc-99m-teboroxime. The presence of previous infarction was recognized by both tracers in the 12 patients with infarct history. The number of abnormal segments and the uptake score were not significantly different in the Tc-99m-teboroxime rest and in the TI-201 redistribution images (segments: 2.8 +/- 1.4 vs 2.8 +/- 1.6; score: 5.6 +/- 4.2 vs 6 +/- 4.5). The diagnosis of effort ischemia was made in 13 patients with Tc-99m-teboroxime and in 12 patients with TI-201. The number of abnormal segments in the exercise Tc-99m-teboroxime and TI-201 myocardial scintigraphy was not significantly different (3.3 +/- 1.3 vs 3.3 +/- 1.5); on the contrary the defect score was significantly higher with Tc-99m-teboroxime than with TI-201 (9.5 +/- 4.3 vs 8.4 +/- 4.6, p < 0.03). Therefore the ischemic score (exercise defect score minus rest defect score) of Tc-99m-teboroxime was significantly higher than that of TI-201 (3.9 +/- 2.8 vs 2.4 +/- 2.2, p < 0.02). The two tracers gave comparable results in terms of recognition of patients with one-vessel or multi-vessel coronary artery disease. CONCLUSIONS: Planar myocardial scintigraphy with Tc-99m-teboroxime can be performed without major problems. In terms of clinical reliability the results are comparable to those of TI-201 scans. On the other hand, taking into account the poor image quality of Tc-99m-teboroxime scintigraphy, it is still impossible to predict its future role in the radionuclide imaging of coronary artery disease.