Role of 64-slice cardiac computed tomography in the evaluation of patients with non-ST-elevation acute coronary syndrome.

PURPOSE: This study was done to evaluate the feasibility, sensitivity and specificity of 64-slice computed tomography (CT) in identifying haemodynamically significant (>50%) coronary artery stenoses in patients with suspected acute coronary syndrome (ACS) by correlating the CT findings with the clinical event and data provided by conventional coronary angiography (CCA). MATERIALS AND METHODS: Sixty-four patients (38 men and 26 women; mean age 65 years; range+/-10 years) presenting to our hospital's emergency department with a clinical suspicion of ACS were studied with 64-slice CT followed by CCA within 24 h of arrival. RESULTS: Two patients (3.1%) were excluded from the analysis due to artefacts. Per-patient analysis in the remaining 62 patients identified 24 cases (38.7%) of negative CT findings (no stenoses or stenoses <50%), 35 cases of positive CT findings (56.4%) with identification of the culprit lesion, two cases in which the culprit lesion was not identified and one patient with unconfirmed stenosis. Sensitivity and specificity were 94.6% and 96%, respectively. Per-vessel analysis (186 vessels) revealed 17 non-evaluable vessels (9.1%) due to motion artefacts, 61 vessels (32.8%) with stenosis >50%, seven overestimated vessels (3.7%) due to extensive calcifications, three vessels (1.6%) with underestimated stenosis and 98 vessels (52.6%) without stenosis. Sensitivity and specificity were 95.3% and 93.3%, respectively. CONCLUSIONS: In this type of emergency, coronary CT angiography could lead to considerably lower healthcare costs by identifying patients without coronary disease and allowing immediate discharge without any need for further diagnostic procedures.

Evaluation of venous and arterial conduit patency by 16-slice spiral computed tomography.

BACKGROUND: Computed tomography has been shown to be useful in the evaluation of aortocoronary bypass grafts (CABG). This is the first prospective study to evaluate the accuracy of a new-generation scanner in the detection of patency and significant stenoses (>50% decrease in diameter) of venous and arterial grafts in patients with previous CABG. METHODS AND RESULTS: In 96 patients (80 males, mean age 62 years) with previous CABG, a multislice computed tomography (MSCT) scan was performed (collimation 16x0.625 mm). Patients with atrial fibrillation, renal failure, severe respiratory disease, severe heart failure, heart rate >70 bpm despite therapy, or unstable angina were excluded. A total of 285 conduits implanted on the native coronary arteries at the time of CABG were evaluated. MSCT data were analyzed by 2 independent radiologists and compared with the results of conventional angiography. Three patients were excluded from analysis. All conduits were judged evaluable in 84 patients. Among these patients, MSCT correctly diagnosed 54 occluded grafts and 4 significant stenoses on the body of the grafts. Of the 17 significant anastomotic lesions, MSCT correctly diagnosed 15. For these 84 patients, diagnostic accuracy was 99%, sensitivity was 97%, and specificity was 100%. When all 93 patients were considered, the sensitivity of MSCT in diagnosing significant stenoses was 96%. CONCLUSIONS: MSCT with the new-generation scanner allows for accurate assessment of venous and arterial conduits in patients with previous CABG with a high degree of sensitivity and specificity. Exclusion criteria and radiation exposure remain limitations of the method.

Rheumatic fever recurrence: a possible cause of restenosis after percutaneous mitral valvuloplasty.

BACKGROUND: We evaluated the occurrence of a rapid process of restenosis after percutaneous mitral valvuloplasty (PMV), initiated by the recurrence of acute rheumatic fever. Restenosis after PMV has been mainly related to a high echocardiographic score (> or = 8) indicating a severely compromised mitral valve apparatus. METHODS: From 1986 to 1996, 120 patients underwent PMV by the transseptal approach at our Institution. The mean follow-up time was 58 +/- 32 months (range 3 months to 9 years). RESULTS: Restenosis occurred in 10 patients (8.3%): in 4 restenosis was found within a relatively short period of time (1 to 3 months) following a documented recurrence of acute rheumatic fever; in the other 6 patients there was a gradual loss of the initial gain in the mitral valve area. CONCLUSIONS: These data suggest two potential mechanisms of restenosis: 1) a more common slow process, due to turbulent flow-trauma on the mitral valve; 2) a rapid process that relates to valvulitis consequent to a recurrence of acute rheumatic fever. In consideration of the second possibility, after PMV prophylactic treatment may be warranted at least in those patients who are at high risk of streptococcal infection.

Woven coronary artery: differential diagnosis with diffuse intracoronary thrombosis.

Woven coronary malformation is characterized by the branching of a major epicardial coronary artery into thin channels which then merge again in a normal conduit. The angiogram can suggest a filling defect instead of a malformation and an undue coronary angioplasty could be performed determining some damage to the arterial wall. In this case report we describe a patient with a stenosis on the left anterior descending coronary artery and a woven coronary artery on the right coronary artery. In 1995 a coronary angioplasty was performed on the left anterior descending coronary artery. Four years later a coronary angiogram did not show any changes in the right coronary artery. In this patient the malformation did not induce any reduction in the coronary reserve as shown at cardiac scintigraphy. We need more information about the natural history of such a malformation.

Seropositivity against Chlamydia pneumoniae in patients with coronary atherosclerosis.

BACKGROUND: Results of therapy in patients with unstable coronary syndromes with antibiotics directed against Chlamydia pneumoniae have been variable, perhaps due to the heterogeneity of patients in these trials. HYPOTHESIS: The aim of the present study was to correlate the severity of coronary artery disease (CAD) with seropositivity against C. pneumoniae prospectively. METHODS: We measured the frequency of seropositivity (IgG levels > or = 1/64 and IgA levels > or = 1/16 against Chlamydia pneumoniae) in 110 patients with CAD and in 49 controls. RESULTS: As expected, traditional CAD risk factors were seen more often in patients with CAD than in controls. Mean values of total cholesterol (184 +/- 52 and 166 +/- 44 mg/dl, respectively) and triglyceride (143 +/- 60 and 112 +/- 63 mg/dl, respectively) in serum were significantly higher in patients with CAD than in controls (both p < 0.04). There were no significant differences between the two groups in serum high-density lipoprotein cholesterol (34 +/- 13 and 32 +/- 14 mg/dl, respectively) and lipoprotein (a) (Lp(a):241 +/- 247 and 223 +/- 263 mg/l, respectively) levels. The rate of IgG seropositivity was 52% (28/54) in patients with stable CAD, 41% (23/56) in patients with unstable CAD, and 35% in controls (p = NS). The rate of IgA seropositivity was 25% (14/54) in patients with stable CAD, 12% (6/49) in patients with unstable angina, and 12% (6/49) in controls (all p = NS). CONCLUSIONS: Only a small percentage of patients with CAD demonstrate seropositivity against Chlamydia pneumoniae. Antibiotic therapy in these selected patients, but not in the remaining patients, may be considered rational. These considerations may underlie the failure to see consistent benefits of antibiotic therapy in patients with CAD.

Stent implantation versus balloon angioplasty in chronic coronary occlusions: results from the GISSOC trial. Gruppo Italiano di Studio sullo Stent nelle Occlusioni Coronariche.

OBJECTIVES: In this multicenter, randomized trial we evaluated whether stent implantation after successful recanalization of a chronic coronary occlusion reduced the incidence of restenosis. BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) in chronic total occlusions is associated with a higher rate of angiographic restenosis and reocclusion than PTCA in subtotal stenoses. Preliminary reports have suggested a decreased restenosis rate after stent implantation in coronary total occlusions. METHODS: We randomly assigned 110 patients with recanalized total occlusion to Palmaz-Schatz stent implantation, followed by 1 month of anticoagulant therapy versus no other treatment. The primary end point was the minimal lumen diameter (MLD) of the treated segment at follow-up, as determined by quantitative angiography at a core laboratory. RESULTS: Repeat coronary angiography was performed 9 months after the procedure in 88% of patients. The MLD (mean +/- SD) at follow-up was 1.74 +/- 0.88 mm in patients assigned to stent implantation and 0.85 +/- .75 mm in patients assigned to PTCA (p < 0.001). Stent implantation was associated with a lower incidence of restenosis (defined as diameter stenosis > or =50% at follow-up) (32% vs. 68%, p < 0.001) and reocclusion (8% vs. 34%, p = 0.003) than balloon PTCA. Likewise, stent-treated patients had less recurrent ischemia (14% vs. 46%, p = 0.002) and target lesion revascularization (5.3% vs. 22%, p = 0.038), but experienced a longer hospital stay. CONCLUSIONS: Palmaz-Schatz stent implantation after successful balloon PTCA of chronic total occlusions improves the midterm angiographic and clinical outcome and could be the preferred treatment option in selected patients with occluded vessels.

Functional and ultrastructural evidence of myocardial stunning after acute carbon monoxide poisoning.

OBJECTIVE: To study human myocardial ultrastructural changes after carbon monoxide (CO) poisoning inducing reversible cardiac failure. CASE REPORT: clinical, functional and morphologic findings. SETTINGS: Public university-affiliated hospital and electron microscopy laboratory. PATIENT: A 25-yr-old woman with functional evidence of cardiac failure after acute CO poisoning. INTERVENTIONS: Hyperbaric and intensive care treatment over 10 days. Scintigraphic and cardiac angiography with endomyocardial biopsy. MEASUREMENTS AND MAIN RESULTS: Scintigraphy with 99mTc hexakis 2-methoxy-2-isobutyl isonitrile (sestaMIBI) showed an uptake defect in the left anterior descending artery territory. The cardiac angiography demonstrated a slight hypokinesis of the superior two thirds of the anterior wall and of the septal region with completely normal coronary angiograms. Electron microscopy of left ventricular biopsies showed slight ultrastructural changes in the myocytes. In addition, large glycogen deposits were mostly associated with swollen mitochondria. The patient was discharged in good clinical condition on day 10. CONCLUSIONS: Presence of glycogen deposits associated with abnormal mitochondria may be signs of the incapability of myocardial cells in utilizing energy substrata. In the presence of normal myocardial perfusion, our findings are consistent with the presence of a stunned myocardium-like syndrome. Early recognition and treatment of this clinical syndrome allow the prevention of myocardial infarction.

Coronary sinus plasma beta endorphin levels in cardioischemic patients undergoing PTCA.

Plasma beta-endorphin levels were studied in the coronary sinus of 8 patients undergoing percutaneous transluminal coronary angioplasty (PTCA). All the patients had ECG ischemic signs and pain during the inflation of the balloon. No significant changes in plasma beta-endorphin levels were observed during PTCA-induced ischemia. Baseline coronary sinus plasma beta-endorphin levels were found to be elevated when compared with peripheral ones which would suggest an accumulation of beta-endorphin in the ischemic heart.

Concurrent nitroglycerin administration reduces the efficacy of recombinant tissue-type plasminogen activator in patients with acute anterior wall myocardial infarction.

The aim of this study was to evaluate the impact of concurrent nitroglycerin administration on the thrombolytic efficacy of recombinant tissue-type plasminogen activator (rTPA) in patients with acute anterior myocardial infarction (AMI). Sixty patients (53 men, 7 women; mean age 54 +/- 7 years) with AMI entered the study. Thirty-three patients were randomized to receive rTPA alone (100 mg in 3 hours) (group A) and 27 to receive rTPA plus nitroglycerin (100 micrograms/min) (group B). Time from the onset of chest pain and delivery of rTPA was similar in the two groups of patients. Patients in group A had signs of reperfusion more often than the patients in group B (25 of 33 or 75.7% vs 15 of 27 or 55.5%, p < 0.05). Time to reperfusion was also shorter in group A than in group B (19.6 +/- 9.4 minutes vs 37.8 +/- 5.9 minutes, p < 0.05). Group B had a greater incidence of in-hospital adverse events (9 of 27 vs 5 of 33, p < 0.05) and a higher incidence of coronary artery reocclusion (8 of 15 or 53.3% vs 6 of 25 or 24%, p < 0.05). Peak plasma levels of rTPA antigen were higher in group A compared with group B (1427 +/- 679 vs 512 +/- 312 ng/ml, p < 0.01). In conclusion, concurrent nitroglycerin administration reduces the thrombolytic efficacy of rTPA in patients with AMI probably by lowering the plasma levels of rTPA antigen. The diminished efficacy of rTPA is associated with an adverse outcome.

Effectiveness of prolonged low dose recombinant tissue-type plasminogen activator for refractory unstable angina.

OBJECTIVES: The aim of the present study was to evaluate the effectiveness of prolonged administration of thrombolytic therapy with low doses of recombinant tissue-type plasminogen activator (rt-PA) in patients with refractory unstable angina. BACKGROUND: Intracoronary thrombosis is often the cause of instability in patients with unstable angina. Thrombolytic therapy has been tested in these patients with conflicting results. METHODS: Sixty-seven patients with unstable angina refractory to standard antianginal therapy were randomized to receive, in addition to the common antianginal therapy, either rt-PA (0.03 mg/kg body weight per h for 3 consecutive days) plus heparin (to achieve activated clotting time of 250 to 400 s) (36 patients, group A) or the same dose of heparin plus placebo (31 patients, group B). RESULTS: No major bleeding was observed in either group of patients. One patient in group A and four in group B (2.7% vs. 12.9%, p < 0.01) developed acute myocardial infarction during the hospital period. Eight patients in group B underwent emergency coronary artery surgery or angioplasty because of worsening of symptoms. Group A patients had a significant reduction in the occurrence of chest pain compared with those in group B (95% confidence interval -7.2 to -2.1 episodes/3 days, p < 0.01). Patients in group B had a greater number of episodes of transient myocardial ischemia (237 vs. 103, p < 0.01) and a longer total ischemic burden (114 +/- 23 vs. 45.6 +/- 8.9 min/day, p < 0.01) than group A patients. After a mean follow-up of 14 +/- 6 months, group A patients were more frequently angina free and had a lower incidence of readmission to the hospital than group B patients. CONCLUSIONS: The combination of heparin and protracted administration of rt-PA at low doses is effective in stabilizing and reducing in-hospital adverse events in patients with unstable angina refractory to antianginal therapy.

Long-term follow-up of patients initially diagnosed with syndrome X.

The clinical course of 30 patients (27 women and 3 men) diagnosed with syndrome X (angina pectoris, positive exercise test and normal coronary arteries) was evaluated during 5-year follow up. Patients were divided at the control examination into 2 groups according to the median value of the heart rate/blood pressure product variation from rest to the first stage of a modified Bruce protocol, as follows: group 1 < or = 1,050 (n = 15) and group 2 > 1,050 mm Hg x beats/min (n = 15). All patients were followed at 6-month intervals during a mean follow-up of 60 +/- 8 months. During follow-up, chest pain was unchanged in 20 patients, decreased in severity and frequency in 9 (7 in group 1, and 2 in group 2), and disappeared in 1 in group 2; 3 patients in group 1 had prolonged episodes of anginal chest pain (> 30 minutes) that needed hospitalization. In group 2, 7 patients developed systemic hypertension, 4 had a progression of exercise-induced left bundle branch block to constant left bundle branch block, and 4 continued to develop rate-dependent block during exercise, but at a reduced heart rate. In the latter 8 patients, left ventricular ejection fraction at rest during follow-up decreased significantly from 61 +/- 6% to 51 +/- 8% (p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical significance of small left-to-right shunts after percutaneous mitral valvuloplasty.

Left-to-right shunt after percutaneous mitral valvuloplasty was evaluated by contrast echocardiography in 29 patients at 24 hours and at 1, 3, 6, and 9 months after the procedure. The patients were divided into two groups: in group A (13 patients) the double-balloon technique was used; in group B (16 patients) the Inoue single-balloon technique was used. The two groups were comparable in terms of age, gender, and mitral valve area before and after percutaneous mitral valvuloplasty. A left-to-right shunt was detected in all patients 24 hours after the procedure. At 1 month follow-up the shunt was present in 12 patients of group A (92%) and in 13 of group B (81%) with a statistically significant difference (p < 0.001). At 3 months the values were 7 (54%) in group A and 6 (37.5%) in group B (p < 0.05); at 6 months the values were 3 (23%) in group A and 3 (19%) in group B (NS). At 9 months a left-to-right shunt was no longer detectable in any of the patients in either group. The disappearance of the shunt could be related to a healing process of the atrial septal injury that occurs within a few months after percutaneous mitral valvuloplasty. This process seems to be more rapid in group B patients, probably because of the smaller lesion that is produced in the atrial septum by the passage of the Inoue balloon.

Physico-chemical surface characterization of hyaluronic acid derivatives as a new class of biomaterials.

Three hyaluronic acid derivatives with different types and/or percentages of esterification, were analyzed by means of static contact angle measurements, SEM, ESCA, ATR/FT-IR, WAXS, DSC and TGA. The physico-chemical characterization of the three different samples, in both dry and wet state, was provided in terms of surface and bulk properties. ESCA and infrared analyses showed that the surface composition of all samples differs from that of the bulk. The hydrophilic-hydrophobic character of the samples changed according to the chemical composition as shown by ESCA and contact angle measurements. Both infrared and contact angle measurements reveal that surface restructuring occurred upon hydration for all the samples and the greater the hydrophilic character of the sample, the greater and faster the restructuring phenomenon. A clear picture of the different types of chemical groups has been established at different depth for the three materials.

Unstable angina: role of silent ischemia and total ischemic time (silent plus painful ischemia), a 6-year follow-up.

To assess the long-term prognostic significance of total ischemic time (silent plus painful ischemia) and silent ischemia in patients with unstable angina whose condition stabilized with medical treatment, 76 patients were studied. All patients underwent Holter ambulatory electrocardiographic (ECG) monitoring for greater than or equal to 48 h beginning within the 1st 12 h of the hospital stay. Forty-three patients (Group A) had a total ischemic time greater than or equal to 60 min, whereas 33 patients (Group B) had a total ischemic time less than 60 min. More than 78% of the ischemic episodes in patients in Group A and 62% of those in Group B were silent (p less than 0.05); nine patients in Group A and six in Group B had only silent episodes. Patients in Group A frequently showed three-vessel disease (65% vs. 18%, p less than 0.01), angiographic findings of subtotal occlusion of the coronary arteries (TIMI grade I) (76.7% vs. 42.4%, p less than 0.01) and ischemic alterations in the rest ECG (51.2% vs. 30.3%, p less than 0.05). During a 6-year follow-up period, 15 patients in Group A and 8 in Group B experienced myocardial infarction (p less than 0.05); 9 patients in Group A and 4 in Group B required coronary artery surgery (p less than 0.05) and 10 patients in Group A and 4 in Group B died of cardiac causes (p less than 0.01). Multivariate analysis showed three-vessel disease to be the most important predictor of cardiac mortality and morbidity (p = 0.025); it was followed in predictive power by a total ischemic time greater than or equal to 60 min and by left ventricular dysfunction. The presence of silent ischemia was not shown to be an independent predictor of long-term morbidity and mortality. In conclusion, patients with unstable angina and a total ischemic time greater than or equal to 60 min frequently have silent ischemic episodes on Holter ECG monitoring, a greater extent of coronary atherosclerosis and ischemic alterations of the rest ECG. The long-term prognosis of patients with unstable angina whose condition stabilizes with medical treatment depends on the extent of coronary atherosclerosis and on the longer duration of total ischemic time but not on the presence of silent ischemia.

Characterization and long-term prognosis of patients with effort-induced silent myocardial ischaemia.

The aim of this study was to evaluate the anatomo-clinical correlations and the prognostic significance of silent myocardial ischaemia (SI) during exercise testing (ET). Four hundred and six patients with angiographically proven CAD and positive ET were studied. Patients were divided into two groups: 309 patients (Group A) with positive ET for both electrocardiographical findings and angina, and 97 patients (Group B) with positive ET for electrocardiographical findings but not for angina (SI). In Group A the following clinical characteristics differed significantly from Group B: incidence of diabetes mellitus (15.8% vs 27.8%, P less than 0.04); duration of disease (less than 1 month from its first manifestation) (30.4% vs 54.6%, P less than 0.001) and a positive ET at low work-load (41.7% vs 50.5%, P less than 0.05). Mortality during follow-up (mean 72 +/- 11 months) was 8.6% in Group A and 8.2% in Group B (NS). Incidence of sudden death was similar in the two groups (2.9% vs 2.06%; NS). The multivariate analysis shown as independent variables, related significantly with a poor prognosis in both groups: left ventricular function (P less than 0.0001); prior myocardial infarction (P less than 0.0001); and multivessel disease (P less than 0.001). In conclusion, patients with a recent onset of symptoms, a positive ET at low workload and diabetes mellitus are more likely to present SI during ET. The long-term prognosis and the incidence of sudden death are similar in patients with painful and painless myocardial ischaemia during ET.