Adjunctive stent implantation following directional coronary atherectomy in patients with coronary artery disease.

OBJECTIVES: This prospective case-control study evaluated the acute and long-term results of stent implantation preceded by debulking of the plaque by means of directional coronary atherectomy. BACKGROUND: In comparison with balloon angioplasty, intracoronary stenting produces a larger luminal diameter, maintains artery patency and reduces the incidence of restenosis. Optimal stent deployment is a pivotal factor for achieving the best results, but the bulk of the atherosclerotic plaque opposes stent expansion and may limit the success of the procedure. Debulking of the plaque may provide a better milieu for optimal stent deployment. METHODS: Directional coronary atherectomy followed by a single Palmaz-Schatz stent implantation was attempted in 100 patients. The successes, complications and angiographic results of the combined procedure were evaluated both acutely and during follow-up. Matched patients undergoing successful Palmaz-Schatz stent implantation alone during the same period served as controls. RESULTS: Atherectomy followed by stent implantation was performed in 94 patients with 98 lesions; periprocedural complications were observed in four cases. The stenosis diameter decreased from 76+/-9% at baseline to 30+/-13% after atherectomy (p < 0.0001), and 5+/-9% after stent implantation (p < 0.0001); it increased to 27+/-15% at 6-month angiography (p < 0.0001). During the 14+/-10 months of follow-up, none of the patients died or experienced myocardial infarction, but three patients underwent target lesion revascularization. The patients undergoing stent implantation alone achieved smaller acute gains, tended to have a higher late lumen loss, had a higher restenosis rate (30.5% vs. 6.8%, p < 0.0001) and showed a greater incidence of clinical events during follow-up (p < 0.0001). CONCLUSIONS: Debulking atherosclerotic lesions by means of directional coronary atherectomy before stent implantation is a safe procedure with a high success rate and a low incidence of restenosis at follow-up.

[Coronary lesion with an aneurysm: their correction via angioplasty and the implantation of a coated stent]. / Lesione coronarica con aneurisma: correzione mediante angioplastica ed impianto di stent ricoperto.

We describe the good angiographic results obtained using a new polymeric prosthesis combining a stent with expandable polytetrafluoroethylene (PTFE) graft material in the treatment of proximal left descending coronary artery stenosis complicated by the presence of a coronary aneurysm.

Susceptibility to pain in hypertensive and normotensive patients with coronary artery disease: response to dental pulp stimulation.

An association between a decreased responsiveness to varying painful stimuli and arterial hypertension both in animals and in humans has been documented. The relationship between essential hypertension and silent myocardial ischemia in coronary artery disease (CAD) populations is not well understood. The aims of this study in CAD patients with and without essential hypertension were (1) to determine dental pain threshold and reaction to tooth pulp stimulation and (2) to ascertain whether hypertensive CAD patients differ from normotensive ones in reactivity to pain. This study involved 182 patients who were affected by mild and moderate hypertension (G1) and 174 normotensive patients (G2). The inclusion criteria were reproducible exercise-induced myocardial ischemia, CAD documented at angiography, and dental formula suitable for pulp test. All patients underwent an ergometric stress test, coronary angiography, and pulp test. Our CAD hypertensive patients showed a lower prevalence of angina during daily life (64.8% in G1 versus 81.6% in G2, P<.05) and a higher incidence of exercise-induced silent myocardial ischemia (60.4% in G1 versus 48.8% in G2, P<.05) than the normotensive group. The mean anginal pain intensity, which was suffered both during spontaneous transitory episodes of ischemia and/or during acute myocardial infarction, was significantly lower in G1 than in G2 patients (P<.05). During pulp test, 31.8% of G1 and 13.7% of G2 referred no symptoms, even at the highest current intensity of 500 mA. The hypertensive patients with symptoms during pulp test had a higher mean dental pain threshold and lower mean threshold reaction and maximal reaction than did the normotensive symptomatic ones. In patients of both groups, a positive correlation between the mean maximal reaction during pulp test and the prevalence of angina during daily life was also found. In conclusion, patients with CAD and essential hypertension differ from normotensive CAD patients in reactivity to pain. Significantly higher pain thresholds and lower reactions to tooth pulp stimulation characterized patients with increased blood pressure values.

[Coronary angioplasty: use and cost]. / Angioplastica coronarica: consumi e costi.

OBJECTIVES: The goal of the study was to examine the utilization of cardiac catheterization laboratory resources in surgical procedures in order to determine the cost impact of introducing new devices such as stents and atherectomy. METHODS: Detailed resource utilization and costs of each cardiac catheterization laboratory procedure performed in 1995 were determined. Costs were analyzed for single-vessel and multivessel coronary angioplasty, also taking into account the additional costs for coronary stent placement or for the use of directional atherectomy. RESULTS: The mean cost of a surgical procedure was ITL 8,280,010, while the mean cost for conventional coronary angioplasty was ITL 4,352,427 (ITL 4,293,108 for single-vessel PTCA; ITL 5,072,841 for multivessel PTCA). The mean cost for a procedure with stent implantation was ITL 10,084,563. As compared to conventional angioplasty, coronary stenting had a 131.6% higher catheterization laboratory cost and an additional cath-lab resource utilization in terms of contrast medium (257 +/- 136 ml vs 216 +/- 109 ml, p = 0.018) and balloon catheter (1.97 +/- 1.27 vs 1.54 +/- 0.78, p = 0.0009). The cost for a directional atherectomy followed by stent placement was ITL 18827545, which is 332.5% higher than the cost of a conventional angioplasty. CONCLUSIONS: Coronary stents and directional atherectomy have a significant economic impact on catheterization laboratory resource utilization and costs. This aspect should be taken into consideration in analyzing the short- and long-term results of these techniques.

Absence of correlation between coronary thrombosis and postatherectomy restenosis.

This study endeavored to assess whether thrombus in directional coronary atherectomy was correlated with later subsequent restenosis. We concluded that the presence of thrombus in native plaque is not correlated with the occurrence of postatherectomy restenosis.

Mental status and pain perception during stressor tests in patients with coronary artery disease.

Asymptomatic myocardial ischaemia is frequently observed in patients with coronary artery disease (CAD), both during daily life and during stressor tests. Psychological mechanisms seem to be involved in the lack of pain during myocardial ischaemia. The aim of this study was to verify in a selected population of CAD patients whether mental status might influence the pain perception during different stressor tests. The study population contained 73 male patients (mean age 52+/-8 years) with stable angina during daily life, reproducible exercise-induced myocardial ischaemia during ergometric stress test (EST) and angiographically documented CAD. All patients underwent cold pressor test (CPT), mental arithmetic stress test (MST), hyperventilation test (HT) and mental stress in association with cold pressor test (combined test, MST + CPT). During the stressor tests, myocardial ischaemia was induced in 15/73 (21%) patients by CPT, in 18/73 (25%) by MST, in 15/73 (21%) by HT and in 19/73 (26%) by MST + CPT. Out of the patients with stressor test-induced myocardial ischaemia, silent ischaemia was observed in 43/73 (59%) during EST, in 10/15 (67%) during CPT, in 16/18 (89%) during MST, in 7/15 (47%) during HT and in all patients during MST+CPT (100%). Among the ischaemic symptomatic patients during stressor tests, the lowest anginal pain intensity was experienced during MST (4.0+/-2.2) and the highest during EST, both at peak exercise and at the ischaemia threshold (6.6+/-2.9 and 5.9+/-2.7, respectively, p<0.05). During MST, the prevalence of silent ischaemia was higher than was observed during the other tests. All study patients remained asymptomatic when myocardial ischaemia was induced by MST + CPT. Even the intensity of CPT induced hand pain was significantly higher during CPT alone than during MST+CPT. These results confirm that mental status may influence pain modulation.

Susceptibility to pain during coronary angioplasty: usefulness of pulpal test.

OBJECTIVES: This study in patients with coronary artery disease (CAD) sought to 1) determine the dental pain threshold and reaction to tooth pulp stimulation; 2) correlate the clinical, ergometric and angiographic features of patients with and without pain during percutaneous transluminal coronary angioplasty (PTCA) to pulpal test response; 3) verify whether reactivity to dental pulp stimulation could help to identify patients particularly prone to perceiving angina during myocardial ischemia. BACKGROUND: Silent myocardial ischemia is frequently observed in patients with CAD. Higher pain thresholds have been documented in asymptomatic subjects, suggesting a generalized hyposensitivity to pain. METHODS: Eighty-six consecutive male patients with reproducible exercise-induced myocardial ischemia and CAD documented by angiography underwent PTCA. A pulpal test was performed in all patients by means of an electrical tooth pulp stimulator. RESULTS: Seventy-one patients (82.6%) with and 15 (17.4%) without angina during daily life were studied. During the pulpal test, 57 patient (66.2%) reported dental pain, whereas 29 (33.7%) were asymptomatic, even at maximal stimulation of 500 mA. The study cohort was classified into two groups according to the presence (58 patients [group 1]) or absence (28 patients [group 2]) of angina during myocardial ischemia induced by PTCA. Ergometric variables, extent of CAD, presence of ST segment elevation during PTCA, number of inflations, inflation time and maximal inflation pressure were similar in the two patient groups. Dental pain was provoked by pulpal test in 81% of patients with and 36% of patients without symptoms during PTCA (p = 0.0004). The absence of dental pain even at maximal tooth pulp stimulation (500 mA) was observed in 11 (18.9%) patients in group 1 and 18 (64.2%) in group 2. Patients who were asymptomatic during PTCA had a higher mean dental pain threshold, lower mean threshold reaction and lower mean maximal reaction than those who were symptomatic during both PTCA and the pulpal test. CONCLUSIONS: A correlation between the prevalence of symptoms during pulpal test, daily life, exercise-induced myocardial ischemia and PTCA was found. A higher dental pain threshold and lower reactivity characterized those subjects who were prone to silent ischemia both during daily life and during PTCA. Ergometric variables, extent of CAD and techniques used during PTCA were unrelated to the tendency to perceive pain during myocardial ischemia. Response to the pulpal test and the presence of symptoms during daily life were highly related to the presence of angina during PTCA.

Expression of neutrophil and monocyte CD11B/CD18 adhesion molecules at different sites of the coronary tree in unstable angina pectoris.

To assess the site of leukocyte activation in unstable angina, the expression of neutrophil and monocyte CD11B/CD18 adhesion molecules in 26 patients was measured from blood samples taken from the coronary ostium, the coronary sinus, and the coronary artery just distal to the culprit lesion (postobstructive chamber). CD11B/CD18 adhesion molecules detected by direct immunofluorescence evaluated by flow cytometry were significantly higher in the coronary sinus blood than in both the coronary ostium and the postobstructive chamber blood, suggesting that leukocyte activation takes place at the microcirculatory interface with the injured myocardium, probably as the result of short but repeated episodes of myocardial ischemia.

Interaction between exercise training and ejection fraction in predicting prognosis after a first myocardial infarction.

BACKGROUND: Although recent meta-analysis trials have shown that exercise training may improve survival after myocardial infarction, the mechanism of this beneficial effect is still unknown. The purpose of this study was to detect possible interactions between exercise training and predictors of prognosis after a first myocardial infarction. METHODS AND RESULTS: Patients with uneventful clinical courses after a first myocardial infarction were randomly assigned to a 4-week training period (125 patients, group 1) or to a control group (131 patients, group 2). Before randomization, all patients underwent a symptom-limited exercise test (28 +/- 2 days after myocardial infarction), 24-hour Holter monitoring, and coronary arteriography (31 +/- 3 days after the acute episode). After a mean follow-up period of 34.5 months, 18 patients had cardiac deaths (5 in group 1 and 13 in group 2). Multivariate analysis by Cox regression model showed that ejection fraction was the only independent prognostic indicator (P = .03). Evidence existed of an interaction between ejection fraction and exercise training, showing an effect of physical training on survival that depended on the patient's ejection fraction. Among patients with ejection fractions < 41%, the relative risk for an untrained patient was 8.63 times higher than for a trained patient (P = .04), whereas for ejection fractions > 40%, the estimated risks for trained and untrained patients were similar. CONCLUSIONS: These data show that exercise training may prolong survival in post-myocardial infarction patients with depressed left ventricular function. A randomized trial in such patients seems warranted.

[Evaluation of efficacy and mechanism of action of angioplasty and directed atherectomy assisted by intravascular ultrasonography]. / Ocena skutecznosci i mechanizmów dzialania angioplastyki oraz aterektomii kierunkowej za pomoca ultrasonografii wewnatrznaczyniowej.

Intravascular ultrasound (IVUS) is a unique method of coronary lumen visualization enabling also examination the structure of the artery wall. Aim of this study was to assess efficacy and mechanisms of action of balloon angioplasty (PTCA) and directional atherectomy by means of IVUS. IVUS examination was performed before and after mechanical revascularization procedure in 37 pts (DCA-19 pts, PTCA-18 pts). Both PTCA and DCA resulted in enlargement of the coronary artery lumen (2.29 +/- 1.19 mm2 vs 2.93 +/- 1.55 mm2) but, also external diameter of the vessel increased after the procedure (1.94 +/- 1.10 mm2 and 0.74 +/- 1.01 mm2 retrospectively). In 55.6% of cases after PTCA plaque rupture or artery wall dissection was observed, mainly in eccentric lesions (70%). IVUS allowed to recognize details of artery lumen and define efficiency of procedure. In about 15% cases decision to continue PTCA or DCA was made on the basis of IVUS images only. The mechanism in which PTCA modifies the artery lumen is diverse and depends on the structure of lesion. Factors possibly responsible for enlargement of the lumen are: stretching, squeezing and translocation of atheroma as well as cracking and dissections along the arterial wall. DCA effectiveness depends on the withdraw of the atheromatous deposit, however, in over one-half of cases also stretching has some effect.

[Histopathologic features in atherectomy samples obtained from patient with unstable angina, stable angina and restenosis. Directional Atherectomy Lombardi Group]. / Reperti histopatologici [corrected] in campioni di aterectomia ottenuti da pazienti con angina instabile, con angina stabile e con ristenosi. Gruppo Lombardo Aterectomia Direzionale, GLAD.

BACKGROUND: The present study was aimed at investigating the pathologic features of directional coronary atherectomy (DCA) samples obtained from 194 patients (14 females) with stable (n = 68) and unstable (n = 95) angina, and with restenosis (n = 27). METHODS: DCA samples were obtained from culprit lesions, using the Simpson technique. Unstable angina was classified according to E. Braunwald criteria. Stable angina was grouped according to the presence or absence of a prior myocardial infarction (MI). DCA samples were fixed, processed, serially cut and stained with hematoxilin-eosin and with Movat pentachrome stain. RESULTS: The major pathologic findings were thrombosis, inflammation of the superficial plaque layers, and neointimal hyperplasia which often coexisted within a same sample. Their frequencies, in that order, were distributed in the differing groups of patients as follows: 21% (n = 9), 29.2% (n = 12) and 51% (n = 21) of the 41 cases with stable angina without prior MI. 40.7% (n = 11), 40.7% (n = 11), and 51.8% (n = 14) of the 27 cases with stable angina with prior MI. 25% (n = 4), 56.2% (n = 9) and 68.7% (n = 11), of the 16 cases with BI unstable angina. 35.3% (n = 14), 55.8% (n = 19) and 44% (n = 15), of the 34 cases with BII unstable angina. 44.4% (n = 4), 33.3% (n = 3) and 33.3% (n = 3), of the 9 cases with BIII unstable angina. 48.2% (n = 14), 48.2% (n = 14) and 51.8% (n = 15), of the 29 cases with CII unstable angina at 35.8 days after MI. 60% (n = 3), 60% (n = 3) and 40% (n = 2), of the 5 cases with CIII unstable angina at 8.3 days after MI. 26% (n = 7), 48% (n = 13) and 85.1% (n = 23), of the 27 cases with restenosis. According to above observation, the frequency of coronary thrombosis increases with the increase of the severity of myocardial ischemia. However, thrombosis is not found in most unstable angina without prior MI (63% of BI-II-III unstable angina cases do not have thrombus). In addition, thrombus is not a specific finding of unstable angina, given its occurrence, although in a much lower percentage of cases, in stable angina and in restenosis. CONCLUSIONS: Present data show that different ischemic and plaque lesions. This observation questions on the pathogenetic role of thrombus in unstable angina and calls for further investigations on inflammation and neointimal hyperplasia, as well as on the the reciprocal relation between these findings which are often combined within a same lesion.

Correlation between clinical and morphologic findings in unstable angina.

This study was undertaken to verify the hypothesis that the discrepant findings in published reports on the prevalence of thrombus in unstable angina depend on the inclusion of different clinical subsets in the various studies. We therefore correlated the clinical characteristics of patients included under the label of unstable angina with the morphologic features assessed by coronary angiography and intravascular ultrasound, and with histopathologic findings of atherectomy specimens. Fifty-eight patients with unstable angina (class B of the Braunwald classification) undergoing coronary arteriography followed by either coronary angioplasty (n = 20) or directional coronary atherectomy (n = 38) were studied. Fifteen patients were in class IB and 43 were in class II to IIIB. Among these 43 patients with angina at rest, 28 had ST-segment elevation during pain, and 15 had ST-segment depression, and 26 developed negative T waves on the baseline electrocardiogram (ECG) as a result of prolonged or repeated episodes of resting chest pain. Intravascular ultrasound examination of the culprit lesion was performed in 43 patients before the interventional procedure, and histopathologic analysis of atherectomy specimens was performed in 38 patients. Complex lesion morphology by angiography was observed in 31 patients (53%) without any significant relation to various clinical subsets. Patients in Braunwald class IB had more calcific plaques than patients in class II to IIIB (p < 0.001). Among patients with angina at rest, those with negative T waves on the baseline ECG, as well as those with transient ST elevation during pain, had a significantly higher incidence of noncalcific lesions (p = 0.001 for both). Analysis of atherectomy specimens revealed acute coronary lesions (thrombus and/or intraplaque hemorrhage) in 18 patients (47%). The incidence of acute coronary lesions was significantly higher in patients with than without negative T waves on the baseline ECG (p = 0.005), and increased further when negative T waves were combined with ST elevation during pain (p = 0.001). Multivariate analysis revealed that the presence orf negative T waves on the baseline ECG was the only explanatory variable related to the presence of acute coronary lesions by histology (p = 0.03). Patient subsets included in the broad spectrum of unstable angina have different morphologic features and incidence of acute coronary lesions by histology. These data provide an explanation for the discrepant findings in published reports on the relevance of thrombus formation in the pathogenesis of unstable angina.

Effect of the increasing use of coronary angioplasty on outcome at one year in patients with unstable angina.

OBJECTIVE: To determine whether the increasing use of percutaneous transluminal angioplasty in patients with unstable angina has reduced the need for bypass surgery and whether this change in the choice of treatment affected the outcome at one year in patients with unstable angina who were admitted to hospital in two different periods of time. DESIGN: Retrospective analysis of consecutive patients with unstable angina (angina at rest with ST-T changes during pain) who underwent coronary arteriography in two different periods of time. PATIENTS: 158 patients were admitted to hospital between January 1988 and June 1989 (group 1) and 140 patients admitted between January 1992 and June 1993 (group 2). RESULTS: Coronary angioplasty procedures nearly doubled from 29% in group 1 to 56% in group 2 whereas bypass surgery decreased from 36% in group 1 to 23% in group 2 (P < 0.01). Coronary angioplasty increased and bypass surgery decreased in patients with one vessel disease (P < 0.01), two vessel disease (P < 0.05), and three vessel disease (P < 0.01). Coronary angioplasty also increased and bypass surgery decreased in refractory angina and in patients with ejection fraction < 0.50 (both P < 0.05). At 1-year follow up, 14 patients in group 1 (9%) and 10 in group 2 (7%) either died or had myocardial infarction (P = NS). Revascularisation procedures were needed in 16 group 1 patients (10%) and 27 group 2 patients (19%, P < 0.05). CONCLUSIONS: Coronary angioplasty became more widely used in patients with unstable angina. This reduced the need for bypass surgery in patients with multivessel disease, refractory angina, and depressed left ventricular function. This change in treatment did not affect 1-year mortality or the myocardial infarction rate. More patients in the more recent group in which angioplasty was the preferred treatment required a further revascularisation procedure than in the earlier group in which bypass grafting was more often used as the initial treatment.

Clinical and angiographic correlates of leukocyte activation in unstable angina.

OBJECTIVES: This study sought to evaluate the relation, if any, between clinical and angiographic findings in patients with unstable angina and monocyte and neutrophil CD11b/CD18 receptor density. The expression of HLA-DR molecules on T lymphocytes, an index of activation of these cells, was also investigated. BACKGROUND: Although activation of neutrophils and monocytes has recently been shown in unstable angina, no studies have correlated activation indexes with clinical and angiographic features of patients with this clinical condition. METHODS: Sixty patients underwent diagnostic coronary arteriography and simultaneous blood sampling from the aorta and coronary sinus before injection of contrast medium. Cell surface receptors were detected by direct immunofluorescence evaluated by flow cytometry using monoclonal antibodies tagged with fluorescent markers. RESULTS: In 38 patients with unstable angina, neutrophils and monocytes showed a significantly higher expression of CD11b/CD18 adhesion receptors in coronary sinus than aortic blood (p < 0.0001 and p < 0.001, respectively). When these patients were analyzed according to clinical characteristics or angiographic findings, no difference in CD11b/CD18 receptor expression in coronary sinus blood was found between the various subgroups, except for patients with at least one episode of chest pain at rest within 48 h of coronary arteriography and a higher neutrophil adhesion molecule density than patients who remained asymptomatic (p = 0.04). Lymphocytes in patients with stable and unstable angina showed a similar percent expression of CD2/CD19 and CD3/HLA-DR antigens, with no difference between aortic and coronary sinus blood. CONCLUSION: These results in a larger cohort confirm previous data that neutrophil and monocyte CD11b/CD18 adhesion molecules show a higher expression in the coronary sinus blood of patients with unstable angina. Among clinical and angiographic findings in patients with unstable angina, only the occurrence of chest pain within 48 h of coronary angiography was related to significantly higher values of neutrophil fluorescence intensity, suggesting that the degree of neutrophil activation is related to the proximity of rest angina episodes to blood sampling. Finally, our data do not support the concept of systemic or transcardiac lymphocyte activation in unstable angina.

Influence of plaque composition on luminal gain after balloon angioplasty, directional atherectomy, and coronary stenting.

This study was conducted to correlate the acute luminal enlargement achieved by three different nonsurgical revascularization procedures in 79 patients (32 treated by balloon angioplasty, 29 by directional atherectomy, and 18 by coronary stenting) with the morphologic characteristics of coronary plaques assessed by preprocedure intravascular ultrasound. The absolute luminal gain was 2.41 +/- 1.54 mm2 for balloon angioplasty, 3.17 +/- 1.8 mm2 for directional atherectomy, and 4.56 +/- 1.45 mm2 for coronary stenting (p = 0.00005). However, when luminal gain was corrected for the external vessel area (luminal gain index), such difference was no longer present (0.22 +/- 0.12 for balloon angioplasty, 0.24 +/- 0.15 for directional atherectomy, and 0.30 +/- 0.12 for coronary stenting, p = not significant). Concentric plaques treated by coronary stenting had a higher luminal gain index than eccentric plaques (p = 0.01). A comparison of the three devices showed that a similar luminal gain index was achieved in soft plaques, whereas coronary stenting was superior to directional atherectomy (0.41 +/- 0.10 vs 0.20 +/- 0.09, p = 0.002) and balloon angioplasty (0.41 +/- 0.10 vs 0.19 +/- 0.08, p = 0.0005) in concentric plaques. Coronary stenting also induced a greater luminal gain index than directional atherectomy in calcific plaques (0.30 +/- 0.11 vs 0.18 +/- 0.09, p = 0.04). In conclusion, these data show that plaque morphology assessed by preprocedure intracoronary ultrasound influences the acute luminal enlargement achieved by different coronary interventions. The knowledge of plaque composition may be useful in guiding the choice of the device to be used to obtain a larger acute luminal gain.

Influence of plaque morphology on the mechanism of luminal enlargement after directional coronary atherectomy and balloon angioplasty.

OBJECTIVE: To relate the mechanism of luminal gain after directional atherectomy and balloon angioplasty to the morphological characteristics of the coronary lesions, assessed by intravascular ultrasound imaging. DESIGN: Intravascular ultrasound imaging was performed before and after the revascularisation procedure to assess the contribution of wall stretching and plaque reduction in luminal gain. SUBJECTS: 32 patients undergoing balloon angioplasty and 29 undergoing directional coronary atherectomy. MAIN RESULTS: The main luminal area in vessels treated by balloon angioplasty increased from 1.51 (SD 0.30) to 3.91 (1.09) mm2 (P < 0.0001) with a concomitant increase in total vessel area from 11.44 (2.73) to 13.07 (2.83) mm2 (P < 0.0001). Therefore stretching of the vessel wall accounted for 68% of the luminal gain while plaque reduction accounted for the remaining 32%. This mechanism ranged from 45% in non-calcific plaques to 81% in echogenic plaques. The main luminal area in vessels treated by directional atherectomy increased from 1.49 (0.32) to 4.68 (1.73) mm2 (P < 0.0001), with a concomitant increase of total vessel area from 13.61 (4.67) to 15.2 (4.04) mm2 (P = 0.006). Thus stretching of the vessel wall accounted for 49% of the luminal area gain and plaque reduction for the remaining 51%. The presence of calcium influenced the relative contribution of these two mechanisms to the final luminal gain after directional atherectomy, since in calcific plaques stretching of the vessel wall accounted for only 9% of the luminal gain as compared to 56% in non-calcific plaques. After balloon angioplasty there was greater evidence of coronary dissections (32% v 3% after directional atherectomy, P < 0.01) and plaque fissure (60% v 0%, P < 0.01). Plaque fissure was more frequently seen in echolucent and concentric lesions, whereas dissections prevailed in echogenic and eccentric lesions. CONCLUSIONS: Intravascular ultrasound imaging may allow the assessment of acute changes in lumen and vessel wall after revascularisation procedures, and help in evaluating the potential effect of the structure and morphology of coronary lesions on the mechanism of luminal enlargement.

Comparison of coronary lesions obtained by directional coronary atherectomy in unstable angina, stable angina, and restenosis after either atherectomy or angioplasty.

The present study investigated the incidence of the histopathologic lesions and of growth factor expression in a consecutive series of directional coronary atherectomy (DCA) samples from 40 unstable angina pectoris patients without prior acute myocardial infarction and compared the findings with those obtained in DCA samples from 18 patients with stable angina without previous infarction and 18 patients with restenosis. We investigated coronary thrombosis, neointimal hyperplasia, and inflammation. For unstable angina, we correlated the angiographic Ambrose plaque subtypes with the histopathologic findings. The immunophenotype of plaque cells and the growth factor expression were assessed with specific antibodies for cell characterization and for the expression of basic fibroblast and platelet-derived AA and AB growth factors and receptors. The incidence of coronary thrombosis was 35% in patients with unstable angina, 17% in those with stable angina, and 11% in patients with restenosis. Neointimal hyperplasia was found in 38% of unstable angina cases, in 17% of stable angina cases, and in 83% of restenosis cases. Inflammation without thrombus or accelerated progression occurred in 20% of unstable angina and 6% of stable angina samples. In 52% of unstable angina cases, inflammation coexisted with thrombosis and/or neointimal hyperplasia. In the unstable angina group, 71% of the plaques with thrombus had a corresponding angiographic pattern of complicated lesions. The growth factor expression, reported as percentage of cells immunostaining with different growth factor antibodies, was highest in restenosis, followed by unstable angina and stable angina lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

[The evolution of the therapeutic choice in patients with the outcomes of non-Q myocardial infarct: 2 periods compared]. / Evoluzione della scelta terapeutica nei pazienti con esiti di infarto miocardico non-Q: due periodi a confronto.

BACKGROUND: Over the last years there has been a tremendous increase in coronary angioplasty procedures (PTCA), due to the availability of better materials and to the refinement of operators skill. It is not known however if this "PTCA boom" has modified our approach to the patients with particular clinical situations, such as those with non-Q wave myocardial infarction. The purpose of this study was to verify, in patients undergoing coronary angiography for clinical reasons after a non-Q wave myocardial infarction, the clinical decision concerning the therapeutical choice in two different periods (101 patients in 1988 vs. 102 patients in 1992). METHODS AND RESULTS: Patients in the two groups had similar clinical manifestations whereas patients observed in 1992 had more frequently 2-vessel disease than single vessel disease as compared to patients studied in 1988 (p < 0.05). The distribution of patients with normal coronary arteries or with 3-vessel disease was similar in the two periods. In 1988 medical therapy was the most recommended treatment at discharge (47%), followed by aorto-coronary bypass (29%) and coronary angioplasty (24%). On the contrary, in 1992 PTCA was performed in 48% of patients, medical therapy was recommended in 28% while the incidence of coronary surgery was reduced to 24% (p < 0.01). From a clinical point of view a significant increase in PTCA procedures was seen in patients presenting with unstable angina after the non-Q wave myocardial infarction (54% of these patients undergoing PTCA in 1992 vs. 30% in 1988, p = 0.03) and in patients with effort angina and a positive exercise test at low workload (53% of these patients undergoing PTCA in 1992 vs. 22% in 1988, p < 0.05). Moreover, in 1992 PTCA procedures increased in patients with single vessel disease (64% in 1992 vs. 49% in 1988) and in patients with 2-vessel disease (64% in 1992 vs. 9% in 1988). Therefore, in these patients the need of aorto-coronary by pass was reduced from 39% in 1988 to 19% in 1992 (p < 0.05). The success rate of PTCA procedures was 98% in 1992 and 83% in 1988. No major complications were observed in the two study periods and no patients underwent urgent coronary surgery. CONCLUSIONS: These data show an increase in PTCA procedures over the last years in patients undergoing coronary angiography for clinical reasons after a non-Q wave myocardial infarction. The greater experience of operators allowed for improved results, thus reducing the need of coronary surgery in these patients.

[Diagnostic and research potential of directional atherectomy]. / Potenzialità diagnostica e di ricerca dell'aterectomia direzionale.

Directional coronary atherectomy (DCA) is the sole technique for the in vivo study of coronary artery plaques which are responsible for myocardial ischemia. The technique confers the following advantages to the pathologic study of plaque samples: the brevity, in general, of the interval between acute myocardial ischemia and sampling of the guilty plaque; the absence in samples of autolytic phenomena (such as those that affect autopsy samples), an effect that enables the use of conventional histopathology, immunohistochemistry and molecular biology; the certainty with which the researcher can identify, and thus sample, the truly guilty lesions. The drawbacks of the technique are: the fragmentation of the plaque; the difficulty the pathologist has in correctly orientating the samples in the embedding phase, in distinguishing pre- from post-procedural lesions, and in providing a detailed description of the findings. Given the foregoing, the diagnostic information to which DCA sampling enables access is as follows: plaque derivation--the recognition of whether tissue removed with DCA originates from eccentric or concentric, atheromatous of fibrosclerotic, calcified or not calcified plaques; histopathology of coronary lesions that cause ischemia with regard to: evidence of acute events, such as thrombosis, ulceration and hemorrhage, thrombus composition, when it occurs, and definition of its age and presence of material deriving from the vascular wall that lies beyond the plaque; identification and immunophenotypical characterization of inflammatory infiltrates. As regards research, the main implications of DCA are for the study of the pathogenetic mechanisms that lead to plaque instability in acute ischemic syndromes.(ABSTRACT TRUNCATED AT 250 WORDS)

[The ergometric test after a heart transplant: its usefulness and limits]. / Test ergometrico dopo trapianto cardiaco: utilità e limiti.

Aim of this study was to analyze the cardiovascular response to graded physical exercise in patients who have undergone cardiac transplantation and to assess the ability of exercise stress testing in early detection of coronary artery disease. We studied 114 transplanted subjects (100 men and 14 women, mean age 46.6 +/- 11.3 years), who performed exercise stress testing 6 months after bypass and then every 6 (+/- 1) months during a 5-year follow-up. Variations of hearth rate (HR), systolic blood pressure (SBP), heart rate-pressure product (RPP) values and exercise stress tolerance were studied both in basal and maximum workload conditions. Mean HR values at basal conditions (103.9 +/- 11.3 b/min at 6 months and 89 +/- 12.7 b/min at 60 months, p < 0.05) and maximum workload tolerance (67.7 +/- 20.4 W at 6 months and 100 +/- 17 W at 60 months, p < 0.05) were significantly different at the beginning and at the end of follow-up. SBP values both at basal conditions and at peak exercise had always been constant. Exercise was stopped for leg muscle fatigue in 92% and dyspnea in 7% of the subjects; isolated T-wave and ST segment changes were found in 29.8% and in 10.5% of the patients respectively, whereas 11.4% exhibited both ST-T variations. Angiographic examination (performed in 80/114 patients) showed significant coronary disease (stenosis > 50%) in 8, coronary atherosclerosis (CAD) of minor degree in 4 and provoked spasm in 2 subjects. In this subgroup exercise stress testing induced ischemic ECG changes (ST segment depression > or = 1 mm) without angina in 1 patient, ST-T segment variations only in 5 and no electrocardiographic alterations (negative tests) in 2 patients. Four subjects with CAD and 1 with coronary spasm induced by angiography showed isolated ST segment and T-wave changes. Our work demonstrated that exercise stress testing plays a relevant role in the study of the denervated heart response to dynamic exercise. The rise in workload tolerated, observed in our population, seems to be related to time elapsed from surgery, improvement in clinical conditions, psychological stability and patient's confidence in his own abilities. The tolerance to exercise 6 months after graft seems to predict the quality of performance in the following tests. Our angiographic results reveal a low sensitivity of the exercise stress test in detecting CAD in this population according to traditional electrocardiographic criteria for myocardial ischemia.(ABSTRACT TRUNCATED AT 400 WORDS)