Biomedical subjects
Publications and source records attributed to C Macaya.
Our findings indicate the value of IVUS in the study of aortic intramural hematomas in ruling out other aortic diseases such as classic aortic dissection. This technique appears especially attractive for patients with suspected aortic dissection and a normal aortography.
Compared with pathologic studies coronary angiography is a relatively insensitive technique to detect early atherosclerosis. Coronary angioscopy is a new technique providing direct information on luminal vessel surface. To determine whether coronary angioscopy may detect the presence of atherosclerotic disease on angiographically normal coronary segments, 52 patients underwent a study with coronary angioscopy before coronary angioplasty. The mean age was 59 +/- 10 years; 46 patients were men and 6 were women. The reason for coronary angioplasty was unstable angina in 36 patients, stable angina in 8 patients, and silent ischemia in 8 patients. In seven patients angiography revealed luminal irregularities on the coronary segment proximal to the culprit lesion, and all these patients also had proximal disease as demonstrated by coronary angioscopy. In the remaining 45 (87%) patients angiography revealed a smooth-vessel contour proximal to the target lesion. On quantitative angiography these "normal" coronary segments measured 2.8 +/- 0.4 mm in luminal diameter. In 30 (67%) of these patients angioscopy revealed proximal disease on the vessel wall, but in 15 (33%) patients the luminal surface of these segments also appeared normal on angioscopy. Disease as detected by angioscopy in angiographically normal segments included yellow plaque in 19 patients, mural thrombus in 5, mixed plaques in 4, and small flaps in 2 patients. In eight patients coronary angioscopy detected that atherosclerotic disease extended proximally from the target lesion, but in the remaining 22 patients the angioscopic findings appeared to be discrete and well separated from the angiographic lesion. All these plaques were relatively small and did not protrude into the coronary lumen.(ABSTRACT TRUNCATED AT 250 WORDS)
OBJECTIVES: This study sought to elucidate angioscopic findings in totally occluded vessels before and after intervention. BACKGROUND: Coronary angioscopy allows direct visualization of the lumen surface of the coronary arteries; however, the utility of coronary angioscopy during coronary angioplasty of vessels with a total occlusion is unknown. METHODS: Twenty-one consecutive patients (mean [+/- SD] 58 +/- 9 years, range 39 to 77; 3 women, 18 men) undergoing dilation of an occluded vessel were studied with coronary angioscopy. Occlusions were classified as functional in 8 patients (Thrombolysis in Myocardial Infarction [TIMI] flow grade 1) and anatomic in 13 (TIMI flow grade 0). Once the guide wire had crossed the occlusion, coronary angioscopy was attempted before and after angioplasty. RESULTS: In all patients, coronary angioscopy before dilation visualized protruding material occluding the coronary lumen where the guide wire was wedged. The occlusion consisted of red thrombus in 19 patients (90%) (2 with isolated occlusive thrombus, 17 with thrombus associated with atherosclerotic plaque) and protruding yellow plaque in 2 patients (10%). However, on angiography only 7 occlusions (33%) had data consistent with thrombus (p < 0.01 vs. coronary angioscopy). Successful dilation was obtained in 20 patients. After dilation, coronary angioscopy was repeated in 18 patients, revealing residual thrombus with plaque in 16 (89%) and a residual yellow plaque in 2. In addition, coronary angioscopy revealed coronary dissections in 13 patients (72%); however, angiography revealed dissections only in 10 patients (55%) and residual thrombus in 2 (10%) (p < 0.001). In one patient, coronary angioscopy visualized silent distal embolization of a red thrombus not previously recognized on angiography. CONCLUSIONS: Before intervention, coronary angioscopy provides unique insights into the pathologic substrate of occluded coronary vessels. An occlusive plaque with thrombus is the most common underlying substrate in these lesions. After successful dilation, angiographically silent mural thrombus is seen in most patients. This information could be used to assist in the selection of candidates and type of coronary interventions and could also prove to be of prognostic value in patients with occluded vessels.
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BACKGROUND AND OBJECTIVE: Percutaneous coronary angioscopy (CAG) provides in vivo visual information about the luminal aspect of the vessel. In this report we describe our initial experience with CAG during coronary angioplasty (PTCA). METHODS: Fifty-five patients (age 60 +/- 9 years), 8 female, were included. Most patients, 42 (76%) were treated for unstable angina. RESULTS: In 49 patients (89%) CAG was performed prior to PTCA, and in all cases the intraluminal material responsible of the stenosis was recognized. This included plaque associated to thrombus in 29 patients (59%), isolated plaque in 15 (31%) and isolated thrombus in 5 (10%). Of these plaques, 25 (57%) were yellow, 14 (32%) were yellow and white and 5 (11%) were white. Of the 34 thrombi, 23 (68%) were mural and 11 (32%) protruding. CAG post-PTCA was performed in 43 patients (78%). CAG visualized residual plaque in 41 patients (95%) and residual thrombus in 34 (79%). In addition, CAG recognized dissections in 30 patients (70%). CAG was more sensitive than angiography for the detection of thrombus (pre-PTCA 34 [69%] vs 11 [22%]; p < 0.05, and post-PTCA 34 [79%] vs 5 [12%]; p < 0.05]) and coronary dissections (post-PTCA 30 [70%] vs 19 [44%]; p < 0.05). CAG before intervention caused angina in 39 patients (80%), ventricular fibrillation (successfully managed with DC cardioversion) in 1, and AV block in another patient. The angiographic result deteriorated in 4 patients (9%) immediately after the CAG performed following PTCA. A repeat balloon PTCA was required in these patients. CONCLUSIONS: CAG provides unique information on coronary lumen surface that complements angiographic data. As compared with angiography, CAG is more sensitive in the detection of intracoronary thrombi and dissections. Further studies are required to determine whether the additional information provided by CAG may be used, to select coronary interventions according to specific lesion characteristics, to optimize dilation results and, eventually, to improve the clinical outcome of these patients.
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BACKGROUND: Balloon-expandable coronary-artery stents were developed to prevent coronary restenosis after coronary angioplasty. These devices hold coronary vessels open at sites that have been dilated. However, it is unknown whether stenting improves long-term angiographic and clinical outcomes as compared with standard balloon angioplasty. METHODS: A total of 520 patients with stable angina and a single coronary-artery lesion were randomly assigned to either stent implantation (262 patients) or standard balloon angioplasty (258 patients). The primary clinical end points were death, the occurrence of a cerebrovascular accident, myocardial infarction, the need for coronary-artery bypass surgery, or a second percutaneous intervention involving the previously treated lesion, either at the time of the initial procedure or during the subsequent seven months. The primary angiographic end point was the minimal luminal diameter at follow-up, as determined by quantitative coronary angiography. RESULTS: After exclusions, 52 patients in the stent group (20 percent) and 76 patients in the angioplasty group (30 percent) reached a primary clinical end point (relative risk, 0.68; 95 percent confidence interval, 0.50 to 0.92; P = 0.02). The difference in clinical-event rates was explained mainly by a reduced need for a second coronary angioplasty in the stent group (relative risk, 0.58; 95 percent confidence interval, 0.40 to 0.85; P = 0.005). The mean (+/- SD) minimal luminal diameters immediately after the procedure were 2.48 +/- 0.39 mm in the stent group and 2.05 +/- 0.33 mm in the angioplasty group; at follow-up, the diameters were 1.82 +/- 0.64 mm in the stent group and 1.73 +/- 0.55 mm in the angioplasty group (P = 0.09), which correspond to rates of restenosis (diameter of stenosis, > or = 50 percent) of 22 and 32 percent, respectively (P = 0.02). Peripheral vascular complications necessitating surgery, blood transfusion, or both were more frequent after stenting than after balloon angioplasty (13.5 vs. 3.1 percent, P < 0.001). The mean hospital stay was significantly longer in the stent group than in the angioplasty group (8.5 vs. 3.1 days, P < 0.001). CONCLUSIONS: Over seven months of follow-up, the clinical and angiographic outcomes were better in patients who received a stent than in those who received standard coronary angioplasty. However, this benefit was achieved at the cost of a significantly higher risk of vascular complications at the access site and a longer hospital stay.
Prevention of restenosis after successful percutaneous transluminal coronary balloon angioplasty (PTCA) continues to present the greatest therapeutic challenge in interventional cardiology. Experimental and pathological studies describe restenosis as no more than the biologic healing response to arterial injury. Studies of serial quantitative coronary angiography have demonstrated that this biologic process may be measured as the loss in minimal luminal diameter (MLD) from post-PTCA to follow-up angiography and that it is essentially ubiquitous and normally distributed. Thus, quantitative coronary angiography has become the gold standard for evaluation of the angiographic outcome of clinical trials of new agents and devices aimed at prevention of restenosis. The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors inhibit biosynthesis of mevalonate, a precursor of non-sterol compounds involved in cell proliferation, and thus may control the neointimal response, which forms the kernel of restenosis. Experimental evidence suggests that fluvastatin may exert a greater direct inhibitory effect on proliferating vascular myocytes than other HMG-CoA reductase inhibitors, independent of any lipid-lowering action. The Fluvastatin Angioplasty Restenosis (FLARE) Trial was conceived, in collaboration between the Thoraxcenter, Erasmus University, Rotterdam, The Netherlands, and Sandoz Pharma, to evaluate the ability of fluvastatin 40 mg twice daily to reduce restenosis after successful single-lesion PTCA. Treatment of suitable patients begins 2 weeks before PTCA and continues after successful PTCA (residual diameter stenosis < 50%, without major cardiac complications) to follow-up angiography at 26 +/- 2 weeks. Restenosis is measured by quantitative coronary angiography at a core laboratory as the loss in MLD from post-PTCA to follow-up angiography. It is calculated (90% power, alpha = 0.05) that 730 evaluable patients will be needed to test the hypothesis that fluvastatin will reduce the expected post-PTCA loss in MLD by 40%. Serial lipid analysis will be carried out at a central laboratory. Trial evaluation is focused on the primary endpoint (change in MLD) but includes primary clinical endpoints (death, myocardial infarction, or the need for coronary artery bypass graft surgery or reintervention up to 40 weeks after PTCA) as well as secondary and tertiary clinical, angiographic, and laboratory endpoints. According to this methodologic approach, the effect of fluvastatin in luminal renarrowing and clinical events after successful PTCA as well as possible associations of lipid parameters with restenosis can be comprehensively investigated.
OBJECTIVES: The aim of this study was to elucidate determinants of coronary compliance in patients with coronary artery disease. BACKGROUND: Intravascular ultrasound potentially enables in vivo evaluation of coronary artery compliance. METHODS: Twenty-seven patients (mean age [+/- SD] 57 +/- 11 years, three women) undergoing coronary angioplasty were studied with intravascular ultrasound imaging. A mechanical intravascular ultrasound system (4.8F, 20 MHz) was used. A total of 58 different coronary segments (proximal to the target angiographic lesion) were studied. Of these, 35 were located in the left anterior descending, 9 in the left main, 8 in the left circumflex and 6 in the right coronary arteries. During intravascular ultrasound imaging, 22 segments (38%) appeared normal, but 36 (62%) had plaque (24 fibrotic, 3 lipidic and 9 calcified). Systolic-diastolic changes in area (delta A) and pressure (delta P) with respect to vessel area (A) were used to study normalized compliance (Normalized compliance = [delta A/A]/delta P [mm Hg-1 x 10(3)]). RESULTS: Lumen area and plaque area were 12.6 +/- 5.7 and 3 +/- 3 min2, respectively. Plaque was concentric (more than two quadrants) at 10 sites, but the remaining 26 plaques were eccentric. Compliance was inversely related to age (r = -0.34, p < 0.05) but was not related to other clinical variables. Compliance was greater in the left main coronary artery (3.9 +/- 2.1 vs. 1.8 +/- 1.2 mm Hg-1, p < 0.05) and in coronary segments with normal findings on ultrasound imaging (2.9 +/- 1.9 vs. 1.6 +/- 1.1 mm Hg-1, p < 0.01). Moreover, at diseased coronary segments compliance was lower in calcified plaques than in other types of plaques (1.2 +/- 0.7 vs. 2.3 +/- 1.6 mm Hg-1, p < 0.01) but was similar in concentric and eccentric plaques (1.6 +/- 1.5 vs. 1.6 +/- 0.9 mm Hg-1). Plaque area (r = -0.38, p < 0.01) was inversely correlated with compliance. On multivariate analysis, only age and plaque area were independently related to compliance. CONCLUSIONS: Intravascular ultrasound may be used to evaluate compliance in patients with coronary artery disease. Compliance is reduced with increasing age and is mainly determined by the arterial site and by the presence, size and characteristics of plaque on intravascular ultrasound imaging.
OBJECTIVES: The purpose of this study was to assess the effects and clinical implications of Palmaz-Schatz stent implantation on coronary blood flow in side branches arising from a stented coronary artery segment. BACKGROUND: The occlusion of a side branch is a well defined risk after balloon angioplasty. However, the impact of stenting on the coronary flow in side branches arising within the stented segment is unknown. METHODS: Forty-six stented coronary artery segments with 79 side branches emerging from the stented segment were analyzed. Angiographic studies were performed before angioplasty, after balloon dilation, immediately after stenting and 24 h later. Side branches were classified as follows: type A (> or = 1 mm in diameter, with ostial narrowing), type B (> or = 1 mm in diameter, without ostial narrowing), type C (< 1 mm in diameter, with ostial narrowing) and type D (< 1 mm in diameter, without ostial narrowing). Quantitative angiography was used to assess the diameter of the side branches. RESULTS: Stents were implanted electively in lesions with restenosis (41 stents, 89%) or with a suboptimal result after angioplasty (5 stents, 11%). Nine side branches (11%) were type A, 25 (32%) type B, 7 (9%) type C and 38 (48%) type D. At baseline, 68 side branches had Thrombolysis in Myocardial Infarction (TIMI) trial flow grade 3; 10 had grade 2; and 1 had grade 1. Flow worsened (TIMI grade > or = 1) in six side branches (8%) after balloon dilation and in four side branches (5%) after stenting. One additional side branch (1%) was occluded at 24 h. Of the 34 side branches > or = 1 mm in diameter (mean diameter 1.5 +/- 0.3 mm), 2 (6%) had flow impairment after stenting. Three patients experienced transient angina, but no acute myocardial infarction occurred as a result of a side branch occlusion. CONCLUSIONS: Coronary artery stenting does not modify anterograde flow in 90% of side branches. Coronary flow is reduced after stenting in a few branches, but this does not appear to have major clinical relevance.
Intravascular ultrasound (IVUS) imaging of the coronary arteries has recently been introduced for the study of coronary lesions, but the angiographic effects produced by an IVUS examination before coronary angioplasty are unknown. Accordingly, the feasibility of and the potential angiographic changes caused by IVUS study (4.8F catheter) of severe coronary lesions was prospectively studied. Thirty consecutive coronary lesions were analyzed before intervention (29 patients, mean age 61 +/- 9 years, 5 women and 24 men). Before and after IVUS examination, intracoronary nitroglycerin 0.2 mg, was administered and two orthogonal angiographic views obtained. In 17 (57%) lesions the transducer of the IVUS catheter (radiopaque) could be gently advanced for precise location at the lesion site, and in every case the ultrasonic images revealed that the catheter was wedged into the plaque. In the remaining 13 lesions only the catheter tip but not the transducer could be located at the lesion site. Baseline minimal luminal diameter was similar in the crossed lesions and in lesions that prevented complete advancement of the IVUS catheter (0.86 +/- 0.2 vs 0.82 +/- 0.2 mm, difference not significant). Lesion characteristics could not predict the feasibility of the IVUS study. No complications resulted from the IVUS study. Quantitative angiography (automatic edge-detection system) revealed a significant increment in minimal luminal diameter (0.84 +/- 0.2 vs 1.16 +/- 0.3 mm, p < 0.001) and minimal luminal cross-sectional area (0.67 +/- 0.4 vs 1.09 +/- 0.5 mm2, p < 0.01) after passage of the IVUS catheter.(ABSTRACT TRUNCATED AT 250 WORDS)
Intravascular ultrasound imaging (IVUS) constitutes a new diagnostic technique that provides unique information concerning arterial wall structure and luminal dimensions. To assess the anatomic features of angiographically normal coronary arteries in patients with coronary artery disease, 25 patients (aged 61 +/- 9 years) underwent an IVUS examination before coronary angioplasty. A mechanical (20 MHz) IVUS system was used. Atherosclerotic plaques were identified by IVUS as well-defined structures of variable echodensity protruding into the coronary lumen or disrupting normal coronary wall architecture. Five (20%) patients had minor angiographic irregularities proximal to the target lesion, and all 5 had plaque on IVUS. In the remaining 20 patients the coronary segments proximal to the target lesion were angiographically normal. Of these, IVUS demonstrated the presence of plaque in 16 (80%) patients at 19 different angiographic sites (3 lipidic, 13 fibrotic, 3 calcified). Fifteen plaques had a semilunar appearance and did not disrupt luminal contour, but four clearly protruded into the coronary lumen. Six plaques were located in the left main artery, 4 in the left anterior descending artery, 4 in the left circumflex artery, 4 in the right coronary artery, and 1 in a vein graft. On quantitative angiography, luminal diameter, at sites angiographically normal but with plaque on IVUS, was 3.6 +/- 1 mm. At these sites, both minimal luminal diameter (3.5 +/- 1 mm) and maximal luminal diameter (4.3 +/- 1 mm) on IVUS correlated (r = 0.59 and r = 0.61, respectively) with angiographic measurements (p < 0.05). No complications resulted from the IVUS study.(ABSTRACT TRUNCATED AT 250 WORDS)
OBJECTIVES: The aim of this study was to assess the implications of residual coronary dissections after stenting. BACKGROUND: Coronary stenting is currently used in selected patients with coronary dissection after angioplasty. However, in some patients the total length of the dissection may not be completely covered with the device. METHODS: Forty-two consecutive patients (mean [+/- SD] age 58 +/- 11 years; 39 men, 3 women) undergoing stenting for a major coronary dissection after angioplasty were studied. RESULTS: Thirty (67%) coronary dissections were small (< or = 15 mm), and 29 (64%) were occlusive (Thrombolysis in Myocardial Infarction [TIMI] flow grade < or = 2). In 3 patients, coronary stenting was unable to open large occlusive dissections, but a good angiographic result was obtained in 39 patients (93%). After stenting, 22 of these patients (56%) had no visible residual dissections, and 13 (33%) had small and 4 (10%) had large residual dissections. These residual dissections were stable and did not compromise coronary flow. In a repeat angiogram (24 h later) the stent was patent in all 39 patients. However, two patients experienced a subacute stent occlusion. Of the remaining 37 patients, 36 (97%) had a late angiogram after stenting. Quantitative angiography revealed a reduction in minimal lumen diameter at the stent site (2.6 +/- 0.4 vs. 2 +/- 0.7 mm, p < 0.05) and a trend toward improvement in vessel diameter at the site of the previous residual dissection (1.7 +/- 0.6 vs. 1.9 +/- 0.5 mm, p < 0.1). The angiographic image of residual dissection disappeared in all patients. These factors provided a rather smooth angiographic appearance at follow-up. The four patients with large residual dissections after stenting did not have restenosis and were asymptomatic at last visit. CONCLUSIONS: Coronary stenting is effective in the management of acute coronary dissections after angioplasty. In this setting, small residual dissections are frequently seen but have a good outcome and disappear at follow-up. Large residual dissections may have a good outcome if coronary flow is not impaired and no residual stenosis is visualized.
The long-term clinical and angiographic outcome of 76 elderly (> or = 65 years) patients undergoing coronary angioplasty (PTCA) (83 lesions attempted) for post-infarction angina (PIA) (group I) was compared with that of 83 elderly patients undergoing PTCA (105 lesions) for stable angina (group II). Age (70 +/- 4 years), gender (70% male) and major demographic variables were similar in both groups. The mean left ventricular ejection fraction was 56 +/- 14% in group I vs 67 +/- 14% in group II (P < 0.01). In group I, PTCA was performed more frequently for lesions located in the right coronary artery (35% vs 18%, P < 0.01) and less frequently in the left circumflex artery (12% vs 26%, P < 0.05). Although the percentage of lesions with thrombi was higher in group I (16% vs 2%, P < 0.001), the rate of angiographic success was similar in both groups: 94% (78/83 lesions) in group I vs 93% (98/105) in group II (ns). PTCA was successful in 67 patients (88%) in group I and in 74 (89%) in group II (ns). The rate of major complications was also similar in both groups (4%). Restenosis occurred in 36% vs 31% of the lesions in groups I and II respectively (mean time to angiographic follow-up 7 +/- 2 months) (proportion of cases with a repeat angiography: 79% in group I and 72% in group II). Restenosis was asymptomatic in 57% vs 50% of the patients respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
A patient with an excellent angiographic result after directional atherectomy suffered an acute coronary closure during an intravascular ultrasound study performed after the intervention. Intravascular ultrasound revealed a large medial dissection which could be successfully managed only with intracoronary stenting. The pathogenesis and implications of this rare major complication are discussed.
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The aim of this study was to assess the initial and midterm outcome of patients with severe pulmonary hypertension undergoing percutaneous mitral valvuloplasty (PMV). Accordingly, the baseline characteristics, immediate results and follow-up of 64 consecutive patients with severe pulmonary artery hypertension (systolic pulmonary artery pressure > or = 60 mm Hg on cardiac catheterization) (group I) were analyzed and compared with those of 194 consecutive patients with lower pulmonary pressures (group II). Patients in group I were more symptomatic (New York Heart Association functional class > or = III, 72 vs 40%, p < 0.001) and had higher echocardiographic scores (8.6 +/- 2 vs 7.4 +/- 1, p < 0.05). Before PMV, mitral gradient was higher (17 +/- 6 vs 13 +/- 5 mm Hg, p < 0.025) and mitral valve area smaller (0.79 +/- 0.2 vs 0.96 +/- 0.2 cm2, p < 0.005) in group I patients, who also had higher pulmonary vascular resistances (469 +/- 299 vs 157 +/- 125 dynes s-1 cm-5, p < 0.005). On multivariate analysis patients in group I were more symptomatic, had smaller mitral valve areas and higher mitral gradients. PMV success (area gain > 50% without complications) was similar (89 vs 87%) in both groups. After PMV final mitral gradient (5 +/- 2 vs 4 +/- 2 mm Hg) and area (1.82 +/- 0.5 vs 1.87 +/- 0.5 cm2) were similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)
To assess the influence of mild mitral regurgitation (MR) on the initial and long-term results of percutaneous mitral valvuloplasty (PMV), the baseline characteristics, early results and follow-up of 102 consecutive patients with mild MR before PMV (group I) were prospectively analyzed and compared with those of 186 consecutive patients without MR (group II). Age, gender and symptomatic status were similar in both groups, but more patients in group I were in atrial fibrillation (70 vs 54%, p < 0.05) and had had a previous episode of pulmonary edema (25 vs 14%, p < 0.05). On echocardiography, patients in group I had larger left atria (58 +/- 12 vs 53 +/- 10 mm, p < 0.05) and more calcified mitral valves (score 1.9 +/- 0.8 vs 1.5 +/- 0.7, p < 0.05), but the total echocardiographic score (8.0 +/- 2 vs 7.3 +/- 2) was similar in both groups. Baseline hemodynamic data were also similar in both groups. On multivariate analysis, group I patients were only independently associated with more calcified mitral valves and larger left atria. PMV success (area gain > or = 50% without complications) was similar (88 vs 86%) in both groups, but mitral valve area gain was smaller (0.8 +/- 0.3 vs 1.0 +/- 0.3 cm2, p < 0.05) in group I. After PMV an increase in the severity of MR > or = 2 grades (17 vs 6%, p < 0.05) occurred more frequently in group II patients.(ABSTRACT TRUNCATED AT 250 WORDS)