Biomedical subjects
Publications and source records attributed to C Macaya.
Coronary angioscopy was used to elucidate the underlying substrate of the culprit lesion in 20 patients with postinfarction ischemia and in 19 patients with other types of unstable angina. Plaque characteristics were similar in both groups, but red thrombi and occlusive thrombi were more frequently seen in patients with postinfarction ischemia.
Four hundred seventy-three patients with acute myocardial infarction (AMI) were treated with either saruplase (80 mg/hour, n = 236) or alteplase (100 mg every 3 hours, n = 237). Comedication included heparin and acetylsalicylic acid. Angiography was performed at 45 and 60 minutes after the start of thrombolytic therapy. When flow was insufficient, angiography was repeated at 90 minutes. Coronary angioplasty was then performed if Thrombolysis In Myocardial Infarction (TIMI) trial 0 to 1 flow was seen. Control angiography was at 24 to 40 hours. Baseline characteristics were similar. Angiography showed comparable and remarkably high early patency rates (TIMI 2 or 3 flow) in both treatment groups: at 45 minutes, 74.6% versus 68.9% (p = 0.22); and at 60 minutes 79.9% versus 75.3% (p = 0.26). Patency rates at 90 minutes before additional interventions were also comparable (79.9% and 81.4%). Angiographic reocclusion rates were not significantly different: 1.2% versus 2.4% (p = 0.68). After rescue angioplasty, angiographic reocclusion rates of 22.0% and 15.0% were observed. Safety data were similar for both groups. Thus, (1) early patency rates were high for saruplase and alteplase treatment, (2) reocclusion rates for both drugs were remarkably low, and (3) complication rates were similar. Thus, saruplase seems to be as safe and effective as alteplase.
OBJECTIVES: This study sought to determine the results of coronary stenting in thrombus-laden lesions. BACKGROUND: The angiographic evidence of intracoronary thrombus has classically been considered a formal contraindication to stent implantation. However, with increasing use of stenting, the indications for this technique have widened to include treatment of patients who have an acute coronary syndrome or lesions with adverse anatomic features. METHODS: We studied 86 consecutive patients (mean age +/- SD 61 +/- 11 years, 14 women) undergoing coronary stenting of a thrombus-containing lesion; the procedure was performed electively in 39% and after angioplasty failure in 61%. Sixty-four patients (75%) were treated for unstable angina, and 19 (22%) underwent the procedure during an acute myocardial infarction. A specific protocol that included clinical and late angiographic follow-up was used. RESULTS: Angiographic success was obtained in 83 patients (96%). Five patients (6%) died during the hospital stay despite angiographic success; four of these had cardiogenic shock, and one (1%) had subacute stent thrombosis. Non-Q wave myocardial infarction developed in five additional patients (6%), and four of these five had data consistent with distal embolization. Of the 78 patients discharged with angiographic success, 67 (86%) were event-free and clinically improved at last follow-up visit (12 +/- 11 months). During the follow-up period, eight patients required repeat angioplasty, one patient required heart transplantation, and two patients died. Quantitative angiography demonstrated excellent angiographic results after stenting (minimal lumen diameter 0.31 +/- 0.4 vs. 2.77 +/- 0.6 mm). Late angiographic follow-up (5.5 +/- 1 months) was obtained in 50 patients with 54 lesions (93% of eligible), revealing a minimal lumen diameter of 2.0 +/- 1 mm and restenosis (lumen narrowing > 50%) in 18 lesions (33%). CONCLUSIONS: Coronary stenting constitutes an effective therapeutic strategy for patients with thrombus-containing lesions, either after failure of initial angioplasty or electively as the primary procedure. Coronary stenting in this adverse anatomic setting results in a high degree of angiographic success, a low incidence of subacute thrombosis and an acceptable restenosis rate.
This review of consecutive, single Palmaz-Schatz stent implantations reveals that coronary lesion angulation does not result in suboptimal results or increased restenosis after stenting. The implantation of a rigid stent at an arterial hinge point is associated with an increased restenosis rate.
Intravascular ultrasound (IVUS) provides unique information about the coronary arterial wall that can be used to guide transcatheter therapy. In this prospective study, two different IVUS systems were compared with respect to feasibility of imaging before intervention and angiographic changes induced by the simple advancement of the catheter across the lesion. Eighty-five patients (mean age 59 +/- 10 yr, 11 female) were studied with IVUS before intervention. In 34 patients, a 4.8 F (1.6-mm) IVUS catheter was used (Group I), whereas in the remaining 51 patients, a 3.5 F (1.2-mm) IVUS catheter was used (Group II). Quantitative angiography was performed before and after the IVUS study to determine potential changes in lumen diameter. Clinical and angiographic characteristics were similar in the two groups. A successful IVUS interrogation of the target lesion was obtained more frequently in Group II (45/51 (88%) vs. 19/34 (56%) patients, P < 0.01). After the IVUS study, a change in minimal lumen diameter was seen in Group I (baseline 0.84 +/- 0.2 vs. final 1.17 +/- 0.2 mm, P < 0.001) and Group II patients (baseline 0.80 +/- 0.3 vs. final 1.03 +/- 0.4 mm, P < 0.01). In the 64 lesions successfully crossed, the absolute gain in lumen diameter was significantly higher in Group I (0.40 +/- 0.2 vs. 0.23 +/- 0.2 mm, P < 0.05). In addition, an inverse correlation was found between baseline minimal lumen diameter and the absolute lumen gain induced by the IVUS study in Group I (r = -0.47, P < 0.05) but not in Group II patients (r = -0.16, NS). Neither angiographic nor echogenic lesion characteristics were associated with the change in lumen diameter. When multivariate analysis was applied, catheter size was the only independent predictor of lumen gain induced by IVUS after adjustment. Thus, the advancement of IVUS catheters across severe coronary lesions induces significant angiographic changes consistent with plaque remodeling and a Dotter effect. The use of smaller catheters not only allows a higher number of lesions to be studied before intervention, but also lessens the mechanical disruption of the plaque, yielding a more accurate and veracious picture of baseline plaque characteristics.
A localized acute aortic dissection was produced in 2 patients, complicating coronary angioplasty. In both cases a coronary dissection provided the entry door, with subsequent retrograde progression of the dissection into the aortic root. After sealing the entry door, both patients could be managed conservatively using transesophageal echocardiography to accurately define the location of the intimal flap and to rule out dissection progression.
BACKGROUND: Intravascular ultrasound (IVUS) is currently used to study lesions during transcatheter coronary therapy. However, before dilation some lesions cannot be reached or crossed with the imaging catheter. HYPOTHESIS: This study seeks to elucidate which factors determine the feasibility of IVUS examination before coronary interventions. METHODS: Accordingly, 100 consecutive patients undergoing IVUS examination before coronary angioplasty were prospectively studied. The clinical and angiographic characteristics of 77 patients with a successful IVUS study (Group A) were compared with those of 23 patients in whom IVUS was attempted but the target lesion could not be interrogated (Group B). The echogenic characteristics of the target lesion [before (n = 77) or after intervention (in 18 patients in Group B)] were also studied. RESULTS: Patients in Group B were significantly older (62 +/- 7 vs. 57 +/- 10 years, p < 0.05) and more frequently had stable angina [8 (35%) vs. 9 (11%), p < 0.05]. The distribution of lesions within the coronary tree and angiographic lesion characteristics including length, eccentricity, calcification, bend location, and the American College of Cardiology/American Heart Association classification were similar in both groups. However, proximal tortuosities (> 45 degrees at end diastole) were more frequently found in Group B [20 (87%) vs. 47 (61%), p < 0.05]. In addition, by quantitative angiography, patients in Group B had smaller arteries (reference diameter 2.8 +/- 0.4 vs. 3.1 +/- 0.4 mm, p < 0.05) and more severe lesions (minimal lumen diameter 0.46 +/- 0.24 vs. 0.65 +/- 0.34 mm, p < 0.05). On IVUS, calcified lesions were more frequently visualized in Group B (61 vs. 38%, p < 0.05). On multivariate analysis, catheter size, baseline minimal lumen diameter, angiographic proximal tortuosities, and lesion calcification on imaging were independent predictors of the feasibility of IVUS studies. CONCLUSIONS: Unsuccessful IVUS studies before intervention occur more frequently (1) in vessels with proximal tortuosities or severe lumen narrowing, (2) in lesions that are calcified on IVUS, and (3) when large imaging catheters are used.
Coronary angioscopy (CA) provides direct visualization of the endoluminal surface of coronary vessels. The usefulness of CA during coronary angioplasty of angiographically complex lesions remains to be established. This study was designed to determine the value of CA to elucidate the underlying substrate of angiographically complex lesions. Forty-seven consecutive patients with angiographically complex lesions were studied with CA before coronary intervention. Mean age of the group was 59 +/- 9 years; six patients were women. Forty (85%) patients had unstable angina. Complex angiographic lesions included coronary occlusions (n = 23) (14 with Thrombolysis in Myocardial Infarction coronary flow grade 0 and nine with flow grade 1), lesions with intraluminal filling defects suggestive of thrombus or ulceration (n = 8), and lesions that were highly eccentric (n = 16). Items analyzed with CA included red thrombus (lining or protruding) and plaque color (yellow, white, or mixed). In all patients, CA visualized the protruding material causing the angiographic appearance. At this site CA detected red thrombus in 34 (72%) patients (14 protruding, 20 lining) and atherosclerotic plaque in 45 (96%) patients. At the site of the angiographically complex lesion, plaque was classified as predominantly yellow in 24 patients, mixed in 12, and white in nine. The incidence of thrombus on CA was higher for occluded vessels (91%) or lesions with intraluminal filling defects or ulceration (87%) than in eccentric lesions (37%) (p < 0.05). However, plaque coloration was not significantly different among these three angiographic subgroups. Initial procedural success (without stent requirement) was lower in lesions showing protruding thrombus on CA (64% vs 91 %, p < 0.05). Thus most angiographically complex lesions contain thrombus. On CA red thrombus was more frequently identified on occluded vessels and lesions with filling defects or ulceration than in eccentric lesions. Yellow or mixed plaques are common in these patients, suggesting lipid-laden plaques as the underlying pathologic substrate of angiographically complex lesions.
OBJECTIVES: The purpose of this study was to determine the feasibility, safety and efficacy of elective and urgent deployment of the new intravascular rigid-flex (NIR) stent in patients with coronary artery disease. BACKGROUND: Stent implantation has been shown to be effective in the treatment of focal, new coronary stenoses and in restoring coronary flow after coronary dissection and abrupt vessel closure. However, currently available stents either lack flexibility, hindering navigation through tortuous arteries, or lack axial strength, resulting in suboptimal scaffolding of the vessel. The unique transforming multicellular design of the NIR stent appears to provide both longitudinal flexibility and radial strength. METHODS: NIR stent implantation was attempted in 255 patients (341 lesions) enrolled prospectively in a multicenter international registry from December 1995 through March 1996. Nine-, 16- and 32-mm long NIR stents were manually crimped onto coronary balloons and deployed in native coronary (94%) and saphenous vein graft (6%) lesions. Seventy-four percent of patients underwent elective stenting for primary or restenotic lesions, 21% for a suboptimal angioplasty result and 5% for threatened or abrupt vessel closure. Fifty-two percent of patients presented with unstable angina, 48% had a previous myocardial infarction, and 45% had multivessel disease. Coronary lesions were frequently complex, occurring in relatively small arteries (mean [+/-SD] reference diameter 2.8 +/- 0.6 mm). Patients were followed up for 6 months for the occurrence of major adverse cardiovascular events. RESULTS: Stent deployment was accomplished in 98% of lesions. Mean minimal lumen diameter increased by 1.51 +/- 0.51 mm (from 1.09 +/- 0.43 mm before to 2.60 +/- 0.50 mm after the procedure). Mean percent diameter stenosis decreased from 61 +/- 13% before to 17 +/- 7% after intervention. A successful interventional procedure with < 50% diameter stenosis of all treatment site lesions and no major adverse cardiac events within 30 days occurred in 95% of patients. Event-free survival at 6 months was 82%. Ninety-four percent of surviving patients were either asymptomatic or had mild stable angina at 6 month follow-up. CONCLUSIONS: Despite unfavorable clinical and angiographic characteristics of the majority of patients enrolled, the acute angiographic results and early clinical outcome after NIR stent deployment were very promising. A prospective, randomized trial comparing the NIR stent with other currently available stents appears warranted.
Coronary stenting is increasingly used during transcatheter coronary therapy. Coronary angiography, mainly since the advent of quantitative angiography, provides an effective tool to obtain excellent clinical results with coronary stenting. However, during this procedure some limitations inherent to the angiographic techniques may become apparent. Accordingly, great enthusiasm has been generated regarding the potential value of alternative diagnostic techniques to guide coronary stenting. Intravascular ultrasound is able to study the arterial wall and provides a unique tool to assess stent expansion, apposition and symmetry. Therefore, this technique is increasingly used to optimize stent deployment. Coronary angioscopy directly visualizes stent expansion and is able to precisely recognize protrusion of redundant fronds of tissue or residual dissections within the stent struts. In addition, this technique is the procedure of choice to identify intracoronary thrombus. Intracoronary Doppler permits the application in the catheterization laboratory of sophisticated methods of functional assessment of lesion severity. Coronary stenting allows a faster and complete normalization of coronary flow reserve than balloon angioplasty. Thus, all these new techniques of intracoronary diagnosis provide unique and useful information, which is complementary to that obtained with angiography, potentially useful during coronary stenting.
Angiographic optimization of coronary stents, using high-pressure balloon inflation, was complicated by vessel rupture in 3 patients. The risk of this potentially life-threatening complication should be considered during stent optimization.
Nine patients with systemic embolization complicating intracoronary stenting (incidence 1.8%) are described. Although this rare complication was not associated with any clinical sequelae, great care should be taken to prevent this possibility, especially in patients with unfavorable anatomic characteristics, including lesions in the left circumflex artery, at bend points, and calcified lesions.
BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors may exert some of their benefits in the therapy of hypertension, congestive heart failure, and acute myocardial infarction by their improvement of endothelial dysfunction. TREND (Trial on Reversing ENdothelial Dysfunction) investigated whether quinapril might improve endothelial dysfunction in normotensive patients with coronary artery disease and no heart failure, cardiomyopathy, or major lipid abnormalities so that confounding variables that affect endothelial dysfunction could be minimized. METHODS AND RESULTS: Using a double-blind, randomized, placebo-controlled design, we measured the effects of quinapril (40 mg daily) on coronary artery diameter responses to acetylcholine using quantitative coronary angiography. The primary response variable was the net change in the acetylcholine-provoked constriction of target segments between the baseline (prerandomization) and 6-month follow-up angiograms. The constrictive responses to acetylcholine were comparable in the placebo (n = 54) and quinapril (n = 51) groups at baseline. After 6 months, only the quinapril group showed significant net improvement in response to incremental concentrations of acetylcholine (4.5 +/- 3.0% [mean +/- SEM] versus -0.1 +/- 2.8% at 10(-6) mol/L and 12.1 +/- 3.0% versus -0.8 +/- 2.9% at 10(-4) mol/L, quinapril versus placebo, respectively; overall P = .002). CONCLUSIONS: TREND shows that ACE inhibition with quinapril improved endothelial dysfunction in patients who were normotensive and who did not have severe hyperlipidemia or evidence of heart failure. These benefits of ACE inhibition are likely due to attenuation of the contractile effects and superoxide-generating effects of angiotensin II and to enhancement of endothelial cell release of nitric oxide secondary to diminished breakdown of bradykinin.
BACKGROUND: The purpose of the Benestent-II Pilot Study was to evaluate the safety of delaying and eliminating anticoagulant therapy in patients receiving a heparin-coated stent in conjunction with antiplatelet drugs. METHODS AND RESULTS: The study consisted of three initial phases (I, II, III) during which resumption of heparin therapy after sheath removal was progressively deferred by 6, 12, and 36 hours. In phase IV, coumadin and heparin were replaced by 250 mg ticlopidine and 100 mg aspirin. Of the 207 patients with stable angina pectoris and a de novo lesion in whom heparin-coated stent implantation was attempted, implantation was successful in 202 patients (98%). Stent thrombosis did not occur during all four phases, and the overall clinical success rate at discharge was 99%. Bleeding complications requiring blood transfusion or surgery fell from 7.9% in phase I to 5.9%, 4%, and 0% in the three following phases. Hospital stay was 7.4, 6.1, 7.2, and 3.1 days for the consecutive phases. The restenosis rate for the combined four phases was 13% (15% in phase I, 20% in phase II, 11% in phase III, and 6% in phase IV). The overall rate of reintervention for the four phases was 8.9%. At 6 months, 84%, 75%, 94%, and 92% of the patients of phases I to IV, respectively, were event free. For the four phases, the event-free rate was 86%, which compares favorably with the rate observed in the Benestent-I study (80%; relative risk, 0.68 [0.45 to 1.04]). CONCLUSIONS: The implantation of stents coated with polyamine and end-point-attached heparin in stable patients with one significant de novo coronary lesion is well tolerated, is associated with no (sub)acute stent thrombosis, and results in a favorable event-free survival after 6 months.
A 75-year-old woman with severe rheumatic mitral stenosis was admitted for percutaneous mitral valvuloplasty. Two-dimensional echocardiography disclosed severe calcification of the posterolateral left atrial wall and interatrial septum. Percutaneous mitral valvuloplasty, using the inoue technique, was successfully performed after a transseptal puncture through the calcified interatrial septum, avoiding the need for surgical intervention.
A patient with rheumatic mitral stenosis associated with cor triatriatum is described. The anomalies were detected by two-dimensional echocardiography and confirmed by transesophageal echocardiography. Percutaneous mitral valvuloplasty was successfully performed with the inoue technique. The clinical and technical implications during the procedure of this previously unreported association are discussed.
OBJECTIVES: This study sought to determine the 1-year clinical follow-up of patients included in the Benestent trial. BACKGROUND: The Benestent trial is a randomized study comparing elective Palmaz-Schatz stent implantation with balloon angioplasty in patients with stable angina and a de novo coronary artery lesion. Seven-month follow-up data have shown a decreased rate of restenosis and fewer clinical events in the stent group. It is not established whether this favorable clinical outcome is maintained for longer periods or whether coronary stenting defers restenosis and its subsequent clinical manifestations. METHODS: To clarify this uncertainty, we updated clinical information on all but 1 of 516 patients enrolled in the Benestent trial (257 in balloon group, 259 in stent group) at least 12 months after the intervention. Major clinical events (primary clinical end point) were tabulated according to the intention to treat principle and included death, the occurrence of a cerebrovascular accident, myocardial infarction, the need for bypass surgery or a further percutaneous intervention in the previously treated lesion. RESULTS: After 1 year, no significant differences in mortality (1.2% vs. 0.8%), stroke (0.0% vs. 0.8%), myocardial infarction (5.0% vs. 4.2%) or coronary bypass graft surgery (6.9% vs. 5.1%) were found between the stent and balloon angioplasty groups, respectively. However, the requirement for a repeat angioplasty procedure was significantly lower in the stent group (10%) than the balloon angioplasty group (21%, relative risk [RR] 0.49, 95% confidence interval [CI] 0.31 to 0.75, p = 0.001), and overall primary end points were less frequently reached by stent group patients (23.2%) than those in the balloon group (31.5%, RR 0.74, 95% CI 0.55 to 0.98, p = 0.04). No differences were found between groups with respect to functional class angina and prescribed medication at the time of follow-up. CONCLUSIONS: These clinical follow-up data show that the benefit of elective native coronary artery stenting in patients with stable angina is maintained to at least 1 year after the procedure and results in a significantly reduced requirement for repeat intervention.
BACKGROUND AND OBJECTIVES: Intracoronary ultrasound allows to study in vivo the morphology of the arterial wall, the presence and composition of atheroma and the associated lumen encroachment. The objective of our study was to assess the value of intravascular ultrasound to determine the dilatation mechanism after a conventional balloon angioplasty. PATIENTS AND METHODS: Sixteen patients were examined with intravascular ultrasound before and after they had undergone percutaneous transluminal coronary angioplasty. A mechanical intravascular ultrasound system was used. Two different types of imaging catheters were used in this study: a 20 MHz, 4.8 F catheter in 5 patients and a 30 MHz, 3.5 F in 11 patients. RESULTS: Quantitative and qualitative assessments were made from the angiograms and the ultrasound images. Seven out of 16 patients had a calcified plaque, in 8 patients the plaque was fibrotic and in 1 patient soft. Rupture of the plaque was the most common dilatation pattern. Post-PTCA the cross-sectional arterial area was increased from 15.3 +/- 5.2 mm2 to 17.3 +/- 6.2 mm2, the intraluminal area was increased from 2.7 +/- 2.5 mm2 to 7.3 +/- 3.4 mm2, and the plaque area was reduced from 12.3 +/- 4.8 mm2 to 9.7 +/- 3.4 mm2. The quantitative analysis showed that the "most frequent dilatation mechanism" found was the reduction of size plaque, an increase in cross-sectional arterial area was present in only 4 patients (25%). The incidence of depth rupture of the plaque was greater in patients with a calcified plaque than in those without (NS). CONCLUSIONS: 1). Intracoronary ultrasound provides a complete description of plaque composition and geometry before and after coronary balloon angioplasty; 2) several morphologic dilatation patterns were found, and plaque tearing was the most common, and 3) increase in luminal area was most frequently due to a reduction in plaque area. Nevertheless an increase in the cross-sectional arterial area was also common, but less important.