Pedro Zarco

Determinants of coronary compliance in patients with coronary artery disease: an intravascular ultrasound study.

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.

Intravascular ultrasound imaging of angiographically normal coronary segments in patients with coronary artery disease

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)

Coronary stenting for acute coronary dissection after coronary angioplasty: Implications of residual dissection

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.

Early angiographic changes of side branches arising from a Palmaz-Sehatz stented coronary segment: Results and clinical implications☆

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.

Stenting for elastic recoil during coronary angioplasty of the left main coronary artery.

Abstract Conventional percutaneous transluminal coronary angioplasty (PTCA) of the left main coronary artery (LMCA) constitutes a therapeutic challenge because it is associated with significant immediate morbidity and mortality and a high restenosis rate. 1–4 Special difficulties may arise during PTCA of ostial LMCA lesions including technical problems concerning precise balloon location and the possible appearance of elastic recoil despite the use of adequate-sized balloons. 4 We report 3 patients with “unprotected” ostial lesions of the LMCA in whom significant elastic recoil after PTCA was successfully managed with coronary stenting. In each patient the strategy for stent deployment consisted in leaving the proximal edge of the stent slightly protruding into the aortic root. This was successfully accomplished and subsequently confirmed in the 3 cases.

Midterm outcome of patients with asymptomatic restenosis after coronary balloon angioplasty

Although many patients with restenosis after balloon coronary angioplasty have recurrence of angina, others remain asymptomatic. To assess the clinical implications of asymptomatic coronary restenosis, we analyzed clinical and angiographic characteristics of 277 consecutive patients with restenosis, 133 (48%) of whom were asymptomatic (group I) and 144 (52%) symptomatic (group II). Restenosis was documented 6 to 9 months after the index procedure, or earlier if angina recurred, and was defined as a greater than 50% lumen narrowing (visual estimation). Group I (asymptomatic group) included fewer female (9% vs. 18%, p less than 0.05) and hypertensive patients (38% vs. 56%, p less than 0.005) and more patients with a previous myocardial infarction (48% vs. 28%, p less than 0.05) and single-vessel disease (67% vs. 55%, p less than 0.05). Before angioplasty, symptoms had lasted for a shorter period (10 +/- 25 vs. 23 +/- 42 months, p less than 0.001), ischemia after a recent infarction was a more frequent indication (21% vs. 10%, p less than 0.05) and total revascularization more frequently obtained (74% vs. 63%, p less than 0.05) in group I than in group II patients. Only a normal blood pressure, previous myocardial infarction, single-vessel disease and a shorter duration of symptoms were independent correlates of asymptomatic restenosis. No differences were found in stenosis severity before angioplasty (90% in both groups) or after angioplasty (22% +/- 12% vs. 24% +/- 16%).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioscopic findings during coronary angioplasty of coronary occlusions

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.

Early and late results of percutaneous mitral valvuloplasty for mitral stenosis associated with mild mitral regurgitation

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)

Repeat coronary angioplasty during the sameangiographic diagnosis of coronary restenosis

To determine whether any differences exist in results of treatment of restenosis with repeat angioplasty when the procedure is performed during diagnosis or, as an alternative, when it is performed as a separate elective procedure, we prospectively compared the outcome of 48 consecutive procedures (including 51 lesions) at the time of initial cardiac catheterization (group 1) with the outcome of 26 consecutive elective procedures (including 30 lesions) (group 2). Before control angiography was performed, the anatomic and procedural characteristics of the previous dilatation and the new symptomatic status were carefully reevaluated in all patients. Baseline clinical and angiographic characteristics including age, sex, ejection fraction, and number of diseased vessels in which repair was attempted were similar in both groups. Reasons for angioplasty were also similar with unstable angina being the most frequent indication: 29 (60%) in group 1 versus 13 (50%) in group 2. (p = NS). Morphology of the lesions was also similar, although longer lesions (greater than 12 mm) were dilated in group 2 (13 (43%) vs 10 (20%) in group 1; p less than 0.05). Angiographic success was achieved in 51 lesions (100%) in group 1 versus 28 (93%) in group 2 (p = NS). Primary angioplasty success (in the absence of major complications) was achieved in 46 (95%) procedures in group 1 versus 24 (92%) in group 2 (p = NS). Two patients in group 1 had a myocardial infarction, but there were no other major complications in either group. Preliminary data suggest that the outcome of repeat coronary angioplasty for restenosis is similar whether it is performed at the time of diagnostic catheterization or later on as an independent elective procedure.

Angiographic changes (Dotter effect) produced by intravascular ultrasound imaging before coronary angioplasty

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)